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|Appedix Xjes I- SOUTH CAROLINA SURVEY REPORT ON BEACH EROSION CONTROL / & HURRICANE PROTECTION COASTAL ZI<'E U.S. ARMY ENGINEER DISTRICT, CHARLESTON CORPS OF ENGINEERS Charleston, South Carolina ;GB 459.4 UBMITTED: 1F64 l v97.2 AUGUST 1979 v. 2 17 -F Folly Beach ~p ~South Carolina Feasibility Report N U.S. DEPARTMENT OF COMMERCE NOAA COASTAL SERVICEs CENTER 2234 SOUTH HOBSON AVENUE CHARLESTON, SC 29405-2413 i TABLE OF CON'TENTS 4~~ LIST OF APPENDIXES ~-~ NO. TITLE W~~ 1 ~ TECHNICAL REPORT if P 2 ~ ENVIRONMENTAL IMPACT VA~~ 5!~ ~ STATEMENT 3 PERTINENT CORRESPONDENCE *; 4 SECTION 404(B) EVALUATION cZ Property of CSC Library lz-_s ~ ~Propert~y of csc ,Library FOLLY BEACH SOUTH CAROLINA FEASIBILITY REPORT Technical ReportA SECTION A THE STUDY AND REPORT SECTION B RESOURCES AND ECONOMY OF THE STUDY AREA SECTION C PROBLEMS AND NEEDSE SECTION D MATERIAL INVESTIGATIONSN SECTION E ESTIMATED BENEFITS SECTION F DESIGN AND COST ESTIMATESD SECTION G PROJECT FORMULATIONI SECTION H THE SELECTED PLANx PREPARED BY THE CHARLESTON DISTRICT, CORPS OF ENGINEERS 0 ~~~~~~~~~DEPARTMENT OF THE ARMY Wi3SU 6tiL''5';~ .:mov u Li SECTION A THE STUDY AND REPORT COASTAL ZONE INFORMATION CENTER THE STUDY AND REPORT TABLE OF CONTENTS ITEM PAGE PURPOSE AND AUTHORITY A-i SCOPE OF THE STUDY A-2 STUDY PARTICIPANTS AND COORDINATION A-3 THE REPORT A-4 PRIOR STUDIES AND REPORTS A-5 LIST OF FIGURES NO, TITLE FOLLOWING PAGE A-1 MAP OF FOLLY ISLAND, S. C. A-2 A-2 CHARLESTON SMSA A-2 (INCLUDES ALL OF TRI-COUNTY AREAS) SECTION A THE STUDY AND REPORT 1. An understanding of the background and other characteristics of the study and the report provides a'useful introduction to the pre- sentation of the study and its results. Purpose and Authority 2. The purpose of this study, the results of which are presented in this technical appendix, was to investigate the beach erosion, hurricane protection and related problems at Folly Beach, Charleston County, South Carolina. Inherent in the investigation was the development of the most suitable plan for alleviating these problems. Recommendations are presented in the main report. 3. The study and report are in compliance with the following resolu- tion adopted 15 June 1972 by the Committee on Public Works of the * ~~United States Senate which reads: Appendix I A-1 "That in accordance with Section 110 of the Rivers and Harbors Act of 1962, the Secretary of the Army be, and is hereby, requested to cause to be made under the direction of the Chief of Engineers, a survey of the shores of the State of South Carolina at and in the vicinity of Folly Beach, Charleston County, South Carolina, and such adjacent shores as may be necessary, in the interest of beach erosion control , hurricane pro- tection, and related purposes." Scope of the Study 4. The studies in this report focus on the water and related land resource needs in the vicinity of Folly Island in Charleston County, South Carolina as shown on Figure A-1. 5. As is the case with many water resource studies, the boundaries of the immediate planning area are different from the political boundaries in the vicinity. Therefore, to characterize the setting in which the planning area lies, Figure A-2 gives the geographical locations and boundaries of the broader political and user areas. The Berkeley-Dorchester-Charleston planning area is congruent with those of the Charleston Standard Metropolitan Statistical Area (SMSA). 6. The immediate planning area encompasses the six miles of coastline on Folly Island. Investigations were made of the area to determine damages, either by erosion of the coastline or by storm tides and Appendix I A- 2 S~~~~~~~~~~~~~~~~T ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~4.....C~ IN SOUETH N ~~~~~~~~~~~~SUH CAROLINA ill~~~~~~~~~~~~~~~~~~~ ECL RN E LLE 0~~~~~~~~~~~~~~~~~~~~~~~~~~~01 CIA waves; measures for protecting the area or preventing the damages; the accompanying costs and benefits; the selection of the most feas- ible plan; and related matters, including coordination with concerned agencies and the public. The studies were made in the depth and detail needed to permit the development of an economically feasible, environmentally compatible and socially acceptable plan of improve- ment. Study Participants and Coordination 7. Charleston District was assigned the responsibility for the con- duct and coordination of this study, consolidation of information from other agencies and local interest, formulation of a plan and preparation of the report. A multi-disciplinary team was used to accomplish these tasks. This team was composed of a project engineer, biologist, coastal engineer, economist, cost estimator, and a foun-.;? dationis and material specialist. Additional assistance was provided by geologists, hydrologists, real estate appraisers, surveyors, and others asspecific data and analysis were required. 8. The studies and investigations were coordinated with various Federal, State and local agencies. Comments concerning problem identification and possible solutions were received from sucbhagen- cies as the U. S. Bureau of Sport Fisheries andWildlife; National; - Appendix I A-3 Park Service; U. S. Coast Guard; U. S. Environmental Protection Agency; U. S. Public Health Service; National Oceanic and Atmos- pheric Administration; South Carolina Wildlife and Marine Resources Department; S. C. Highway Department; S. C. Department of Parks, Recreation, and Tourism; and Charleston County Park, Recreation and Tourist Commission. Several local environmental groups also parti- cinated in the study. A total nf three public meetings were held during the course of the study to afford interested parties and the general public an opportunity to express their views concerning the imnrovempnts dpqired and the need and advisibility of their execution. Dates of these meetings were 8 April 1976, 29 November 1977, and 7 December 1978, The Report 9. The organization and format of this report is in compliance with instructions contained in ER 1105-2-402 and ER 1105-2-403. This report has been arranged into a main report and four appendixes. 10. The main report is a non-technical presentation, with recommenda- tions, concerning the need for and advisability of providing beach erosion control and hurricane protection works at Folly Beach. It presents a broad view of the overall study for the benefit of both general and technical readers. Included are a description of the study area; the problems and needs for protective measures; formulation of a Appendix 1 A-4 plan for meeting these needs, a summary of project economics indicating the benefits, costs, and justification; the division of project responsi- bility between Federal and non-Federal interests; a summary of environ- mental, social, and economic effect assessment; and recommendations for implementing the selected plan. The main report is a summary document where brevity and ease of comprehension are emphasized. 11. Appendix One is a technical report having the same general outline as the main report but in greater detail . It is the key document for the technical reviewer. Here, more emphasis is placed on methods of analysis and supporting detail so the reader will be able to evaluate the validity of the decisions made in selecting the measures included in the recommended plan of improvement. 12. Appendix Two contains the Environmental Impact Statement. 13. Appendix Three contains'pertinent correspondence. 14. Appendix Four contains the Section 404(b) Evaluation for the recommended project plan. Prior Studies and Reports 15. In 1935, a beach erosion report on Folly Beach was submitted by the Beach Erosion Board (renamed Coastal Engineering Research Center) in cooperation with the Sanitary and Drainage Commission of Charleston Appendix1 A- 5 County. In this report the Board identified three methods of protection but refrained from making any recommendation as to the adoption of any0 specific one of the methods given, as it was considered that the selection must necessarily be made by local interests. The problem area at that time was on the southwestern portion of Folly Island where storms of September 1933 and May 1934 destroyed the first row of houses. The plans presented were: Plan A -Restoration of eroding beaches; Plan B -Construction of bulkheads and groins; and Plan C -Beach restoration with groin construction. All of the cost of these improvements would be paid by local interests. 16. A study of Charleston Harbor Jetties, 1935, wsas done by the Char- leston District, U.S. Army Corps of Engineers, to become a part of the Shore Protection Board, OCE report entitled "Report on Jetties". The study was niade to determine the effect of the Charleston Harbor Jetties on adjacent shorelines. The report that was completed in 1938 found some erosion down drift of the south jetty, on Morris Island, with some accre- tion at the north end of Morris Island where the jetty approaches the shore. The report also concluded, from a number of jetties studied,that the extent of erosion that might be expected beyond the down drift jetty was only about one mile. 17. An appraisal report, Investigation on Hurricanes and Associated Problems Along the South Carolina Coast, was prepared by the U. S. Army Corps of Engineers Office of the District Engineer, Charleston, S. C., It was submitted in January 1957 and approved July 1957. The investi- gation indicated the need for further study and report with a view AppendixlIi A- 6 toward effecting protective measures for minimizing loss of human life, damage to property and health hazards, and for improving hurricane fore- cast and warning services. 18. A hurricane survey interim report on Folly Beach was printed as House Document-No. 302, 89th Congress, Ist Session, on 7 October 1965. It was concluded in this report that protective works to prevent hurricane damage were not economically justified. 19. In 1968, the U. S. Army Corps of Engineers, Charleston District, completed the Folly Beach Detail Project Report on Beach Erosion Control. This report evaluated the erosion problem on the northeastern portion of Folly Beach. A reach of beach, extending about one-half mile downcoast from the United States Coast Guard Loran Station, was recommended for beach nourishment using sands deposited in Lighthouse Creek. The recommended project called for initial placement of a 5-year supply of sand or about 45,500 cubic yards at an estimated first cost (1967 dollars) of $52,000. Cost apportionment was to be 55 percent local to 45 percent Federal. The project was economically feasible; however, the local sponsor (Folly Beach Township Commission) was unable to provide the allocated items of local cooperation. For this reason, it was recommended that no Federal project be authorized. * ~~~~~~~~~~~~~~~~~~Appendix I A-7 g SECTION B RESOURCES AND ECONOMY OF STUDY AREA 0 RESOURCES AND ECONOMY OF THE STUDY AREA TABLE OF CONTENTS EM PBRAGE ENVIRONMENTAL SETTING AND NATURAL RESOURCES OF THE STUDY AREA B-2 'GEOGRAPHY AND TOPOGRAPHY B-2 GEOMORPHOLOGY AND'SEDIMENTOLOGY B-3 CLIMATE B-5 BIOLOGICAL RESOURCES B-5 ARCHEOLOGICAL RESOURCES B-6 SUMMARY OF NATURAL RESOURCES B-7 HUWilA RESOURCES B-8 POPULATION B-8 EDUCATION B-9 DEVELOPMENT AND ECONOMY B-9 PROJECTED POPULATIONEiMPLOY1iENTAND INCOME B-10 ECONOMY OF THE IMMEDIATE PLANNING AREA B-10 LAND USE ANALYSIS B-12 TABLE OF CONTENTS LIST OF TABLES NO. TITLE B-1 POPULATION, INCOME, AND EMPLOYMENT FOR CHARLESTON, SMSA. B-i! LIST OF FIGURES .ITLE FOLLOWING PAGE 1 GENERAL MAP - FOLLY ISLAND, S. C. B-13 SECTION B RESOURCES AND ECONOMY OF STUDY AREA 1. A general understanding of the resources and development trends of the study area is helpful in identifying its problems and needs and formulating the various solutions thereto. The following pages discuss the environiiental , natural, and human resources of the area as well as its development and economy. 2. Charleston County which contains Folly Island and the Town of Folly Beach has a well diversified economy. The principal economic activi- ties of the area can be related to the availability of several natural resources. A temperate climate, along with favorable topography and soil conditions are conducive to both agriculture and silviculture, which are engaged heavily in the county and account for the greatest land use. A coastal location with several navigable rivers makes Charleston a favorable place for import/export shipping and related port and terminal activities. The South Carolina Ports Authority is presently planning additional port facilities with a view towards improving the economic development of the county and the state. Is Appendix I B-i 3. Also, attributable to the geographical and geological situation of Charleston County are several military and government installations, including Air Force and Navy Bases, which employ a large segment (approximately one-third) of the work force in the area. The coastal location also affords opportuniti~js for arda residents to engage in several fishery related activities, including shrimping, fin- fishing, oystering, clamming and crabbing. The historical background and fine architecture of Charleston, in addition to the beauty and aesthetic appeal of the Lowcountry's beaches, marshes and rivers, combine to make Charleston extremely popular with tourists from the entire eastern seaboard. Tourism, recreation, and associated services provide 12,000 jobs and 45 million dollars per year in personal income to residents of the area. In fact, tourism-related employment is second only to Government employment within the county. In the imme- diate vicinity of Folly Island which is located about 10 miles south of the City of Charleston, recreation, tourism and fisheries are of primary importance, both in terms of income and local employment. Environmental Setting and Natural Resources of the Study Area GEOGRAPHY AND TOPOGRAPHY 4. Charleston County is at the center of what is known locally as the Carolina Lowcountry. The name fits, elevations are typically Appendix I is ~~less than twenty feet above mean sea level and relief is extremely limited. The study area lies within the lower coastal plain bordering the Atlantic Ocean which was once a submerged portion of the Continental Shelf. The coastline in this region is composed of a chain of barrier islands, which are usually between two and ten miles long and often less than one mile wide. They are fronted by gently sloped sandy beaches on the seaward side and backed by vast expanses of extremely productive saltmarsh. Folly Island is one of more than a dozen such islands in Charleston County. Separating these islands from each other are broad tidal rivers (such as the Stono River) which drains the interior. Tributary to these major rivers, flowing laterally between the islands and the mainland, are series of dendritic tidal creeks which alternately flood and drain the marshes. Folly River is the main artery for such a system of creeks located behind Folly Island and Lighthouse Creek is a smaller tidal stream at the northeastern end of the island. As one proceeds inland, the larger estuaries taper into meandering brackish rivers penetrating into low wooded lots and farm land. Continuing further upstream, relief increases gradually. At some locations in the interior of the county there are small series of rolling hills, which are relics of beach dunes from previous stands of the sea. GEOMORPHOLOGY AND SEDIMENTOLOGY 5. The geologic formations of the Coastal Plain Provinces are com- prised of layers of unconsolidated sands and gravels underlain by is ~~layers of loams, clays and marls of different ages, all lying nearly Appendix I B-3 horizontal. This stratification of inorganic and organic materials is a result of the alternating predominance of physical and biological factors over recent geological time. As various climactic conditions have changed, the ocean shoreline has alternately receded and advanced as have the other features associated with it such as, the dune system, saltmarsh and tidal rivers which back the barrier islands. Changes in the littoral environment have also caused Stono Inlet and Lighthouse Inlet to migrate up and down the coast. Sub-surface investigation in the inlet areas have produced fine sand with occasional layers of organic material which are remnants of this inlet migration. Soil boring in Folly River behind Bird Key and Folly Island produced fine silty sand to a depth of twenty feet below mean low water. Grain size analysis demonstrates that this material is similar to native beach sand, which indicates that it was derived from the littoral environment. Soil borings were also taken in Stono and Lighthouse Inlet shoals. The grain size analysis of this material revealed the existence of fine sand to a depth of about 20 feet below mean low water. There is considerable amounts of littoral material deposited in the two inlet shoals: approximately 135,000 cubic yards of sand lies above the low water level and another 720,000 cubic yards of sand is incorporated in subtidal shoals of Stono Inlet; the shoals of Lighthouse Inlet contain about 315,000 cubic yards above mean low water and at least 800,000 cubic yards in the subtidal shoals. A review of hydrographic maps and aerial photographs, covering the period from the years 1854 to 1973, indicates that although the orientation of Stono Inlet has oscillated considerably over time, Appendix I B-4 the general location has remained fairly constant. Over the same period, Lighthouse Inlet has had a gradual southerly migration and the ocean shoreline of Folly Island has generally been unstable with erosion prevailing. CLIMATE 6. Climate of the 'Lowcountry's" barrier islands is classified as marine subtropical. The mean average annual temperature near Folly Island is 66OF with an average high temperature in July of 81OF and an average low of 49OF in February. Relative humidity in the area is around 75 percent, but the discomforting effect of this high humidity is modera- ted by an afternoon sea breeze. Precipitation occurs chiefly as rain- fall, averages about 50 inches per year, and is fairly well distributed throughou t the year. Between morning and evening twilight, the sun shines an average of 65 percent of the time in Charleston during the year. flay and September are thE sunniest months; with the sun being visible as much as 90 percent of the time during daylight periods. These conditions provide Charleston County with a relatively long growing season of 295 days per year. These conditions further allow human comfort the year round and provide a situation that is well suited for outdoor recreation and tourism. BIOLOGICAL RESOURCES 7. There are some 4,000 acres of saltmarsh in the immediate planning area. These wetland areas play a very important role in the ecology Appendix I. B-5 of the area; providing habitat for waterfowl, nursery area for juvenile stages of many important species of fish and shellfish, water quality improvement and primary biological production which supports a host of marine life in adjacent coastal waters. 8. There are public oyster grounds and private leases for oysters and clams in the planning area. Crabbers also fish Folly and Stono Rivers extensively. Shrimp are taken recreationally. The area is a favorite one for local fishermen who catch numerous different species of fish in and around the estuary. ARCHEOLOGICAL RESOURCES 9. The National Register of Historic Places lists no structures., places or items of historical significance in the area of proposed work or in areas immediately adjoining the work area. It appears likely that the Stono and Folly Rivers were used by aborigines prior to settlement in the area by Europeans. Due to the proximity of Charleston and the reliance on water-based transportation from colonial times to the 20th century, the two rivers were probably used extensively during this period. 10. Wrecks or abandonments of vessels have probably occurred in the planning area; however, due to the shifting nature of the channels involved, it is highly unlikely that dredging to a depth adequate for use as a borrow area - ten to twelve feet below MLW - would cause the loss of significant archeological resources. The migration of the Appendix I B-6 natural channel has scoured, redeposited and rescoured the area numerous times to a depth greater than that which would be accomplished by dredging a borrow area in Folly River, Stono Inlet, or Lighthouse Inlet. This scouring action has probably eroded any wooden structures away and metal objects would have settled to the bottom of the channel and been reburied. 11. In spite of the small chance of any cultural resources being located in the shifting sands of the project area and the sanitary facility sites, a documentary search and a magnetometer survey will be performed for the area prior to construction. If the search and survey provides evidence that historically significant resources are present in areas which would be affected by construction, work in these areas would be ,delayed so that any significant resources or data may be recovered. SUMMARY OF NATURAL RESOURCES 12. In short, the major natural resources of the study area are: a temperate climate; topography and soil conducive to agriculture and silviculture (which are important to the County but of little signifi- cance within the immediate planning area); geologic features such as, a coastal location with sheltered highground areas having access to the ocean via navigable rivers; the ocean itself harboring abundant biological and mineral resources; long stretches of gently sloped sandy beaches for walking and bathing; and vast expanses of extremely productive saltmarshes which serve as nursery areas for a variety of marine Appendix I B-7 Rev 6 Nov 79 organisms and in turn supports large commercial and recreational fisheries. Human Resources POPULATION 13. Historically, Charleston County has been the most populous county in the state. However, in the past decade both Richland and Spartanburg Counties in the upcountry have come to be about equal in population to that of Charleston County. 14. The population in Charleston County has grown from 216,382 in 1960 to 247,650 in 1970 and 260,400 in 1975. This population is expected to reach 271,000 by 1980. At the same time, the James Island Division has grown from 13,872 in 1960 to 24,197 in 1970, 25,525 in 1975 and is expected to reach 28,090 in 1980. The population of Folly Island has been more stable. In 1960, there were 1,137 permanent residents of Folly Beach; -in 1970, there were 1,157 persons and in 1975, the population was 1,500.1/ 15. It is estimated that Folly Island's resident population increases to about 4,500 persons during the summer months and on peak weekend days, visitors to this island may exceed 30,000. The beaches of the entire Charleston area receive about 3,000,000 visits each year. 1/ Provided by Berkeley-Dorchester-Charleston Council of Governments. Appendix i O ~~EDUCATION 16. Based on 1970 census, the median school year completed by the 25-year and older segment of the study area was 11.8. This was slightly better than the state average. There are numerous institutions offering post secondary education in the area. The Medical University of South Carolina is located in Charleston and besides offering technical educa- tion and health services, the Medical University complex is the third largest employer in the County. The College of Charleston offers liberal arts education and some graduate programs. Liberal arts pro- grams are also offered at the Baptist College at Charleston. The Military College of South Carolina, The Citadel, offers liberal arts plus an excellent Engineering curriculum. Trident Technical College offers associate degrees in many technical disciplines. Development and Economy 17. The Federal Government is the largest employer in the area. Other economic activities are recreation and tourism, shipping and trade related activities, education, fisheries, silviculture and agri- culture. Recreation, tourism and fisheries activities provide the majority of employment opportunities in the immediate planning area. 18. Unemployment in Charleston County was on the increase during the early 1970's due in part to a general recession and reduced Military and Govern- Appendix I ment spending in the area. However, in recent years the percentage of Charleston County residents who are employed has been increasing. It is locally hoped that increased activity in the tourism, trade and educational areas will replace the reduced military generated employment and continue this downward trend in unemployment. Increased recreational use of the beach area would provide more secure employment for those already employed in this sector, and there would be some potential for increased employment due to the improvement of Folly's shoreline. PROJECTED POPULATION, EMPLOYMENT. AND INCOME 19. An indication of historical and projected future growth in population, per capita income, and employment in the study area is given in Table B-1. It should be noted that the immediate planning area is extremely small in comparison to the entire Charleston Metropolitan Area and is much more heavily dependent on recreation, tourism and fisheries than the larger demographic area covered in Table B-1. ECONOMY OF THE IMMEDIATE PLANNING AREA 20. The Town of Folly Beach's economy is based on the sea, shore and surrounding estuary natural resources. As a summer resort, it caters to modest income vacationers and day visitors who come, mostly from nearby, to enjoy the water based recreation and enter- tainment available there. Typical diversions are: swimming and surfing along the island's 6-mile shore; fishing and boating in the Appendix 1 B-10 Table B-1 POPULATION, INCOME, AND EMPLOYMENT FOR CHARLESTON SMSAI/ Item Year 1959 1970 1980 1990 2000 2010 2020 2030 Population 274,909 336,837 389,000 421,000 457,500 477,500 497,500 515,200 Total Personal Income 451,033 909,500 1,487,900 2,121,400 3,114,700 4,358,100 5,775,200 7,475,500 (Thousands of 1967 Dollars) Per Capita Income 1,641 2,700 3,825 5,039 6,808 9,127 11,608 14,510 (1967 Dollars) Total Employment 94,533 127,950 161,800 175,500 196,900 210,900 213,500 221,500 Employment ToPopulation Ratio 0.34 0.38 0.42 0.42 0.43 0.44 0.43 0.43 Total Earnings: 388,437 784,130 1,252,400 1,745,900 2,518,900 3,485,600 4,586,700 5,905,600 Government 159,244 347,346 517,200 710,600 1,012,600 1,380,300 1,839,300 2,362,200 Manufacturing 59,228 121,892 205,400 284,600 395,500 526,300 644,000 767,700 Wholesale and Retail Trade 57,343 102,107 161,500 218,200 306,600 414,800 527,500 649,600 Services 41,924 86,284 170,300 263,600 418,600 637,900 892,600 1,240,176 l/Charleston SMSA consists of Berkeley, Charleston, and Dorchester Counties. The data is generally from Summary of Protections of Economic Activity in the Southeastern States (Series E Population), October 1976, U.S. Army Corps of Engineers, South Atlantic Division. -l .-_ surrounding waters; and dining on local seafood available at the numerous restaurants in the vicinity. Nearly all local employment and income is derived from these visitors, who may number as many as 30,000 on a peak summer day. 21. Folly Beach's amusement area, about 8 acres in the center of the island, was purchased in February 1978 by a church group intent on changing the character of recreation offered to the public at this facility. They plan to restore the storm damaged fishing pier to its original 600-foot length. The pavilion and boardwalk will be repaired and the dance pier, which recently burned, will be redecked. Tennis and basketball courts, a swimming pool, and a waterslide will be added to the attractions. Local leaders believe that the redi rection of recreational opportunities at the central amusement area will increase and refine its clientele to the bene- fit of the entire community. LAND USE ANALYSIS 22. Within the Town of Folly Beach, there are approximately 1500 acres of land, half of which is marshland. Of the 750 acres of high ground within the corporate town limits, 327 acres remain un- developed leaving about 420 acres of developed land. Residential usage is made of 204 acres or about half of the presently developed land. Of the 1,329 housing units, most (80%) are single family cottages. Only one third of these units are occupied on a year- round basis. This bears witness to the resort nature of this shore community. Appendix I B- 12 23. The second largest category of land use on Folly Island is transportation rights-of-way. The town has a roadnet that occupies 120 acres of land. Commercial properties occupy only about 20 acres and consist mostly of retail establishments, such as gro- cery stores, filling stations, restaurants and arcades, located in the central portion of the island. 24. On the northeast end of the island, the U. S. Coast Guard occupies 32 acres from which it operates electronic aids to naviga- tion (Loran Station). The southwest end of the island is presently undeveloped. This 190 acre parcel is a narrow recurved spit which consists of a mile long primary and secondary dune system backed by maritime thicket, salt marsh and the Folly River. Only 55 acres of this land lies above mean high water. Southwest of this end of Folly Island, across a series of sand flats, lies an extremely small sand island, Bird Key, which serves as a rookery for several species of shore birds. Appendix I B-13 iro~~~~~~~~~~~~~~~~~~~o INI. E T~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~'- '6~~~~~~~~~~~~~~~EEA A I 0 1 2 34 5 6 FOLY ISLAN SCALE IN HOUS FEE B,,d~~~~~~~~~~OTHCRLN a~~~~~~~~~~~~~~~~~~~~~~~~~IUEB SECTION C PROBLEMS AND NEEDS PROBLEMS AND NEEDS TABLE OF CONTENTS liT~~~Ed~ ~PAGE NATURAL FORCES C-1 WINDS C-1 WAVES AND LITTORAL PROCESSES C-3 TIDES AND TIDAL CURRENTS C-7 STORMS AND STORM FREQUENCY C-8 THE STORM PROBLEM C-11 EARLY HURRICANES C-12 RECENT HURRICANES C-12 HURRICANE OF 1940 C-13 HURRICANE OF 1959 C-13 SYNTHETIC STORMS C-14 STORHi TIDE FREQUENCIES C-15 DESIGN WAVES C-15 WAVE RUN UP C-16 HURRICANE PROTECTION PROFILE C-18 THE BEACH EROSION PROBLEfl C-19 SHORE HISTORY C-19 PRIOR CORRECTIVE ACTION AND EXISTING STRUCTURES C-23 TABLE OF CONTENTS (CONT'D) ITEM1 PAGE THE CONTINUING PROBLEM C-25 IMPROVEMENTS DESIRED C-27 LIST OF TABLES ilO, TITLE FOLLOWING PAGE C-1 AVERAGE WIND SPEED AND DIRECTION (ON) C-2 C-2 COMPUTATION FOR WIND WAVES OVER THE CONTINENTAL SHELF - FOLLY BEACH, S. C. 50 YEAR HURRICANE SURGE C-16 C-3 COMPUTATION FOR WIND WAVES OVER THE C-16 CONTINENTAL SHELF - FOLLY BEACH, S. C. 100 YEAR HURRICAiNE SURGE C-4 WAVE CHARACTERISTICS - FOLLY BEACH, S. C. C-17 C-5 HISTORICAL SHORELINE CHANGE RATES BY REACHES C-21 C-6 GROINS AT FOLLY BEACH, SOUTH CAROLINA C-24 C-7 EROSION CONTROL STRUCTURES (OTHER THAN GROINS) AT FOLLY BEACH, SOUTH CAROLINA C-24 TABLE OF CONTENTS (CONT'D) LIST OF FIGURES iO, TITLE FOLLOWING PAGE C-1 SEA, SWELL AND WIND DIAGRAMS C-4 C-2 CHANGES IN SEA LEVEL - CHARLESTON, S. C. (CUSTOM HOUSE DOCK) C-6 C-3 HURRICANE TRACKS N4EAR FOLLY ISLAND,S.C. C-9 C-4 TIDAL STAGE-FREQUENCY - FOLLY ISLAND, S. C. C-15 C-5 HURRICANE WAVE RUN UP BEACH PROFILE MODEL - FOLLY BEACH, S. C. C-18 C-6 MAP SHOWING SHORELINE CHANGES IN THE VICINITY OF FOLLY BEACH, S. C. C-20 C-7 EXISTING BEACH EROSION CONTROL STRUC- TURES - FOLLY BEACH, S. C. C-24 LIST OF ATTACHMENTS IQL TITLE C-1 LITTORAL MOVEMENT STUDY - FOLLY BEACH EROSION AND HURRICANE PROTECTION STUDY C-2 FOLLY ISLAND LORAN STATION EMBATTLED SECTION C PROBLEMS AND NEEDS 1. This section of Appendix I discusses the problems and needs to which this study addresses itself. It discusses natural forces, such as winds, waves, and tides, and their influences over the movements of sand along the beach. Storms are also discussed and storm damage information is given. The beach problems are then discussed, both in terms of physical damage and recreational needs. Lastly, improvements desired by local interests are discussed. Natural Forces WINDS 2. A study of recorded and possible wind speeds, duration and direction was made to determine their effects on the wave charac- teristics in the Folly Beach area. Wind generated waves are the Appendix I c-1 primary cause of material losses from the beaches. The height and force of waves likely to be experienced are factors critical to the design of shore protection structures. 3. Wind data recorded at the National Weather Service at Charleston, South Carolina, have been compiled for the 58-year period 1918-1974 (see Table C-l). The coastline in the study area is exposed to onshore and alongshore winds from northeast through east, southeast, and south to southwest. Winds from the northeast through east to southeast move over practically unlimited fetches of the Atlantic Ocean. Fetches to the south and southwest are limited but that to the south still is extensive. The wind data indicate that the stronger winds have a northerly component. Considerable transport of sand takes place during periods of high wind causing dunes to form and at times sand to be deposited in streets where it must be removed. The following table shows the average velocity and percent of the time winds occur from the eight points of the rose. Table C-1 AVERAGE WIND SPEED AND DIRECTION Direction Speed in Miles Per Hour Percent Occurrence N 9.9 15.9 NE 10.8 13.0 E 10.3 9.5 SE 9.1 8.0 S 9.4 16.3 SW 9.8 17.0 W 9.4 12.0 NW 9.3 7.4 Calm 0 0.9 Appendix 1 C-2 * ~~~WAVES AND LITTORAL PROCESSES 4. Waves and currents are important considerations in the planning of shore protection methods and ways by which shore erosion might be controlled. Waves and currents supply the necessary forces to move littoral materials. The mechanics of littoral transport are not precisely known, but it may be generally stated that littoral material is moved by one of three basic modes of transport: a. Material known as "littoral drift", moved along the foreshore in a saw toothed or zig-zag path due to uprush and back- wash of obliquely approaching waves. b. M~aterial moved principally in suspension in the surf zone by long shore currents and the turbulence of breaking waves. c. Material, known as bedload, which is moved close to the bottom by sliding, rolling, and saltation, within and seaward of the surf zone by the oscillating currents of passing waves. Regardless of the mode of transport, the direction and rate of littoral transport depend primarily upon the direction and energy of waves approaching the shore. Exceptions exist on short stretches of shore adjoining tidal inlets where the tidal currents may be dominant. * ~~~~~~~~~~~~~~~~~Appendix I C-3 5. While within the area in which they are generated, waves are referred to as "wind waves" or "sea". As they pass out of the stormy area in which they are generated, the "sea" becomes known as "swell", and such waves gradually diminish in height and steepness (ratio of wave height to wave length). As swells, waves may traverse great stretches of open ocean without much loss of energy. When they reach the shoal waters of the continental shelf, the wave fronts are bent until they almost parallel the shoreline. The irregular waves of deep water are organized by the effect of the bottom into regular lines of crests moving in the same direction at similar velocities. The depth continues to decrease until finally in very shallow water it becomes impossible for the oscillating water particles to complete their orbits. When the wave breaks the momentum carries the broken water onward until the waves' remaining energy is expended on the sandy beach face. 6. Wave data. Sea, swell and wind diagrams for the area offshore of Folly Island extracted from charts prepared by the U. S. Navy Oceanographic Office (Oceanographic Atlas of the North Atlantic Ocean, Section IV Sea and Swell, 1963), are shown on Figure C-1. The sea and swell diagrams indicate that waves of all magnitudes approach more frequently from the northeast quadrant. Wave period and breaker height data were taken from the Coastal Engineering Research Center (CERC) wave gauge at Savannah Light Tower. 7. Littoral transport. Under a contract with the Corps of Engi- neers, the South Carolina coastline surrounding Folly Beach was Appendix I C-4 SWELL DIAGRAM SEA DIAGRAM E NE 0 SW SE S S 4 % NO SWELL (SEE NOTE AT BOTTOM LEFT) CALM SEE NOTE AT BOTTOM LEFT) % CONFUSED I % CONFUSED LOW (1-6') SLIGHT 1< 3') IH MODERATE (6-12') MODERATE (3-5') HIGH (>12') ROUGH (5-8') VERY ROUGH (8-12') HIGH (> 12') N N / 94M PH S S SURFACE WINDS (OFFSHORE STATION) SURFACE WINDS (ONSHORE STATION) 6.7 % CALM WAS EXTRACTED FROM THE 1963 % CALM WEATHER BUREAU CHARLESTON,S.C. OCEANOGRAPHIC ATLAS, NORTH FROM JAN 1,1918-DEC. 1965. ATLANTIC OCEAN, PUBLISHED BY z ZlJ t (4-10) KNOTS THE U.S NAVAL OCEANOGRAPHIC AVG. WIND VELOCITY ~LLId ~ ~OFFICE, WASHINGTON, 0. C FOR THE FOR 47 YEAR PERIOD (11-16) KNOTS 5 DEGREE QUADRANGLE LATITUDE W n t (17-27) KNOTS AND LONGITUDE 75 DEGREES TO 80 DEGREES WEST (>28) KNOTS 9.5 M.PH. SEA, SWELL AND WIND DIAGRAMS modeled using the computer program WAVNERG to determine rates of littoral transport. The report prepared by Dr. Frank W. Stapor, Jr. of the Marine Resources Institute is presented as Attachment C-1. Model-predicted areas of erosion and deposition generally agree with annual rates determined from other methods. The follow- ing conclusions were derived from the model results. a. Littoral transport is northeasterly along all of Folly Island from Stono Inlet region to Lighthouse Inlet with annual amounts varying between 5,000 cubic yards to 20,000 cubic yards. b. No net littoral transport is taking place in the Stono Inlet region between Folly and Kiawah Islands. c. The southernmost Folly Island beach is experiencing net erosion at a maximum rate of 14,000 cubic yards per year. Nearly half of this amount is deposited on the beaches lying northward up to 12th Street East, or at the "bend" in the shoreline. Net erosion begins again from that point to the United States Coast Guard Station with a maximum rate of 20,000 cubic yards per year. Deposi- tion begins again at the Coast Guard Station and continues north to the southwestern border of Morris Island, across Lighthouse Inlet with a maximum deposition rate of 14,000 cubic yards per year. Sand is also moving in the inlet region from the northeast with Folly Island suffering a net loss of 5,000 cubic yards per year to Morris Island. Appendix 1 C-5 d. Lighthouse Inlet can be seen to be a major deposition site receiving sand moving both to the northeast and southwest. This may help account for the permanence of this shoal system in the fact of significant landward retreat of the adjacent part of Morris Island. e. The Charleston Harbor jetties do influence littoral processes on the northern half of Morris Island but probably do not affect Folly Island. 8. Proposed works for the reduction of shoaling in Charleston Harbor, in which waters entering Cooper River from the Santee River will again be channeled through the lower reaches of the Santee River, should have an insignificant effect on the quality and quantity of materials moving within the littoral zone. Likewise, future engi- neering works provided for the purpose of stabilizing shorelines to the north and possible future deepening of channels in Charleston Harbor should have little effect on the littoral regimen off Folly Island. 9. Sea level rise. In connection with the tidal action in the vicinity of the problem area, possible erosion of the shoreline as a result of the gradual rise of mean sea level elevation should be recognized. At Charleston, South Carolina, the average sea level elevation was 4.93 feet gage datum for the five-year period 1925- 1930 (see Figure C-2). The average sea level now is about 5.38 feet Appendix I C-6 5 I i I I I I I i I I I I I I I I I ~~~ ~ ~~~ ~ ~ ~~~~~I I I f - 5.60- 5 YR. MOVING AVERAGE h ~5.38' I ~~~~~~~~~~~ 5.40 - I~~~~LJ~~I '- , LL Q0 5.20 Lo U, 0 $ I ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~+ w~~~~~~~~~~~~ 'I =E 5.00 4.9 3 'I~~~ __ _ ANNUAL MEAN I - 4.80 DATUM OF GAGE IS 4.93 FEET BELOW M.S.L.,OATUM OF 1929 4 .6 0 1 1 1 1 1 I 1 1 1 1 I 1 I I 1 1 I I I I I I I I I I I I I I I I I I I I I I I I C)~~ 0')_ C> U- .u' ) C)% C CHANGES IN SEA LEVEL mn CHARLESTON, S.C. o (CUSTOM HOUSE DOCK) I'~~~~~~~~~~CS7MHJS OK gage datum, an increase of 0.45 feet. This rise in sea level is a contributing factor to the recession of shoreline at Folly Beach with about 10 to 15 feet of erosion o'ccuring as a result of this rise. This factor is contained in the observed shoreline changes which were used to compute design erosion rates. 10. There have been numerous technical reports on sea level rise published in recent years documenting the fact that the sea level is rising slowly and irregularly. Among these are: a. Per Brunn, W.H.M., (1962), Sea-Level Rise as a Cause of Shore Erosion: Engineering Progress at the University of Florida, Leaflet No. 152, Gainesville, FL., (Also published as ASCE paper 3065, February, 1962, 117-130) b. U. S. National Ocean Survey, (1973), Trends and Variability of Yearly Mean Sea Level (1893-1971), NOAA Technical Memorandum Nos. 12, Rockville, MD. c. King, C.A.M., Beaches and Coasts, (1972), 2 Ed., St. Martin's Press, New York. TIDES AND TIDAL CURRENTS 11. Tides. Tides in the vicinity of Folly Beach are semi-diurnal; that is, there are two highs and two lows in a tidal (or lunar) day. National Ocean Survey Tide Tables give the following Mean and Spring Ranges of Tide: Mean Range Spring Range (ft) (ft) Folly Beach, outer coast 5.2 6.1 Folly River (behind Folly Beach) 5.4 6.4 Appendix 1 C-7 12. Tidal currents. Tidal Current Tables of the National Ocean Survey give tidal current velocities in knots for a number of nearby locations. These velocities can be altered considerably by local winds. Several of these are in the vicinity of the Charleston Harbor Jetties just north of Folly Beach. In the entrance channel between the jetties maximum flood and ebb velocities are 1.8 knots; at the break in the south jetty the maximum flood current velocity is 1.2 knots directed towards true north, while the maximum ebb current velocity is 2.8 knots, directed 5 150 W. These tidal currents in the vicinity of Charleston Harbor are also shown graphically in the Coast and Geodetic Survey publication entitled "Tidal Current Charts, Charleston Harbor, S. C.", first published in 1967. To the south of Folly Beach, in Stono Inlet, the maximum flood and ebb velocities are 1.9 and 2.7 knots, respectively. The offshore tidal currents are rotary, ranging from 0.1 to 0.3 knots, and are given for (1) Whistle Buoy 2C at the harbor entrance, (2) 2 miles east of Folly Beach, and (3) 3.5 miles east of Folly Beach. STORMS AND STORM FREQUENCY 13. A hurricane is a well-developed cyclonic storm, usually of tropical origin. Hurricane characteristics are violent, counter- clockwise winds, producing tremendous waves and surges and torrential rainfall. Size and duration vary with each hurricane. They generally extend over thousands of square miles, reach a height of 30,000 feet or more, and last about 9 to 12 days from origin to dissipation. Appendix 1 C-8 0 ~~~14. Origins and tracks. Hurricanes originate exclusively in the shifting zone of equatorial calms called the "doldrums" which lies between the two trade wind systems. Early in the hurricane season, June to July, there is a tendency for the storms to develop in the western Caribbean Sea, while late in the season, September and October, storms are more likely to develop in the Atlantic Ocean. While still in the initial stages of development, the storms are affected by the trade winds and begin to move toward the west or northwest. In the vicinity of 300 N. latitude, they recurve and begin to move in a northeasterly direction at an accelerated speed. This is only a very general path that hurricanes follow and actually there are many deviations. Hurricanes have been known to circle back and cross over their paths. See Figure C-3 for hurricane tracks near Folly Island, S. C. 15. Barometric pressure and winds. Normal barometric pressures in the tropics are about 30 inches of mercury, whereas the pressures recorded in hurricane centers range between 27 and 29 inches or some- times even lower. The wind system of a hurricane follows a counter- clockwise circular pattern with the wind direction deflecting about 300 inward toward the center of the storm. At the outer limits of the storm, the winds are light to moderate; at about 35 miles from the center, they reach a maximum 5-minute average velocity of about 100 m.p.h. although higher averages have occurred. Gusts as high as 190 m.p.h. have been reported. At the center, winds are relatively calm. This calm area, called the "eye" of the storm, ranges between 7 and 20 miles in diameter. The point of lowest barometric pressure is located in the vicinity of or within the eye. The lowest recorded Appendix 1 C-9 -~~~~~~ L ~~~~~~~~~~~ ~~OHIO / ( ,I U ~~~~~~~~~~VA ~~~~~~~~~~~~~~~~~~~~~AI I A _ N T iOEA ofu, r 0 ,~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~' :-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~. A~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ss K1!vvIN ~~~~-JA ~ ~ ~ ~ ~ ~ ~ ~ A ~~~~~~~~~~~~~~~~~~~~~~~~~mm X ~~~CARIBBEAN SEA ;D~~~~~~~~ -1- O FIH T"MIOPAL sF IU fli I -~~~~~~~~~~~~~~~~~~~~~ -- N~~~~~~~~~~~~AVft AFFECTED THE~ PWHHEM~ 0 - A~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~REA FROM 1491 TO I 9.1 CORPS OF ENGINEERS U. S. ARMY FORT JOHNSON 3,000 3,000/ 2,000~~~~~~~~~~~~~~~~~~~~~~~~ z N0 FR z R SUMTERz ( 2,000---- - z2,0 . - _ �OT .00 Il,~~~~~~~~~~~~~~~~~~~~,0 0 *0 -H~~~~~~~~ -2,00 -2 .0 -1,0000 I w 400 -4I 000 0~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ IT ID O SHREIN CHANGES A T FOLLY ISLAN S HREIN CHNGETMRRSILN ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Calson,/U z (0 (0~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Lgt 0 0~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Os SHORELINE CHANGES AT FOLLY ISLAND SHORELINE CHANGES AT MORRIS ISLAND~ ~ ~ ~ ~ ~ ~ ~~~~~~~~~~~U.S CASTH.. horlie 133U..C.a .S S I -.-~~~~~~~/H. W. Shoreline 189-155 U.S. C. G G. S. H.W. Shoreline 1957715 U.SC. Cop ofEgines -D= -0~~~~~~~~~~~~~~~~~~~~~~~~ ---a----H.Shrln86USC.&GS 0-:ZZ":~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~- .W hrln 90 S.&GS SHORELINE CHANGES /4, ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~FOLLY BEACH,S.C. 0 ________ 1000 0 2000 4000 eooo~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~10 020040060 ~~~~~, R~~~~~~~~~~~~~~AC~~~~~~~~~~~ NO. 4 ~~~~~~~~~~~~~~~~~~~~~~SCALE IN FEET FIGURE C-6 barometric pressure for hurricanes occurring along the Atlantic Coast is 26.35 inches. This measurement was recorded at 33 0 N. lati- tude in 1935. 16. Hurricane surge. The hurricane surge or storm tide which inundates low coastal lands is the most destructive of the hurricane characteris- tics. It alone accounts for three-fourths of the lives lost from hurricanes. It is the product of meteorological and beach, shore and inland topographic conditions. All other factors being equal, a higher surge will be produced if the hurricane path is perpendicular to shore, the velocity of forward movement is fast, or the diameter of the storm is very large. Along the Atlantic Coast, a major component affecting the height of the hurricane surge is the timing of the storm's landfall and the predicted astronomical tide. At Folly Beach, a storm arriving at the time of the predicted high tide can produce a surge more than five feet higher than if it arrives at low tide. (See paragraph 11 of Section C of this Appendix, Tides.) Maximum surge heights experienced along the Atlantic Coast range between 10 and 20 feet. 17. Hurricane waves. The waves generated by hurricane winds cause extensive damage to shore structures and the adjacent beaches. At sea, the waves are high and turbulent, particularly in the right front quadrant and near the eye of the storm. Near shore, wave heights which have diminished some since origin begin to increase again because of the shoaling effect of the shallow water. Further, breaking waves can run up and overtop shore structures whose crowns are higher than the wave heights. The force expended when waves break causes the most damage to shore structures. Methods for estimating the height Appendix I C- 10 of hurricane waves will be discussed in subsequent paragraphs. 18. Rainfall. Rainfall accompanying a hurricane usually is heavy and sometimes torrential. However, its distribution during the passage of a hurricane is not uniform. The rain may begin long before the arrival of the storm. Prior to the passage of the eye, rainfall generally reaches its maximum rate, and after the eye has passed it ceases almost entirely. Rainfall is particularly heavy in the right front quadrant. Some hurricanes, however, are accompanied by little or no rainfall over considerable lengths of their paths. The Storm Problem 19. Most hurricanes that affect the South Carolina coast form west of the Antilles, while some form in the Caribbean. In most cases, as these hurricanes approach the Florida and Georgia coasts, they turn northeastward and remain over the ocean before landfall in South Caro- lina. Others make a limited penetration of the Florida and Georgia mainlands and then move parallel to the southeastern seaboard. The majority of hurricanes pass well offshore of South Carolina and inflict little damage. Figure C-3 shows the paths of some of the hurricanes that have affected the Folly Beach area. Appendix I C-1i EARLY HURRICANES 20. The earliest recorded hurricane along the South Carolina coast is that of 16 September 1700. It was reported that the streets of Charleston were flooded and a number of settlers perished when their vessels sank in the harbor. The storms of September 1713, September 1728, September 1752, and September 1804, were reported to have caused considerable loss of life and property damage. The hurricane which occurred on 27 August 1813 was described by the Charleston Courier as "one of the most tremendous gales of wind ever felt on our coast and a night of horrors." Torrents of rain accompanied this hurricane, and the tide rose 18 inches higher than in 1804. Extensive damages were reported to have occurred on Sullivans Island, and as many as 15 lives were reported lost. RECENT HURRICANES 21. Some of the more recent hurricanes that have inflicted damage on the study area are those of 25 August 1885, 27 August 1893, 28 August 1911, 14 July 1916, 18 September 1928, 11 August 1940, 30 August 1952, and 29 September 1959. The 1885 storm cost 21 lives in the Charleston area and inflicted damages estimated at $1,690,000. The 1893 storm cost 1,000 lives and caused property damages of $10,000,000 in South Carolina. Charleston experienced gusts of 120 miles per hour, and a maximum 5-minute velocity of 96 miles per hour. The 1911 storm made landfall between Savannah and Charleston, where wind velocities of 106 miles per hour were recorded. It is reported to have cost 17 lives, Appendix i Rev C-12 6 Nov 79 and to have caused damages totaling $1,000,000 in the state. The 1916 storm was of small diameter, and caused little property damage and no loss of life; however, it caused heavy rains and flooding, and there was an estimated $10-$11 million lost in crop damage. The 1928 storm was also notable for its rain, which caused about 52 million damage through flooding, of a total of about 54 million damage to the state. HURRICANE OF 1940 22. The center of the storm was first observed in the Virgin Islands on the morning of 5 August. During the next 5 days it moved in a generally northwesterly direction over the Atlantic Ocean. It struck the South Atlantic seaboard near Savannah, Georgia, about 4:00 p.m., on 11 August. The lowest barometric reading occurred at Savannah (28.78 inches), while a low of 29.64 inches occurred at Charleston. Maximum 5-minute wind velocities of 73 and 66 miles per hour were recorded at Savannah and Charleston, respectively. Tides ran about 6 feet above normal in the Charleston area. Damage in Charleston was estimated at $1,500,000, mainly due to inundation of the waterfront perimeter. Damage on Sullivans Island was estimated at $116,000, and was caused mostly by wind. Only minor damage was experienced on Isle of Palms. HURRICANE OF 1959 23. This hurricane, Gracie, the most intense tropical cyclone to enter the southeastern United States since 1954, passed inland near Appendix 1 C-13 Beaufort, South Carolina, during the morning of 29 September. The lowest observed pressure in the area was 28.05 inches. A maximum 5-minute wind speed of 97 miles per hour, and wind gusts of 138 miles per hour were recorded. The highest tide at Charleston was about 6.0 feet above mean sea level. This represented something in excess of an 8-foot surge, and it is fortunate that it occurred within an hour of the predicted low tide. Damages from wind were extremely heavy. Many roofs were blown off, or damaged by trees broken and blown down by the wind. Damages were estimated at $13 million in South Carolina and $7 million of this amount was estimated for Charleston County, within which the study area lies. SYNTHETIC STORMS 24. Parameters for certain synthetic storms and methods for derivations of others are contained in Report No. 33, Meteorological Considerations Pertinent to Standard Project Hurricane, Atlantic and Gulf Coasts of the United States and Memorandum HUR7-120, Revised Standard Project Hurricane Criteria for the Atlantic and Gulf Coasts of the United States. A Standard Project Hurricane (SPH) is one that may be expected from the most severe combination of meteorological conditions that are considered reasonably characteristic of the region. The general SPH that is considered characteristic of the South Carolina coast corres- ponds to one having a frequency of once in 100 years for a zone having north and south boundaries at approximate latitudes 33 0 N. and 270 S., respectively and west and east boundary paralleling the Atlantic coast- line 50 miles inland and 150 miles offshore. The specific SPH used in Appendix I C-14 this study has a central pressure (CPI) of 27.46 inches of mercury, a maximum over water wind velocity of 100 m.p.h., at a radius to maximum winds of 30 nautical miles and a forward speed of 11 knots. The para- meters for SPH as well as parameters for other synthetic storms having different frequencies were used to estimate hurricane waves at Folly Beach. The method is discussed in paragraph 26. STORM TIDE FREQUENCIES 25. The National Oceanic and Atmospheric Administration (NOAA) has at the request of the Federal Insurance Administration (FIA) developed estimates of storm tide frequencies along the South Carolina coast. Figure C-4, which was reproduced from the NOAA Technical Report NWS-16 entitled "Storm Tide Frequencies on the South Carolina Coast", June 1975, shows the tidal stage-frequency relationship applicable to the Folly Beach Study. As can be seen, the estimate 100-year storm surge at Folly Beach is 13.2 feet MSL. This stage along with the 50-year frequency storm surge were used to formulate the proposed hurricane protection plans for Folly Beach. DESIGN WAVES 26. Techniques for predicting the deepwater significant wave height and period for various synthetic storms are outlined in Paragraph 3.73, Volume I of the Shore Protection Manual, 1977. In applying the technique, various storm parameters including CPI, radius to maximum wind, and the forward speed are required. The parameter for storms approaching Appendix 1 C-15 1 i I / 1 I I 9 ii ~~~~~~~~~I I I! 1 5I j jI Ijl ~~~~~~~~~I I I ~~II I i I I 22 ~~~~~~ii III i I l I ,-iLtiIt i~i I ,. L i ~l _-LC II I ~~~i 14 20 A- is - -1 7 __ 12 7 -j~~~~~~~~~~t -+f4 - --"-"-- H 6 ~ 12 -TECHNIC A L R EPOR MS-1.- -i 3 --- -�� tCit-f-- --C-- - THE SOTH CARLINA COAST H - 2.~~~~'~~'~~' -I�~~~- - 4- JUNE 1975 TI DAL STAGE -F H 12- --:-------~~~. vi', -24-2- Lill- -- - jt -FOLLY BA.C. � --�L11 -~ri-- -t~-1 - - 4- - --- f iFG- -C-4 9~~~~~~~~~~~I -i;. .'-i-'--i - -t ; -- 10-A-~~~~i�''i A-- ----~~~~-. r fr- +tfr� - ~ I 1 11 8~~~~~~~~ - -t 1:47> - - ci A. ttztr 4- >17 ;LzqC - 7 _ _--LL ~L.5-fr�jt tS t--+ -C1 C-I - 10 50 100 250 500 RETURN PERIOD (YR.) NOTE: CURVE REPRODUCED FROM NOAA TECHNICAL REPORT MWS-I6 "~STORM TIDE FREOUENCIES ON THE SOUTH CAROLINA COAST" JUNE 1975 * ~~~~~~~~TIDAL STAGE-FREQUE NCY FOLLY BEACH, S.C. FIGURIE CA4 the South Carolina coast were obtained by methods discussed in Para- graph 24, Synthetic Storms. At sea, the waves in a hurricane are high and turbulent. As these waves propagate shoreward their heights and period are modified by the effects of shoaling and refraction. Tables C-2 and 0-3 show the computed deepwater wave heights and period for the SPH and the SO year frequency hurricane. In applying the method, offshore depths were taken from Coast and Geodetic Survey Chart number 1239. For each Synthetic Storm, the total depth along the range was obtained by converting the mean low water depths to mean sea level and to this depth adding the incremental storm surge. For each of the Synthetic hurricanes, stage frequencies were taken from the stage frequency curve shown on Figure 0-4. The source of this curve was dis- cussed in Paragraph 25. It should be noted that the 100 year stage at Folly Beach, S. C. (13.2 Ft. MSL) was used in conjunction with the (SPH) storm parameters to compute the design waves for the 18-foot high dune plan. WAVE RUN UP 27. General wave runup on a protective structure depends on the character- istics of the structure (i.e., shape and roughness), the depth of water at the structure, and the wave characteristics. The vertical height to which water from a breaking wave will run up on a given protective structure determines the top elevation to which the structure must be built to prevent wave overtopping and resultant flooding of the area to be protected. Wave runup is considered to be the ultimate height to Appendix I C-16 Table C-2 COMPUTATIONS FOR WIND WAVES OVER THE CONTINENTAL SHELF FOLLY BEACH, S.C. 50 Year Hurricane Surge 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 , , , ,2 X dx dl d2 dT Fe Ho To To2 Ks A Kf Ho Fe To TO Ks2 H N Hmax MLW d2 dT 65 420 777 423 600 74.59 39.39 13.4 .297 .998 .033 1.00 39.38 74.59 13.4 .422 .987 38.9 734 70.6 60 270 423 273 348 74.59 39.4 13.4 .513 .973 .096 .999 39.34 74.44 13.4 .653 .949 37.3 735 67.8 55 222 273 225 249 74.59 39.4 13.4 .717 .939 .181 .993 39.1 73.5 13.3 .79 .931 36,4 737 66.1 50 186 225 189 207 74.59 39.4 13.4 .863 .925 .260 .986 38.8 72.5 13.3 .93 .921 35.8 740 65.0 45 114 189 117 153 74.59 39.4 13.4 1.17 .913 .470 .965 38.0 69.5 13.2 1.47 .916 34.8 747 63.3 40 96 117 100 108 69.5 38.0 13.1 1.60 .920 .911 .90 34.2 56.3 12.5 1.55 .918 31.4 788 57.3 35 90 100 95 97 56.3 34.2 12.5 1.60 .920 1.020 .89 30.4 44.6 11.7 1.45 .916 27.8 835 51.1 30 78 95 84 89 44.6 30.4 11.7 1.55 .918 1.070 .89 27.1 35.3 11.1 1.46 .916 24.8 885 45.7 25 60 8467 75 35.3 27.1 11.1 1.64 .920 1.350 .855 23.2 25.8 10.2 1.57 .919 21.3 958 39.4 20 45 6754 60 25.8 23.2 10.2 1.75 .925 1.810 .80 18.5 16.5 9.2 1.56 .919 17.0 1070 31.8 15 43 5453 53 16.5 18.5 9.2 1.58 .919 1.840 .81 15.0 10.8 8.2 1.28 .913 13.7 1190 25.8 10 41 5353 53 10.8 15.0 8.2 1.28 .913 1.480 .87 13,0 8,2 7,7 1,12 .914 11.9 1276 22.5 5 32 5345 49 8.2 13.1 7.7 1.21 .913 1.510 .875 11.4 6.3 7.2 1.15 .913 10.4 1363 19.8 0 0 4514 29 6.3 11.4 7.2 1.79 .926 3.830 .65 7.43 2.7 5.8 2.41 .953 7,0 1690 13.7 Explanation of symbols: (See next page) Explanation of symbols: Column No. Symbol Definition ~1 ~x Distance from shoreline in nautical miles 2 dx Depth at shoreward end in feet, MLW 3 d1 Depth at the beginning of section 4 d2 Water depth at shoreward end of section 5 dT Average of d1 and d2 6 Fe Effective fetch in nautical miles 7 Ho Deepwater significant wave height in feet 8 T Deepwater significant wave period 10 Ks Shoaling coeficient 11 A Friction loss parameter 12 Kf Friction factor 13 Ho' Equivalent deepwater wave height 14 Fe' Equivalent effective fetch length 15 To' Deepwater significant wave period corresponding to Ho' 17 Ks2 Friction factor at location 2 18 H Wave height in feet 19 N Total number of waves applicable to significant wave 20 Hmax Maximum wave height in feet Table C-3 COMPUTATION FOR WIND WAVES OVER THE CONTINENTAL SHELF FOLLY BEACH, S.C. too Year H'~rricane Surge i 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 X dx dI d2 aT Fe Ho TO To2 Ks A Kf Ho' Fe' To' To'2 Ks2 H N Hmax MLW dT d2 65 420 777 423 600 76.3 42.2 13.84 ,319 .997 .035 1.000 42.2 76.3 13.84 .452 .982 41.4 709 75.1 60 270 423 273 348 76.3 42.2 13.84 .55 .965 .102 .998 42.1 76.0 13.82 .70 .942 39.7 710 71.8 55 222 273 225 249 76.3 42.2 13.84 .77 .934 .193 .992 41.8 75,0 13,80 .84 .927 38.8 712 70.3 50 186 225 189 207 76.3 42,2 13.84 .92 .921 .275 .983 41.5 73.7 13.72 .995 .917 38.0 715 68.9 45 114 189 118 153 76.3 42.2 13.84 1.25 .913 .500 .955 40.3 69.6 13.5 1.55 .918 37.0 726 67.1 40 96 118 101 109 69.6 40.3 13.5 1.68 .922 .950 .890 36.2 56.2 12.8 1.63 .920 33.3 767 60.7 35 90 101 96 98 56.2 36.2 12.8 1.68 .922 1.060 .880 31.9 43.5 12.0 1.51 .917 29.2 816 53,5 30 78 96 85 90 43.5 31.9 12.0 1 60 .920 1.100 .885 28,2 34.1 11.3 1.50 .917 25.9 868 47.5 25 60 85 68 76 34.1 28.2 11.3 I 68 .922 1.340 .850 24.0 24.6 10.4 1.60 .920 22.0 941 40.8 20 45 68 55 61 24.6 24.0 10.4 i 78 .926 1.810 .800 19.2 15.7 9.3 1.58 .919 17.6 1052 32.8 15 43 55 55 55 15.7 19.1 9.3 I 58 .919 1.770 .810 15.5 10.3 8.4 1.30 .913 14.2 1171 26.6 10 41 55 54 54 10.3 15.5 8.4 i 30 .913 1.480 .870 13.5 7.8 7.8 1.13 .914 12,3 1255 23.4 5 32 54 47 55 7.8 13.5 7.8 1 11 .914 1.240 .905 12.2 6.4 7.4 1.18 .913 11.1 1319 21.1 0 0 47 16 31 6.4 12.2 7.4 I 79 .926 3.570 .670 8.2 2.9 6.1 2.32 .949 7.8 1611 14.9 Explanation of symbols: (See previous page). which water in a wave ascends on the proposed slope of a protective structure. This condition usually occurs when the surge is at the maximum elevation. 28. In order to compute wave runup on a protective structure, the signifi- cant wave height (HS) and wave period (T) in the vicinity of the structure must be known. They were determined as described in paragraph 26. 29. Wave runup was calculated by use of model study data developed by I Savelle and others which relates relative runup (R/H0 ), wave steepness (Ho'/T2), and relative depth d/Ho'. The method employed is explained in paragraph 7.21 volume II of the Shore Protective Manual. Once the sig- nificant wave height (Hs) and wave period (T) are known, the deep water wave length (L0) can be computed from the following equation: L= 5.12 T2 The equivalent deepwater. wave height (H0o) can then be determined from Table C-l, volume III of the Shore Protection Manual. Table C-1 relates d/L0 to H/HO'. Table C-4 lists the wave characteristics used to compute runup for two Hurricane Protection plans considered at Folly Beach. 30. With the terms d/H0 and H0 /T2 known, runup on a protective struc- ture can be computed if the slope of the structure is known. The dune configurations used for the Folly Beach study, see Figure C-5, are com- prised of a composite of slopes. In order to use the runup charts in the Shore Protection Manual, the composite slopes must be replaced by Appendix 1 C-17 Table C-4 WAVE CHARACTERISTICS - FOLLY BEACH, S. C. Symbol Characteristics 50 Yr. Hurricane 100 Yr. Hurricane Hs Significant Wave Height (FT) 7.0 7.8 T Wave Period (SEC) 5.8 6.1 Lo Deepwater Wave Length (FT) 172 184 d/Lo Relative Depth .1686 0.1685 Hs/Ho' Shoaling Coefficient .9133 0.9133 Ho' Deepwater Wave Height (FT) 7.7 8.5 Ho'/T2 Wave Steepness (FT/SEC2) .2288 0.2372 a single hypothetical constant slope. This hypothetical slope is comn- 0 ~~puted by estimating a value of wave runup and then determining the slope of a line from the point where the wave breaks to the estimated point of runup. The breaking point may be located by subtracting the breaking depth db from the still water level elevation and extending the elevation horizontally to its intersects with the composite slope. The breaking depth is determined from the following equation: db =0.667 H (Ho /T )1/3 Using the slope of this line, which is the hypothetical slope, a value of runup is determined. If the runup determined is different from the estimated runup, the process must be repeated using a new estimate runup. This process is repeated until the estimated value and the computed value agree. Slopes for the plan I and plan 2 beach dunes are designed to pre- vent overtopping by the significant waves for each of their respective design storms. The equivalent deepwater wave height for smaller breaking waves was also tested to insure that waves smaller than the significant waves would not overtop the design dunes. HURRICANE PROTECTION PROFILE 31. The hurricane protection profile, shown in Figure C-5, was determined from an estimate of the quantity of material likely to be eroded during the occurrence of the design storms and from estimates of heights of wave * ~~runup for different dune and berm dimensions which would prevent wave Appendix 1 C-18 P1 -IHEIGHT VARIES (18',15',&12') DISTANCE VARIES BETWEEN /: \30 9 NOURISHMENT PERIODS -7 a.;1l ~+4' MSL (or 6.4' MLW) Existing ._ . , z Ground ' HURRICANE WAVE RUN UP BEACH PROFILE MODEL FOLLY BEACH, S.C. FICIDIRF rP-E overtopping of the dune through the period of maximum design storm tide elevation. The most desirable dimensions are those which provide the lowest practicable dune grade and the widest beach berm fronting the dune. The breaking point of the significant wave was placed approximately 200 feet oceanward of the dune centerline for both dune heights (18 ft. and 15 ft.), so that most of the wave energy will dissipate before reach- ing the dune. A 12-foot dune project was also analyzed. The artifi- cially created hurricane protection dune, for the most part, will straddle the existing dunes along the present shoreline. The Beach Erosion Problem 32. Another significant and related problem involves the instability and recession of the beach due to erosion. Stabilization of the shore is needed to protect existing and future development against damage from erosion and to insure the availability of adequate beach for recreational use. Encroachment of the ocean has destroyed both private and public works along most of the ocean shoreline. Homes, roads, erosion control structures, and valuable beach-front lands have suffered severely. Much of the dry beach area also has been lost in recent years. SHORE HISTORY 33. Available Data. Data on shoreline location, land topography and ocean and inlet bathymetry are available from coastal charts of the Appendix 1 C-19 U. S. Coast and Geodetic Survey (now the National Ocean Survey). Corn- parative analyses of land and bathyometric features, made by the Coastal Engineering Research Center of the Corps of Engineers, were used in the Folly Island analysis. This information was supplemented with data contained in aerial photographs flown in January 1977 by Continental Aerial Surveys, Incorporated, Alcoa, Tennessee for the Charleston District; in the "Beach Erosion Inventory of Charleston County, South Carolina" (S. C. Sea Grant Technical Report No. 4, 1975); and in a letter report prepared by the Charleston District in 1935 entitled "Report on Jetties, Charleston, S. C." 34. Comparative highwater shoreline locations displayed in Figure C-6 allow independent review and analysis of the erosion history of Folly Island. A graphical display is included (mass curves) which facili- tates the quantification of erosion rates at four points along the shore of Morris Island and seven points along Folly Island. These same analysis points are used later in predicting future shoreline positions of Folly Island. To facilitate understanding of the erosion problem, the two islands have been divided in reaches. All of Morris Island is considered as a single reach and Folly Island is divided into four reaches of unequal length. 35. Morris Island. An abrupt change in the trend at Morris Island appears to have taken place after jetties protecting the entrance to Charleston Harbor were completed. Before the construction, the mean- high-water shoreline was receding along the northern three-quarters of Appendix I C-20 Morris Island at a fairly uniform rate and at the southern quarter the shoreline was moving oceanward. After the jetties were completed, the direction of shoreline change was reversed. The subsequent trend is one of erosion from the southern end with a decreasing rate to the north until near stability i's encountered at the shoreward end of the submerged portion of the south jetty. 36. U. S. Coast Guard Loran Station (Folly Island Reach No. 1). The Inlet side of this reach has had very significant erosion as a result of southwesterly migration of Lighthouse Inlet. The remainder of the reach eroded a couple hundred feet during the period 1849 to 1858, then fluctuated only short distances from this position until about the turn of the century when accretion began. By 1933, the shoreline was 400 feet or more seaward of the 1849 position. This position held until 1955. Between the years 1955 and 1977 (Referred to in Table C-5 as "Recent") all of this reach experienced erosion at such a hnigh rate that f aciIi ti es at the Loran Stati on we re jeopardi zed. In 1962, the Coast Guard began constructing groins and seawalls. This work by the Coast Guard is described in Attachment C-2. Since 1977, this reach has been accreting to a point where many of the groin compartments are filled to capacity and this shoreline appears to be stablilized. 37. East Folly Shore (Folly Island Reach No. 2). This reach, which extends 18,080 feet from Center Street to the Coast Guard Station, is currently eroding over most of its length. A segment of about 3,000 feet nearest to the Coast Guard Station appears to have stabilized recently. Severe erosion has taken plate along this segment since 1955 with two streets, which ran parallel to the coast, being lost Appendix I C-21 Table C-5 HISTORICAL SHORELINE CHANGE RATES BY REACHES Location of Erosion or Accretion Annual Rate of Erosion(-) or Accretion(+) 2/ Reach Reach Average Total Volume- No. Period1/ From To Lenqth (ft) Width (ft) (cu. yds) ! Long term 180+80 N 203+00 N 2,220 + 1.0 + 1,300 Loran Station Recent 203+00 N 208+00 N 500 -13.0 - 3,900 180+80 N 208+00 N 2,720 -23.2 -37,900 2 Long term 0+00 180+80 N 18,000 - 3.8 -41,200 East Shores Recent 3+00 180+80 N 18,080 - 7.0 -76,000 3 Long term 76+70 S 0+00 7,670 - 7.4 -34,100 West Shores Recent 76+70 S 20+00 S 5,670 + 8.5 +28,900 20+00 S 0+00 2,000 - 6.3 - 7,200 4 Long term 118+70 S 76+70 S 4,200 -20.0 -50,400 Bird Key Area Recent 118+70 S 83+00 S 3,570 - 7.1 -15,200 83+00 S 76+70 S 630 + 7.0 + 2,600 / Long term: 1849-1977; recent: 1955-1977. 2/ Using a conversion approach where one square foot of surface area eroded equals six-tenths of a cubic yard of volumetric change. to the ocean. The remaining 15,000 feet of the reach has a serious problem with- about 25 feet of erosion having occurred in the last five years according to local residents. 38. West Folly Shore (Folly Island Reach No. 3). Locals report that this reach, which extends from Center Street southwest to the end of the developed coastline, a distance of 7,670 feet, has eroded an average of about 15 feet between 1972 and 1977. The high water shore- line is very near the front street edge at the popular day-use area extending from Center Street to a point about 2,000 feet southwest of this point. Two houses located along this segment of beach no longer have any land above the mean high water level beneath them. Erosion along the remaining 5,670 feet of this segment is not considered critical to improvements at this time since beachfront houses are protected by a well developed dune system. 39. Bird Key Area (Folly Island Reach No. 4). This undeveloped reach at the southwest'end of the island has had the greatest recession of shoreline since 1849, about 1,500 feet or about 20 feet per year. The erosion rate over the last five years, though, is estimated by the locals at only about five feet per year with some areas at the island's southwest end having experienced accretion. 40. Erosion Rates. Since the year 1849, approximately 560 acres (0.875 square miles) of beachfront has been lost from Folly Island. This is equivalent to an average annual erosion rate of 5.9 feet Append ix I C-22 over the entire length of the ocean shoreline. In reality, the erosion has not been uniform as implied by the computation of the average figure. It varies greatly with both location and time. Pictorial and graphical displays of the erosion contained in Figure C-6 have been discussed previously. This information has also been reduced in tabu- lar form and is presented in Table C-5. Two time periods are evaluated to demonstrate the wide variation in the erosion problem relative to the sampling period selected as typifying historical conditions. The long term record period is for the 128 year period 1849 to 1977, and the recent record is for the 22 year period 1955 to 1977. Values displayed in the table were derived by planimetering the area of beach lost in each reach over a given period of time. The values generated were then divided by their respective reach lengths to calculate the average annual erosion rate. PRIOR CORRECTIVE ACTION AND EXISTING STRUCTURES 41. On the northeast end of Folly Island, at the Loran Station, the U. S. Coast Guard has constructed a combination groin-retaining wall structure which apparently has significantly reduced erosion at that site. The timber wall and much of the six timber and rock groins have been covered with sand, and vegetation is migrating oceanward beyond the wall along most of this reach. Coast Guard stabilization structures consist of a timber sea wall around the east end of the island from which six groins spring oceanward, and a combination training breakwater structure composed of segments of stone and of fabric sand bags on the Appendix I C-23 inlet side. Attachment 0-2 gives an account of the Coast Guard efforts to succumb erosion on the east end of Folly Island. Photographs of these structures and of others described later are displayed in the main body of this feasibility report. 42. The S. C. Highway Department has constructed and is maintaining 41 timber and rock groins alonci the developed coastline of Folly Beach from the Loran Station to the northeast to within about 4,000 feet of the southwest end of the islandi. Lu--ations are shown on Figure C-7 and pertinent data tabulated in Table 0-6. A rock revetment approxi- mately 1,200 feet long has also been constructed between Groins 16 and 18 where erosion narrowed the island to the point that a break- through might occur, severing the northeast end from the reniainder of the island. 43. Beachfront property owners are using many different type struc- tures to protect their property. These include: concrete sheet- pile, asbestos corrugated sheet pile, timber seawalls, rock revetment, rubber tire walls, sand-fencing, and one property owner is experimenting with concrete block breakwaters constructed just oceanward of the mean high water line. Type, lengths and ownership of these erosion control works are given in Table C-7. Property owners have had varying degrees of success with their erosion control efforts. One problem stems from the piecemeal way in which these structures were constructed. Some property owners are unable or unwilling to attempt to control the erosion of their property while others cannot agree with their neighbors on a Appendix I C-24 Table C-6 GROINS AT FOLLY BEACH, SOUTH CAROLINA (All Constructed by S. C. Highway Department Except Nos. 1 through SA by U. S. Coast Guard) No. Location Length Distance Type Year Year Present Condition (Jul 77) (Hwy. Dept.) (Baseline (feet) to next Rock (R) Constructed Repaired Station) groin(Feet) or Timber (T) Good Slightly Badly Damaged Damaged 1 201 + 30 N 900 630 T + R 1962 1963 & 1974 X 2 195 + 00 N 300 330 T + R 1962 1963 X 3 191 + 70 N 200 400 T 1064 X 4 187 + 70 N 200 350 T 1970 - X 5 184 + 20 N 200 320 T 1970 - X 5A 181 + 00 N 250 710 T 1970 - X 6 173 + 90 N 250 600 R + T 1970 -X 7 167 + 90 N 350 610 R + T 1970 X 8 161 + 80 N 350 590 R + T 1968 X 9 155 + 90 N 350 590 R + T + R 1963 1972 X 10 150 + 00 N 350 610 R + T 1968 X 11 143 + 90 N 300 570 T + R 1963 1972 X 12 138 + 20 N 300 620 R + T 1968 !1977)1/ X 13 132 + 00 N 350 730 T + R 1963 1972 X 14 124 + 70 N 300 510 R + T 1967 (1977)1/ X 15 119 + 60 N 300 560 T + R 1963 1972 X 16 114 + 00 N 300 570 R 1967 1975 X 17 108 + 30 N 300 550 T + R 1964 1975 X 18 102 + 80 N 350 690 T + R 1966 1975 X 19 95 + 90 N 350 620 T + R 1966 1975 X 20 89 + 70 N 300 600 R + T 1970 - X 21 83 + 70 N 300 510 R 1949 - X 21A 78 + 60 N 300 470 R + T 1970 - X 22 73 + 90 N 250 630 R + T 1949 1968 X 23 67 + 60 N 250 570 R + T 1970 - X 24 61 + 90 N 250 550 T + R 1952 1973 X 25 56 + 40 N 300 680 R + T 1970 - X 26 49 + 60 N 350 550 T + R 1952 1968 & 1973 X 27 44 + 10 N 300 590 T + R 1954 1973 X 28 38 + 20 N 300 600 T + R 1953 1973 X 29 32 + 20 N 250 540 T + R 1954 1973 X 30 26 + 80 N 250 770 T + R 1953 1973 X 31 19 + 10 N 250 570 T + R 1954 1973 X 32 13 + 40 N 250 600 T + R 1953 1973 X 33 7 + 40 N 200 600 T + R 1955 1975 X 34 1 + 40 N 200 920 T + R 1955 1975 X 35 7 + 80 S 200 1,130 T + R 1955 1975 X 36 19 + 10 S 250 560 T + R 1958 1975 X 37 24 + 70 S 250 610 T + R 1961 1975 X 38 30 + 80 S 250 690 T + R 1958 1975 X 39 37 + 70 S 250 550 T 1961 - X 40 43 + 20 S 250 590 T 1958 - X 41 49 + 10 S 250 550 T 1961 - X 42 54 + 60 S 250 610 T 1958 - X 43 60 + 70 S 350 1,160 T 1958 - X 45 72 + 30 S 350 640 T 1959 - X 46 78 + 70 S 400 - T 1959 - X Total Number of Groins = 47 26 6 15 I/ Planned for repair during the year 1977. Table C-7 EROSION CONTROL STRUCTURES (OTHER THAN GROINS) AT FOLLY BEACH, SOUTH CAROLINA Linear Feet of Structure by: Local Property S.C.Highway U.S.Coast Type of Structure Owner Department Guard Concrete seawalls 4,160 - Rock revetment 600 1,230 - Timber seawalls 920 - 2,200 Rubber tire seawalls 160 - - Asbestos seawalls 100 - - Rock training walls - 600 Fabric sand bags - 700 Timber sand fencing 200 - 500 Concrete block off- shore breakwater 140 - - TOTAL LENGTH 6,230 1,230 4,000 TRAINING WALL$ ~~~~~~~~~~~~~~~26 ~~~~~~~~~40 41~~~~~' ~~~~~~~42 Key NOTE: LENGTH OF STRUCTURES ARE EXAGERATED s ToNo FOR CLARITY. I AQ E 7' ~~~~~~~~~~~~EXIST ING Sny BEACH EROSION PO.It ~~~~~~~~~~~CONTROL STRUCTURES 0 I 2 3 4 5 6 FOLLY BEACH SCALE IN THOUS FEET SOUTH CAROLINA Vr-11 ,MC r. best "solution." The City of Folly Beach is attempting to organize beachfront property owners so that an integrated erosion control system can be constructed. Currently, they are seeking State and County help in constructing a continuous seawall and placing approximately 700,000 cunic yards of sand on 22,UUU linear feet of ocean shoreline. The city plans to use the same borrow areas that are considered for use in the Federal project. such a project would only serve as a stop-gap measure for the preservation of nign ground until such time as a more permanent solution ib effectea Lnrougn Federal programs. THE CONTINUING PROBLEM 44. Future Shoreline Positions. To gain insight into the future, historical shoreline change rates measured at the seven selected locations on Folly Island were used to predict future positions of the shoreline. Possibilities were plotted on the January 1977 aerial photographs so that the hazards to development, existing at that time, could be reasonably determined. Both the long term rates and the short term rates are displayed. A display of the predictions i~, presented in the main body of this feasibility report. 45. Beach Problems. Had there been no efforts to control the erosion at Folly Beach, the condition of the beach in the future Appendix I C-25 would be essentially the same as it has been in the past. Man, in his attempts to hold the high land, has placed artificial bar- riers to the erosive energy ~-, incoming waves. These structures have at best resulted in a teaiporacy solution to the problem they were meant to solve; however, the erosion of the beach strand and berm goes on, often at an accelerated rate because of the reflective nature of corrective structures. As the beach continues to erode, less and less area is available for recreational use while founda- tions supporting protective structures become more and more exposed to the forces of the ocean. For that matter, the whole structures' exposure increases as the erosion continues. 46. With the passage of time, many of the structures will fail from the piping of materials from behind. This process is visibly apparent at the Pavillion area sea wall. The beach fronting this wall has been lowered by erosion to such an extent that cracks in the con- struction joints, which are not sand tight, are now exposed to wetting and to pulsating hydraulic forces for a considerable portion of the noriiial tide cycle. Sand has piped out through these cracks and failures are apparent in the concrete slab walks which are supported on wall backfill. 47. Should this piping be allowed to continue, all of th6 backfill, which resists the overturning forces of the sea as well as serving as a base for walks and some of the buildings, will ultimately pipe away. When this happens, the wall will probably fail, leaving an Appendix 1 C-26 exposed headland. This will erode at an accelerated rate until that segment of shore better conforms to the alignment updrift and down- drift. Proof of this geomorphic phenomenon is shown in photographs of lesser structures at Folly Beach displayed in the main body of this report. 48. Existing structures which incorporated features to prevent piping failure (filters) may fail from foundation undermining or from the battering of the sea. When such situations occur, rapid adjustment of exposed steep embankments and/or headlands will take place unless adequate repairs are made in a timely fashion. 49. Failure of protective structures allows nature to create a higher and wider beach than that normally found fronting such structures before failure. This, of course, is achieved with a loss of high land and of the apertenances constructed thereon. Improvements Desired 50. During the course of this study, individuals and groups were afforded many opportunities to express their desires concerning cor- rective works for hurricane surge and shore erosion problems. View- points varied widely depending upon the hazard to one's property, pocketbook, and/or one's recreational opportunities. Appendix I C-27 51. Back Island Citizen's Viewpoint. It should be noted that not all of the permanent residents of the Town of Folly Beach are there because of the recreational beach opportunities. Many are living there because the island is separated from other communities and has in the past allowed individualism withnn the framework of a close- knit small and very personal community. These people are active in self improvement projects, community politics and activities, and may enjoy crabbing and fishing in nearby protected water more than they do surfing, swimming, sun bathing, etc. on the front beach. 52. These mostly back island citizens appreciate only to a liniited extent the problem their neighbors are encountering on the front beach. They feel that the front beach owners were aware of the hazards of locating where they did. In spite of these hazards, they elected to invest their money to gain convenience, aesthetics, prestige, and/or income. Also, in spite of the wide publicity given the erosion problem, new construction is taking place along the front beach, possibly with the thought that nature will reverse itself or that the government (whatever level) will step in to cor- rect the situation. With this background in mind, it is apparent, to the most casual observer, that a large segment of the town's population is only willing to go along with a level of involvement in erosion control works that does not result in a significant in- crease in their tax liability. 53. Town Consensus. As a feature of the Folly River small navigation project, the Charleston District proposed Federal participation in a Appendix I C-28 * ~~beach access/biological observation park at the presently undeveloped southwestern end of the island. This park was to be sponsored by the Charleston County Parks, Recreation and 'Tourism Commission; however, the Town of Folly Beach held a referendum to determine the towns- people's feelings towards the park. The vote was overwhelmingly against its creation. From the discussions which preceded the vote, it appears that the townspeople objected to the increased traffic that would accompany the development of the park and favored private residential developnient that would increase the town's tax base. Seldom were arguments heard expounding the benefits from in- creased sales and traffic fines associated with an increase in tourism. 54. Front Beach Owner Viewpoint. Front beach property owners are interested mainly in preserving their land and the appurtenances con- structed thereon. As far as the beach strand is concerned, this special interest group would be satisfied with enough beach to meet their personal needs and the needs of those who rent their cottages and apartments. Recognizing that the opportunity for Federal assistance along private shores is contingent upon public use, this group is willing to encourage widespread public use of the beach. Merchants in the business district also support widespread usage-of the beach as a means of stimulating business. 55. Visiting Day User Viewpoint. The majority of beach users during the season come from many areas of South Carolina and from other Appendix I C-29 states. A majority of these day users come from Berkeley, Charleston i and Dorchester Counties. They are concerned primarily with problems of low quality and crowded beaches; hazards to bathers caused by groins, other protective works and root stubble; difficult access to the beach; lack of parking; and sanitary facilities for public use at strand segments apart from that adjacent to the central business district. 56. "Dynamite Hole" Viewpoint. The last identifiable group comes from no specific locality and/or special interest group. These are the people who are convinced that a dynamite hole was blown in the south jetty at the entrance to Charleston Harbor. Some even cite a specific date that this occurred; however, none has ever been able to show any proof concerning their claims nor have our own researchers been able to lend any evidence to the claims. This group has been referred to 19th century Annual Reports of the Chief of Engineers which record the design end purpose of the low sections incorporated in both of the jetties protecting the entrance to Charleston Harbor. The gaps were incorporated into the design to properly fill the estuary and to reduce ebb currents. This second feature was necessary to allow sailing ships to enter the harbor under favorable tide conditions. The low jetty sections in both jetties also were intended for a third purpose, that being to admit the littoral drift over the tidal weirs and then letting the sand be carried to sea by the ebb tides through the jetties and south- ward by the general movement of this. drift. The design appears to be working and it is the Corps' position that the jetties are not affecting changes in the Folly Beach shoreline to any discernible degree. This evidence has had little, if any, effect on the thinking of the group.0 Appendix I C- 30 They are very vocal in expounding the liability of the United States Government for eradicating erosion along Folly and Morris Islands at no cost to the local people as restitution for damages caused by the "dynamite hole" in the south jetty. This group contends that closure of the "dynamite hole" will immediately resolve the erosion problem of each island. 57. From the preceding discussions, it is apparent that the view- point as to what is a proper solution to the erosion problem is influenced mainly by individual point of perspective. Boiling all of these viewpoints down, it is concluded that the people want a cost and environmentally effective solution that will receive signi- ficant Federal funding. They also feel that the non-Federal cost should be supplied by the direct beneficiaries of the work with little or no additional tax burden or direct cost burden being placed on non-beneficiaries. As far as hurricane surge protection is concerned, most would consider approval of this type of protection only if the Federal Government picks up the tab, and if the protective structure doesn't block views and/or interfere with private land use and beach access. Appendix 1 C- 31 ATTACHMENT C-1 LITTORAL MOVEMENT STUDY, FOLLY BEACH EROSION AND HURRICANE PROTECTION STUDY CONTRACT DACW60-'76'-C-0028 FRANK W. STAPOR, JR. MARINE RESOURCES RESEARCH INSTITUTE APRIL 29, 1977 TABLE OF CONTENTS LIST OF FIGURES. .......................2 WAVNERG COMPUTER MODELING................... 3 Folly Beach Study Details. ..............3 Discussion of WAVNERG Results, Edisto Island to Capers Island............ 5 Discussion of WAVNERG Results, Folly and Morris Islands. ..............6 Summary and Conclusions................ 8 SAND BUDGETS......................... 9 Morris Island Region. ................9 Charleston Entrance, Cuimmings Point and Sullivans Island Region. ...............10 Stono Inlet Region. .................11 Folly Island Region. .................12 Summary and Conclusions. ...............12 BOTTOM TIDAL CURRENTS. ....................13 Charleston Harbor Entrance. .............13 Lighthouse Inlet to Kiawah Island. ..........14 Folly River/Stono Inlet Region. ...........15 CONCLUSIONS. .........................17 BIBLIOGRAPHY. ........................19 DATA APPENDIX I, AVERAGE VELOCITY VECTORS FOR LUNAR TIDAL CYCLES AT EACH CURRENT METER STATION. ............20 -2- LIST OF FIGURES Figure 1. Location map of Folly Beach region, Charleston County, South Carolina. Figure 2. Plots of Q (m3/year) and PL (joules/m-sec) determined by WAVNERG computer program for the Folly Beach region, Charleston County, South Carolina. Figure 3A. Volumes of net erosion and deposition for the Morris Island region between 1851 and 1895. Figure 3B. Volumes of net erosion and deposition for the Morris Island region between 1895 and 1921. Figure 3C. Volumes of net erosion and deposition for the Morris Island region between 1921 and 1964. Figure 3D. Volumes of net erosion and deposition for the Charleston Entrance, Cummings Point and Sullivans Island region between 1934 and 1963. Figure 4A. Volumes of net erosion and deposition for the Stono Inlet region between 1862 and 1921. Figure 4B. Volumes of net erosion and deposition for the Stono Inlet region between 1921 and 1964. Figure 5A. Bottom tidal currents in the Charleston Harbor Entrance region. Figure 5B. Bottom tidal currents between Lighthouse Inlet and Kiawah Island. Figure 5C. Bottom tidal currents in the Folly River/Stono Inlet region. -3- WAVNERG COMPUTER MODELING Folly Beach and nearby coastal regions were modeled using USCGS chart 1245 on a scale of 1:80,000. The area comprises the region between Seabrook and Capers Islands, focusing on Folly Beach. Program WAVNERG (May, 1974) was used to compute the littoral component of wave power (PL) at various points along the coastline, for given wave parameters and wave approach directions for the three tidal levels of low-, mid-, and high-tide. Input into the system includes depth values in a square matrix bathymetric grid, deep water wave height, wave period, and wave approach direction. With this data the program tracks coasting waves from a given point offshore to the shoreline. At the point of breaking, the program computes the littoral component of wave power. Noise in the system, attributable to many factors (May, 1974), was initially reduced by examining the printed output for bad values. This raw data was then used in the plotting program TWIST (Berquist and Murali, unpublished, FSU, 1974), which computes five point running median values of PL' further reducing the noise in the system, and then plots PL values against distance. These plots show changes in littoral component of wave power along the coast and also indicate the direction of drift. Positive values indicate littoral drift to the right (viewed from ~ffshore) and negative values indicate littoral drift to the left. Positive and negative values strictly indicate drift directions. For details of program WAVNERG see May, 1974. FOLLY BEACH STUDY DETAILS Part of the South Carolina coastline surrounding Folly Beach was modeled using program WAVNERG. Bathymetric data was obtained from USCGS charts with a scale of 1:80,000. Wave period and breaker height data were taken from the CERC wave gauge at the Savannah Light Tower. Deep water wave height was estimated through repeated trials of WAVNERG for which various wave heights were checked against their resultant breaker height. That deep water height yielding the breaker height measured by the CERC wave gauge was chosen as the deep water wave height estimate.1 The three wind directions used were south, southeast, and east; these directions were determined from observed 1 Shipboard Marine Observations (SSMO) data for Area 10 (Charleston) furnished by T. Morgan (personal communication) were received after WAVNERG computer modeling was finished. These data indicate that waves having a period of less than 6 seconds occur about 52 percent of the time, and that these on the average, have a deep water height of about 3 feet. Thus the deep water wave parameters used in the WAVNERG computer modeling appear to be about the annual median as measured from SSMO data. wind data presented in Corps of Engineers, U.S. Army, 1966. Tidal stages have a significant effect on the amount of wave power delivered to the shoreline. To determine the influence of the tidal stages on the waves and the resulting differences in drift systems, it was necessary to compute the littoral component values for the low-,mid-, and high-tides. The following parameters were used for the Folly Beach Study: Deep Water Wave Height: 1.00 Meters Wave Period: 6.50 Seconds Wave Approach Directions: From South, Southeast and East Tidal Stages: High, Mid and Low Using these conditions P L plots were produced for each approach direction and each tidal stage. At every distance position or geographic point, for each approach direction, values of P Lfor the three tidal stages were combined and averaged.L According to the Army Corps of Engineers Report on Folly Beach (Technical Report on Beach Erosion Control at Folly Beach, Charleston County, S.C.) frequency of wind waves in terms of sea and swell are as follows: Direction Sea Swell Northeast 12% 9% East 11% 6% Southeast 9.5% 6% South 4% 4.2%. By assuming a sea to swell ratio of 2:1 the following frequencies were derived: Direction All waves -overall frequency Northeast 11% East 9.3%. Southeast 8.3% South 4.1% Total 32.7% The values obtained for the frequencies are minimum (absolute) since storm conditions have been ignored. Also, it is seen from the above that no drift occurs during 67.3% (100 - 32.7%) of the year. Weighting factors were obtained from the various directions using the overall frequency data. These factors represent the weight- ing to be given the PL values for the various approach directions. The weighting factors are: Direction Weighting Factors Northeast 2.7 East 2.3 Southeast 2.0 South 1.0 The P or littoral component of wave power values obtained after weighting are presented in Fig. 1 for south, southeast and east approach directions. These values indicate the instantaneous littoral power given to the coastline by coasting waves approaching from the south, southeast and east. This instantaneous power has to be converted into a yearly longshore transport rate (Q), using the dimensionless proportionality constant 'k'. Following Komar (1970), the breaker height (Hb) is assumed to be equal to significant wave height (Hs) which is equal to 1.416 times the root mean square of the wave height (Hrms). Using this relationship, the value of 'k' was computed as 0.299. It should be borne in mind that 'k' values differ based on whether one is considering longterm or instantaneous changes. For longterm changes a value for 'k' can be computed by map differencing techniques (Stapor, 1971); this value of 'k' is likely to be much less than the value obtained for instantaneous changes. DISCUSSION OF WAVNERG RESULTS, EDISTO ISLAND TO CAPERS ISLAND P values generated by waves approaching from the south indicate northeasterly drift or transport for this coast, except for 1) Edisto Beach State Park, 2) Seabrook Island and the southwestern half of Kiawah Island, 3) the Stono Inlet region, including northeastern Kiawah Island, and 4) northwestern Capers Island where southwesterly drift is indicated, see Fig. 2. Northeasterly littoral transport should result from the interaction of NE-SW coast and waves approaching from the south. The drift reversals to the SW are probably caused by refraction about the large shoals which flank major tidal inlets, i.e., the high magnitude SW drift in the vicinity of the North Edisto Inlet. The magnitude of PL generally decreases to the NE, possibly a result of the shallow offshore bottom soaking up more and more wave energy as the wave travel path becomes longer and longer. PL values generated by waves approaching from the southeast indicate the existence of many longshore drift cells of variable lengths and magnitudes of transport, see Fig. 2. The two cells of greatest lengths (10.4 and 12.8 kilometers respectively) and magnitudes of transport are located between Edisto Beach State Park and the middle of Kiawah Island. The 12 remaining drift cells vary in length between approximately 3.0 and 10.0 kilometers. Given the complicated nature of the inshore bathymetry, large shoals flanking tidal inlets, and the essentially 'head-on' approach for southeast waves, many longshore drift cells of highly variable lengths and magnitudes of transport should be the expected result. PL values generated by waves approaching from the east indicate the existence of 3 longshore drift cells, one experiencing SW littoral transport and two NE transport. Southwesterly transport occurs from Seabrook Island to Edisto Beach State Park and northeasterly transport in two separate cells located 1) between Kiawah Island and Morris Island and 2) from Morris Island to Capers Island, see Fig. 2. The presence of projecting shoals and 'shorelines' greatly influences the magnitudes of these PL values, i.e., the vicinity of the North Edisto Inlet and the Charleston Harbor jetties, respectively. For a NE-SW trending coastline to experience northeasterly littoral transport under the action of waves approaching from the east, significant wave refraction must occur in the offshore region. Offshore submarine features as well as the projecting shoals which flank the major tidal inlets probably effect this observed/model-predicted refraction. Coasting waves approaching from the northeast probably do not affect the South Carolina coast, largely because of its NE-SW orientation. As a test of this hypothesis, a WAVNERG analysis was made using NE-approaching waves on a 1:450,000 bathymetric grid. No waves (1 meter, 6.5 second) reached the shoreline when they were started on a NE approach direction in waters sufficiently deep so that they didn't 'feel bottom' and immediately begin refracting. All waves, even those started so close inshore that they did immediately 'feel bottom' and begin refracting, exited the grid on its SW border without reaching the coast. DISCUSSION OF WAVNERG RESULTS FOR FOLLY AND MORRIS ISLANDS PL values generated by waves approaching Folly Island from the south, southeast and east all indicate northeastward littoral transport. Furthermore, waves from all these three directions indicate net erosion for 1) the 800 to 1600 meter long portion of Folly Island adjacent to the Stono Inlet region and 2) the 800 to 2400 meter long portion of the island south of the United States Coast Guard Station, see Fig. 2. Erosion in this latter region is predicted to be more intense -7- than that in the former. Material eroded on the beach adjacent to the Stono Inlet is deposited along the 800 to 2400 meters of beach lying immediately northward. The material eroded south of the Coast Guard Station is also deposited along 800 to 2400 meters of beach lying immediately to its north. Between these two erosion/deposition areas, sand is being transported northeastward and the island suffering very slight erosion. Thus, Folly Island has two major erosion/deposition areas on each end, connected by a stretch of beach simply transporting small amounts of sand northeastward. The WAVNERG analysis of the Morris Island region is complicated by the presence of the Charleston Harbor jetties. As each bathymetric grid measured 800 meters by 800 meters, the jetties appeared as a narrow finger projecting straight out into the Atlantic Ocean. The shoreline is then continuous from Sullivan's Island, out along the jetties, and then back onto Morris Island. An admittedly artificial situation, but one, perhaps, not far removed from reality. These jetties are wave 'breaking' structures or 'shorelines', although no sand is moved down and/or up a 'beach'. For waves approaching from the east, Morris Island completes the deposition region for material eroded south of the Coast Guard Station on Folly Island, see Fig. 2. For waves from the southeast, Morris Island comprises a longshore drift cell transporting material to the southwest. The northern 800 to 1600 meters of Morris Island are undergoing net erosion, the central 3200 meters are transporting this eroded material southwestward, and the southern 800 meters are acting as the deposition site. Waves from the south have a minor, rather variable, effect on Morris Island, see Fig. 2. Lighthouse Inlet can be seen to be a major deposition site, receiving sand moving both to the NE and SW. This may help account for the permanence of this shoal system in the face of significant landward retreat of the adjacent part of Morris Island. Plot 'Q' in Fig. 2 shows the combined, weighted average values of littoral transport in m3/year moving past a given geographic point between Bay Point on Edisto Island the Price Inlet, separating Capers and Bull Islands. PL values for south, southeast and east approach directions were averaged over three tidal positions, weighted according to wind/swell frequency, combined to yield an overall, grand PL value which was converted to 'Q' using a 'k' factor of 0.299. Littoral transport is northeasterly along all of Folly Island, from the Stono Inlet region to Lighthouse Inlet. The southernmost Folly Island beach is experiencing net erosion at a maximum rate of 11,000 m3/year. Nearly half of this amount is deposited on the beaches lying northward up to 12th Street, or the 'bend' or 'angle'. Net erosion begins again between 12th Street and the U. S. Coast Guard Station, with a maximum yearly rate of 15,000 m3. Deposition begins at the Coast Guard Station and continues north to the southwestern border of Morris Island, across Lighthouse Inlet, -8- with a maximum deposition rate of 11,000 m3/year. Folly Island suffers a net sand loss of 4,000 m3/year to Morris Island. There is essentially no net littoral transport of sand in the Stono Inlet region between Folly and Kiawah Islands, see Plot 'Q' of Fig. 2. Furthermore, 'Q' values on Morris Island are either so small or so potentially complicated by the 'artificial' behavior of the Charleston Harbor jetties, that little meaningful interpretation can or should be made. SUMMARY AND CONCLUSION Using computer program WAVNERG developed by May (1974), a model of the littoral component of wave power was constructed for the Folly Island region, Charleston County, South Carolina. The bathymetric grid was constructed at a scale of 1:80,000 with each grid square measuring 800 meters x 800 meters. Coasting waves approaching from the south, southeast and east with deep water heights of 1 meter and periods of 6.5 seconds were modeled for low-, mid- and high-tide situations. The resulting PL values for each approach direction were averaged over three tidal positions, weighted according to frequency, combined into a grand average, and then converted to 'Q' (m3/year), using a 'k' factor of 0.299. P1L values for each approach direction, averaged over three tidal positions and weighted according to frequency, are presented in Fig. 2, along with final 'Q' values. Given the limitations of this technique--no tidal effects considered, no onshore/offshore effects, and, of course, limited, sketchy wave climate data--a reasonable model of littoral transport was produced for the Folly Island region. Reasonable in that model-predicted areas of erosion/deposition, as well as magnitudes of transport, agree well with data determined from independent techniques. Littoral transport is northeastward on Folly Island, with a rate varying between 4,000 m3/year and 15,000 m3/year. Folly Island suffers a net loss of 4,000 m3/year to Morris Island. No net littoral transport is taking place in the Stono Inlet region between Folly and Kiawah Islands. The Charleston Harbor jetties do influence littoral processes on the northern half of Morris Island but probably do not affect Folly Island. -9- 0 SAND BUDGETS Estimates of material eroded and deposited in the Stono Inlet and the Morris Island regions were calculated by the method of bathymetric map differencing. U. S. Coast and Geodetic Survey boat sheets, surveyed at scales of 1:10,000 and 1:20,000, provided the bathymetric data. First-order triangulation points (common to the various boat sheets compared) provided the planimetric control. Differencing or comparison of two boat sheets was done by superimposing one over the other and marking all positions where isobaths crossed. These 'crossings' generate a number field consisting of positive (deposition) and negative (erosion) differences. This number field was then contoured and the resulting areas planimetered to calculate volumes of material eroded and/or deposited. After planimetering each specific area, an amount equal to 3 mm in the scale of the compared surveys was added and subtracted from the radius of each specific area to provide a first error estimate, incorporating the uncertainties as to isobath position as well as first-order triangulation point location. MORRIS ISLAND REGION The sand budget for the Morris Island region was calculated by comparing boat sheets H-254 (1851), H-2221 (1895), H-4181 (1921) and H-8781 (1963). The resultant volumes of material eroded and deposited during the intervals 1851 to 1895, 1895 to 1921, and 1921 to 1963 are presented in Figures 3A, 3B, and 3C respectively. 1851 to 1895 (see Figure 3A) During this period, Morris Island proper eroded at an average rate of 96,000 m3/year. The Civil War fortifications constructed in the early 1860's were all destroyed and the northern tip of Morris Island removed by coastal erosion. Offshore erosion and deposition were essentially balanced at a rate of approximately 60,000 m3/year each. The Charleston Harbor jetties were constructed during the period of 1886 to 1896. Their effect on sand movement in the Morris Island region during this interval is unknown, but as the jetties were in existence during only 25% of this period (a liberal estimate) their effect may have been minimal. The transport path of the material removed from Morris Island proper, approximately 96,000 m3/year, is somewhat of a puzzle. This eroded material would make its way offshore to the main ebb channel, either directly or by transport to the northern tip of the island. Once in this ebb channel, sand would be transported south for deposition on the ebb delta in the vicinity of Lighthouse Inlet. Now, i if the Lighthouse Inlet region had a net deposition rate of 96,000 m3/year, a map differencing should have identified it and as it did not, then either 1) the material was thinly spread over a great area or 2) the material passed through this region to be redistributed elsewhere. 1895 to 1921 (see Figure 3B) The effects of the Charleston Harbor jetties are very much in evidence during this interval. Offshore erosion and deposition were essentially balanced at a rate of approximately 120,000 m3/year each, double that rate of 1851 to 1895 interval. The ebb tidal delta appears to have been experiencing net landward migration, a situation to be expected as a result of the jetties deflecting the bulk of the ebb tidal discharge away from the original ebb tidal channel. Erosion on Morris Island proper greatly decreased, down to approximately 27,000 m3/year, and much of this 'material' may not have been sand, but rather marsh silts and clays. Erosion during the 1851 to 1895 interval pushed the island back almost to the limit of the sand dune topography depicted on the 1950- and 1860- vintage topographic maps. Deposition took place on the island's northern tip (Cummings Point) at an average rate of 13,000 m3/year. Much of this deposited sand could have come from local Morris Island erosion. Construction of the jetties had, in all probability, changed the basic tidal current transport along Morris Island from ebb-dominated to flood-dominated, by the partial sealing of the original ebb tide channel. 1921 to 1963 (see Figure 3C) The offshore deposition rate was at least three times that of offshore erosion during this interval, 94,000 m3/year versus 30,000 m3/year respectively. The original ebb tidal channel had been largely filled by the landward migrating tidal delta. Furthermore, the sand deposited at the northern tip of Morris Island, 70,000 m3/year, probably came from offshore rather than from local Morris Island erosion because erosion which occurred on Morris Island during this interval, 76,000 m3/year, affected marsh clays and silts, the bulk of the sand having been removed previously. Of the 76,000 m3/year eroded, perhaps 10% to 20% at most represents sand loss. CHARLESTON ENTRANCE, CUMMINGS POINT AND SULLIVANS ISLAND REGION A detailed sand budget for this area was calculated by comparing boat sheets H-5455 (1934) and H-8768 (1963), both of which were surveyed at a scale of 1:10,000. The resultant volumes of material eroded and deposited during this 29 year interval are presented in Figure 3D. The Cummings Point region of Morris Island north of the south jetty experienced a minimum net deposition rate of 95,000 m3/year. Most of this deposition occurred immediately adjacent to Cummings Point, allowing growth of the Point back to its mid-nineteenth century position relative to Ft. Sumter. Not all of this region northeast of Cummings Point experienced net deposition, the edge of this shoal adjacent to the Charleston Entrance Channel has undergone erosion. The Sullivans Island coast and immediate offshore region lying west of the north jetty experienced a minimum net deposition rate of 30,000 m3/year. A small, although measureable, region adjacent to the Charleston Entrance Channel experienced net erosion. These measured net deposition rates provide minimum estimates of the amount of sand delivered to Cummings Point and Sullivans Island by tidal and wave action. The combined value of 125,000 m3/year is an order of magnitude higher than transport under coasting waves. Even allowing a 10% to 15% clay/silt content of the deposited material (to account for possible deposition of clay/silt material coming down the Santee-Cooper) does not alter this order of magnitude difference. Tidal currents are probably playing the major role in sand transport at both of these locations, not a startling conclusion given the size of the tidal prism flowing through this inlet. Wqhat is startling is the magnitude of sand involved given the general low level of deposition/erosion rates predicted for the open beach coasts of this region. Furthermore, this situation strongly suggests net onshore transport of sand. The Morris Island/Cummings Point area may well demand net onshore transport as all of Morris Island except Cummings Point is an eroding marsh coast. It should be emphasized that these rates are minimum net values and thus the "real" transport is probably greater. STONO INLET REGION The sand budget for the Stono Inlet region was calculated by comparing boat sheets H-803 (1862), H-4181 (1921), and H-8879 (1964). The resultant volumes of material eroded and deposited during the intervals 1862 to 1921 and 1921 to 1964 are presented in Figures 4A and 4B. 1862 to 1921 (see Figure 4A) Erosion and deposition essentially balanced each other at the Stono Inlet during this interval at approximately 270,000 m3/year each. The southwestern tip of Folly Island and the eastern portion of the ebb tidal delta experienced erosion; the eastern tip of Kiawah Island, the Bird Key region, and the southern portion of the ebb tidal delta experienced deposition; and the main Stono channel -12- migrated to the west. There is no direct evidence to suggest that the Stono Inlet region received significant amounts of sand from external sources, or contributed significant amounts of sand to external areas. Rather, the evidence suggests a closed, independent system in which sand was locally reworked and redistributed. 1921 to 1964 (see Figure 4B) Erosion and deposition cannot be demonstrated to be 'significantly' different, given the associated errors, and statistically 'balance' each other at 120,000 m3/year and 205,000 m3/year respectively. The average of these two values represents a 40% reduction in the rate of sand movement from the 1962 to 1921 interval. Once again the evidence suggests, although not as strongly as during the previous interval, that the Stono Inlet region acted as an independent system reworking local sand neither receiving nor losing significant net amounts from or to external sources. FOLLY ISLAND REGION Using boat sheets 1--4181 (1921) and H-8870 (1965) no significant net changes could be measured in either the offshore bathymetry or shoreline position. Thus, map differencing cannot be employed to calculate a sand budget for this region. This apparent stability of the region lying immediately offshore of Folly Island is in marked contrast to the Morris Island and Stono Inlet regions. SUMM4ARY AND CONCLUSIONS Sand budgets have been calculated for the Morris Island and Stono Inlet regions for the 100 year period 1860 to 1960. The Charleston Harbor jetties have significantly effected the Morris Island region, changing it from ebb-dominated to flood-dominated, with the results that the original ebb tidal delta is migrating landward toward Morris Island. This landward migration during the interval 1921 to 1964 took place at a minimum rate of 165,000 m3/year. The Stono Inlet region has probably experienced no significant net exchange of sand with either Folly or Kiawah Islands. Erosion and deposition balance each other for this inlet at an average rate of 162,000 m3/year each over the period 1921 to 1964. The Folly Island region has remained essentially stable or static with respect to measureable net erosion and/or deposition during the period 1921 to 1964. -13- 0s CURRENT METER STUDY Bottom tidal currents in the lower Folly River/Stono Inlet region, the Charleston Harbor Entrance region between Sullivans Island and Lighthouse Inlet and the immediate offshore region between Lighthouse Inlet and Kiawah Island were measured using General Oceanics film recording current meters. These meters were deployed at each station for a minimum of 48 hours and were located as close to the bottom as possible, in order to measure velocities where sand actually moves. Forty three stations were monitored and all except six yielded meaningful results. Stations 5, 28, 29, 30, 38, and 42 (see Figures 5A, 5B and 5C for locations) suffered mooring malfunctions which so altered their recorded observations as to make them meaningless. Average velocities for the ebb and flood portions of the tidal cycle as well as a net or resultant velocity for the entire tidal cycles monitored were calculated and are presented in Figures 5A, 5B, and 5C. Only those ebb and flood average velocities greater than or equal to 15 cm/sec were plotted. This velocity was chosen to represent the minimum critical velocity necessary to entrain the fine sand (1/2 to 1/8 mm diameter) present in the study region. This choice was made using the Hjulstrom-diagram as presented by Sundborg (1956). Now, the minimum critical velocity for fine sand entrainment covers a range from 15 to 25 cm/sec. The lower end of the range was taken in an attempt to account for the potentially greater erosive power of silt/clay laden sea water. No attempt was made to consider the effect of wave turbulence, either in the entrainment of sand or its subsequent transport. Thus, the current meter data has been interpreted as describing bottom tidal currents only. CHARLESTON HARBOR ENTRANCE (see Figure 5A) Of the 15 stations monitored about the Charleston Harbor Entrance 4 malfunctioned (27, 30, 38, 42) and two recorded no average minimum critical velocities (33, 43). Station 41, located on the northside of the entrance, recorded average minimum critical velocities only during flood tide (17 cm/sec to the west). In the Cummings Point region north of the south jetty, Stations 39 and 40 recorded average minimum critical velocities for both ebb and flood tides. Hence as sand is always entrained, the resultant indicates the sand transport rate and direction. At Station 39 the resultant of 12 cm/sec to the east indicates a transport toward the entrance channel as does the resultant at Station 40 (5 cm/sec to the east). These both indicate regions of erosion and are 'geographically positioned in the major erosion area north of Cummings Point defined by map differencing (see Figure 3D). -14- South of the south jetty, the bottom tidal current data indicates that flood tides are the only ones competent to entrain sand at Stations 34, 36, and 32 (see Figure 5A). Station 37, located immediately south of the south jetty, offshore of Morris Island recorded average minimum critical velocities during both ebb and flood tides with a resultant of 5 cm/sec to the east or offshore. Station 35, located in the deep channel immediately south of the south jetty, recorded average minimum critical velocities during both ebb and flood tides (25 cm/sec to the south and 15 cm/sec to the northwest respectively). The resultant of 3 cm/sec to the northeast indicates sand transport toward the jetties. These results do not contradict the hypothesis developed from the sand b~udgets that the pre-1900 ebb tidal delta is migrating landward, serving as the source of sand depositing at Cummings Point. However, they do indicate a rather involved transport path, expecially in the area immediately adjacent to Cummings Point. The net offshore transport indicated at Station 37 is unexpected and emphasizes the "involved" nature of the actual transport path. The southerly resultant at Station 31 may indicate a shift in position of the ebb channel from its 1964 location. The observation that only northerly flood currents are capable of entraining sand at Station 32 further supports this shift in position. LIGHTHOUSE INLET TO KIAWAH ISLAND (see Figure 5B) Of the eight stations monitored in the offshore waters from Lighthouse Inlet to Kiawah Island, three suffered mooring malfunctions which rendered the recorded data meaningless (9, 28, 29) and two yielded average velocities less than the minimum needed to entrain sand (25, 26). Station 27, located off the southwest tip of Folly Island, recorded an average minimum critical velocity only during flood tide (17 cm/sec in a due south direction). Apparently, water flooding into the Folly River near this point is located either on the surface or closer to Folly Island. Station 24, located on the seaward boundary of the Stono Inlet channel, recorded an average minimum critical velocity only during ebb tide (22 cm/sec in a due south direction). Station 10, located on the west side of the Stono ebb tidal shoal/delta complex recorded an average minimum critical velocity only during ebb tide (17 cm/sec in a due south direction). From this admittedly sketchy data it appears that flood currents operating in the waters seaward of both Folly Island and the Stono ebb tidal shoal/delta are not competent to transport sand. Station 8 recorded an average minimum critical velocity only during flood tide (16 cm/sec to the north). Average minimum critical velocities were recorded during both flood and ebb tides at Station 7. -15- As sand is always in motion, the resultant velocity of 11 cm/sec in a northeasterly direction indicates the net sand transport. Both of these stations indicate the presence of flood tide-dominated transport in this section of the Stono ebb tidal shoal/delta (see Figure 5B for location). Stations 5 and 23, located in the seaward end of the Stono Inlet, recorded average minimum critical velocities only during ebb tide (26 cm/sec to the south and 19 cm/sec to the southeast, respectively). Station 6, located in the Stono Inlet throat, recorded minimum critical velocities during both flood and ebb tide (32 cm/sec to the northwest and 35 cm/sec to the southeast, respectively). Thus, sand should always be in motion and has a net transport path of northeast at 2 cm/sec. Now, this indicates transport across the throat section rather than up or down tne channel. Divers from the Coastal Research Division, Department of Geology, Tiniversitv of South Carolina, report that in this portion of the throat channel the bottom is floored with phosphatic pebbles and cobbles (Denis Hubbard, personal communication). Hence, there may well be no fine sand present to be moved. FOLLY RIVER/STONO INLET REGION (see Figure 5C) The lower Folly River is divided into two main channels separated by a mid-river sand bar. The northern channel runs from the Stono River northeastward to the vicinity of Station 15 and was monitored by Stations 2, 21, 13, 17, 16 and 15. The southern channel runs from the southwestern tip of Folly Island northeastward to Station 16 and was monitored by Stations 3 and 16. The "mid-river" sand bar runs from the vicinity of Station 13 northeastward to Station 15, and was monitored by Stations 20 and 18 (see Figure 5C for these locations). Northern Channel: The portion of this channel between Bird Key and Cole Island was monitored by Station 2. This station recorded an average minimum critical velocity only during ebb tide (27 cm/sec to the southwest). The next reach to the north was monitored by Station 21 which recorded average minimum critical velocities during both ebb and flood tides (34 cm/sec to the south and 36 cm/sec to the northeast respectively). Thus, as sand is always entrained and in motion the resultant velocity of 19 cm/sec to the southeast indicates the sand transport rate and direction. This suggests that this reach may be shifting seaward but is halted by sand moving landward over the adjacent shoal. The reach in the vicinity of Station 13 experiences average minimum critical velocities only during ebb tide (25 cm/sec to the southwest). Sand is constantly entrained during both ebb and flood tides at Station 19 (25 cm/sec to the southwest and 19 cm/sec to the northeast respectively) with -16- a resultant tansport due south at 2 cm/sec. This moves sand directly onto the "mid-river" bar. The same general pattern persists at Station 17 with a resultant transport southeast at 21 cm/sec onto the "mid-river" bar (flood of 32 cm/sec to the southeast and ebb of 25 cm/sec to the southwest). Station 15 recorded an average minimum critical velocity only during flood tide (29 cm/sec to the east) which again feeds sand onto the "mid-river" bar. Mid-river Bar: The highest resultant velocity was recorded at Station 18, 33 cm/sec to the south. Sand is constantly entrained and moving during both ebb and flood (41 cm/sec to the south and 30 cm/sec to the southeast, respectively). Station 20 recorded an average minimum critical velocity only during ebb tide (29 cm/sec to the southwest). Southern Channel: Station 3 recorded an average minimum critical velocity only during ebb tide (22 cm/sec to the west). Sand is constantly entrained during both ebb and flood tides at Station 16 with a resultant transport of 6 cm/sec to the east (ebb of 25 cm/sec to the south and flood of 33 cm/sec to the northeast). Station 11, situated in a small channel in the shoal between Folly Island and Bird Key, recorded quite variable currents during its 3�- tidal cycle monitoring period. Only one flood tide was recorded, ebb flow occurred during the rest o~f the time. An average minimum critical velocity was reached, however, only during ebb tide (25 cm/sec to the south). This location may be serving as a significant ebb channel for water coming down the Folly River southern channel, and, consequently, sand then moves from the "mid-river" bar to this shoal area. Station 12, located immediately offshore of the southwest tip of Folly Island, recorded average minimum critical velocities during both ebb and flood tides (34 cm/sec to the south and 43 cm/sec to the north respectively). Sand movement follows the resultant of 10 cm/sec to the northwest. This is the major flood channel at the southwest of Folly Island and may well serve to feed sand into the Folly River southern channel where it is moved to the shoal of Station 11. Stations 14 and 4 are located at the landward and seaward ends respectively of the channel separating Bird Key from the shoal southwest of Folly Island. Sand is constantly entrained at both stations. The net resultant at Station 14 is 2 cm/sec to the northeast, indicating a shifting channel. That of Station 4 is 2 cm/sec to the southeast, indicating dominant ebb transport out to sea. Station 22, located in the Stono River at the junction with the Folly River northern channel, recorded average minimum critical velocities during both ebb and flood tides (28 cm/sec to the south and 26 cm/see to the north respectively). The net resultant of 2 cm/sec to the southeast indicates dominant seaward or ebb transport of sand. Hence, any sand coming down the Folly River northern channel between Cole Island and Bird Key would be transported seaward in the -17- Stono River. Current meter data from Stations 21, 14, and 2 suggest that although the Folly River reach between Cole Island and Bird Key experiences only southerly sand transport, the sand actually moved probably can come from no further north than Station 14. Stations 21 and 14 both indicate net sand transport away from this Cole Island/Bird Key reach. Stations 19, 20, 17, 18, 15, 16, 3, and 11 indicate a unidi- rectional sand transport among the northern channel, "mid-river" bar, southern channel, and the shoal between Folly Island and Bird Key. Sand moves from the northern channel to the "mid-river" bar and then down to the shoal. It is unknown at present if the shoal is the final resting place or if sand moves from it back into the northern channel. CONCLUSIONS 1. Littoral transport is northeastward on Folly Island, with a rate varying between 4,000 and 15,000 m3/year. Folly Island suffers a net loss of 4,000 m3/year to Morris Island. No net littoral transport is taking place in the Stono Inlet region between Folly and Kiavah Islands. The Charleston Harbor jetties do influence littoral processes on the northern half of Morris Island but probably do not affect Folly Island. 2. Map differencing techniques were successful in producing sand budgets for the Charleston Harbor Entrance region, including Morris Island and for the Stono Inlet region, including the southwestern end of Folly Island. However, shoreline and isobath changes over the bulk of Folly Island have not been of a magnitude large enough to be measured. The Cummings Point region of Morris Island is experiencing a deposition rate of 70,000 to 95,000 m3/year. The Stono Inlet region is essentially an independent system, reworking local materials at a rate of between 120,000 and 205,000 m3/year. 3. Bottom tidal currents competent to entrain sand only during flood tide are predominant south of the south jetty at the Charleston Harbor Entrance. These currents are causing the pre-1900 (or jetty construction) ebb tidal delta/shoal to migrate toward Cummings Point on Morris Island. 4. Bottom tidal currents define a unidirectional sand transport system in the lower reaches of the Folly River, near the southwestern tip of Folly Island. Sand is transported south and east from the north side of the river to a "mid-river" bar and then southwest and south to a shoal adjacent to the southwest tip of Folly Island. This -19- BIBLIOGRAPHY Corps of Engineers, U.S. Army, 1966 (?). Technical report on beach erosion control, Folly Beach, Charleston County, S.C. Komar, P. D. and D. L. Inman, 1970. Longshore sand transport on beaches: Journ. of Geophys. Research, V. 74, p. 5914-5927. May, J. P., 1974. WAVNERG: A computer program to determine the distribution of energy dissipation in shoaling water waves with examples from coastal Florida: Sediment transport in the near- shore zone, proceedings of a symposium published jointly by Coastal Research Notes and the Dept. of Geology, Florida State U., Tallahassee, Fla. 1974, Chap.3, p. 22-61.' Stapor, F.W., 1971. Sediment budgets on a compartmented low-to- moderate energy coast in northwest Florida: Marine Geology, v. 10, p. M1-M7. Sundborg, A., 1956, The River Klaralven, a Study in Fluvial Processes: Geografiska Annaler, vol. 38, pp. 125-136. -20- DATA APPENDIX I AVERAGE VELOCITY VECTORS FOR LUNAR TIDAL CYCLES AT EACH CURRENT METER STATION The following tables contain average hourly (lunar) velocity vectors for a complete tidal cycle (12 lunar hours). Each vector is an average of all such lunar hours monitored at each station. The station identification is the last two digits of the hand printed four digit number appearing in the upper left hand corner. The column labeled "VALID POINTS" contains the number of observations used to determine the respective hourly average. The columns labeled "VELOCITY*SIN OF DIRECTION" and "VELOCITY* COS OF DIRECTION" list both mean values and variances. The column labeled "COVARIANCE" lists the covariance between the previously mentioned values. VAIF)T VELOCITY * SIN OF nIPFCTION VFI nr TTY * Cnl; OF PrW rF FTI o, ro A~. oI)1A .C- PFe,1 TAlJT PF-,IILTANT .a c'i 'W~~~~~MAN VAr)IANCF FA' Vr-wr.r rSFC r DEGREES e4A6NFTIC *O"AVFPAGF VALUFS FOR A LUNAR CYCLF STAPTYNrG AT.cSIJPFArF nfln l ,(w-' rpAMF COUNT a 8GDOUP COIJNT a 4A Tljr.Pf7AFl'T=I 32 -33,779 1~.O -.6q'7. 3?4 3 f~i 7.1414?4. 32 -34.710 5A*333 1 4 F i i 3Q3.?n9 5 32 -27.454 l ;R.4r 11.,& 1, 4 P ) '022 32 16.?Ol 376%*791 -11.73n P ?7~,'A 9f~lj 2. 32 13.702 Qfl6.315 -?.40.A M?.LI.4 -RP4.f 4A.,4.043A 32 13.01 l,;I.oA3 -IA? J 0*n -4P'' 1 0', 144.945 32 4248 1,171A70 ffQ4 n.A5I f, PI% 1 163 .83 7 32 -0.515 103 . I25 -1P. 743 k A,1?.- v~? 1?.?4 jA.?.40F 24 -1 1.5A2 214.?A4 -1f.S ~ ~.?.o26.604 24 3209201.1?0 -10.558 II? 3'~7% ;P 2cil. 761 P31~01 nFA A * * * 0 it At 0 Itt, ic t il t It it a 0 it * it it it t It it 'i * I VA[L In VF-t TTY * S P, nF I) I CT CT I VWLOC[TY a COS OF fIOFCTTION COVAPIANCF RE SIL T ANT RFSHLTANT PO I NTS, - - - -- -- -- - -- -- -- - -- -- -- -- -- -- -- -- -- -- -VFLOCITY DIRFCTION k4F AN v Af., I P y"(-FT 'ARCF CM/SEC DFCRFFS MA(NFTIC *****r AVFPAGF VALItj-- F41R A L1IMAQ CYCLE SrAPTIN(G AT SIIwFi;" ' A- -DICH+2 FPAMF COUNT = 17 CGwOLJP Co(iPr = 43 INCREMENiT= 12 68 I?, ~Aq 5u.:1l1 - I a 0 50.572 168.4 18.925 190.951 68 -1].7-6 ' A i.804 lI.540 701.5 31.115 202.199 69 -??.473 45. 44h , -1 3.;8 7.757 1551. 40.663 213.551 68 -18.04h 3p.1Q8 -3?.106 7.b?7 1186. 36.830 209.340 68 -R. 0- 1I.714H -?4.189 17.728 407.4 25.496 198.423. 68 -?.((3 h.?71 -11.547 87.303 80.91 17.661 186.514 68 -0.3?Q 1.816 -IP.66Q 1 .959 7.344 1'.674 181.487 51 -1.6R1 ?4. 0' -7 uI 11.260 42.07 9.850 189.828 51 1.3695 ?.SSS -.3.88? 1.977 -?0.47 7.016 168.779 51 2.246 6.0?? -7.405 3.qR5 -36.95 7.796 163.253 51 3.574 14.O k? -H.734 9.713 -66.96 9.437 157.746 51 3.084 11.ll1 -9.140 10.784 -63.69 9.646 161.355 STATI5ITJS BAsr[) ON 14iim~f R OF~ YCI! Yctr iccisrH VOtlUFS RErPESUNT rlTHinR LUNAh POURS OF A o305 ~EBB ANO FLOOD TIOF. CHECK CYCLES PEP HOUR VAL ID VELOICITY I SfN OF DIPFCTION VELOrITY COS OF DIRECTION CCVArTANCF RESULTANT RESULTANT -POINTS - IA. AN VAF!.JNEF1,F A NVAfxANCF VE LOC ITY DIRECTION JrC. V142oc~ F.,.' P) L-k_~--A c'1c~e_! TL -r rk r\ 3V, P- r~j %,- CM/Sac DeF C~~-~1 FRAME COUNT= 17 GROUP ('OUF.T= 46 INCPEMENT=_ 12 68 -0.331. 617.550 -681,91 192.094 224.5 6.170 183.103 65 -7.37) 277.576 -14910 153.945 _____97.49 7s628 255.193 657 -32.55A 91.993 -10C 221.921 637.9 33.56t' 255.881 68 ~~~~~~36.71c' 46.136 -7.O0O 295.410 627.1 37.397 259.072 68 -31.637 36.440 n.751 21R*716 23.04 31.646 271.359 67 -17*24') 61.553 10.105 163.77P -31R%1 1qg991 300*362 641. .9 60 92.3 3 -0.*31 5 161 o435 -96.1 9 1.0011I 108.el6 4 A? 7.431. 22#650 -1 5.017 1 7.1 52 __ -2 2 75 16. 7 57 1 53.662 ___ 68 -0.483 107.058 -2?.332 25*080 37.67 22.338 181.2,40 68 -4.*872 276.*708 -1Q V%590 602.977 ___ _4 9 5 * 10*226 194.679 51 -6.m999 414.917 -1 .31 7 917.520 660.p2 12.*466 214.149 51 -~32 6 4 43 .156 -RO207 78R.574 663.4 _ I2. 422 2 2 P.65_? VAI. TF) N/Ft.flCTTY * SIN (IF flTQF(Tlofj VFIOCITY * COS OF 1)11FCTION COVARIANCE RESULTANjtLTN PrOfNT~,---------------�---------------VFLOCITY flIPFCTION A fl, V A L IA NrF " F AN VAPTANCE CM/S.FC DEGRFFS MAGNETIC AVFPRAGF VAIIIFS FOR A L001AQ CYC[F STARTING AT SURFACE DFAD HIGH+1 FPAMF COUINT If 11 (HPlja rot'~li 44NCPFmf:Nl 12 68 S*.-i74 I k .WV3 -?3.820 712.223 -411.6 24.464* 1660831 68 19.140 6fl . -1? -44.747 148.349 -1388. 47.239 161*J*4 68 ?f).4Qj 34.751 -93.q2R 40.516 -2233. 57.310 159.651 68 16.144 4fl*9AO-fjR~ 44.380 -1699. 53.350 162.3" 68 6.AR4. ~ ii663 -38.455 85.279 -608.7 39.067 16941151 68 -3.161 1 1 1.36 3 -4 . '86 1264.740 -278.0 5.570 214.578 68 -10.409 116.78i 33.0b8 830.2B(6 -Q44.0 34.668 342.5211 68 -15.004 27.945 44.72B 32.563 -1386. 47.206 341.352 51 -15.5q4 ?91.HC5 42.442 24.232 -1347. 45.203 3396873 51 -13j.A6Q Pli.10H 41.061 21.006 -1092. 43.091 342.345 51 -7.0-45 44.4c9o 37.?08 24.047 -535.2 37.867 349.292 51 -.t1?10.9?4 17.413 318.709 -135.4 17.693 349,967 i P31010FA I t * * 0 VAL-T VELOCITY * SIN OF )T-4C-TT0N1 VFLOCITY r COS OF DIPECTION COVARIANCE RESULTANT RFSJLTANT POINT-----VELOCITY DIRECTION 0FJ %N i VAsTAN'C F MFAN VARIANCE CM/SEC DEGRFFS MAGNETIC. 0305 ***** AVFRA(,F VAL.UF FOR A LLINIP CYCLE STARTING, AT SURFACE DEAD LOW*? FRAME COUNT = 17 ;4POUIP COUNT 65 INCREMENT= 12 283 -3.441 711.906 -6.034 95.918 38.09 6.946 209*695 100 -18.A86 297.813 5.194 269.644 -164.1 19.395 285.53? 10? -15.663 ?5O.R57 8.623 208.487 -242.6 17.880 298.834 102 -5.175 419.142i 8.811 244.852 -133.2 10.21A 329.576 10? 11.'i4 364.3rR 9.7~6 263.917 186.3 15.159 49.890 8P 17.pQ) 369.4k3 -1.900 246.798 -116.3 18.000 96,061 85 15.54A1 318.202 -1?.563 220.116 -364.0 20.015 128.880 A5 7.404 317.6A4 -24.?23 195.290 -234.4 25.330 163m004 85 -.'9?5 240.93' -34.398 133.610 305.4 34.522 184.860 85 -13.r70 90.27A -39.749 48.155 1118. 42.132 199.364 P5 -11.0?3 37.319 -33.569 201.382 1227. 38.101 208.231 85 -16.3A3 (45.949 -19.968 191.227 b68.9 25.829 219.366 ST ITIIST ICS 1BA SED ONJ 111UPER OF YL LE S C HUSrf# --VA !UFS IREPRESENT FITl-rR LUNAR P4CUP! LF A FM' ANO FLOOD I WDE * il CIIK LYc 11 s V( V HOUR VALID - FLOCITY SIM Or' DIRFCTT(ON VLLOCITY COS OF OTRECTION COVARIANCE __RESULTANT RESULTANT -~~~-P0If'TS N~~FAN ' VA FIA fgCF hVARIANCtr VELOCITY D C I N a~~~~~c ~ ~ ~ ~ P -r~'~s~~ ~~L j~ lLVv~& c~ r.1e 53~. e-~- ct~sc. ba~,,eon FRAM4E COUNT= 17 GROUP fOUHT= 40 INCREMFNT= Iz___________ Q5~ ~~-.2 212.180 10966. 1 69 .08 1 -468.*4 2 1.0819 334..159 68 -~~~~24 1 76 2 76.1 65. __ ?A.205.2 _ -1 31? 2 35.700 9 ___ 31 7*38R ___ 68 -3s5.585 11 2.056 3 39.152 41.1.60 - 21 60a 46,e64 310.275 69 -37.244. 40*23P '6.9Q1 43.596 _____-201.1. ________ 996_____ 305.931 68 -2R .761) 294..817 23 *645 1 1 7983 -1 307.o 37.232 309a142 5 ___________ -3.506 ___450.01? __ 5057Q 25 5.aa91 -92.03 6.9588 327.854. 68 16.16? 41R*~332 -4.84.8 232.122 -110.2 16.873 106.69q 67 4 ___15.797 __ 2~6_241_ -17.653 554o471 -1350. 49.082 111.080 ___ 68 4 .5.783 312.100 -pc*91.1 675.177 -2007. 52.622 119.536 68 37.525 273.682 -27.74.7 547*01Q -1708!L______ 46.669 126.480 68 17,450 7PO?-29.*533 206.732 -1101. 31-.303 149.1422 68 5.632 --6?.193 ---2 so31 ___ R*979 ____-124.3 _ 5.989 1 09 891___ M. TOl Vf.1-rTrY *SINJ OF OfDFCTT0NI MFOCITY *COS OF-DT'4CTTON COVARTANCF RESULTANT RFSLILTANT IFT POINT; -------------- -- ------------ VFLOCITY T)IRFCTION VP AN Alji -AN VAP'TAN'CF CM/SFC DEGREE~ MAGiNETIC 037 ***AVFP.AGF' VAI-UFc% FOR A LIJW.AQ CYCLF STAIRTINf, AT SURFACE DFAD LOWel FRAMF COUNT 17 G~OOU c0hiff" 4 $4 INCPFEMN7= 12 68 l4711.9 ~ ?3.(88 499.146 538.0 25.754 26.315 6A 31.4?7 17'5.h(4 43.481 9t).898 ?8?7. 1.3.651 35.857 2' ~~~68 39.83? 166.317 iit.04A 197.437 3733. 60.885 40.860 67 36.759 247.?94 47.07R 3So.350 3607. 59.729 37.983 68 ?4.'J4O 4Sl.2F'2 31.1`20 3c)5.374 1873. 40.429 38.008 67 ?.III 184.poo 6.1~,3 S87.d22 313.5 6.505 18.932 671 1.494 P14.'j?f -10.79i 81.?00 .7660 10.901 172.121 66 - 14. (?8 ?k 3. 75 CI _2.518 22?i.5fl3 F159. 4 27.016 213-.542 ;j ~~ 68 -?7.439 ?87.477 -30.351 144.9?3 1737. 40.916 222.115 68 -?l.57h 142.174 -?8.543 10A.2114 1314. 35.781 217.086 64 -4.010 16R.m(,4 1459111.268 204.0 15.058 195.524 68 1.347 3r,7.3116 -500356.531 19.50 5.188 164.949 rn ~~IAI TO. 1~~;ig n~rry_ D. -,as 1Fl fl.BTyr'CT_.tnMv 't~v rr~. nr -T-rrrT-'. 'rrCI'f TAT DP-,III TAAJT FOAMF r~~~hINT = i V'''P F- cnp 4IlIFI6 j~rj p qT MTyfjn ,,-AT 2 8 - . 239 ?56.865 P 4 1 6 1 A7 1 -4 7,17 347.768 32 -3 .50 7 365. 030 P3.41q 9.7- 35 I.462 28 -4 .631 3 34. 646 1 7 . F7? ?llO'I 2.i 345 .316 25 -6 .930 324.733 - . 4 L4 2 a I11,67 -ih9 t- 1,U i!31 .9b 27 -9.682 1 55. 874 -1 I . 8 F UII.44 1r. a4 . ~,o 221 .b 6 26 -4. 1 17 214.7Pi9 -1 I.95A 2?7. ?S3 -j".i 1/~ ~ .u 32 2.737 167. 051 - 7. 588 1 '{)D.t3 v w. i' -~u f,l lb 0. I 3 3 0 -4.845 146. 6 14 -4 .7 31 1 07.~ L I 7..I(e 32 -3 .90 3 1 87. 544 .0.42A 2'? :4j 27b .2b> ST AT ISTICS B#SFD ON Ntl?4DER OF CYCLFS5 CH OSFN. VII UES REPPESFWT F ITHFR LUNAR HOURS Eg AO 2310 EF10 PRO FLOOD TIDE. CHECK CYCLES FEHU _____VALID ___WLOCITY 9 SIN OF VPPRCTION VELOrITY 9 COS OF OIFECTION COVARIANCE 'RESULTANT RESULTANT __ P011TS ~~~~~MFAN ' VA~ANC - 1FN' -- h~C -VL0IYtETt FRAME COUNT= 17 GROUp r-oUNT= 26 INCFEMENT= 12 6I -15.*96( 487.597 -1 09 9 640.707 1 99.a4 1 6.a085 262.860 51 ______-P,32L 617,,89P ____ '2 7 5?7 -89 *I2 ________p617 284oQ79 34 -5011" 733.946 14.247 433.44n -298.0 15.157 340.265 34 I 113 5 34,#9 06____ p.21 ' 547.959 1 31.o7 1 1.547 44.it639 34 12 9990 350.760 -2.690 5 62 ?.340 -1 61.U 1 3.31 1 102.607 34 15.v770 2e665 76 -1 3.45q 46 3.951 4 -49RO8 20.0738 130.4I62 34 1'**735 254 *509 -15.a257 330*345 -6 27 0 24.a94 5 127*70?t ____ _______ 11 .390____ 380 .90 7_ _____?4,f 3659254S -626~.o 27.01 1 155o038 34 3.675 367s33c0 -17,177 546.594 -99.62 17.565 167.923 34 -1.632 404.36? -15.817 461*590 38.78 15.901 185.891 34 -7.313 500*881 -IA*945 43Re25R 2711.8 13.456 203.344 34 -20.510 405.796 09906 592.053 90.56 20a530 272*52P STATISTICS VASFD ON' NUMLEP OF CYCLF' CV4OSEN.___________ _______ VVDLUF S1 REP F'TSFT FTTHFP LUJJAWi-9UU1ZS'OF A _____ )311 R ANn FLOOD TIDF. C'HiEIK CYCLI S FEF HOtIP VAI.11- VELOrITY *SIN OF DIPFCIICN VELOCITY COS.Ofr DIRECTION. COVAPTANCEE____RFSULTANT PFSULTANT_____ POINTS-- NFAN -- VAiRIAtf V Fp VARIAN~CP V E LOC I TY ITR E CT I N J'Ae~o-oe VOo- F-C>V- cx- LLC-je--l~e SV-t\ 1zT ~--race- cco~ IA c3. Cr~/ FRAME COUNT= 17 GROUP rOUNT= 4? INCVEMENT=__ 12 ____ AS -1.646 17.495 -270904 56o53R I 1OQ.9 2 1 a04 2 183.365 ~~~~~68 -3,547 _______ 1..GbO(in_ -3 3.o77) 119987 24?.9 33m956 185.997 68 -1 .5 4'1 1?.737 -3.4f ?*76f 107*4 33.68? 1820628 68 _______8 0 f.96'3_____ 4 oJop _____-?70301 1?*032 _____50.94 27*31P 177*969 60 ~~-9.223 20m702 -1 4 .1 r7 215.073 1 7.25 11..108 180.907 ~~~~~6 -1.1 61 23.,5 30 _~_____ -6.a020 5 24 6 67 _____86.63 6 a1 31 1 90.a91 4 5 1 0*03Q 26967c) -7*784. 624.45~ 52 .1 5 7.78 I 179.710 51 __ ____ '.4~~41 _ 26.710 -6.a9 ?5 79R*631 -4 0.5 7 7 .34 3 ____160#586 5 1 5 .0 54 1009~9 -7.7~c6 803*328 -150.4 9.0291 147a041 ~~~~~51 3.*67' 29 el7 L -7 *I 7 4 1.a23 4 -1 51.a8 8.082 1 52.*933 51 0.94? 41 *956 -1.o924 671 99 29 -73*A3 2.142 1 53*9GQ 49 0 5 67 83*49( -1.1l5 3 31 ~.773 -1 6.22 1.s285 1 53.8U6 ST AT IST ICS p p~rfl OiiNi isirt~p OF r YLar rIIosrN VALUES REPPESENT F ITHEP LUJNAR HOURS OR A._____ EAR ANn FLOOD TIDP. CHECK CYCLES PF HOOP VALID VFLOrITY * SIN OF DIcFCTTICN VELOCITY COS Oc 61RECTTGN. COVAPIANCF RFSULTANIT PFSuLTANT POU~TS MrON VAkIAI.Cr K F$N VARlAbCF VELOr.ITY - --DIRECTION e~- v o ~e vU e Fg Wv.- cL- L) .V'.o, C~c e c Ioy e-c St~-j~ pT 0r-/6 eC bec.. eea- __FRAMECOUNT=_ _ 17 CROUP COUNT= t? INCFEMENT= 12 53 -1"79.043 -?p.90? 410.58? 9. 2')*071 186,17Q A6 -10.*46h 1 80.7 85 -4 4 .71) 9 .3 53 907.6 ______45*998 193.149 6 8 -12.571 2 1494 4 7 -.5 05n 60.73? 107R. 4 7.a21? 195o442 -~~~~ ~ 67 -10.752 137.456 ___ -35.853 6?.76q__ 7138,8 ____ 37.430 196.693 1.5 -3.*061 i 0.9[24 -1 ".2 62 1 95.002 1 37 .6 18.517 1 89.-5 14 14 ____ 0.802 1383,300UP ___ 41.403 1772'~.477 __5440. ______ 4?.635 13.291 48 fl.929 235.145? 31.437 203.02'! -135&4 31 .450 1 .693 5 1 ____ -1 0.11I1 72.003 46 .3 33 8 6 .96 5 -98 2 01 47.423 347 .689 51 -11.373 95.817 46.72t 236*627 -1145.e 4,R.092 3450321 51 -13,420 65.437 4'1*431 93.571 -1347. 50.256 3449512 1.9 -11095? 116.510 1.0*04A. 13?*036 -1055. 41.791 343.382 3 2 0.32? 2 70.a0J69 1 6.*63. 2 289.6 24 -139.6 1 6.6 41 1,10 9 ___ STAT IS TICS OA Sr DOF! NU'IBER OF C YELP ~ rt4OScN-, ------VJLUFS-FEPFESFNT FITHcR LU~qAR-14OURS' OF A- ________- ~~g ~~ EBn ANT) FLOOD TIOF. riI C K C YC I F s H OUP VALID V97LOr I TY X. SI N OF f, IiFFL TI ON V ELor I IY COS, Or' 0 1RE C TI GN COVARIANCE RF S ULTA NT ___RFSULTANT POINITS M . rANVtRIANCF ~ .NV A RI A CE VELOCITY- 'TIRECTION FRA'4E rOUNT= 17 GPOUP rOUNT= 47 IICfrEMFNT= 12_____ 618 (.097 81.853 -11,35e) 27.073 7.579 111350 17Q.509 68 -27.911 190.503 -loaplVo 1711.12-_____ 612.9 _____ 20.952 248.723 65 ~ 3*2~3P.767 -1i..ORS 1011.877 ills. 41.022 249.919 _______A8 -M *681 40.1 11 -1 t.*91 1 54 *860 ____ 1071. 3R*673 247.31 4 -2 7 *24 F 54 *7,' -1 3.841 93. 3 65 796.6 30.561 24 3.9071 68 -79543 87.057 -5.373 1 Oknol? 66.03 O'.261 234.537 51 1.666 9a934 -,R,2n9 255 -27.73 So377 16R*529 ____51 __ - .9 47 3 7 *554 I ?QQ Thf). 525 -100. o7 7o__ 7567 1 __ 13.340 49 1 3.83 0 94.175 r.1 47 1 4 9 61 1 -44.*51 1 3.83( 89.*391 49 24.62A 69.~201 -1*699 2 21.8 19 -1 13.3 24.687 93*945 45 32.305 83.0101 1oq 1 47.69f -1 14.4 32.339 92.631 51 _____16.319 100-414 -7.076 36.143 -204.3 17.786 113.444 * ~~~~JI iir- *d.F(.1 'I v~~~~~~~~~~~~~~I factn fi CII ti III PF 'WI~~'~C It~i R LAN I A VF A1t- V aLP It- Oq- LI IN PA'~ C' YC.L , A. 1 1 ,i4AI ~.1h I FA cmml I .,l 1,011' ICn'- ~ 1 I ~ ~~~ ~~~~~~~~~~~~~~~~~~ 7 3. 544i if,. 7 ?.-I i." Militia~~~~~~~~3v,.z~ P~l DI OF A 4***O** ti f0 *4* a~** di, tA~ o4,g Vhl- F) VcLOrTTY *'>IN OF OlP;FCTTON~ VFI~LOITY * COS OF DIPECTION COVARIANCE RFSULTANT RFS[JLTANT POTNTc�---------------�---------------VFLOCTTY DIRFCTTON MF 11 P I A h C. MFAN VAPTANCE CM/SEC DFGRFES M4AGNFTIC ***AVrPAGF VALtJFS FOP A LIJNIdAQ CYCLF STAPTING AT SURFACE DE,-n IAW FRAMF COUJNT = 1 7 GPOUP COUNT = AINCREMENTm 12 102 2. 6f,1 137.0r,? -3P635.476 -38.81 4.213 140.831 102 JR.411 310.687 -A.?39 29.656 -325.8 20.171 114.109 102 39.1IQ1 ;10.944 -8,644 33.308 -675.5 40.133 162,438 I102 c;7.6()S 7Q35q.1 -8.65 153.195 -21.83 58.342 )A*527 102 43.519 1?6.397 -10.046 26.759 -852.1 44.659 103.1000 102 12.A33 715.Sp? -8.698 28.8(4 -240.4 15.0 24.129 95 -11I.31 4;616 -S.R17 65.126 , 228.5 12.738 ?42.A26 as-1.? 618.A49 -5.608 144.645 490.5 21.961 255.135 a5 -?3.471 3?7.123 -9.361 73.891 544.7 25.265 248.278 8.5 -13.P73 ?OA.713 -b.666 67.403 257.5 15.482 244.495 *85 -1I. 804 32.508 -7.164 61.44 8 31.08 7.387 194.134 81i -0.812 ?9.876 -5.741 59.457 10.51 5.799 188.049 VALID VELOCITY SbINj OF DIRECTION VFLOCITY CO CobF !)[PF~C'T[ot COVAq I ArCE, RESILTANT w~SULTANT MEAN VApI PA 1C.F mF AI V A-.' IAt.CF C.SC j)F(,iwFFS MA04'.FTIC AVERAGE VALUES FOR A LUNAP CYCLE STf4PIN(, AT 5LJNFACE DFAD LOW F#4AMF COUNT 11 G ROUP~ COUNT r)6 I 102 2.888 86.26 H ~ jotJI ) 1 1..91 ?16.0 w.-6 1.o09 102 10.067 194.2'i0 23. -O1, 109'O ~ ieI . 3 L I). 9:)I 102 21.773 l80.1977 44.i11 45 1. _9J - 17 I4 . 414. I i 102 25.340) 7 1 . I97 -)0. 3 o.' 3 1.2' e ?-i). , 102 H.164 333.59 9.1 vo.,12.9h95'. 7s32 $5 ~~~~~~-3.065 4 2.1 -.19 L 1i)M, djf1 I1~.~ 85 -6.787 62. 7 3 -47.?d3 10),I~h~. 47.76,i htl. 1 9 8 5 -5. u39 46.18q -4'). SI7 4o3. -00-i; 4~1.( 11 - h7.4.j3 $9 ~~~~~~-B.l4b 147.4j4 -b94339~tjc.;io. 303 l9-12 65 -2. 793 1 (3 . e8l -'4. h7, I -S? . 44 1(. 0 71 19n.ovL) 85 4.0?8 47.410 1.196 ot~o. 39 LII1.23 4 . eUI 7 3.4j ovio i DFA VAI In vtt.OjclY *1' (rIr r)T'JgrCTIoN Vf.LOCITY * COiS OF DIPFCTION COVARIANCF RESULTANT RESULTANT PnINT'; ------- - ------------------- --------------------------- VELOCITY DIRECTION VAQIANrF liFAN VARIANCE CM/SEC DEGREES MAGNETIC **4*+ AVFiPAbF VAI.1IFS F.OR A UIiNAP CYCrtF STARTINC. AT SUDHFACE DEAD LOW FPAMF COUNT = 17 (i-PnP CMINT 66 INCREmENT= 12 10? ].-)7. 313.194 -P0.49? 57.458 -167.9 20.534 176.349 I0 ~ .h 671.911 -?P.700 2A5.542 -1119. 31.729 135.678 102 49.195 90.799 -15.75S 663.226 -1517. 51.657 107.758 102 S3.37A In0.3'4 -9.84? 766.760 -966.1 54.287 100.499 102 42.410 3?9.69? -8.866 728.498 -698.1 43.327 101.809 102 11.896 555.049 -1c.916 356.530 -279.4 19.863 143.350 I 85 -Ih.16'7 376.517 -19.Q37 417.341 928.0 25.668 219.039 85 -?7.073 55.48? -28.326 164.507 1594. 39.183 223.705 85 -20.964 34.661 -?8.081 38.603 1165. 34.806 216.216 85 -13.34Q 25.812 -?P.221 21.823 597.3 25.922 210.995 85 -10.900 19.840 -19.411 8.790 423.2 22.306 209.518 85 -11.209 ?1.881 -16.692 21.352 375.8 20.106 213.883 VALoIDF VfLOCITY SI FDWCIN VLCJT oL~ ov i :~rj~ COVA~IACE EU N F UTANT PO I NIS ------------------------ ------------------------vrLUCWI fY D PFCTIUN MEAN V A i ANCF 1F AN VAPIANCF Cm/s-C DF4RIffs ~AtNF:TIC **4AViERAGE VALUES FOR A LUNAR CYCLE STARTING AT S~kFACE OE.f,G FPAmE COUNT = 1! GROUP COUNT INCWE--I-jI= I 102 -14.426 327.4A3 -?e.947 1 -7 .0i7 ?7 . fb 21e.156 102 -0.246 3bt.96e, -31.910 .35.~86 -1.6931.91 1 02 29.4oS 2fYI1.1 -30.491 3). 7 7 7 -I IL)I. 4?.-+i)4 13'5.911 102 38.494 17b.723 -~16.1101 51..311 4-,?lbl. 4I1.936 1 102 17.540 266.83m -30.4.)O 7 141-q lbo. :0-.14 85 -I.lb6 567.882 -37.7,)3 207.513 396.4~ 37.7lu IAI.7,.4 85 -26.?19 43.646 -4k�P24 ~ 244,i?- i ~o4 .M3 2Q. $5 -29.706 42.~~~ ~ ~~~~~~~499-b -4 t . 4 1. 71. o6c ?It1. ,4 . 311 214.1'i El5t -2b.64-3 31.636 -3H .2t2 6 .57b ?ou1. 46. b'245tP 85 ~~-22.220 1 1.841) - if).ub 9.UH3 1 -IMI. H 835 -21.931 9.479 -28.117 ). 14to 113. ibob eI7.Y>4 P33010tFA VAL.Ti VFLOCTTY * SIN OF DIWFCTIOI VFI.nCITY * CO; OF DIRFCTION COVARIANCF RFSIULTANT RESULTANT POINTS----VFLOCITY nIRFCTION MF A N VAPIANCF 4FAM VARIANCE CM/;FC DEGREES MAGNETIC AVFPAGF VALUVFS FOP A LUNAR CYCLF STARTINC AT $UPFACE DEAD LOW FRAME COUNT 17 GROUP COUN.IT 67 I NCREMENT= 12 102 -5.304 ir.473 -2.183 294.076 113.7 5.736 247.629 102 Q.7?6 J&QJ.0L3 -6.Q14 378.328 -5.296 11.933 125.408 102 36.148 890.563 11.?80 944.807 533.4 37.867 72.669 102 34.962 403.480 27.734 398.815 1605. 44.626 51.577 102 ?6.E49 ??4.374 30.17? 283.059 1432. 40.1R9 41.345 102 1e.874 107.196 13.699 299.263 465.3 18.799 43.222 102 -17.477 387.3Qi -18.031 361.016 606.9 25.111 224.107 85 -37.880 271.407 -23.189 338.356 1619. 44.387 23a.511. 85 -37.379 P27.614 -21.05.4 269.967 1526. 43.349 239.572 85 -28.P8s 246.336 -14.191 174.250 743.2 32.179 243.832 85 -16.755 140.880 -7.549 172.403 259.0 18.377 245.746 85 -6.A51 69.133 1.825 204.130 23.2e 7.090 284..916 P330I0I~ *************auu**********9****** VAHID VFLnCfl.Y %IN (IF DI)JCT1o1I VFlOCITY * COS OF DIQECTION COVARIANCF RESULTANT RESULTANT PnINTS-----VELOCITY DIRECTION "IFAN VAPTANCF MEAN VAPTANCF CM/SEC DEGRFFS MAGNETIC ***c* AVFPA(3F ViLIWIS FOP A LUNAR CYCLF STARTING AT SURFACE DEAD HICGI1+1 FPAMF COUNT = 17 G ,ROUP COUNIT oll INCREMENT= 12 74 0.7S7. 104.471 1.724 538.671 ?23.5 1.883 23.710 80 -19so? 4,3.Qf4 -26.61A 683.4Ab 1421. 32.739 215.607 77 -3?.7M3 380.315 -42.944 303.b62 3009. 54.027 217.358 A? -37.631 3?'7.1 -36.5�O 76.373 3044. 54.570 223.597 PS -?3.774 343.1?4 -37.095 126.276 1958. 44.059 212.655 A3 -6.693 64.?71 -?6.587 56.339 412.0 27.417 194.130 85 ?.154 ?~.96l -14.S21 90.593 -17.68 14.680 171.561 81 7.PR4 7?.6?4 -8.701 177.533 -93.52 11.347 140.068 8? P.677 116.111 -1.659 599.885 130.5 3.149 121,789 85 6.401 4?9.504 10.S37 811.908 590.0 12.329 31.278 85 17.3?5 676.326 20.342 576.106 1273. 26.720 40*420 85 15.141 439.670 17.739 712.632 1041. 23.322 40.482 VALID VELOCITY SIN OF OI0I-CTION VF LOC ITY a' COS QPf) OIPF CTII t COVA-.I ANCF ;4tSIMT ANT RF StLTAI'd POINTS - - - - - - - - - -------------------- ,mnclf rvPIPFCTIurN MEAN VAPIANCF M1~ 61 VAwjAN(: CM/st C i)E6HELb MIAtitTIC ... AVERAGE VALUFS FOR A LUNAR CYCLE STAPT ING AT SIJ,4FACE F. DAo. F14AME COUNT I I GkOUJI COUNT IdCrSE'F 102 14.14?4 31 3.1590 I 1.91i'. 473.0?9 7 l.i..j r3'. 3' l' 102 40.918 448.363 4 13.b''0I Y? 3. 46.4d8' 5 7. 7,y 102 4'3.23L0 4~-2. 4C4 30 . I 871;.11 II5 7. 0L# 5 1.644 102 43.531 ?W4.15?5 ?/i.36 i..170 ?049 5.6-44 -I i. 1 2 102 4 1.4`3 0 356.?99 1 7.4 11 4,,,3 0 1240. 45.104 85 -7.877 342.7ii1 -11.913 336.vl.9 35 3.0)1.6 20:3.73A 85 -5.985 961.967 -46.InI 2S7.454 4'.3.Y 48.�2? 187.0*5 65 -2.522 BA5.816 85i~~ elt,.07t, % bh. -12 IM2.4o2 u5 -0.945 ~ 502.09b -50.513 3 It. M21 -.4 6 bo . t2e 181.012 as -l. 069 175.329 -32.51.3 P51.911 7 94.05 32. 624 IR3.b3b 85 -2.504 I 1I0 .144 -1 0.996 '7 1 .363 6~23 1 1.2l7t 192.8ifo *3I FAI ~0ii J44 i0i ,i, )00iI tQAi V4L VE~~~f)C~~lY * SIN OF OlPFC] 1,11; V~~~~~~ L M' I I Y C(S OF 1) I ~~~~~~0 C. I I Or, COVV41ANCE Rfr %Ut. I at; I~~~~~~~ VALI~~~---------------- ---U ----------------------- V- I-Or I TY 1 O WO F Tkr 0)IAN~~SI J RFSLA1 "f-, A f( V i441 I AfNC i VA' IM Ar: (>11/ C, OFI,140 t S MAbN*~ I~~ 9*'e* AVFPAtF VALFPS F-09 A LIMACP CYCLI- APFi~ Ar- -'IHF-ACi: 34-WAD)'F, FP,%MF rC)UlT I C T I c~.s 11 85 441 6 3-.~ I 3~. 4276 $5 13~~~~~~I.477 T.7,-) -. -4 7I 4?. 11 I 1O~ 4 7 . 7 I 163 03 0 $5~ ~~~~~~~ .- -.; 3(6. I3 il ' 4 93 7-. - 7 r3. 5 -40 .06c) 166. 1 36 1 85 1). 73(3 4 1 364 I 2i~ 4 .1c 7 P4 -, 6 616K 173~ 8'; 5 .4?2 161 .- '-14 1 (.13 0I.69 Id1). 7 711 $5 ~ ~~~~~~~ 7. 06 - A 0 i3 'i.3- 17 co 4 Th7 .3 4 CIP, Cy 85 ~~~~~~~-5. 6 C7 - , ..I.3?7 3 0.3 3 5~.~ ~ A6 - - - - F~~~~~5 - -'i.-.1? 4 4Li4.i'`43 -5.1159 -?'.3 I 28 . 0773j 6A -5.?4 0 - - 4.3t,-i ".-)2p 7 1:3,).3 - 2 V ?,I Tfl %IFI-(. I TY -'- I 'J OF: OT JR`C.TTI VFI OCITY * C(S OF DrPFCTION COVAPIANCIT RESULTANT RFSLJLTANT PnltijTq -------------- -------------- VELOCITY DIRECTION L9 -3 N,~~~~~~F: I I' I, IA t MI- AN VAPIAMCF CM/SEC DEGREES MAcUNETIC '%VFDA(,F VJAL.1iFS Fi)i~ A~ LlIrlIAP (-Y(-L '-TAPTINC, AT SIIPFACFE DEAD Hl(;li.1 FPAI`F r01INT 17 (;tWOhJ)- CO~i~T I f NCPFMFN~IT= 12 Pei ~~1 .4(0I I(O.44) ?3714 154.666 ?.B71 2.760 30.484 AC; 16.11/ Tf'410 -1?06 7.1RA -326.6 1`9.720 140.126 As 17.7'~41 -?Ii. I3F 1?5.415 -937.6 3 0 .79 1 144.727 PS ~~~~~~~~ 1h0.?~~~~~~~~~~~~4 ~~~-?6.klr) 164.li72 -1084. 33.390 143.427 li ?1.177 1S.- .27 20A. is3 2 -1131. 32.253 138.960 AC;1 1.1,05 1 1. I I -1 6.6 30 1 76 .065 -545 .9 2 1.54 3 1 4 0.529 A8; ?.;P)4 13.A - I. 3 31 ?Mb.945 -163.4 ?.58B 121.169 P5 -1 3 . 'i7~ I A.� IB.796 207.904 -S32.3 2 3 .067 324.574 AC - ? ). IV 2-i 11 '-i . ?1.263 ?62.911 -890.2 3?.923 310.230 P5 -1 3 I I O 20arY ?.303 ?I A.27 1 -424 .4 25. 891 329.476 85 -7 .06 4 ( I I 9 1.65 7 156.895 -1 33 .7 20 .881 340.280 AS I .1 'i I.A64 1 O.%74 159.066 -32.00 12.266 329.552 VAL II Vt~LOCITY *SIN OF flT.FCT1ION VFL OC I TY COS OF~ 1) 14 C f I CGVA~~1I 91CF ,-'It h1 tj PF#F;lLTANT MF A N VAIJ I ArCF " -F A N V \~I A i It C.i~ C *(t$5"AI'1TC ** AVFRA(,E VALUES FOR A LUNA9 CYCLE STAPT INGd AT SURiFACE D)Fa.l, FfPAIE COUNT 1 17 6'POUP COi~rj = [,\, ItCh, F, j1 I Id 1 36 -2 0. 4 14 1 0d. 2 0 -3.?77 7 l67 1 36 - 1) . 4 ") 1 919.507 6 . I 67.j u I 1) .3 11d 3.3d3 1 19 1.~( 9 1) t.)00 1). 11~ ~ ~~~~~~ 7. -)P 270.761 -' ?d 1 46?I 14 4sf 1 119 5 . oo- 151 . dc3 - il.374 1 41. t .(7 -3 (,.e 17 11 17tU.,iih 19 1.U tit 143. 7.39 -Pm-.(10 e,1. ,1)- I e 7 1 7 7 7 19 -9.,H4 1 4.3 7-:9 - 17 .4 76 ~ 4,j3 1,7o. 7 Ii1 i?0t. 74 1 19 - I6.2?b 1 26.1 79 - 16. 137 s1l-.400 46 uI.7 1- e-b.1 19 -2 1.021 I p o9 I a -16.0'~7 9dJ9I? 6o/. I h . 4 10 2.32 . )4 19 - 23 .159 67 .3) 1 -14 .34, 'D40 . 46 7 ?I.o d7re . I, 4.j ~ ,.219 P3301 OFA aa~~on~a*��er~uo VAl TO VFtIOr.TTY * SIN OF O1fFC.TT(N VELOCITY * COS OF DOTCTION COVARIANCE RESU(TANT RFSULTANT POTNT------VFLnCITY DTRECTION MF4N VAI ANCF MF7AN VARIANCE CM/SFC DEGREES MAGNETIC AVFPAGF VALUES FOR A LUNAR CYCI F STAPTING AT SURFACE DEAD LOW FRAME COUNT 17 GOUnP COUNT = 86 INCREMENT= 12 1.36 -14.3?8 146.139 -10.376 406.092 227.8 17.690 234.088 136 -1?.373 153.756 -f.070 257.416 136.2 14.772 236.885 119 -4.?49 124.950 -4.661 198.904 -8.521 6.307 2?2.353 119 0.297 96.019 -1.185 170.355 14.64 1.222 165.928 119 0.80 136.937 -P.490 168.384 19.04 2.625 161.514 119 311.243 2.719 255.013 114.3 3.?89 325.765 119 -2.461 243.001 -?.907 245.106 135.4 3.809 220.252 119 -3.706 231.845 -2.590 248.346 75.07 4.521 235.052 119 -9*407 1?2.763 2.127 157.440 -65.20 9.645 282.742 119 -10.280 150.590 -4.152 234.854 -37.57 11.087 248.006 119 -13.259 237.077 -3.805 220.680 -22.38 13.794 253.988 119 -16.82O 249.411 -4.358 325.720 102.5 17.376 255.474 VALID VELOCITY *SIN OF DI)RFCTIN VELOCITY *Co,; )F Df)ItCTIfjN COV4rdAANCE R~SIJL.TATa f4F'SLLTAwT POINTS�------------- -----------------vFLOC.I IY D I ~FC.T 10~j mFAN VAPIANrF ME AN V AP.T ANC E CM/1-0-C 10F(8FE5 ~-A',NF TIC AVERAGE VALUES FOR A LUNAR CYCLE STARTING AT SURNFACE J)EAf) LOW FPANIF COUNT It 1(ROUR COUNT 87 l e C~MjI= 1 136 -1.tilo 04.400 -1l~ 6q.3R8 41.43 1 188.6j 136 -2.306 rq .5?fi -13.?M L e3). 11 3 6 1.,9 13.4t 18.84 136 -12279. u I1 -13. 71)3 33?.446 7t,. Iti 13. 1t)0 185.2el 119 1.486 b9.231s -10.622 ?33.186 -.I 0d 172.035 119 4.070 84 . 628 3. q~3 342.4?9 94.76 b.7(2 45.S5bO 119 4.4L13 112.126 3.840 e94.li31 I. vt 6 S9.038) 119 3. m4t3 112.484 -7.404 e4'9.17b -4n.bb 13-1343.> 119 1.983 32 ..57 0 -9. li9 1 74 .~ -2u~h I.3 61.4 119 -0.012 91.4?? -10.070 177.94U 5~ I(.01( IA070I 119 -2.108 S7.8i49 -14.740 110.656 56. L1 14.1190 I 1Mt. 140 119 -2.065 49.323 -I6l. 61 1 1 18. I32 7 Lo. t-v 16.739 187 . * P3301)1FA VALID VELOCITY * IN OF I)IW-FCTfOfj VF-LOCITY * C01; 0J( M)I-1rIuO4 C(OVA4iANCF. *SuLTANT PFSI)LTAfmT MEAN VAQI A~rF A 1IAN VA~ I ApIcF CA/',f C I)EUWFF mAI'i4i- TC ***AVEPAbE VALUFS FO,4 A LUJNAR CYCLE STAIwTING AT SrPwFACE 0EA0 Low FdAMF COUNT = 11 (3ROUP CflU~T 814l(C&emFfl1= l 136 -7. 877 1I ts. 3"11 . 4W).14 4 -14'i. 7 U*33.4 136 -4.1406 193. 830 JH.143 4 3 -3 '.7 I t -11 3.1 I k.? 345. 164 136 -3-6f~7 21 7. b'l. 1 6. 1,7 386.JM2 -; . 7 1-h.S?3 34Mi.bd3 1 36 -23i1~41.33e! 111.011) n&.7q,) -13.34 I 0 . e4 346.746 1 19 0.770 232.6%m .1)1,1 491 t-9? -R.21' 1. 741)?).I 119 1 .437 26 7 .4 1 -7.41.. b3.o33 4 0. 13 7 .b 169. 0 -H 1 19 3. 067 157. 111 -1 9.75t) 3214. 0 II -1J3. 5 114. 96 171 .1I13 I119 1 .598 1 73.4 73 - Ib~ 3?5.b37 -8 0.79 21-. - 30 17b.gu9 1 19 I et'65 96. 662 -37*?44 1 14 . kil - I (). L J.3 .?, 1 77.44.1 119 0 .744 1 90.468 -? 6 . 27 3t10... ,fl3-t~w 16~ 17ei. 37b 1 19 -4. 743 199.577 -1 3. 001 676. Ci6 3,). (4 1 3. H31 200. 043 119 -6. 802 245.31 7 ). 341 7 ). Z82 -88.69 B. 646 30i. 137 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~I. . ***AVF~-MF VALUiF' Ffl4 A LtINAq CYCLC: ~,TA-Q EW' AT 1A 14 ; Cr t. AI IA' F;~A VF COONT (o1 O C(',(IT 7 r >1 1 3 6 *4~e '4 I '., j-'. i -e'Jd 11 34.O.3 ' 1 36 3 . ?fH I I 7 )l 34-w~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~t~~--7-' VALIF ) VELOCITY * SIN OF nlQ'ECTION VEI-nCTTY * CO'; OF n7l-IT11t,,~ rflv.",~IP ;rF '4.SI 1r,"T RESULTANT POINTS�---------------�---------------%FI --cITY lq.~FcT IoN MEAN VART ANc.F MF A I VAI T fkt'r C / -( il (00 M~A~ill TIC ***** AVERAGE VALUFS FOR A LUNAR CYCLF STARTING AT SlIRFACE nFAn LOW-? FRAME COUNT = 17 GROUP COUNT 13C INC P4Pt= 1A -ITi *136 -0.702 194.3S4 I (I. 795 47 9S A 1r. 35).; 136 -5.019 1 ?6.491 ?I.qr)3 IMI.33? -?h. P?.o 341.16? 136 -7.232 A5.47() P1.393 13R.115 -3.2?'II( 341.3?3 136 -5.457 IIQ.A91 19.312 17R.1A .. -Acj ?~Ih P O 44.2e 119 1.1a1 136.009 Q.170 31 I.33-4- 4;'- 7.3314 I119 3.862 1 06 .1 45 1 . 137 3R7 .I 01 4 '.? 4. 6 7 .6ni 1 19 8.482 150.253 - 4 .7 0 ?466.311 -'44.?7 I .7I 1 9 . 0 1 I119 8 .563 190.27S -1 . 393 ?PR . ?~17 43.13 F, .;74 9 9 . 1t4 1 19 5.266 31 8.589 -0.3-24 399. 331-'-.1 -AL j i. -( 147.6bl 119 3.769 192.547 -94219)R -4.] I A 4. lef 1 19 0 .515 194.955 6. 197 547.R31 -1 7q. 'i 4 753 P33010FA VALID VELOCITY * SIN OF rIPFCTION VFlO-CITY * COS OF DIPFCTTON COVARIANCE RESULTANT RFSULTANT POINTS-------VFLOCTTY DIRECTION MFAN VAPIANCFr MFAN VARIANCE CM/SEC DEGREES MAGNETIC *****, AVFRAGF VALUJFS FOP A LUNAR CYCLF STAPTING AT SURFACE DFAD HIGH FRAME COONT = 17 GROUP COUNMT 6? INCPEMFNT= 12 102 2.173 131.815 -9.726 361.491 57.16 9.966 167.408 102 -1.593 196.785 -7.271 286.545 89.79 7.441 192.286 85 -3.641 162.600 -8.636 268.218 72.69 9.372 202.863 85 -7.348 182.?67 4.368 305.789 -26.42 8.549 300.730 85 -9.??9 91.57? 1.961 479.068 37.83 9.435 281.994 85 -12.707 49.055 4.324 583.231 -70.75 13.423 2R8.792 85 -12.380 43.791 -2.957 621.793 79.06 12.728 256.568 85 -9.2?6 83.3?6 -3.443 606,010 193.9 9.847 249.537 85 -8.313 115.975 -5.679 529.320 220.5 10.067 235.668 85 -5.173 137.182 -9.425 431,223 192.1 10.751 208.761 85 1.566 211.677 -13.222 359.093 -57.24 13.315 173.244 85 5.952 132.639 -11.477 435.407 -75.16 12.928 152.590 PA301IFA VELOCITY * SIN OF DIRFCTTUN VFLOCITY * C) tjF I)1tCTION COVARIANCE RESUt TANT RFSOLTANT lAF AN VARIANCE VANh VAL I ACt C I/'Cf T Y f)EI qM C I TIC **"* 4AVFRAGF VALUES FOR A LUNAR CYCLF iTARTING AT SURFACE DFAD LOW FRAME COUNT 17 G R iOUP COUNT = 89 IJNCWEMFWT= 12 -131 7.777 bf.912 19.172 344.164 3,3.h 20.h,9 ?2.061 123 6.915 47.173 2 1A l.440 413.8 �9.bIo 13.411 128 7.2oa 64.733 2A.214 401.7 6 316.0 27.187 15.374 125 4.399 73.741 2S.93n 151. 91 214.9 ?6.309 9.626 135 0.105 91.175 1 9.1i 444.14"i HA.3( 19.133 2I.112 119 2.095 6 4.034 M .HOJ 406.615 71.74 6.110( 119 3.'i74 8 7 . 0 34 -4.50e 280.803 -54.93 5.748 141.556 119 -2.365 178.604 -6.991 169.141 -11.72 7.380 196.b93 119 5.470 188.926 -4.16( �04.110 -61.37 6.87? 12T.2t9 119 6.112 144.747 3.?51 289.734 -33.50 6.v23 61.990 119 . 6.394 65.144 6.2711 474.966 67.04 A.961 4,.~L3 119 6.753 48.334 10.72j 423.906 134.1 12.672 32.203 r�~~~~~~~ f~ . --i' P 43111OF A VA~L 11, VLLOCITY hf OFN DbEIPIFCT IN VI-1-CITY Co,; OF nffAECT I ON COVARIANCF. NISI~i TANT "- RFSUJLTANI" PO I NT ------- ---------- - ------------------ r. 44 C~ Al V I% w C v C'l, C tr.IIi 00*AVERA6sF VALIIFS FO-4 A LIINAR CYCIF SIARTIN~i AT SUNfFAC~t I)FAJ) LO'. Fwi-Ibr COUN~T 17 64l' ~'!i 'C' -1 126 5 O~3 I 130OO ?~4.I -Ri. 5 7 3 110 - 3. 6'. A7q4 1 leIII-I7.7I 7'.'? -qn. f, 32& a P33010FA VALTO VELOCITY * SIN OF DIRECT101, VFLOCITY - COS (IF DIPI-.CTTION COVAPIANCE R ESUILTANT PF5ULTA.%T POINTS�------------- ---------------- ELOCI I Y I) DFCT I WI 4E AN VAP t AlNF mF A N V-tI A~ Cf-/sk C l'F(,FFS MAb*Nf IC AVFPAGE VALUFS FOR A LUNAR CYCLF STAPTLNC, AT SUR~FACE OF-At, --i, FRAME COUNT = 17 GPOIJP COUNJ = 8 TNC~fmFnjT=I - -102 427 7 2 4 5 .1) -1).1 19 g2f:. 18M 5b.3' 4.z7Y 1.0 102 1 .)76 2883.426 -1 3.1`ol 336.6?l OAO . 4 1 3 .8H9!- 173.4o7 85 -2.042 1534.427 - I9 .li i 314.063~ 142.2 19.t)37 bC) 85 -5.717 246.880 -6.78 3 324.4S4 4 2 . 5ti Hi71 220. I db 85 -13. 046 21 7.51)5 4.996 31 1.tt4t -90.0n 9.472' 301.b48 65 -2.335 190.963 I e12. 0 I 30H.936 -1 15.6 13.012 85 2.039 94.943 24.136 81t.ulo 104.6 24 .,e? 4.82 85 3.423 81.673 213.9.'9 37.343 1 b. 2 ?6.204 7.5u7 85 5.765 31.428 2f.?ie22.71d 305. 7 26.ti83 12,365 85 4.584 62.368 25. (214 21 .5t4 244.6 ?3.44b 10.314 8 5 5.419 q9.427 18.436 131 .r93 ?11.9 192 16f b. 3ts1 85 5.383 144.664 b.476 321.193 64.10 .2 39.736 P33010FA VALI VELOCITY SIN OF DIPFCTION VELOCITY *COS (F DIPCTITON COVAnIANCE RESULTANT R ESULTANT POI IUs ���-------- �---------------VELOCHfY 1) IHF CrIIUPI MEAN VARIANCE MFAN VAPIANCk Ct4/lsC DEREES MA(vETIC 03~31 * **** AVERAGE VALUES FOR A LUNAR CYCLE STARTING AT SURFACE DEAD LOW FRAME COUNT = 11 GROUP COUNT f ig INCNFM-NT= r: 136 20.484 110.217 31.21~ 466.716 1240. 37.335 33.214 136 19.148 70.642 33.920 4M1.098 1320. 3A. l1 29.44S 136 12.558 H9.231 29.203 h3l. 78".3 31.7A9 L03.20 136 6.962 124.394 ?3.466 tihb.24 d42. 4 ?4.49b 16.511 136 1.790 207.4?4 6.12? 159.6A4 6?.43 6.379 l.294 119 -2.596 15i8.6s0 -I 0. 4 970.b76 28.07 11.e57 193.331 119 -5.392 50.357 -31.6a2 I16.61h1 34..b 32.13$ 119 -3.905 22.572 -41.190 16.lip 321 . 41.375 18'3.416 119 -3.718 1-.836 -40.65' 17.1? 301.3 40.823 185.245 119 -1.922 117.644 -28.391 451.764 254.9 29.4t6 183.874 119 7.227 -244.584 -1.755 LA)1.091 333.3 7.437 103.649 119 15.073 237.786 18.637 71b.345 617.6 23.9h9 3d.9t6 P33010FA VALID VFLOCTTY SIN OF OTPFCTION VFLOCITY * COS OF DIRECTION COVARIANCE RESULTANT RFSULTANT POINTS---- VELOCITY DIRECTION MEAN VAPIANCF MrAtN VAPIANCF CM/SEC DEGREES MAGNETIC **4* dAVFRAGE VALIIFS FOR A LUNAR CYCLE STARTING AT SURFACE OEAD HII,- FRAME COUNT u 17 '(;OIIP COUNT 59 INCREMENT= 12 85 25.800 166.1RF -?7.139 91.005 -1407. 37.446 136.449 a5 .34.6S4 125.6?A -30.113 109.794 -2017. 45.591 131.674 85 31.590 131.311 -2?8084 269.194 -1664. 42.402 131.840 85 27.S13 8672.406 -21.S86 1080.162 -3990. 34.970 128.118 85 2.?91 131.772 -10.099 186.105 -96.61 10.356 167.219 85 -2.91? 8A.000 -6.758 570.529 36.38 7.358 203.312 85 -6.386 106.991 15.200 628.152 -78.60 16.487 337.209 85 -I. ?0 100.097 31.225 26.256 -58.06 31.242 358.112 a5 -3.254 97.206 28.426 153.493 -112.7 28.612 353.470 85 1.292 94.182 22.671 126.999 93.92 22.707 3.262 85 10.857 200.523 7.019 301.s40 94.85 12.928 57.115 68 ?1.644 152.328 -4.747 473.524 -265.2 22.159 102.371 _7~~~~~~~~~~~- V A I-T VkLAICITY 5 1W~0.9F olFr!fill)( VF1.1(Illy COS. Il ft1 t-i I COVAS41ANCE Fl P H)DT . RE ANTV P(;I N~T S ----- -------------------- v A'41 Aicl- -W .tg. VH vA- ANCF cN/l-.~c OF1,4 40e ***AVF7PA(, WALOF S F O- ;A LUWoR CYCLE STA,,I N(; ATr S~)kfACt- OFW 4 F~wl' COUNT 1 7 .r-n C0111-T .1 I102 3 ~ 3.'44 4 O . t3 h,,) T I P', -131. I1'~ I I - 169,64 5 5.7~,; 153.1`13? ~ 4 6 0I 443.q 31. o 13;i 85 4 d~j . a 3fl.i' 7 ( 4 I I I Gil' - 1. 401 4 1 4 P6'- ?.14 i4 #~.6?, 73#. 1 *4314 A.,).Ih $5 ~ ~~~~~~~ -.9,,? 14?.A P ?. 9fl' 4. 7~, 73 3.2 pis . 5, If2ri. ?F.'W? 2 o 3 O 27.0 vt 3~ 8S -n. i3.7 1 4 . V5 ?0,4 .1 4- ? 14. 7 T 65 -5~~~~~~~ ~~~~~~~~~~~~~~~~~~ .*-) 3o* A..A.-. 4 13 4.9 <.-.<...avs. P330oiFA ()N'- I1LA LUNAW CYCLE (6 HOURS) AVERAGE VALUES STARTIN6, AT SURFACE DEAD HIGH-1 METE SPHFRF NLIMPFR FRAMES FPAMFS STARTING ENOINY LOCATTON NIIMPFR OF PFP PFP I.NAR PO(INT POINT NU%4RFR POINTS FlioR wflw 1R 0341 M 1097 16. 99 80 1176 VAt in VFt.OrTTY * SIN OF nTQFCTTON VFLOCITY * COs OF nIPFCTTON COVARIANCF RMSILTANT RFSULTANT POINTS--- -------------VELOCITY DIRECTION MEAN VAPIANCF MEAN VARTANCE CM/SEC DEGREES MAGNETIC 99 6.981 74.499 -5.270 205.835 -61.65 8.747 127.047 99 -16.753 10R.045 -3.451 188.682 49.11 17.105 258.361 99 11.031 160.83A -7.382 172.029 -83.25 13.273 1?3.791 99 -9.539 108.6?S -3.998 167.156 50.51 10.343 247.260 99 13.49? 184.887 -7.411 101.633 -69.69 15.394 118.780 99 -15.677 157.618 -2.543 223.060 85.77 15.882 260.787 99 -16.410 90.943 -1.457 58.580 40.54 16.474 264.927 99 -20.800 96.794 2.277 72.744 3.419 20.924 276.247 99 13.367 340.816 -6.030 86.350 -113.6 14.664 114.279 99 -16.455 ?27.635 -4.152 134.617 57.06 16.970 255.840 99 17.341 259.791 -5.638 83.036 -26.35 18.234 108.011 0 0~~~~~~~~~~~~~~~~~~~~~~~~~~~� I<33010FA VALT VELOCITY SI~N OF DW1FCTION VFLOCITY *COS k)F fll-4CTION CUVARIANCE EStJL TAN r PF SULTA'JT POINV--------------- - ----------- S ���VELowlfY 11kF.CTIu-,4 MEAN VARI ANCF f1F AN VA-41I AMCF C P:7,E C 1JF(5,4EFS t-A(,i,4F.TlC AVFRA6F VALUES FOR A LUNAR CYCLE 15-TAWTINN At SURNFACE DEAD Hk1141 FRAMF COUNT = 17 GROU1P COUNT 0? I'4CW~r-t- Ki I= l 102 11.051 9M9 2. 0I') . 1.U4 8U.1, 1 02 6. 4 19 94.742 3. 04 0 fi3. ?lob 4.15. 8b 5. 368 91i .469 ..34 b4. 3 3,.4j 6.-9 5. 85 -3. 142 .161 I .44 7 04bt13 -M 43. 114 ?7pi. IUV 65 -3076 .591 -031 7 .8 3113 .l1 -i.'i3 ?66) 594 85 -6. ?91 I 80.782 -2. 434 -11'3 0 h. 74b 45.d 85 -6.566 68.752 1.366 .3?2.OA7 -so..35 t.7u7 ?ill.771 as -6.374 47.619 7.731 ?3(.031 -le.3.b 1O.f)u 204 85 I 1.t5 53.261 D. b2R 1 14I. 133 - 3-i. 64 5. 61IM 34 1 ts,, 85 2.?81 56.027 ?.12? ` .73L' -14.74 3.116 4 1.0n 85 6.156 53.883 -3.610 2A6.15~3 -4.767 7.136b l2o.36S HARLESTON . SULLIVANS IS. "' Ft. Sumter ummings Pt. Northe jetty MORRISIJetty Charleston Entrance I S. 4 Lighthouse Liqhthouse In/le Figure I Bird Ke"3 oLOCATION MAP KIAWAH IS. I 0 5Km XStono7 , -- _0 2C - ~' / In l/e M~ CL 8 Q DATA FOR FOLLY -BEACH, SOUTH CAROLINA ANALYSIS MADE USING 6.5 SECOND, 1.0 METER WAVES FROM THE EAST, SOUTH, AND SOUTHEAST ds Edisto Island Bot5 0 / |ds ~to~ B/~~~hSeabrook sullivans n - _ FOLLY BEAC \ 4o0- Q (meters3 x 1000 /year) 2�0- |"k"=0.299 -20- O- IL (joules/meter-second) L 'o�->-2 : : -t .. ,,---. --- ./= - ,d , E (2.3)I-- V SE (2.0)-. 0 S (1.0) Positive values of Q and PL indicate northeast transport, negative values southwest transport. 'Weighting factor for wove frequency, calm conditions exist 67% of the time. FIGURE FT: SUMTER Al '\ \ JETTIES: /t~~~~ \~~~~ ~ >a\,1884 -1896 "HOLE" SUBMERGED ,', Ii ~~~I ,~~I D ~~~~~~~ ~ I 1I / (All volumes x14 meters, | O t~m Ad EROSION(offshore) 2899 DEPOSITION II I// / iI Figure 3A Charleston Entrance 1851--1895 , I_ / Erosion/Deposition ,o (All volumes x meters3) / / 0 -' EROSION (offshore) 228 99 ,,.-- DEPOSITION (" ) 3 02+140 FIGURE 3 FT. SUMTER -14 'HOLE" SUBMERGES-- o,~~~,o CO~' 7: )+36 -28 (0~~~11 0 Lighthouse lo Charleston Entrance 1895-1921 Erosion /Deposition (All volumes X1 etr 41~~~~~~~~~~~ / I~~~ 0 Km /,+168 d~~~~~~~~ ,o / EROSION (offshore) 300-123 DEPOSITION 32811 - 95 ~~~~~~~~~~~~~~~~FIGURE 3B 9~~~~~~ FT. SUMTER 30+84 -69 HOLE" SUBMERGED15 0~~~~ I27 4 47 \ +3 I \o \ /- I " 0 ~~~!I~~I Oi 1 327+7 -0 I / I / Lighthouse Ck. '2 \\~~~~~~~~~~~~~~~ \ Charleston Entrance0J 1921-1964 Erosion /Deposition (All volumes XIO4 meters3) 0 1Km 0 +89 ~ I : -~- -0 \0 EROSION_(offshore) 1 26-64 Figure 30 DEPOSITION(") 4O6- 8 FIGURE 3C~ SULLIVAN'S ISLAND( -3~~~~1 +3~~ ~~94-192 EROS/O~~~~~~~N(7YodDEOR/THO(7 A/I volumes x/O~ meters CUMM~~~~~~~~~I N 0GS ~~~~~~Figure 3D *~~~~~~~ ,~~~~ ~~~ -, 0.- ,oo 74- Figure 4A ' - ~~STONO INLET N,0 6 7 + 6 ~1862-1921 EROSION/DEPOSITION VOLUMES KIAWAH / "':.',,'0"x. EROSION . ..DEPOSITION -7 0_ o/~~~~o -~~~~~~~~ -71 f, /,~ N Ci ' ",, ' ",,.9) -/// 65I ~ ', '~- - 0'0 1 x .~. /7~,0 V--U- - - \~..-,o , o/ -~ 439+8 c Figure 4A L� o o, ~STONO INLET N 67i"6 1862-1921 RSO/DPSTO VOLUMES \h - S~~ ~ ,' , \ I AWA H ~ : EROSION---- DEPOSITION. K I A H, o, / \ _ \ \ 4, c~~~ I~~ '~~~ Al volumes xIO meters) I I 2Km x ~ -6 , N . o~ D~ I+I I~ - I _______ I / " oo \ -rl~~~~~~~~~~~~~~ -65 o 1 0� CD P1 p~~~~~~~~~~~~~~~~~~~~~- IZZ~~~~I 4A5 -o 00 00 0 60- _ 53 KIAWAH 498 ISLAND 334-84 ' Figure 4B \\\ \su\\ 34_ STONO INLET 1921-1964 EROSION/DEPOSITION VOLUMES ZO7-45 I47o ~~~~~~~\1I 4c! K d 0~5y~b;3; EROSION- DEPOSITION- +185 --+261 / /4502 151 880220 S.C JI o '-9 (All volumes x104 meters3) I 0 2Km - 4~~~~~~30 m ra~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~r 7 q,411 1 L- N ~YI~ C/Y~~~~~~~~~~~~~ KNo Monnw Figure 5A CHARLE-STON1 F 5 ~ -/ARBOR1 AEJV77RANCE ~~~~ I V 2 4 RLF~k~O /~E,5 / CURI'RENVTS FOLLY ISLAND ~ I I LL)L)\UEBB(Hand FLOOD(F) average F.23 / ( velocities in cm/sec. RESULTANT(R) velocities in cm/sec. Shoreline ond bathymetry from 1964 surveys. MI- isoboalh interval is 6. C *~~~~~~~~~~~~~~~~~~~~~~~~~3 Station location and number 1 (,, H tfteciw so1nd movinq res.ultant CD ~~~~~~~~~~~I 0 - 2Km 11i111t SA MF/ F43 I I 7 *27/ KEY~4 ~~~F~~~2 E,2 0.4 KIAWAH ISLAND Figure 5B 7 E,2 )~vme� t STO/VO INLET PEG/-ON * 9 BOTT7-O7M 77DAL in ~ ey " / CURRENTS EBB(E)and FLOOD(F) average .25 24 No Movemeni velocities in cm/sec. RESULTANT(R) velocities in cm/sec. Shoreline and bathymetry from 1965 surveys miw --, isobath interva is 6. 05Station location and number MF Moiturictior of mete, 0 ~~~2Km FIGURE 5B COLE ISLAND ? ' FF.I17/ STONOt --f 4\ -Z '~'RIVER >.X 2 7 BIRD KEY .Figure 5C WT , 0 ; / N L Y' FP/yEA Fa 6 0 7BOTTOM TIDAL ' � CURRENTS KIAWAH ISLAND EBB(E) and FLOOD(F) average // <~ \velocities in cm/sec. t/ RESULTANT(R) velocities in cm/sec. Ec Shoreline and bothymetry from 1934 surveys. mlw - -. soboth interval is 6. ml I O IKm 12 Station location and number. FIGURIE C 0 ATTACHMENT C-2 0 Attachment C-2 is an account of the Coast Guard's beach erosion problems on the east end of Folly Island and that agency's efforts to control this erosion. Attachment C-2 includes an article entitled "Folly Island Loran Station Embattled" which was written by Mr. B. S. Brown, a civil engineer for the Seventh Coast Guard District in Miami, Florida. The. article was published as part of the July- August-September 1974, Edition No. 184 of the Dpartment of Transportation, _Coast Guard Enqineers Digest (CG-133). Also included in Attachment C-2 is a follow-up letter dated 2 April 1976 giving an updated status report of the beach erosion problem at the Loran Station. FOLLY ISLAND LORAN STATION EMBATTLED MR. B. S. BROWN Civil Engineering Branch Seventh Coast Guard District It would appear strange that a peaceful Coast Guard Station engaged in a mission to provide electronic navigational assistance to mariners, should be engaged in a battle for its life. Yet since 1962, this has been the case. Its adversary has been, is, and will continue to be tough, persistent, unpredictable "Mother Nature" herself, who appears determined to destroy the station. The principle weapon in her arsenal (her most potent being hurricane driven seas), is the winter northeast storm which usually produces massive beach erosion along an unprotected beach. Words such as usually, probably, possibly abound when describing beach erosion processes, as the various controlling forces and conditions. peristntunpeditabe "othr Ntur" hrsef, ho ppers etemind t detro th are many and changing--such as current patterns and velocities, direction of sea and wind, intensity and direction of storms, shifting of offshore bars, etc. The best procedure in battling beach erosion is to formulate a general overall plan with a probable construction sequence, but to be ready to modify them when required to meet a particular assault of nature. The battle was joined in the fall of 1962 when the high water line reached the easterly guy anchor threatening destruction of the main Loran Trans- mitting Tower (See Figures I and 2 showing the sea advancing toward the easterly guy anshor). To combat this threat, the first significant emergency measure, the construction of two creosoted timber groins (which straddled the threatened guy anchor) was begun in October, 1962. However, before the first groin was half completed, a northeast storm eroded the beach, and moved the high water line approximately 20 feet behind the guy anchor. The groin construction was halted, and the contractor was directed to drive a circular sheet steel cofferdam. around the anchor block to pre- vent it from being undermined. He completed this in the nick of time. Shortly after its completion, a second northeast storm removed sand from around the sheet steel cofferdam so that at high tide, there was a water depth of 3 feet adjacent to the cofferdam. But the guy anchor was now safe. (See Figure 3 showing the high water line beyond the sheet steel encased guy anchor, and the half completed northerly groin.) The con- tractor then proceeded to complete the construction of the two groins, with the inboard terminal ends apparently well anchored into the sand dunes behind the high water line. FEBRUARY 1959 FIGURE I MAY 1%?2 FIGURE 2 DECEMBER 1962 FIGUJRE 3 OCTOBER 19603 FIGURE 4 . ~~DETERMINATION OF COAST GUARD TENURE AT SITE In April, 1962 (following a STRUCTALT which approved the first emergency measure to combat erosion described hereinabove but prior to the contract award), the District requested advice from the COMMANDANT concerning Coast Guard tenure at the site, having heard of long range plans to phase out Loran "A" Stations in favor of Loran "C." Obviously, a most significant planning factor for the erosion control project would be the length of time that protection would have to be provided. The COMMANDANT's reply was that the future of Loran "A" Stations appeared to be in the order of ten to fifteen years of additional service. The temporary protection in the approved STRUCTALT should be provided, and an AC&I project prepared for more permanent protection. This direction was followed with the first result being the construction of the above described first two groins at the station along with preparation of an AC&I project. PROPOSAL TO RELOCATE SITE During the development of the AC&I project, it became apparent that a considerable sum of money (estimated at $450,000 in 1962 dollars) would be required to provide the 10 to 15 years protection required. If a longer tenure became necessary, another substantial expenditure of funds would be required with the ultimate outcome far from certain. The principle reasons for such uncertainty are the combination of conditions tending to accelerate erosion along the east coast of the United States in general, and at Folly Island in particular, such as: a. The damming of rivers on the eastern side of the Appalachians. --Sand formerly transported to the ocean from regions in the interior is now deposited in the dam reservoirs. The silt picked up downstream of these dams in reduced in quantity and grain size and thus is less effective in building up the beaches. Ib. The more rapid rate of erosion on beaches having small grain size alluvium.--These materials which are now deposited on the beaches under favorable conditions are of such small grain size, that when unfavorable conditions occur, such as winter northeast storms, or rough seas accompanied by unusually high tides, the shoreline erodes at a con- siderably faster rate than when the beaches were composed of coarser sands. c. The construction of jetties and man made inlets.--Such types of construction, along with natural inlets, act as barriers to littoral drift causing erosion on the downdrift side of such barriers. d. The alternate erosion and accretion of beaches near inlets associated with migration of the bar channel.--Littoral accumulation on the offshore bar forces the ebb tidal channel closer to the downdrift shore causing erosion and shore recession of the adjacent beach. As this bar continues its downdrift enlargement, a critical constriction of the bar channel occurs forcing a breakthrough on the updrift portion of the bar closer to the inlet, shifting the tidal channel through this breakthrough. The portion of the bar downdrift of the new channel is then free to move shoreward under the influence of wave action, and the downdrift shore experiences an interlude of accretion. While this process would appear to neutralize itself, it has two detrimental effects. First, there is an overall net loss in the process, as much of the downdrift littoral material accumulated on the offshore bar is lost either in bays inland of the inlet or in deep water beyond the inlet from regular tidal flow occurring during this cyclic process. Second, during the part of the cycle that forces the ebb tidal channel closer to the downdrift shore, erosion control structures, such as groins, are in danger of being undermined as the shoreline recedes. The District, therefore, recommended that a new site be selected and the station relocated. The COMMANDANT concurred with this recommendation, and a site survey for a new location was undertaken. It appeared that the battle to save the'station would be abandoned due to the uncertain outcome and the high costs involved in resisting nature's relentless attacks. CONTINUATION OF CONSTRUCTION OF EROSION CONTROL STRUCTURES Meanwhile, while the site survey was underway, the assault on the shore- line continued. Both groins were flanked by the sea, which called for quick remedial action. Since time is of the essence'in meeting such attacks, a negotiated contract was executed in the summer of 1963 to extend without delay the northeasterly groin 120 feet inland, and to construct a 43 foot wing wall at right angles to and centered on the southwesterly groin (Figure 4). This wing wall was an attempt to dis- courage flanking action of the southerly groin, while the extension of the north groin inland was for the obvious purpose of again blocking the flanking attack of the advancing sea. Both of the two items of this negotiated contract were very temporary in nature. The sea again flanked both groins following the first northeast storm of the 1963 winter season. It became apparent that in this situation, with little ground remaining to retreat, a line would have to be drawn beyond which the sea would not be permitted to advance. A marginal timber bulkhead interconnecting the groins and proceeding southerly was the method selected. -With regard to the northerly groin, it would have to extend westerly as far as necessary to prevent flanking action of the sea, and to serve as the anchor structure of the remaining work to follow south of it. This anchor groin must be protected against undermining or flanking at whatever cost if the continuing project were to have any chance of success. A contract was executed in October, 1963 to fulfill these concepts, and the contract was successfully completed. It consisted in the construction of a 644 foot long creosoted timber bulkhead interconnecting the two groins, a 300 foot more or less long southerly bulkhead extension tied to the southerly end of the wing wall, and a 200 foot long landward extension of the no rtherly anchor groin (Figure 5). RESULTS. OF SITE SURVEY In March of 1964, the site survey to relocate the station was completed, and several substitute sites were recommended in a comprehensive report submitted to the COMMANDANT. Their review of the site survey, joined to an evaluation of the work already completed at the Loran Station, i WIN MAY 1964 FIGURE 5 NOVEMBER 1969 FIGURE 6 resulted in the following decision: there was insufficient justification * ~~for the purchase of a new site; the station was to remain at the present site until -it was determined that its destruction was certain. The battle was resumed. FURTHER CONSTRUCTION During the fall of 1964, the assault of nature was now directed against the southern end of the existing system. The northerly anchor groin appeared to be holding firm, and the beach had stabilized between the groins. However, erosion south of the then southern terminus threatened flooding of the station. Thi's threat had to be miet at once. In December .1964, a contract was entered into to extend the existing bulkhead 100 feet southerly, and to construct a 200 foot groin a few feet from the new existing southern bulkhead terminus. This construction succeeded in its immediate aim, but made it painfully apparent (as was recognized in the beginning of the project in the development of the initial AC&I Report) that there would be a continuous danger of losing the lone Station access road unless the Coast Guard completed their system to the south AND the State of South Carolina would continue their groin field northerly to meet the Coast Guard's groins to form one unbroken system. Preliminary contacts with the State provided assurance that they were planning to do just that, but the time of construction would depend on priorities and availability of funds. The cooperative effort between Coast Guard and the State of South Carolina to join their groin fields had been initiated. Although the northerly anchor groin was holding at this time, it was fully expected that the forces unleashed by the winter northeast storms would.compel additional work on this groin. For the next few years, the erosion continued, but slowly, with no need for immediate action. However, this relatively placid condition evapora- ted in the late fall and early winter of 1969. On November 1, 1969 a strong northeast storm accompanied by unusually high tides caused extensive erosion all along the beach with a particularly large beach loss southerly of the then southerly terminus of the existing bulkhead. The ocean had advanced considerably closer to the access road, as well as undermining the southerly end of the marginal bulkhead. (See Figure 6.) While arrangements were made to fund the construction of the remaining southerly extension of the groin/bulkhead system, the State of South Carolina was again contacted at this critical juncture concerning their intentions to extend their groin construction up to the Coast Guard property line. They advised that they woulId complete their groins to meet the Coast Guard's planned southerly groins to form one unbroken groin field with the Coast Guard's system. Fortunately, the Station weathered the remainder of the 1969-1970 winter season with only minor additional beach loss. In the summer of 1970, a contract was executed to complete the Loran Station's southerly groin/ bulkhead system. The State, true to their assurances, completed their groins northerly to meet the Coast Guard system. With the arrival of the 1970-1971 winter season, a single unbroken groin field was in place. The immediate threat to destroy the lone access road has been removed. . ~~THE ATTACK SHIFTS NORTH With the attack in the southerly portion of the Coast Guard beach blunted by the completed Coast Guard/State groin field, the expected assault began in earnest against the northerly anchor groin, beginning slowly in the 1970-1971 winter season, and increasing in intensity during the 1971-1972, winter season. As a stop-gap measure, PVC-coated sand filled nylon bags were installed using Coast Guard personnel in the fall of 1971 to extend the bulkhead/groin system northerly of the anchor groin. (The remnants of this work can be seen in Figure 7.) But this measure was insufficient to stop the erosion north of the anchor groin. Reports from the station during the 1972-1973 winter season, which was monitoring the beachside erosion, indicated that the winter northeast storms had once again flanked the northerly anchor groin along with extensive erosion north of and adjacent to the northerly side of this groin. Over 100 feet of beach depth had been lost in this location during the single 1972-1973 winter season leaving the station vulnerable to flooding should no corrective action be taken during the summer of 1973. RECENTLY COMPLETED STRUCTURES In view of the condition of the northerly anchor groin, and the beach northerly of it, it was considered imperative to extend the flanked groin landward, and to take measures to insure that the northerly anchor groin would not be undermined. Particularly dangerous was a channel of deep water that was approaching the groin following the extensive MAY 1974 FIGURE 7 MAY 1974 FIGURE 8 1972-1973 winter season beachside erosion. This deep water had to be diverted away from the groin to prevent undermining of the anchor groin. The last contract work begun in the summer of 1973 and completed in March 1974 consisted principally of the following items: 1. The flanked groin was extended back terminating at the low lying marsh land along the westerly edge of the station. This structure, it is believed, will end the flanking threat as long as it remains intact. Should wave action now follow the groin, it will flow back intp the low lying marsh land, dissipating its energy there, and return back to sea through the many creek-like tributaries leading into ocean connected Lighthouse Inlet lying north of the Station. 2. The outboard end of the anchor groin which was damaged by marine borer action, and subject to scour was reinforced with stone. This reinforcement, by sealing the end of the timber groin, will greatly diminish further borer damage, and will additionally prevent scour by presenting a sloped surface to storm waves to dissipate their energy harmlessly and without scour. The outboard end of the groin adjacent to the south was similarly repaired, and for the same reasons. 3. A 150 foot long stone "Training Wall" was constructed approxi- mately along the northerly extension of the interconnecting marginal bulkhead. This structure has been successful in "training" the ebb tidal currents to flow further away from the anchor groin as well as to protect the portion of the groin inboard of it from wave action. To be more effective, it was originally planned to have this structure attain a length of 400 feet, but was constructed to its present length due to funding limitations. Observing the beneficial effects of this training wall, a second one was constructed along the berm line to protect the inboard portion of the groin should northeast storms again erode the beach north of the anchor groin. 4. The face of the groin seaward of the outboard training wall was armored with stone, in addition to protecting this exposed portion of the groin, the armor (in a manner similar to the reinforcement at the outer end of this groin) will diminish marine borer damage, and reduce scouring action adjacent to the groin. 5. Finally, sand from recently formed dunes southerly of the groin that formed following the construction of the interconnecting bulkhead was used to restore in part the eroded beach between the training walls. It is this area that will serve as a depository for sand nourishment when required. SAND NOURISHMENT Very early in the planning stages it was recognized that should the Coast Guard and the State complete their groins to form one unbroken system (a cooperative effort that was implemented successfully as described herein), the continued expected loss of beach and sand dunes northerly of the northerly anchor groin would still present a problem to be faced. Eventually, sand to replace the beach and dunes lost from northeast storms would undoubtedly be required if the Coast Guard Loran Station continued to remain at the present site over an extended period of time. In a recent Beach Erosion control study (circa 1967) made by the Charleston District Corps of Engineers, it was determined that at the north end of Folly Island, there was a net rate of loss of beach sand requiring an annual replacement of approximately 9100 cubic yards. Their recommendation was that a five year supply of sand be deposited at the north end of Folly Island using the shoal area north of Lighthouse Inlet as a source of material. (This shoal area can be seen in Figure 8.) This recommendation was considered in a 1969 AC&I project (which also included the construction of the groin/bulkhead system at the southerly end of the Station and which was constructed as described herein), but was never accomplished due to the high cost of this item. Inquiries with local hydraulic dredging firms indicated the cost for such sand transfer across the inlet would approximate $100,000, about double the original estimate. A less costly method of nourishment was desired. It is believed that the training walls, installed in the last construction, will trap some sand adjacent to the groin which will reduce the need of nourishment. However, periodic sand nourishment will undoubtedly be re- quired. Since the construction of the interconnecting bulkheads as noted previously, a natural development of sand dunes has formed southerly of the northerly anchor groin, almost completely covering several Coast Guard groins. To augment this natural formation, a pilot project of sand fences was installed to induce further sand dune formation. (These fences can be seen in Figure 7.) When the need for nourishment arises, it would be relatively inexpensive to move these sand dune to the area between the training walls to serve as sand replacement and nourishment. Sand fences could then be reset to again produce sand dunes for further nourishment as required. Should Loran "A" Stations be phased out in the near future, it is hoped that this source of sand will be sufficient to meet requirements. In any event, the planned foregoing method of nourishment will be attempted before expending approximately $100,000 for sand transfer by hydraulic dredge. CURRENT EVALUATION AND FUTURE OUTLOOK At the start of the last contract work begun in the summer of 1973, the inboard end of the northerly anchor groin which was flanked by the sea was so seriously undermined that it was on the verge of collapse. There is no doubt that had this last contract work not been begun this summer, the inboard end of this anchor groin would have collapsed under the force of the winter northeasterly storm seas, and the. Station would have experienced flooding. The current condition, though a vast improvement over its pre-1973 contract condition, will still require upgrading. To better induce ebb currents to flow away from the groin, and to improve its ability to protect the inboard end of the groin, the outboard training wall will need to be 'lengthened. The armor stone protecting the exposed portion of the groin will need to be maintained. Stone reinforcement of the outer end of the anchor groin will need to be extended to diminish marine borer damage. Stone armor will need to be placed on the northerly side of the anchor groin between the training walls should scouring occur in this area. The lengthening of the outboard training wall should, however, diminish this requirement. And finally, sand will undoubtedly be required for replacement and nourishment to be deposited on the north side of the anchor groin between the training walls. In spite of the best of plans and prognostications, the unpredictable and potentially enormous forces of nature, such as those attending a hurricane passing close offshore, or crossing Folly Island, could change the entire outlook. Even with the more predictable storms, tidal flows, longshore currents, etc., vigilance and timely action will be required to continue the battle fought successfully thus far. The story of embattled Folly Island Loran Station has not yet ended. ABOUT THE AUTHOR Mr. Brown graduated from the U. S. Coast Guard Academy in June 1944 and obtained his Bachelor's Degree in Civil Engineering from the University of Miami in June 1956. He served in both line and engineering duty while on active duty in the Coast Guard and subsequently worked for the Dade County, Florida, Engineers prior to joining the Seventh Coast Guard District Civil Engineering Branch in March of 1957, in which office he serves as a senior Civil Engineer. He is a Registered Professional Engineer and Land Surveyor in the State of Florida. j . i! D ID IID D ! DD i~. ; " ||| D 1 l~~~~~~~~~~l il:!i! ~ ~ l,:la -ii~ i i ! !;-- ! ?- ii? ~a 8 111 1110 . v~~~~ECLSUE ~8~i ~ ~ ;~.~i~?~li~iii"~'~iENCLOSURE 1 SECTION D MATERIALS INVESTIGATION 0MATFRIALS IIIVESTIGPTIOI4 TABLF OF CO!TENTS LTEM PAGE No, METHODOLOGY D-1 NATIVE BEACH MATERIAL D--3 BORROW MATERIAL ADJUSTED FILL FACTORS AND RENOURISI SMENT FACTORS OF BORROW MATERIALS D 5 LIST OF TABLES fIlL TITLE FOLLOWING PAGE '10, D-1 MEDIAN GRAIN Si E OF SURFACE SAND SAMPLES (ON) P-3 LOLLECTED ON fEACH PROFILES D-2 BORINGS AND COMPOSITED SAND SAMPLES .-4 COMPRISING EACH SIEVE ANALYSIS OF FOLLY BEACH BORROW SITES D-3 TEXTURE AND SEDIMENTARY PARAMETERS OF P.-4 CHARLESTON OFFSHORE APPROACHES D-4 MATCHING OF BORROW PLIERIAL WITH NATVE BEACH SAND -5 TO DEBIVE AwDgSTED FILL FACTOR IA AND RENOURISH- MENT I'ACTOR (j) L IST OF FIGIIPRES ln Q TITLE FOLLOWING PAGE N1O, D-1 LOCATIONS OF BORINGS AND POSSIBLE BORROW AREAS D-1 NEAR FOLLY BEACH D-2 OBSERVED CURVE AND FbiTTED PHI-NORMAL D-2 LURVE, bORING r10. 1, COMPOSITE OF SAMPLES 1, 2j, ? 3 D-3 THROUGH D-9 FOLLY RIVER DRILLING LOGS D-4 D-10 AND D- l LIGHTHOUSE CREEK DRILL HOLES D-4 D-12 THROUGH D-l1 STONO INLET DRILL HOLES n-4 D-15 AND D-16 LIGHTHOUSE INLET DRILL HOLES D-41 D-17 LOCATIOnr OF SCOOP SAMPLES TAKEN IN CHARLESTON Dl-4 H!ARBOR AND APPROACHES (1Q14) D-13 THROUGH P-53 GRADATION CURVES D-6 SECTION D MATERIALS INVESTIGATION 1. Field sampling of insitu soils was made to determine the nature of the beach materials, and the suitability of borrow material for use as beach nourishment or dune construction. Location of sampling points are shown on Figure D-1. Samples were sent to the South Atlantic Division Laboratory at Marietta, Georgia, for analysis. Laboratory results are shown in the back of this Section, (Figure Nos. D-20 through J-60). Evaluations of compatability of sands allocated for beach nourishment or dune construction are based on grain size, expressed in equivalent phi values, of samples as obtained in the field without having first removed shell fragments. Methodology 2. Using the procedure developed by James 1/ one can estimate the volume of borrow material required to produce one cubic yard of stable sand on the beach, after natural sorting and winnowing processess. In assessing the various borrow materials (sands) for use in nourishing Folly Beach it is useful to make matchings of various borrow samples with various native beach material (the sand found on the beach). Basically what is compared is the grain-sized histograms of the sand to find if the borrow material is generally coarser or finer than the native material. By matching these samples an estimate can be made of the "fill factor" and the "renourishment factor". The "fill factor" is the number of cubic yards required to satisfy the requirement for one cu. yd. of additional native beach material, in order to make allowance 1/ James, William R.,"Technioues in Evaluating Suit;iliy of Borrow; Material for Beach NQu- Kment,, e No. 60, S. Army Coastal ,glerc Ti 1975. " , idi -x 1 D-1 COASTAL ARE A .DUNE BEACH OR SLOPE- I- BERM FORES"DF~~~~d INSHORE ZONE OFFSHORE~~~~_ If BERM -(I FORE~~~~~~~~~~~~~~SIH ORE SLORPNG NOT~~~~~~~~~~~~~~~~~~~~ STO SCALET N V ~~ ~~~~~~~~~~~~R FOLLY RIVER s ~~~~~~~~~~C LIGHTHOUSE CREEK '10s ~~~~~~~~~~~~~~~L LIGHTHOUSE INLET ~~~~~~~~~~ ~~~~~~~~BORROW AREAS ~~-STONO"~~~~~~SQ>~~~~ LOCATIONS OF BORINGS N .1 ~~~~~~~~~~AND N ~~~~~~~~~~~~~POSSIBLE BORROW AREAS N ~~~~~~~~~NEAR FOLLY BEACH SOUTH CAROLINA (NOV. 1976) cr-fI IDP' n_ for the fact that the borrow material will lose some of its finer material during hydraulic placement and immediate reworking. The "renourishment factor" is the rate at which borrow material will erode relative to native beach material; it is used to determine how often the beach will have to be renourished if a certain borrow material is used. The location of the possible borrow sites are shown in Figure D-i. 3. Equivalent phi parameters.' The criteria developed by James (1975/ uses equivalent phi values of grain sizes which are computed as the negative logarithm to the base of 2 of the grain diameter in millimeters: 0 = -log2 d (i) When plotted on probability paper, the curve for most beach sands will approach a striaght line. Because of this characteristic, _o.Th1utations are made on the basis of a straight line drawn through the 16 and 84 percentile points on the phi plot as shown on Figure D-2. Phi parameters evaluated were computed as follows: a. Mean diameter. The phi mean diameter of grain-size distribution where: M= 084 + 0 16 2 b. Standard deviation. Phi standard deviation is used as a measure of grain size sorting in the sample and is computed using the formula: 4= (8 -16)/2 In the case of perfect sorting, the phi standard deviation is zero. Appendix I D-2 ASTM SIEVES - NO. 10 NO. 20 NO.40 NO.60 NO. 100 NO. 200 mm SIZE 2.0 0.84 0.42 0.25 0.749 .074062 DS3.044 .03125 J / / 0o 084= 3.15 /,' 1/ //FIT ED P/i-- 2.iA5 E iFITTED 0 OBSERVED RAN BORING IO 4 COM P O S I T E LOF SAMPLES 1.2,EM3 FIGURE D-2 . o o -2 -I 0 +1 +2 +3 +4 +50 |GRANULER UCOARSE | COARSE |ED.SAND FINE SAND | V.FINE SAN.D SILT OR CLAY WENTWORTH SCALE OBSERVED CURVE AND FITTED PHI-NORMAL CURVE BORING NO.4 COMPOSITE OF SAMPLES 1,2,&3 FIGURE D-2 Native Beach Material 4. Samples were taken at three stations, shown on Figure D-1, to establish the composition of existing or native beach material. Sample points on the beach profile were at the dune face, mid-berm, foreshore slope, and mean low water. A representative beach sample was selected at each station for the purpose of comparing native beach material with material from several possible borrow areas. All the beach samples were well-sorted medium and fine grained sands having median grain sizes of from 0.14 to 0.19 millimeters (2.80 to 2.40 phi units). For the sand samples co-lected along beach profiles, the median grain sizes in millimeters and equivalent phi values are shown in Table D-1. TABLE D-1 Median Grain Size of Surface Sand Samples Collected on Beach Profiles Beach Foreshore Mean Low Profile Dune Face Mid Berm Slope Water Average Station mm 0 mm 0 mm 0 mm 0 mm 50+00 S 0.15 2.75 0.18 2.50 0.16 2.60 0.15 2.72 0.16 2.64 10+00 N 0.16 2.62 0.15 2.70 0.19 2.40 0.15 2.75 0.16 2.62 90+00 N 0.14 2.80 0.15 2.70 0.14 2.80 0.16 2.65 0.15 2.74, All Stations 0.15 2.72 0.16 2.63 0.16 2.60 0.15 2.71 0.16 2.67 ADnendix 1 D-3 Borrow Material 5. Borings and samples tested are listed in Table D-2. a. Folly River. Seven holes, Nos. IR to 7R in Figure D-1, were drilled in Folly River to obtain soil samples for comparison with native beach material to determine compatibility. Samples were obtained with a splitspoon sampler. Drilling logs for holes made in Folly River are presented in Figures 0-3 through D-9.. Samples were tested and were classified as fine sands, of the type that would be suitable for beach nourishment purposes. b. Lighthouse Creek. Two holes, 8C and 9C, were drilled in Light- house Creek. Boring logs for the holes are displayed in D-10 and D-11. Materials encountered were classified as organic, silty, clayey, and very fine sand. These would not be suitable for nourish- ment of the beach. c. Stono Inlet. Holes numbered IDS, 11S, and 12S were drilled in the shoal adjacent to Stono Inlet channel just offshore from Bird Key Island. Drilling logs were displayed in Figures D-12, D-13, and D-14. Materials in this shoal would be suitable for beach nourishment purposes. d. Lighthouse Inlet. Two holes 13L and 14L, were drilled in Lighthouse Inlet. Drilling logs are displayed in Figures D-15, and D-16. Materials tested from these holes indicates that the site contains materials satisfactory for beach nourishment and/or dune construction. e. Maintenance dredging of Charleston Harbor Entrance Channel. More than one million cubic yards of sandy material is taken from the entrance channel to Charleston Harbor via hopper dredge each year. Surface scoop sample taken in the vicinity of the entrance channel indicate that this material is suitable for beach nourishment. However, no feasible means of transporting this material to Folly Beach have been discovered at this time so this areas was not further considered as a borrow source. Location of samples are shown on Fiqure D-17 and descrin- tive Darameters are listed in Table D-3. Appendix 1 D-4 i TABLE D-2 BORINGS AND COMPOSITED SAND SAMPLES COMPRISING EACH SIEVE ANALYSIS OF FOLLY BEACH BORROW SITES Analysis No. Soil Combinations for Analysis Composite of Hole No. Samples Numbered-1/ 1 Folly River 4R 1, 2, & 3 2 1R 1, 2, 3, & 4 3 2R 1&2 4 2R 3 & 4 5 1R & 2R #5 from each 6 3R 1& 2 7 3R 3 8 3R & 4R #4 from each 9 5R 1&2 10 5R 3 11 5R 4& 5 12 6R 3 13 6R 1& 2 14 6R 4 & 5 15 Lighthouse Creek 8C 1 & 2 16 9C 1, 2, 3, & 4 17 Stono Inlet 10S 1 & 2 18 10S 3 19 11S 1& 2 20 11S 3& 4 21 11S 5 22 11S 6 23 12S 1 thru 6, incl. 24 Lighthouse Inlet 13L 1, 2, & 3 25 13L 4 26 13L 5 27 13L 6 28 14L 1, 2, 3, & 4 29 14L 5 1/ For description of samples see following drilling logs. TABLE D-3 TEXTURE AND SEDIMENTARY PARAMETERS OF CHARLESTON OFFSHORE APPROACHES So Sk. Max. Sample Depth Md in 050 Q25 Q75 Sorting Coeff Skewness Quartz (mm) Shell1/ %Fines No. in Ft. mm Md mm mm <0.05 mm CH 1 12 0.12 -3.05 0.10 0.15 1.23 1.04 1.5 M 0.2 CH 2 20 0.13 2.94 0.11 0.17 1.24 1.10 2.2 M 7.8 CH 3 28 0.15 2.73 0.11 0.17 1.24 0.83 1.0 S 0.1 CH 4 12 0.15 2.73 0.14 0.17 1.10 1.06 1.6 S 0.2 CH 5 15 0.10 3.32 0.07 0.12 1.28 0.84 1.1 S 6.3 CH 6 22 0.12 3.05 0.10 0.14 1.18 0.97 1.1 S 3.3 CH 7 24 0.13 2.94 0.10 0.14 1.18 0.83 0.6 A 0.1 CH 8 28 0.18 2.47 0.15 0.19 1.12 0.88 1.2 S 0.1 CH 9 20 0.50 1.00 0.28 1.08 1.96 0.83 1.3 M 0.5 CH 10 21 0.17 2.55 0.13 0.20 1.24 0.90 1.3 S 0.1 CH 11 27 0.30 1.73 0.25 0.65 1.62 3.88 1.8 A 0.1 CH 12 16 0.09 3.47 0.03 0.13 1.29 3.22 1.1 S 30.6 CH 13 15 0.15 2.73 0.13 0.17. 1.14 0.98 2.1 S 0.5 CH 14 21 0.18 2.47 0.16 0.22 1.18 1.08 2.2 M 0.1 CH 15 27 0.15 2.73 0.13 0.19 1.21 1.10 1.6 M 0.8 CH 16 31 0.90 0.14 0.40 1.05 1.63 0.52 1.8 A 0.1 CH 17 15 0.15 2.73 0.13 0.18 1.18 1.04 1.4 S 0.1 CH 18 12 0.15 2.73 0.09 0.16 1.16 0.60 1.2 M 6.5 CH 19 21 0.19 2.40 0.15 0.25 1.29 1.03 1,7 A 0.1 CH 20 29 0.09 3.47 0.08 0.13 1.28 1.28 2.0 M 2.0 1/ Shell content by column: S<5%, M=5% to 30%, A>30% TABLE D-4 MATCHING OF BORROW MATERIAL WITH NATIVE BEACH SANDS TO DERIVE ADJUSTED FILL FACTOR (RA) AND RENOURISHMENT FACTOR (RJ) BORROW MATERIAL BORROW MATERIAL COMPARED WITH AVERAGE NATIVE BEACH SAND (FROM TABLE D-1) Location Analysis No Hole No. Mob t M Ra0n Rj 2, ________Mb M=b (Quadrant) 0On 0n Folly Beach 1 4 2.65 0.50 -0.0312 1.5625 1.20 (2) 0.50 6 3 2.47 0.72 -0.5937 2.2500 1.25 (2) 0.07 7 3 2.25 0.55 -1.2812 1.7188 1.03 (2) 0.12 10 5 2.72 1.02 +0.1875 3.1875 1.60 (1) 0.02 12 6 2.60 0.50 -0.1875 1.5625 1.15 (2) 0.50 14 7 2.32 0.37 -1.0625 1.1563 1.00 (2) 0.33 Stono Inlet 19 11 2.72 0.42 +0.1875 1.3125 1.26 (1) 1.00 23 12 2.77 0.52 +0.3437 1.6250 1.40 (1) 0.67 24 13 2.50 0.30 -0.5000 0.9315 1.00 (3) 0.67 Lighthouse Inlet 25 13 1.30 1.90 -4.2500 5.9375 1.20 (2) 0.02 26 13 2.65 0.55 -0.0312 1.7188 1.25 (2) 0.50 27 13 4.10 2.00 +4.5000 6.2500 3.60 (2) 0.02 28 14 2.40 0.40 -0.8125 1.2500 1.00 (2) 0.33 29 14 2.35 0.35 -0.9687 1.0938 1.00 (2) 0.33 1/ Comparisons are shown for only the most promising 14 samples analyzed of the 29 samples taken from 14 bore holes shown on Figure D-1. 2/ Using a "RA' value of 1.20, one cubic yard of sand subject to sorting will require 1.20 cubic yards removal from the borrow area. 3/ Using a "R value of 0.50, the rate at which one cubic yard of borrow material will erode is one-half the rate at which the natural beach matejail will erode; thus using this Rj only o.50 cu. yds. would be required for renourishment for each cu. yd. of native beach sand lost. I DIVISION IISALTO SHEET 0. 1q.1-LT-11 O I South Atlantic I ol Bea.. S. C 1O I S I4EETS AZ.'. (_T ~~~~~11O. SIZE AND TYPE OF IT 1 3 /8'' 1D S~litsooon I'shen Il. DATUM4 FOR ELEVATION SHOWN (TBM w MSL.) West Bank Folly River. Near Day Mark 1115"1f2. MANUFACTURER'S DESIGNATION OF DRILL 3. FRILLING AGENCY C- . kdRic rit I I 13. TOTAL NO. OF OVER- DISTURSED UNDISTURBED 4. HOLE NO. (Aa?.~ ..p o~-mgrn title BURDEN SAMPLES TAKEN.; and fil 1t~J . S0 5. NA-ME oir DRILLER 14. TOTAL NUMBER CORE BOXES P. Rount ree I'. ELEVATION GROUNDWATER HLW S. DIRECTION OF HOLE !STARTED I COMPLETED 16. DATE HOLE MJVERTIC AL 0IlNCI-NED ______DEG. FROM Vfr I i9 Nov, 1976 9 Nov. 1976 117. ELEVATION TOP OF HOLE MLW -2 .0I 7. THICKNESS OF OVERBURDEN 18IO B. DEPTH DRILLED ~ ~ 18.0 ITORCn '18. TOTAL CORDC RECOVERY FOR BOR;NG S. DEPTH DRILLED INTO R O C K _._u.TURE -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~t: iN3PECZT-0~~~~~~~~~~~~~~~~ ..J N~rL.. S.TOTAL DEPTHGOFHOLE 180 clville I I ~~~~CLASSIFICATIC)N OF- LATERIALS Co2~Dx CR REMARKS ELEVAh(iON1 -EPT4 LRCEOV1 (I~rpto)SAMPLE (Drilling; tim,0 Ac- I.e., d-pfh .1' -2.0 0 b c i d II4~1,13Iu green , sof, wet,13 i ~ ~ jl+.. ........l..~~I II..l No CasinoJ Set 1 -.~~4i.4ri fragmnents &Heavy minerals 16- -5.0 3 -1~~~~~~~~i~~~~ Begin drilling 0845 - 3 :1 ~ dense End drilling 0949 48- 2 5 $p Jet To Top of Drives 57- 10 ~~~~~~~~~31- 35- -20.0~~ I8 - clayey, increasing 24 i8 ~~~~~~~~~~~5 39- - ~~~~BOTTOM OF HOLE 18.01 BLOWS PER FOOT- -NOTE:Soils field classified ~umber required to drive in accordance with the Unificd I 3/811 ID splitspoon wI -Soil Classification System. 140 lb. hammer failing - Folly River Drilling- Log No. I FIGURE D- 3 1South Atlantic INSTALLATION HolE No T TuRM.LING SuhAlanti Folly Beach. S.C. O 0FI SHEETS [I~~~i~~R57~~~~cT tO~1. SIZE ANOTYPE OF BIT 1 3/811 I D SDI itsooon ~-,o'jr ihm-npt it. DA~T119 FOR EL EVAT!V SHiOWN (Tf!~.~z. rC-oCAT ION (Coo-dian.I at SI9dwQ) 1W -WstBank Fol IIv R iver. Near Dav Mark "Il Y' 12. MANUFACTURER'S DESIGNATION OF DRlILL 2.DRILLING AGENICY Skid Riq CD-2 Savannah District 1....... 3. TOTAL NO. OF OVEq- . I TURBED UNDISTURBED L4.440LE NO0. (A 6P- cho,.nnigf1.8 Haf1URDEN SAMPLES TAKEN 5. NAME F DRILLE ..-- #2R _____14. TOTAL NUMBER CORE BOXES 0- P. Rountree 15. ELEVATION GROUND WATER M LW 6. DIRECTION OF HOLE !STARTED ICOMPLETED OVERTIC'AL MIZICLINED _______DEG. FROM VERT. DIC O.E 9 Nov. 1976 q!1 Nov. 1q76 I7. ELEVATION TOP OF HOLE M LW -4.3 ___ 7. THICKNESS OF OVERBURDEN 18 OA OERCVR O BOIN S. DEPTH DRILL~~~~fl I~~119PI~II. SIGNATURE OF INSPECTOR S. TOTAL DEPTH OF HOLE 16.51. Belville CLASSIFICATION OF MATERIALS % CORE t3OX OR REMARKS ELEVATION DEPTH LEEDOCJIQ? RECOV- SAMPLE (Drilling time, -ale? Ioap. depth of ERY NO. .-afhedgjn.*l if s~.ignilc .- -.4,. C d i . - JAR B LOWS - SM-Blue green, soft, viet, No Casing Se~t 12- 4 fine, silty sand~w/shell 1 -7. 3 3 ~~franmnents &heavy mineral ~ Begin'drilflng 10:20 1. -7.3~~~~4 D e ns End drilling, 11:20 3 5 - 2 Jet to top 6f drives 46 _ II ~~~~~~~~~~~~~~~~~56 _ ~~~~~~~~~~~~~~~~~~57- __ El 3 ~~~~~~~~~~~~~~~~~41- _ El ~~~~~~~~~~~~~~~~~50 4 .57- 15- -20.8 16. 5- 56- BOTTOM OF HOLE 16.51 BLOWS PER FOOT:- - NOTE: Soils field Classified -Number required to drive- in accordance with the UnifieJ 1 3/811 ID Splitspoon w/- __ Soil Classification System. 140 lb. hammer failing - 3011. Folly River Drilling- Log No. 2 FIGURE D- 4 -~~. ~~ IN5TA~~~~LATIOH I~~SHEET1 [ -fRILLING LLWlJ South Atlantic Folly Beach. S.C. IOFI SHEETS it. PROJECT 10. SIZE AND TY rE OF BI1T 1 3/~' I D Sp I 'tSpo -n 0Nourishment -fl. -OATUM-FOR ELEVATION S11OWN M3,14 AFSL) 2. LOCATION (Co.,dwaro. a or ~.cjmt) MLW - Behind Bird Key, Near Day Mark "R1-1011 12. MANUFACTURER'S DESIGNATION OF DRILL 3. DRILLING AGENCY CD-2, Skid Ric, Savannah District 13. TOTAL NO. OF OVER- .OSUBD jNITRE 4. HOLE NO. (A. .hoo.~ ~ dring lJI.1 BURDEN SAMPLES TAKENo ar~~ We n.,,b.~~~I #3 14. TOTAL NUMBER CORE B3OXES 0 5. NAME OF DRILLER P. Rountree 15. ELEVATION GROUND WATER U- 6. DIRECTION OF HOLE !*TARTED 1COMPLETED CVERTICAL OINCLINED_______ DEG. FROM VERT. IS. DAT EHOLE 9 Nov. 1976 9 Nov. 1976 17. FLEVATION TOP OF HOLE ML - 7.0' T. THICKNESS OF OVERBURDEN 18I. TOTAL CORE RlECOVERY FOR BORING S B. DEPTH DRILLED INTO ROCr 0.1 9 I. SIGNATURE OF INSPECTOR 9. TOTAL DEPTH OFHOL~E 1.1Bli ELEVATION DEPTH LEGEND CLASSIFICATION OF MATERIALS %CORE leOX on REMARKS (Doeoaplo REcOV- ISAMILE (fl,111jgtit.o~o o.. dpth of -SM-Blue green, 15 I ~~~soft, wet, fine, No Casing Set 2 - 0 silty sand with 22-__ - shell fragments Begin drilling 12:55 - - & heavy minerals - 2 End drilling 13:~43 . -13.0 6 - ~~~~~~~~~~~~~~~~Jet to top of drives 1 - -Clayey, increasing 17- - ~~plasticity -19 3 4 -20.5 13.5HOE1.PEFOT - -NOTE:Soils field classified Number required to drive- - in accordance with the Unifiei I 3/811 ID splitspoon with _ _ Soil Classification System. -1t40- bTb-hamm~r-fa 1-1i ng - 3011. ~Fol11y River Drillinig - Log No. 3 FIGURE D-5 Hole. No. #4 DIVISION INSTALLATION jSHEET DRILLING LOG South Atlantic Folly Beach, S.C. . - Io I SHEsTsI 1. PROJECT 10. SIZE ANO TYP-E OF SITr Nourishment II. V ATU M FO0R EL E VA TIO0N S HOW N (2TBM aMSL) 2. LOCATION (Coonfmdu.I. o S1i~on) M T, W Behind Bird Kev- He.:r Dav Mnrl, "R-Inll 12. MANUFACTURER'S DESIGNATION OF DRILL J. DRILLING AGENCY CD-2 I 13 OTAL ') o~r C *"JvE UN!UO 4. KOLE NO. (At .ao, on .,&.,,jg BURDEN 4APE AE 14. TOTAL NUMBER CORE E30XES 0 B.NAMAE OF DRILLER ~~. Ro,,ndtri~~~~~~~~~~p ~15. ELEVATION GROUND WATER MTJ.7 G. DIRECTION OF HOLE 1 6 A E H L 'STARTED COMPLETED ObVNTIAL INCLINED ______DEG. FIROM VERT. 1.DTHOE i9OV 1976 9 NV176 'Y. THICKF.ESS O F 1 5.0' ~ 17. ELEVATION TOP OF HOLE T'LW -6.8 o.01 18~. TOTAL CORE RECOVERY FOR BORING S. DEPTH DRILLED INTO ROCK 0I0 19. SIGNATURE OF INSPECTOR P. TOTAL DEPTH OF HOLE .0IBvil CLASSIFICATION OF MATERIAL AS COE Isax OR I REMARKS ELEVATION DEPTH LEGEND - RECOV. I SAMPLE (DIfd In,.oti. dihf I RY I O 'MOIC e.i - + SM - Blue-green, dense, wet, I No casing set 23 fine, silty sand, w 41 shell fragments and .29 heavy minerals 5 0 2 Begin Drilling 19 End drilling 1510~~~~1 -21.8' .~~~~~~~~~~--...-. . ~~~~~~~~1415 - 21: Jet to top of 14- drives f 4 -21. 8 ~ l 4 25- - ~~~~BOTTOM OF HOLE 15.0' BLOW4S PER FOOT- -NOTE: Soils field classifi- Number required to - _ed in accordance with the drive 1 3/8" ID split- -Unifed Soil Classification spoon w/140 lb. ham- - -System. mer falling 30". Folly RiVer Drilling Log No. 4 '- FIGURE D- 6 Hole Mo. # DRILING O~ South AtlanticINTLTONET. 1. PROJECT .10. SIZE AND TYPE OF BIT I 3i'S" TD Solitsooon LOAIN(ou~rismnM.rrno IDt U O LVTO SHOWN (TBM -MSL) 2. LOCATION S9.9i" "IllN L W4 Mouth of Fol ly Creek. No~rth h;;nL- nf mrna~h 12. MANU.-ACTURER'S DESIGNATION OF DRILL 3. DRILLING AGENCY CD-2 %'7afl"nl" T)4-,trict 13. TOTAL P~O. OF OVER- DOISTURIEEO UNDISTURBED P_ ROLE -NO. (An nh e''~ gaefoI BURDEN SAMPLES TAKEN land W. -~b~ p #5 ~~~14. T OTAL NUFASER CORE GOXCS 0 S. NAME OF DRILLER _______ P. Roundtree ~~~~~~~~~~~IS. ELEVATION GROUND WATE ~ TT 6.DR ON O HOLE 1TNL CCMPLE T C:D DIRECTION ~~~~~~~~~~~~~16. DATE HOLE i 10 NOV 1976 10 NOV 1976 VERTICAL EJINCLNEGOEO. FROM VERT. 17. ELEVATION TOP OF HOLE TL W -1 . 8 7. THICKNESS OF OVERBURDEN j1 .01 k :E-E;-FAEO;: IS. DEPTH DRILLED INTO ROCK 0.0 19 INTRO NPCO ~9. TO3TAL bt:PT6' OF HOLE L~UBelville ELEVATIONJ ET LEGIEND1 CLASSIFICAT ION OF MATERIALS 1.COE 19OX ORF I REMARKS DEPTH ~~~~~~~~~~~~~~~~~RECOV- SAMPLE I Dil,.g h~. S.,l. -d~reh of -I.8&- O b AR - LN OWS f'W -~ l31ue-gracn, "Tary sott, 1 NO C~asintg Set- wet, silty, Clayec' fije she]nag Begin drilling0- 4~! SNM Very soft, wet, silty, 2 End drilling 4' fine sand w/shell 09172 fragments and heavy -:10.8 9.0 Dense, lense MH~3 241- 9.0' to 9.32- -19.8 i8.~ 29 - ~~~~0BTTOM OF HOLE 18.01 BLOT-S PER FOOT:- - NOTE: Soils field classifi- Number required to - ed in accordance with the drive 1 3/8" ID split-- -Unified Soil Classification spoon w/140 lb. ham- - - System. mer falling 30". Folly River DrillingK Log No. 5-- - 0 ~~~~~Figure D-7- DIVISION INSTALLATION HE. o.T~ I outh A~tlantic Follv Beach *S.C. FIS SHET 1. PROJECT 10. SIZE AND TYPE OF SIT I 3/0" TD Izn0]irsiinon Noiirshirnent It. DATUM FOR ELEVATION SHOWN (TB.W wMSL.) 2. LOCATICNHa S~o, M L W ;0' 0. S. Hr.,. 700 13r dne- FA~t hlnk- Fr-d1v 12. MANUFACTURER'S DESIGNATION OF DR:LL 3.DRILLING AGL:.C- ie CY SavaOLENO(A.h, Diti td jivei- 13. TOTAL NO. OF OVER- IDISTURBED UNDI1SJUR 6E D 4. HOLE HO. (A. ,ho..n . ~..m4 tifl.I RBURDEN SAMPLES TAKEN4 D n~II . .m b*V R6 _____ IL N4AME OF DRILLER 14. TOTAL NUNBER CORE BOXES 0 P. Rotindtree 15. ELEVATION GROUND WATER M L W OfDIRECTION OF HOLE !STARTED [ COMPLETED le. DATE HOLE 1 \C 976 1lO NO'v 1976 [MVERTICAL MINCLINED _______DEC. FRIOM VERT. 7. THICKNESS OF .-VERBURCE" 15.0' 117. ELEVATION TOP OF HOLE ' ILW -4.9 S. DEPTH 0-!LLEO -MTC1 P 0.0' IS. TOTAL COFIE RECOV'CRY FOR BORING IS1. SIQHA_1 UHEQ- ISECQ S. TOTALDES-TMHOF HOLE 15. 0' Belville I CLAA 1 FICATI ON OF MAATERIALS C OR I'O Box.r REMARKS ELEVATION DEPTH LEGEND RECcdjOV- S AMP L time er . lo.. da rh *~~~~~~~~~~~~~~~~~~~~R NOS. it.:a~sj-r -4."9 T .& - j'i ~fl1 - Cray, ~ery soft, No casing set 0 .2 ~~wet, fat silt' Begin drilling 14. ~~~2 0845 5211 End drilling 0- -10.9 6.0 3 0954 - 0 T1 SM -Firm, wet fine silty sand w/ shell frag- 17- � ~~~~~ ~ments and heaymnr Djense 433 I'r~~~~~~~~~~~~~r ~~~~~762 -�'0.9 15 9 63 - ~~~~BOTTOM OF HOLE 15.0' BLOWS PER FOOT: - ~~QT~: ~ ante the ~ Number required to - -Unified Soil Classificationdrv 1./8 IDslt - -System. spoon w/140 lb. hammer- falling 30". Folly River Drilling - Log No. 6 Fi gure D - a 9-. . . ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Halt No. 4 jof VISION NSTAL.LATIOC j SHEET DRILLING LOG South Atlam tic 1"Folly Beach. S.C. i OF I SWEETSI I. PROJECT 10. SIZE AND TYPE OF SIT I. 3/8" ED Sr)1itspoon Nourishment It. DATUM FOR ifLEVATION SHOWN (TBMf wASL-) 2. LOCATION fCoo-d-wat. a, Stagi-%) ME71 West bank Folly River, Near Day makI1I 12.. MANUFACTURER-S DESIGNATIO i~iOF DRILL 3. DRILLING AGENCY CD- 2 Savannah District 1 3 . TOTAL NO. OF OVER- L115TURDED UNDISTURBED 4. HOLE NO. (Am h.ho, on f~i-nd tUitle BURDEN SAMPLES TAKEN 1 S. NAME OF DRILLER 14. TOTAL NUMBER CORE BOXES 0 P. Roundtree IS. ELEVATION GROUND WATER 6. DIRECTION OF HOLE ISTARTED ) COMPLETED nVERTICAL ____________ DEG. FROM VER-7. 16. DATE HOLE 1NO196: 10 NOV~ 1976 17. ELEVATION TOP OF HOLE 7. THICKNESS OF OVERBURDEN i0n1,1 TOTI AL COHIE F~COVEHY FOR BORING S. DEPTH DRILLED INTO ROCK . 0s SIGNTR OFISPCO 9. TOTAL DEPTH OF HOLE 18.01 1 . ' Btiville II CLASSIFICATION OF MATERIA LS % CCOR- eo' OF ! !~MAfKS ELEVATION DEPTH LEGEND RECOV- SAMPLE (D~jljjg th,-, t.ot, Io... d~pth nf ERY NO. s~i~,.~.I ia"Iic.rv -3.3 0 b I JAR 7C:! SM - Bluegreen, loolse, wet, No easing set fine silty sand, w/ 2 10 -6.3 s hell frnRmeots and 3 3.0 _ ne~~vv rn~nt~ra~s 4 Begin drilling 1 *1300 5 ~~ Dense 5 End drilling 23 v 76 1410 27 Thin lenses of MH 10 - ~~~~~12.0 to 13.5 1093E- 11 ~~~~~~25r ~~~~~~~~~~~~~~~182 -21.3'18 27- - ~~~~~BOTTOM OF HOLE 18.01 BLOWS PER FOOT: - ~~~NOTE: Soils field classif- Number required to drivE - ~~~ied in accordance with the 1 3/811 ID splitspoon - ~~~Unified Soil Classificatior w/14o lb. hammer - ~~~System, falling 3011. Folly River Drilling Log No. 7 Figure D-9 - Hole No. #8 ( DIVISIONt INSTALLATION ISHEET I DRILLING LOC South Atlantic Folly Beach. S.C. OF 1 SHEETS I. PROJECT t1. SIZE AND TYPE CF SIT 1 3/,!" :n Splitspoon Nourishment Il. DATUM FOR ELEVATION SHOWN (TBM MSL) 2. LOCATION (CoOrdmwete rS tijr M L W Upstream of Iiaht house in liqht house Ck. z2. MANUFACTURER'S DESIGNATION OF DRILL 3. DRILLING AGENCY CD-2 97nlr.nVh ni ct'i- 13. TOTAL NO. OF OVER- I DISTURSED UNDISTURBED 4I HOLE NO. (Age hown ol dmra ti Ui9 SURDEN SAMPLES TAKEN 2 O - d . tilel. ! C; 2 C 3L. NAMiE OF DRILLER R-- 14. TOTAL NUMBER CORE BOXES 0 P. Roundtree Is. ELEVATION GROUND WATER M L W J. DIRECTION OF HOLE ! STARTED ICOMPLETED t7VEORTICAL rINCb INED age. WRue VEST. 16. DATE HOLE I 11 NOV 1976 11 NOV 1976 17. LLEVATION TOP OF HOLE M L W -19.8 ?. THICKNESS OF OVERBURDEN 13 . 5' S OF OVERURDEN 13.518. TOTAL CORE RECOVERY FOR BORING I. DEPTH DRILLED INTO ROCK 0.0 19. SIGNATURE OF INSPECTOR I. TOTAL DEPTH OF HOLE 13.5' Beltille CLASSIFICATION OF MATERIALS % CORE BOX OR REMARKS ELEVATION DEPTH LEGEND (Deerpl&rt RECOV- SAMPLE (Drillingl te, water loae, depth of ERY NO. welthering. etc., if e;gnficnll -6.3 Oas d * JAR w. BLOWS: SC - Gray, wet soft organic,sing set silty, clayey, very No casing set I /,v./ fine sand w/shell fragments and oder of Begin drilling rotten eggs. 1009 - 5 - ^^z97 End drilling "-F l 11.02 1-. 10- 2 21~3= -19.8 13.5- 5 - BOTTOM OF HOLE 13.5' BLOWS PER FOOT: NOTE: Soils field classifi- Number required to - ed in accordance with the drive 1 3/8" ID split- - Unified Soils Classificaticn spoon w/140 lb. hammer - System. falling 30". Lighthouse Creek Drilling Log 8 Figure D-10 DRILLING LOG jSO~~th Atlantic INSTAL LATION S HlEE Io I. PROJECT ' O. SIZE ANDTYPE OF B31T I 3/8 *CD Spis ooniHE Nourishment It. DATUM FOR ELEVATION SHOWN (TEN 'MSL) 2. LOCATION oCd,.. Siamion) M, L W1 Upstream of I iqht house in light house Ck. 12. MANUFACTURERSODESIGNATION OF DRILL 3. DRILLINGk'AGENCYCD Savannah DistrictCD 13. TOTAL NO. OF' OVER- IDIS-rURB5ED 1UNDISTURBED 4. 44OLE NO. (As a.-I~o on &An titis I CBURDEN SAMPLES TAKEN I 40 S. NAME OF DRILLE R ~~~~14. TOTAL NUMBER CORE BOXES 0 P. Roundtree 15. ELEVATION GROUND WATER Li L W 6. DIRECTION OF HOLE I6 ~~EHL STARTED 1COIAPLZTED r~VERTICAL �JINCLINFED ______ EG. PROM VERT. I11 Nov 1976 :!11 NOV 1976 7. THICKNESS OF OVERBURDEN 12.0'17 E LVTNTOOFHE LIV8. S. DEPTH DRILLED INTO ROCK 15. TOTAL CORE FECOVERY FOR BORING 8. DEPTH DRILLED INTO ROCK 0.0' 9 . SIGNATURE OF INSPECTOR 9. TOTAL DEPTH OF HOLE 12.0' BelvillE. ELEVAION DPTH LGEND CLASSIFICAT1ION OF MATERIALS % CORE BOX OR REMARKS ELEVATION DEPTH LEGENDoe~pli~ RECOV- SAMPLE (DrdI,,g tb,,e. ,.,1Ie j-'s.d.t, -8. 06 Ob E d * JAR ZiL6WS: CH - Gray, very soft, wet, No-casing set _ silty, fat clay, w/ begin drilling 13190- some very fine sand, end drilling 1405 oder of rotten eggs 2 2Z 10 ~~~~~~~~~3 Weight of hammer - drives to 6.0 2- -20.0 12.0- / 4- - ~BOTTOM OF HOLE 12.01 BLOWS PER FOOT: - - ~~NOTE: Soils field classi- Nme eurdor~ 1 3/8" ID splitspoon fled in accordancd with w/140 lb. hammer f.all-- the Unified Soil Classifi- ing 30"I. - ~~cation System. Lighthouse Creek- Log No. 9 FIGURE D-11 Hole No. 1 IO qIVI~t-, AI~nnt-io sel non-1 q 1OF 1 SHEETS I. PROJECT 10. SIZE'AND TYPE OF BIT 1 Jjj6" fl Spli-Lspoon. Nou r shnen t 11. nATUM FOR ELEVATION SHOWN (TRM =.OL) 2. LOCATION (Ca~dmat.. at-j~j. M. L. W. Shoal 'near b ird key 12. MANUFACTURER'S DESIGNATION OF DRILL 3. DRILLIHG ACNC CD-6 Savannah Dist-ri-ct 13. TOTAL NO. OF OVER. J013TURDED , UNDISTURBED ,L HOLE NO. (A. .ho.. on d~a..'U,, ticiel BURDEN SAMPLES TAKIEN 3 endfjj. ntt,b~d 3 S. NAME OF DRILLER -14. TOTAL NUMBER CORE BOXES 0 P. Roundtree IS. ELEVATION GROUND WATER M 6. DIRLC'rlOf4 OF HOLE STrARTED 1COMPLETED MVERTICAL ~ICIE ______oEo. FnOM VCRT. i AT OL 16 NOV 1976 16 NOv 19716 7. THICKNESS OF C .'ERBURDEN 1 00LVAINTP'FHL .of ~~~18. TOTAL CORE RECOVERY FOR BORING S. DEPTH lRIILE~ ~TO ~ fl(1 1 9 I. SI-GNATURE Or INSPECTOR S. TOTAL DEPTH OF KOLE 9.01 Brlville ELEVTIONDEPT LEGNDI CLASSIFICATiON OF MATERIALS % CORE BOX OR REMARKS ELEVATION DEPTH LEGEN~~j (Descrj:jar, RECOV. SAMPLE (DIIIt,- ti~e. Wore- I..., dpth of 0.0'a 0 a ER fQ. ~ *C.i IgIUA,,. SIM - Green gray, wet, soft. 1 -3.0' . ~~~~~very fine, silty sand,w/ Begin drilling- 3.0~~~~~~~~~~~~~~~~~ ~~~shell fragments and heavy16mnrs End drilling 5iI~ ::~~ Dense 2 05 9 No casing set7 Hole not completed 35 I I~~~~~i~~~~i ~~~to -20.OI due to jc :9.0' -TL 3 'incominiq tide.31SI - ~~~~~BOTTOM OF HOLE 9.0' BLOWS PE1R FOOT: -NOTE: Soils field classifi- Number req':ired to drive -ed in accordance with the 1 3/8" ID splitspoon L -Unified Soil Classification -w/140 lb. hammer falling- -System.30. Stono Inlet Drilling- Log No. 10 FIGURE D-1Z VISION ~~~~~INSTALLATION sE 1.PROJECT 0SIEADTPOFSTI36 DSlspo Nou rishrnent it. AU OLVTO SHOWN fTamM j4SL) 2-LOCATION (CM4.,I.~o, . L. W.- North side oF Bi rd Key 12. MANUFACTURER'S DESIGNATION OF DRILL 3. DRILLING AGENCY T- Savannah Discrict 13. TOTAL NO. OF OVER- DISTURBED UNDISTURBED 4. HOLE NO. (A. eho.-- d.-g ltiji* BURDEN SAMPLES TAKEN~ 60 and DIle *,vb.) #iS 5. INAME OF D9ILLER .-14. TOTAL NUMBER CORE BOXES P. Roundtree IS. ELEVATION GROUND WATER T, 6. DIRECTION OF HOLE S3TARTED I COMPLETED __ ~~~~~~~~~~~~~~~6. DATE H4OLE ffqVERTICAL EINcLINED _______DE. FPROM WERT. 6 NOV~ 1976 :16 '~'M 1976 7. THICKNESS OF OVEREURDENA 22.51 �7. ELEVATION TOP OF HOLE + 3 .0 ?'T. ____ 18. TOTAL CnRE RECOVERY FOR POR!NG S. DEPTH DRILLED INTO POCK 0.0 1 9. S IGIJATUrE OF IN4SPECTOR 9. TOTAL DEPT HOF HOLE 225' Belville ELEVATION I ~~CLASSIFICATION OF- uATERIALS s CP ox OR R EMARKS DLVTO EPTH LEGENDs RECOV- SAMPLE I (DOiflg Ii-, - I",, 1.*s. deEth of (2..cI-qnt~~s) ERY NO. f~ i do.'jgM1.f.'w~l a Ob 6 TM~ 9. RT nMjq. +3.0' SM - Green gray, wet,dense,�,12 fine sil,:y sand w/shell +11 ~~fragments and heavy Begin drilling 27 I ~~~minerals. 11 -~~~~~~ . ~~~~~~~ 2 End drilling 5 5 ~~~~~~~~~~~~~~1055 65 - ~~No casing set 66 3 ~~~~~~~68 65 64 61 - -16.5' 195 6 6 ' I 2 0-7- SCWet, dense, fine, silty, -~~~ ~ clayey fine sand, w/shell 68~ -19.5' 22.5' *y/ fy~gments and heavy miner- 6 62- BOTTOM OF HOLE 22. 5' BLOWS PER FOOT: Number required co driv~7_ - NOTE: Soils field classifi- 1 3/811 ID Splitspoon - - ed in accordance with the w1140 lb. harrm-er fall-- - Unified Soil Classification ing 30". - System. Stono inlet Drilling Log N6.11- FIGURE D-1-3 Hal*� No. 1 tNSTALLA...,, LSHEET j DRILLING LOG South Atlantic FCIUA Rench. S.C_ 1OF 1 SHEETS L PROJECT 1o. SIZE AND TYPV OF RIT 1 3/8' ID Splitspoon MoUri Sh"m.ent II. DATUM FOR ELEVAT*ION SHOWN (TBM mr.-SL) 2 2. LrZ..i h.. (L.oo-d-..t** or ii. L. W. Bird Key 20001 off shore. South Tin 12. MANUFACTURER'S DESIGNATION OF DRILL 3. DRILLING AGENCY rm_;- Savannah District 13. TOTAL NO. OF OVER- DOISTURBEO UNDISTURBED 4.44OLE "O. (As xhoe M d-t # 1,1910 BURDEN SAMPLES TAKEN4 and file rn-bw) 12 S . AM ODILER- 14. TOTAL NUMBER CORE BOXES L NAME: OF DRILLER P. Roundtree IS. ELEVATION GROUND WATER MT1. G.DIRECTION OF HOLE .STARTED JCOMP4ETEO 16. DATE HOLE ___________ DCNDEG. FROM VENT. 17 NOV1J 10C7A 17 \'CVIT 1079 17. ELEVATION TOP OF HOLE 0.r*lq 7. THICKNESS OF OVERBURDEN ')I 01 - 7. THICKNESS OF OVERBURDEN 21.0' 18. TOTAL CORE RECOVERY FOR BORING % B. DEPTH DRILLED INTO ROCK I , _ . S;GN.ATURE OF IN6PECTOR 9. TOTAL DEPTH OF HOLE 21.0' xe vi I P CLASSIPICATION OF MATERIALS . CORE BOX OR REMARKS LCG ENVATAGN (DEcPTpHiC,.) RECOV- SAMPLE (Drili,,g -Ir o... d.pth ot ERY NO. -ath"ling. *Io., it argmfJcar!) III (~ b JAR SBLOWS: -0.0' tlIl SIS - G'av green, soft wet, 1 [ fine sil4t sand wi sell . 10 idiI fragments and heavy Begin drilling minerals 0935 14 4.5 19 End drilling 5~ 419`~ 1034 - - 2 37 Dense No casing set 45 20 - 24_ 4 36- - Small clumps black ch 47 16.5' to 17.0' '-17.0' 17.0- i ~~~~~~~~~~~~~~~59 6 62 - - i j ( Iijr ,I Black and gray green 5 ~~~~1?J. ~~~~~~~~~~~~~64- 20.1 69 BOTTOM OF UOLE 21.0' BLOWS PER FOOT: NOTE: Soils field classified Number required to drive- in accordance with the Unifi- 1 3/8" ID splitspoon ed Soil Classification Systefr. w/140 lb. hammer falling- 30". t Stono Inlet Drilling Log No. 12 FIGURE D-14 Hole No. 13 oDVISIOH INSTALLATION ISHEET I DRILLING LCG .South Atlantic Folly Beach, S.C. OF 1 SHEETS 1. PRUOJCI IC,. S;Ie AD TY^r C" 9IT ._.. I Nou r i shfien t 11. DATUM FOR ELEVATION SHOWN (TBM e ;iSL) 2. LOCATION (CoMrdmra oor, Stjcs~ TM I. J. Near licht house on shoal in lioht house 12. MANUFACTURER'S DESIGNATION OF DRILL 3. DRILLING AGENCY Lreek Savannah District n_ SnhDs c 13. TOTAL NO. OF OVER- i DISTURBED UNDISTURBED 4. HOLE NO. (A.n n Mh ddraw n IItIi. LJ BURDEN SAMPLES TAKEN 6 0 And lfe n-b') #P13 L S FNAME OF DRILLER - 14. TOTAL NUMDER CORE BOXES P. Roundtc Is.15 ELEVATION GROUND WATER 6. DIRECTION OF HOLE sT ARTEOD COMPLET D 16. DATE HOLE WVERTICAL OINCLINEDo DEC. FSROM VEtT. T 18 NOV 1976 1 .8 .NO 1 9.7 17. ELEVATION TOP OF HOLE 0.0 7. THiCKHNESS OF OVEP-u C<EN : j.*0j B. DEPTHiC~ DRILLED INTO ROCK 02i.0 j18. TOTAL CORE RECOVERY FOR BORING S t. OE0. 0 119. SIGNATURE OF INSPECTOR 9. TOTAL DEPTH OF HOLE )1.0 ;,elville ERY NO. sreherlrn. ec. il a '_niifcend 0.01 SM - -Green ray, wet, firm,| 1 12 - fine, silty sand w/shell fragments and heavy Begin drilling 17 - a minerals 0935 -4.51 4. -I 2 End drilling 22 Dense 31 - No casing set - 39 _ lo3~ - 46 52 - 57 53 4 15- - -- Thin layers, gray and black 49 - 817.5' 17.5' CH- 17.51 to 18.0' -18.0' 18. ---. --, 54 SC - Blue gray, wet, dense, 5 fine, silty, clavey sand 52 w/shell fragments and 6 -21.0 21.0' ., ..- BLOWS PER FOOT: - BOTTOM OF HOLE 21.0' Number required to drive = _ NOTE: 1 3/8" ID splitspoon - -- Soils field classified in w/ 140 lb. hammer fallinE_ -- accordance with the Unified 30",. -- Soil Classification System. :7~~~~~~ ~~Lighthouse Inlet Drilling No. 13 FIGURE NO. D-15 Hal*o , Di. o Ss Vill ~INSTALLATION jSHEET DRILLING LOG !South Atlantic Follv Beach. S.C_ IOF I1 SHEETS 1. PROJECT ID. SIZE AND TYPE OF BIT 1I3,LaL TI) itpn Nourishment It. 0ATU'_ 'OR ZLLVA17iC HVWN(T8w~;MA;S 2. LOCATION (C-~d.iStmgo-j M. L. 1. Near 1 icht house on shoal in 1 ight house iz. MANUFACTrURER'S DESIGNATION OF DRILL S. DRILLING ACNC Creek Savannah District 13. TOTAL NO. OF OVER- IDlSTlR BED UN401STURBED 4. HOLE NO. (A. d...,I o, tti.I BURDEN SAMPLES TAKEN0 5. NAME OF DRILLER -. ~~~~14. TOTAL NUMBER CORE BOXES0 P. Roundtree 15. ELEVATION GROUND WATER S. DIRECTION OF HOLE !STARTED 1COWPLETED [2VERTIC AL _____________ DUG. FROM VERT. 1.DT OEi 3-,D 96~ 8NV17 7. THICKNESS OF OVERBURDEN 24.0' 1 7 'ETINOPFHLE5-11 18. TOTAL CORE RECOVET1Y FOR BORING B. DEPTH DRILLED INTO ROCK IS01 F. SIGNATURE OF INSPECTOR 9. TOTAL DEPTH OF HOLE 2,!..0' .e11'4 I 1" ELEVAION DPTH LGENDCLASSIFICATION OF MATERIALS fCORE Box OR REMARKS ELEVATION DEPTH LEGEND I ~~~~~~~~~~RECOV. SAMPLE (lriflirmg ti.,,o -t,o~ lo... d.1wh .1 ~~~~~~ERY? NO. ...I)Ordne, ift. sif ,n~jil.nz fine, silty, sand w/shrell6 ~~~SnPntRAnd he avy minel Begin drilling- 40fI 2 l 1105 14 -0 4P2 n drilling 5-Ill ~~Blue gray, wet, dense 1202 2 6.0'.... 32: -ii ~~~Blue gray, wet, dense w/thir Ncsiget36- j~41discontinuous clay lenses3- 6.0' to 11.515 11. 5- 68- Blue gray, wet, dense, fine 11 silty sand, w/shcll frag- 62 4 1ments and heavy minerals4 54- 63- 2 O-~~~~~~~~ 59- 73- 65- 24.0!- 6 66- - ~~~~~BOTTOM OF HOLE 24.01 BLOWS PER FOOT: - - ~~~~~~NOTE: Number required'to drive- -Soils field calssified in I. 3/8"ID Splitspoon wI - accordance with the Unified 140 lb. hammer falling - _ Soil Classification System. 3011. Lighthouse Inlet Drilling No. 14 FIGURE No. D-16 00 vIAN~~~~~~~~~~~~~~~~~~~~A 3 p~~~~~~~~~~~~~~~~~~~~3 36~~~~~~~~~~~~~~~~~~~6 3 0 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 6 36~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~3 3~~~~~~~~~~~~~~~~0 APPROACHESH164 FIUR 0-f ADJUSTED FILL FACTORS AND RENOURISHMENT FACTORS OF BORROW MATERIAL 6. Matchings of the various borrow materials with a composite rep- resentative sample of native beach sands are shown in Table D-4. The locations of the various borrow areas cited in this table are shown in Figure D-1. It will be noted that in addition to showing the fill factors (Ra), and the renourishment factors (Rj) (see Shore Protection Manual, 1977, Figures 5-3 and 5-4), that the quadrant of each matching is shown, and this relates to the Quadrantal information in Table 5-1, Shore Protection Manual, 1977. Matchings fallinq in quadrants 1 and 4 indicate borrow material finer than native beach sand. and those fallinc in quadrants 2 and 3 indicate borrow material coarser than native material. Appendix 1 D-5 7. Adjusted fill factors (RA) and renourishment factors (Rj) of suitable borrow material in the Folly Island area are summarized in the following Paragraphs. a. Folly River. Fnr all samples analyzed from Folly River the average RA equals 1.20. The material from Boring Hole No. 5 at the mouth of Folly Creek (shown on Figure D-1) was found to be the least promising with a RA value of 1.60 and Hole No. 7 was the most suited for beach fill borrow material with a RA equal to unity. The overall average of 1.20 appears to be a good representation of borrow material in Folly River. The Rj values average from 0.26 for all Folly River Holes. From the computed Rj values it appears that the borrow material after sorting action has occurred, will erode at a lower rate than the native beach sand but the average values is considered excessively low; therefore, a larger value is considered appropriate. The procedure for calculation and application of the renourishment factor presented in the Shore Protection Manual, 3rd edition (1977) was discussed with a consultant with the Coastal Engineering Research Center (CERC). This consultant recommended, contrary to the example shown in SPM, that a minimum R1 value of unity be used due to the unknown natural forces involved in erosion such as winds, waves, storms, and tides. b. Stono Inlet. Only two sand samples were analyzed from this borrow area. The average RA equals 1.33 and the average Rj equals 0.84. Since the number of samples taken from Stono Inlet shoals are small, the RA value to be used is rounded upward to 1.40. The Rj value of 1.00 was used. c. Lighthouse Inlet. The average RA is 1.51 for the six samples analyzed from Lighthouse Inlet shoals and the average R is 0.31. Four of the six samples were taken from Hole No. 13 (for location see Figure D--l) and two were taken from Hole No. 14. Using an average RA value for each of these two holes, the weighted average RA equals 1.38 (rounded to 1.40). This value is considered to be appropriate for use when computing overfill amounts of this material. The computed values of Rj give evidence that this borrow material, after sorting action, would erode slower than the native beach sand, however, the more conservative 1.00 was applied as the Rj factor. Appendix 1 D-6 DEPARTMENT OF THE ARMY, SOUTH ATL-PUTIC DIVISION LABORATORY WORK ORDER NO. 0712 CORPS OF ENGINEERS, 611 SOUTH COBB DRIVE, MARIETTA, GA. 30061 Req. NG. SACEC-77-58 U. S STANDARD SIEV OPENING IN INCHES U . S. STANDARD SIEVE VUMIBERS FrVOP(ROETER 6 43 2 1+ 1 - +i 3 4 6 I 1 :416 ~030 4 50 701LOD 140200 tao~ ~~_ - t141- 70 3 70 ___ �-.--.--..-- - - -- .-..- --.---7 ---- I - - 1jtj7 ____ ____-- �----- _ fti s S2 ----- - -_ _ I __ __ 50 s o _ _ _ . - - - - - - - --5 30 T O 1 . F.~~~~~~~~~~~~~~. -. <iF GPAIN SIZE IN MILUE RS I ___~ ~~~CAS FN xz~ji4- ___ -.__ 500 130 50 L) 5 1 0.5 0.1 0.05 0.01 0.105 oJIla GFIN SIZE: IN MILLiMETERS _____ GRAVEL SAN __ _____________ COBBLES CR IIL ________ --SIT P LA ,....H LmSaple No. Elev or Depth Clori"-,5cn riN LI I Pi C1AiRLESISO.J DiSTli.LCT, Foily Beach -a -.. Cray~p~Qriy (A~ -Lab. No. 74/2366 m -wurmcSta. No. .50+10CS K2],~I~. 1 GRADATION CURVES Date 3 ik-gnst 1977 ENG F O RM____ MAY , 3 2087 DEPARTMENT OF THE ARMY, SOUTH ATLANTIC DIVISION LAEORATORY WO'RX ORDER NO. 0712 CORPS OF ENGINEERS, 611 SOUTH COBB DRIVE, MARIETTA, GA. 30081 Req. N . sACIC-77-53 U. S, STANDARD SIEVE OPENING IN INCH,:S U. S. S-ANDARD SIEVE 1NUMCERS HYDoME TER 6 A 3 2if 1 4 - 3 6 810o 14 16 30 40 50 70 100140 'C0 100 - 6 4 2 i I ~I I I i I I IIi 70- ___ . .-4 -- - - - -41 ___ I __~~__- ,I__T rll~l_ _--__ _.____ ___ ___ _ _ _ K I . ~~ _ _ _ I . L - + 1 _ A i 60~~~~~~~~- - - -0 0 -. 30 10__ _ _ _ I ~ ' ' - K _ _ _ _ 10 _ 0-~~~~~~~~~1 _____ 500 100 50 10 5 1 0.5 01 0.05 001 0.005 OWXI GRA:N SIZE 114 MILLINETERS CO3BLES GR AE L SAND SILT OR CLAY -n1 Sample No. Eley or Depth CLc.i cs~n Nat v LL PL PI For' M 2 Gray poorly grnaicdYends) S- (S - -- ---- C C: :P- Lab. -to.- 7412367 _ _ _ _ _ - - . - _ - . . __-. - 2 ~~~~~~~~~~~~~~~~~~~~~~~~~~JA r e a -_ _ I - tz 3ta2lic. 50OWOS, Sam-ple No. 2 GRADATION CURVES _,,,_ K3 ekutgU3t 1977 ENG M1AyR03 2037 DEPARTMENT OF THE ARMY, SOUTH ATLANTIC DIVISION LABORATORY WORK ORDER NO. 0712 CORPS OF ENGINEERS, 611 SOUTH COBB DRIVE, MARIETTA, GA. 30061 Req. NO. SACEC-77-58 U. a STANDARD SIEVE OPENING IN INCHES U.S. STS.'DARD SIEVE NIJIBERS IIYROMETER 6 4 3 .2 If I3 2 6 8 _ 3 1014`3ZO 30 40 50 70 100140 2W0 90 1 $-I- I j ' : 1 1 _ _ _ __ __--- .1. -- - - _ _ _ I K -�- --4------ ___ 20 70------~~~~~~~~~~ _______ r I ____ ___ i-I 0 W- - 3 0 30- __ _ _ --H 40- -----__ ---- -L -- - -- - - _ "?-~ ~ ~ __ _--~v ____ 20~~-- -i 1 W _ i i L _ _-If_ _ _ too~ ~~~~~~~~~~~RI 52E IN MILMt RS 112 -I-i 100J 500 100 50 10 5 1 0.5 0.1 005 0.011 0005 O O.(D GRAIN S;ZE IN MILLIMETERS COBBLES G SA14_ SILT OR CLAY I~~~mrs lr COARS I CORE ADIUM _ Sample No. Ev or Depth Cliosnifio:t oa w w LL PL PI y 1i- 3 jGray poorly gra(.cli snnd(Sp) LI-SI - - -6-CR-"c: ro'iyQcSc. ________- ] - L~~~~~~~~~~~~~~~~~ab. Ila. 2/38__ - - -- ---- - -- IZI~~~~~~ ~jrrxa~$ssI.taao. 350+00:8, Sizmple No. 3 GRADATION CURVES Date3 Au~gust 1977 ENG MAY 53 2087 DEPARTMENT OF THE ARMY, SOUTH ATLANTIC DIVISION LA1ORATORY WORK ORDER NO. 0712 CORPS OF ENGINEERS, 611 SOUTH COBB DRIVE, MARIETTA, GA. 30061 Req. Na. SA-CEC-77-53 U.S. STANDARD S&EVE OPKNING IN INCHES U. S. STANDARD SILVE NJUMBERS HYDRCAZIER 4 3 6 1 I Z 1 3 6 8 10 14 16 20 30 43 5! 0 100140200 IM ~ ~ I I ii I "~' I i j _I_____ 2011: 7.7111 _ !_Ti 71111>__ .0 90----------- -------- ---- _1 11 L . 711 ___ ____ -. ..............L~~~~r L~ ~. _..L4.-.-i--- _.__-~. . _ ____ 8_ � - _ .100 0 50---___.- .. -.___ I~~~~~~~~~~~L----~ .1--- C' 10~~~~~~~~~~~~~~~~~~~~~~~~~~~~~. --�--t- -.------.-----.-..- I-- 2 - -- I. - 0- -- . - - . - . L . 103 500 100 50 10 5 1 0.5 0.015 0.01 0000 -0-001 GRAIN SIZE IN MILLIMETERS_________ COBBLES GRAVEL ------ -SAND S IL O il ~C L A Y j ~~~~ 50-- ~ ~ ~ ~ ~ ~ ~ ~ --F Sampl~e No, Etev or Depth --t -- L , -- I' P t 7 ___4 - Grany.poorly- ra~X 2 - -d -s Renort, FoPT~ak.S. .~~~~ 1 r~~~~~~~a-a.nta.11o ...50i:-'5S, Jiwpe-No- -.4___ 1'..) - ~~~~~~~~~~~~~GRADATION CURIVES ___'S_7__ ENG IMA 0 2087 DEPARTMENT OF THE ARMY, SOUTH ATLANTIC DIVISION LABORATORY WORK ORDER NO. 0712 CORPS OF ENGINEERS, 611 SOUTH COBB DRIVE, MARIETTA, GA. 30061 Req. 110. SACEC 77-58 U.S. STANOARD SIEVE OPENING IN INC.IES U.S. S'.UIDARD SIEVE NUMBERS HYDROMETER 3~ 21 31 46 IO1 1416 2 304('5070 100140 2)0 w-- ~ ~I r-r F 1_ _____ 1 -1 - --T T- I- 90-- __~ __ . _ --- -. ---1 ___ L-.- __ ..:r~:::: __-_I-- {J 70 - --- i __ ~I!IIII7 ~7i7X .2171 L ITIZ_._II __ 40 _ _ _ - - ED--_ 20 500 -Do D ID 5 105 0.1 0.05 6.61 0.00 0.0__ GRAII SIZE '4 MILLIMETERS LES GRAVEL S SILT__OR__LA M%-S f HE L F114E I I -SL RC~ Sample No. Elev or Depth C il ar ~ t w LI PL I[ ___- _1 .__- _~.F~:~e~ i l:ac ~d(SP)or -g i-.e y)ePO 11y.Beac - _ _ -- -----. - ----.---.---._ ..- - __ - - -- Lab, No. 7A/2319...._ _ _ _ _ r:~ ~ ~ ~ ~ 1--- -*-----------l- - -. 1O�OO~ ~.NSample~lo.L.. .. N ~~~~GRADATl!ION~ CUVES -~n L 3 A:~us t _977 ENG 1MAY03 2087 DEPARTMENT OF THE ARMY, SOUTH ATLANTIC DIVISION LA3ORATORY WORK ORDER NO. 0712 CORPS OF ENGINEERS, 611 SOUTH COBB DRIVE, MARIETTA, GA. 30061 Req. NII. SACEC 77-58 U.S. STANDARD SIEVE OPENING IN I1NCHES U. S. STANDARD SIEVE NUMBERS HYDROMETER 6 43 2 3 4 6 46 10 14 16 Z0 40 50 70 10 1040 200 too z 4-t-----7---- _44_" I I I I - 10 �i_ ____ i-- _ _ , 90_ - - ---- 70.-- I - _ -3 0 ti50- 40._ _ _ . _ _ _ _0 2C rtt'. - .-ti- -- ----.- �0 ~ffi___- iiii~i<ii 4- ;.Li__Aoo 30~ - .7__ _ _ _ 10-i ~~~~~~~~~~~~t~_ ___ .100 50 0 100 50 10 5 1 0.5 0 1 0.05 0.01 0.005 0.)01 GFAIN SIZE IN MILLIMETERS - COBBLES GRAVEL SAND t SILT OR CLAY c Sample No. Elev or Deh N PL PI 5 = -i Gray pot-ly gradel-d(Sl - - . SUr~eyRper,- Folly Bleaeh, S-C. CD ____Lab. No. 74/2371 ~~~~~~~~~~3 h~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Aea ___ -. -. I 1Ilg�:11S 11Sj~ . _ 1O()_-LOQN~np- 00 .el.e_ J-2 GRADATIhON CURVES _______ 3 h t 1977 ENG FMAYRM3 2087 DEPARTMENT OF THE ARMY, SOUTH ATLANTIC DIVISION LABORATORY WOPK ORDER NO. 0712 CORPS OF ENGINEERS, 611 SOUTH COBB DRIVE, MARIETTA, GA. 30081 Req. Ni. SACEC 77-58 U. S. STANDARD SIEVE OPENING IN INCHES U. S. STANDARD SIEVE NUMBERS MtRO&IETER ioo 6 43 1+ 1 + 4 36 810 1416320304050 70 100140 200 90 - - - I- - - - - - * - - - - - ~ - - - ~ T - ~ _ _ _ I* I H 10 20 _ _ _ _ _ 4 ~~ ~ ~~~~~~~~~~~ _ _ ___ ,____ __ _ Lil 70 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~-30 1 Ii 40- 60 1 _ _ - -r _ a~~~~~~- I-'i I S so 50--__ 4- __ B ..-- -~ 77 - -- ---- 340 70 0.001 500 -- 100 so 10__-. 5 1 0 5 0.1 0.05 0.01 0. .010 'I I COBIBLES GRAVEL _____ SAND FI-O ~ SILT OR CLAY Samp~e No. Elev or Dept.h Claossfication Noat L L PL Pi CHiARLEISTO IXM .STRIC'V Folly B~ach -___ 3 C - __ Gray poorly graded saud(SP)i - - -- -- Pe S t EGMAG 1I" 1 _____ a -- Ib ~1t. No. 74/2372mp~ 4 -. -00 � 100 5~~~~ )0 5 1 O.S D.1 o~~~~~~~~os 091 Oydvista.W . 0 I ' S N FORM ______________IO CURES Auguat 1977 ENG MFOAN Iem 2087 DEPARTMENT OF THE ARMY, SOUTH ATLANTIC DIVISION LABORATORY WORK ORDER NO. 0712 CORPS OF ENGINEERS, 611 SOUTH COBB DRIVE, MARIETTA, GA. 30061 Rcq. No. SACEC 77-58 U.S. STANIARD SIEVE OPENING IN INCiHES U. . STANDARD SIE'E NUMERS HYDROMETER 103 i 1P 1416 20 30 40 5 70 100140 2-0 100 -r1 90 _ _ -_ __ _ so 2 70 _30 --0-I.- I __ - r____ -. .i: ___i i--- - _ 2 0 .... .. __ 10 - 10 500 100 50 10 5 I 05 01 0.05 0.01 0.005 0 001 GRAIN SIZE IN MILLIMETERS__________ COBBLES IGRAVEL I SAND FIN SALT___OR_____ FINE I film INtEO~~SL RCA Samople No. Elev or Dep t CtasifcotWn Nat w6 LL PL Pi ___C.HRLES'LL'N DiZU'RICT, Folly' Beach ____ /o- --- -- -...----- -6 Prj ureyLpr Tllja1 _tG _o ] _ I _ _____ _______ _ ___ ~~~~~~ ..~~. Lab. No. 74/2373 _ __ } 7 j.0g($ - _ _ _____ --. -. - -- A' - - - M~~~~~~ GRADATION CURVES _____tint 3-Augu~t 1977 ENG MAY83 2087 DEPARTMENT OF THE ARMY, SOUTH ATLANTIC DIVISION LABIRATORY WORK ORDER NO. 0712 CORPS OF ENGINEERS, 611 SOUTH COBS DRIVE, MARIETTA, GA. 30061 Req. No. SACEC 77-58 U.S. STANDARD SIEVE OPENING IN INCtil.S U. & STANDAR:) SIEVE NUWBERS HYDROMETER 6 4 3 2 If I 3 _ _ 1310 1416 304) 70100140200 17.~~~~~~~~~~~~~~~it 77 I.-- li'j -�- ---1-iz 100_ -_ T- 70--- _- 4T... - __ -.- ~ II I I S2 60 ~ _i~~~i 30 -- - - �--i-- -~ _ _ _ _ I ___ I ~~~ ~ ~ ~~~~~~~~~~~~ii I s ~ ~ __ ___ ____ -+-- -. r~~u__ �---�- -- - L ---..- . - ___ . I'~ t..... - . 4 . ______ .J __ _ ------- ----.----.-- 20~~ ~~~~~~~~~ ~~~~~~~~~~~~~~~~~ ____ --- -- --------- -- .---------. \ 9:' 10---~T ' \, ____- -- ... 500 100 50 l b 5 1 0.5 O.i 0.05 0.01 00013 00 GRAIN SIZE IN MILLIMETERS -i-f COMES GRAVEL SAND -rl ~ ~~~~~~ I mreL ~ .rSIEZL'7 -~ rr _ G, Sample No. EIev or Depth Clafclion Li;TN l.S'ILICr, Foi].y Bcach _~ ~ ~ ~ G _orl _:~ 4Ee _~ I ~~L~. _CPC .:.I~~_1tI~ S - ____-----. - ________ - - - A, Lab. N]o. 74/4 374 F.', ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ - ---- - - -- -- ___ __- --- --- -- ---- --1 I - I ~ csta. -oa. .9C.0--i -NSa re GRADAT10N CU'FRVES - ,3 August: 1.977 ENG OMAY 6 2037 DEPARTMENT OF THE ARMY, SOUTH ATLANTIC DIVISION LABORATORY WORK ORDER NO. 0712 CORPS OF ENGINEERS, 611 SOUTH COBB DRIVE, MARIETTA, GA. 30061 Req. No. SAcEC 77-5S U. S, STANDARD SIEVE OPENING IN CIICES U. S. STANDAP. SIEVE NUMBERS HYDROMETER 6 4 3 2 1+ I 3 4 6 I 103 1.416 ~3 05 6lOI 100~ ~~ 4 2 -.-- 34 OI 6 040 50 70 100 140 200 0 100~~ ~~ ~ ~~~ I II III I I 1Fi 90 1 70 - - 30 _ _ _ _ _ - . -- - _ 60c ---�------- ___ -- 171771.---- 777iiI7I7O . a50L z 30 - - _ _ _ 0 _ _ to- --1__11_:_=_ _ 1 10- ------., ________. --- - . - 93__ 0- - 10 I' j w L-1 5w too 50 10 1 0.5 0.1 01)5 0.01 0.005 0.001 GRAIN SIZE IN MILLIMETERS COBBLES GRAVEL SAND SILT OR CLAY] *'I Sample No. E:ev or Depth Clasir8abon NaI tw LI PL Pi YRLESTO.~N MUS1RICT, rolly Beach O Gr~~~y_~pao~~Sp 6t~~~t--po 11 and ( S P )II~ C~~~~~~~~~~-r L- -rde ___ - - 1PrcAYI Lab., No. 7142375 o ENG Ma.-Alie 90300 2087ample-No-2- - ~~~GRADATIC)IN CURVES D~-' 3 lluugt 1 977 E14G MAY 6~, 2087 DEPARTMENT OF THE ARMY, SOUTH ATLANTIC DIVISION LABORATORY WORK ORDER NO. 0712 CORPS Or ENGINEERS, 611 SOUTH COBB DRIVE, MARIETTA, GA. 30061 Req. Na. SACEC 77-58 U. S. STANDARD SI'tL OPENING IN INCHES U. S. STANDARD SIEVE NUMBERS HYVROWITER 6 43 21If I + i 6 IA a 416 20 30050701140 200 100 f I I'T - +~~~~~~~~~- - - - ___ I S 0 40 __ sos x,~ ~ --- I -- -- --.---- 40 ___--iE'2 � 20I~~~ ii 1. TS_ !-���- 70~~~~- . 30 _ _ _ _ _- 1 7 20-11i____ -- I------ -- f / : t iB 10 90i T 500 100 5D 10 5 1 0.5 0.1 0.05 0.01 0.005 Or0 GRAIN SIZE IN MILLIMETERS COBBLES I GRAVEL *L � __I~ND SILT OR CLAY Sample No. EEIe or Depth CNo t fictwn LL PL IN CWMESTuN DlCT, Fo lly Burxch 3 I-r-c aalL -Ii - ___- Acea Lab. 1L. 7U1o. 2376 __7______ ma_____ tS ta. N~ 90D-OO N,- Samp flo, GRADATIONCURVES -Det 3 _Augunt 1977 ENG M`AY 63 2087 DEPARTMENT OF THE ARMY, SOUTH ATLPNTIC DIVISION LABORATORY WORK ORDER NO. 07:12 CORPS OF ENGINEERS, 611 SOUTH COBS DRIVE, MARIETTA, GA. 3OC81 R~q. Nil. SA(,E(. 77-58 U. 5. STANDtARD N~EW OP'ENING IN INdCIES U. S.'STAINDARD SIMV PILUMBERS HYD-KNIETER ___ I t __2 If I A 141I 04 0 010102 loc_ _ _ _ _ _ _ _ _1 i 77Z779.--_ L _ 1 _ 40- - ~ CIO_ 500 t oo 50 10 5 I 0 5 - .1 ').01. H I 01 000O5 _00-D1 GVA:N SIE IN Mil-HIVETFRS ~~~~~~~~~~GRVL CC-E SAN !9iz1v,~zz~T Q I CLAY __ ci- ____ Gray T~~~~~~~coriygL Is vf7~~~~~. -. -- - - Survcy J~~~~~~~~z;~~:~~PLPiFcL1.y."'- "--c.....-.Uca..- ENG ~~~~~~~~ 2087 ji--. ~ ~ ~ ~ ~ ~ ~ ~ ~~~~~~~~~ ~Lab,, No.. 7'/12377 - ________ _ ______ ____ ___ ___GRADA LT I IC orI.ON (- -1_' E 3 Ai' st 1977 DEPARTMENT OF THE ARAT. SOUTH ATIJNTIC DIVISMOI LARCRATORY WORK ORDER NO. 044'9 CORPS OF ENGINEERS. 611 SOUTH COBE DRIVE. MAIUETTA. GA. 3O001 Req. N3. SAcEC-77-20 U S, STANDARD S'5'F O-EN:G INl INL-ES U. I STiNI)ARD SIEVE NUMBERS HYDR04MEMR 6 43 2 If 1 3 4 69 1014 16 203040I 50 70 100140 200 Ii--- r rn r t r1r'-V-ItF ~ ~ V -o ____-- I1. * 'i K li 1(0 - Ir -- ilj 7 --L- -0 70 3 0 - --- -L - . ----------__ __.1_i_ -t----- ----�--�-- 4 0 ('0----- ----�---- ---- . - p---- --- I __ 1 ~~7II7Iffi~~~~~-- ------ __ I -- -- -- 70 I. -- - . I.--1T V1- _i _____ ____ -l_ i _ ___ -4---- � _lx 0 El- 100___. I z' 7 _ 500 100 50 10 5 I C.5 0.. 0.03 0.01 0005 Coal GRAIN SIZE IN MILIMETERS __ _ GRAVEL SILT SONRI C COSSLES ------_____ - -~-R------- - I L -FINE -1-11 - I -Ur I F-1INE Sample No. Eiev or DepTh V slai crF7too 7eF 17=Y z.a r~tYp i ly reach, S.C. '- 1 2, 3, --jGr~emish gr.�y ix:,.r'v- Po3. . l2f62O72C823 C-- g r 12 C J- 3 i t F ',aeab. --,. M'2 r6,2307 2308 23)9 org No M. 1_Sa3mpl 2, I3, & I4 o GRADATION C-LIRVES _:1917 ENG A 2037 DEPART~ENT OF THE ARMY, SOUTH ATLANTIC DIVISIOD LABGRATORY WORX ORDER NO. 0449 CORPS OF ENGINEERS. 611 SOUTH COBB DRIVE, MARIETTA. GA. 300GI Req. No. SA.C~C-.77-20 U.&S STANDARD SIEVE OPENING IN INCITES U 7 STANDARD SIEVE NUMOERS HYDROMETER 6 4 3 2 3 4_ 6 8 10 1416 20 30 40 50 70 100140 2)0 100 I 0 90 - - 70---q--_ _ -0 -.- -___ - - 7 0 I- _ _ ---------.------- - --- II- - - - - --. - - - - - 30---- _ 0 1 u 1 -1-______ _______ __I -- 40 - ------___--------- t-60 GRAVEL -i---AN _._._____~~~~~~~~~~~~~~~~~~ III_ _______ y ,-.-~~~~-- ~~-~~~--- i t r 1 -- : -I--- --- - - - ~I * _ I. -~ ~_1 I' I~_ - I -, ____ ---1--- --- ------ I 4---- t- ____ -70-�-- 50 x 10 5 1 o 0.1 COO 0.01 005 0M11 GoINE SIZE IN MIII MyTERS COSOLES Gi~ .E -INS - ~ ____~VE SND ______SiT OECLAT 11 Sample ND. Elev or Deplt .hi- -' CIa&,Iirn _ _ 7 r7 rP -. ~. -~ -4'- I f f O1U.Ir% 2 y;r L Foly 3>ici;,S.C. SI. (t-4-l - I -- *j,,**~. 74:2311, 2312 Do rri~~~~~~~~~~~~~~~~~~~~~~~~~~~r ________ V i... L...L........ R'.:r1P2 It __ -, ;, --'-I1"s 1& L 2 GRADATIO)N CURVES I rc 7 ENG MAY 0, 2CI87 DEPARTMENT OF THE ARMY, SOUTH ATLANTIC DIVISIZN LABORATORY WORK CROER No. 0449 CORFPS OF ENGINEERS, 611 SOUTH COBB ORIVE, MARIETTA. GA. 30061 Req. PIo. SACEC-7?-20 * U S. STANDARD SIM0 OPNING 14 INCHES U. S. STANDARD SIEVE NUMBERS 0L2ER 6 4 3 12 if I 3 4 6 A 10 1.16 1C 304050 70 100 143200 MD -T-~~ ~I- I-r-r I- ~~~~~~~~~~~~~~~~~~~~I i ji 4 90I __i77-77Z74 - ~__ 10 _ _-- _ _ -- --- Ij H --- ------t 1 1__. __ 2 60 4 40 - --_ - - 10_ - ----- - - ii - . . 500 lo0 50 10 5 1 0.5 0.1 OD5 0.01 0005 0.0)1 GRPN SIZE 'N MILLINIETERS GRAVEL SI'ND COSOLES F R I wESIL IT CIR M oxarl rI.K cmYIIEI Ii(pMI____ FIN __________ _ ____nlW_ ____ Sample No. EIev or Depth iCss,(kation Nat w % LI PL j nc L LII - ach Z ~' ~ ~ r~p22~Iy gradsilr~v__ I - - - - Fi~Le~(. iryeyRCP~Cpcr _~C;-S C3 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~2, Samnples 3 44 GRADATION CURVES Z : M,-rh 1977 EN0 IMAYS0 DEPARTMENT OF THE ARMY, SOUTH ATLANTIC DIVISION LADPRATORY WORK ORDER NO. 0"`9 CORPS Of ENGtNEERS. 611 SOUTH COBB DRIVE. MARIETTA, GA. 30061 Req. No. SACEC-77-20 U S. STANDARD SIEVE OPENING IN; INChES U. STANDARD SIEVE NUMBERS IHYDORlMEER 6 43 21+ 2 if I + 46 203040S070 1004 10 200 100 r--'rI" ~ ~ IJ.'L..0 ~~ -T- T 0-- W0 I- --- -- 7. i .4 4^- ---0 I~~~~~~~~~~~~~~~~~6 I 20- -- --I-- 80 --__ .-..- ---I .4-..----- 5~~~~~~~~~~~~~~~- I' ___ It __ L zo- - . I-tI_'_I_~l/i j __~_ ___ t~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~t 50 90 50 11 _____ .4...._ . v., Ij--- [ f L-9 5 too0 5D 10 5 I 0 5 0.1 0.05 0.01 0.005 (001 G7AIN SIZC IN haId METERS COBBLES GRAVEL t SA N D ISILT___ ~~~~~AR$E ~~~~~~~~~~~~~~~~~~~I NE Sample No. Efev or Depth \Ui u1i CM ssc.,tion Not w LLCI S I) I C; Folly 3,2ach 14 5 & 5 ; -- _ ray poorly grad'd" silty - - - : FLhy.3eachS.C. -c ___III-TIT_~-___-- _T s;�-i-sirIsand (S11-..1 Lab. No. 74/23J.0, 23115 m m -- � - ------------~--------__.. -.---.-.---. ..----- Ca __-- __- __ ___--l--- l ____ple iil, Sam.ple #5 1- j ~~~~~~~~~~~~~ aorn N .e<12,'i~ 2aC-pL.cL i5-------~--- 1.14 GRADATION CURVES rota 2 'Search 1077 ENG, NFORY 2087 DEPARTMENT OF THE ARMY, SOUTH ATLAIITIC DIVISION LABORATORY WORK ORDER NO. 0449 CORPS OF ENGINEERS. 611-SOUTH COBB DRIVE. NARIETTA, GA. 30061 Req. No. $ACEC7720 U. S STNIDARD SIEVE OPENING IN IIICIAES U. S. STANDARD SIVE NUMBERS HMJ10IIETER 106 43 I + I I 1 3 6 31014 16 20 3C, 40.50 70D100140 �10 V__ _1 -Li --tk. __ :w1B41 _-----1 70---- ___ __ ____ -- - -- - -- - -- - -- - ___ _ ~~60 ------- ------- ____ --~~~~~~~~~~~~~~~~-�----- ___-- so--- 2-I 70-- -- - 3(_ ___.-----.-.-.-----. ----.--, - ---.---.-.+-.- __ t-- ___ I __ - ----- _ 10 _ 0 ?0 500 100 SO 10 5 1 0.3 0.1 C.05 0.0 0.00 0.)I1 G6CIAi SIZE IN MILLIMETERS COSBLES GRAVEL ___ I--_-- - - -_ SILT OR CLAY . ~~~~~~~~~I NE I--u X1Z1ZZ L -_ - -Mj Sample No. EIev or Depth Visual ClissifrA'ion Not wI% F--LL PL.FPI CARLSTON Dri Folly BaTch ____- ..i- .2 poor !:~_r aded silty - c__ sand (SP-S:1) with a trace of coarsc-mnediuum sand sizes_ A_ Shell appro.A.;~:ttcly 52. j j I r .__ Samples I & GRADATIOCN CURVE'S ___________ Dato 2 ?Karch 1.977 ENG 2:. 2087 DEPARTMENT OF THE ARMY, SOUTH ATLANTIC DIVISION LABORATORY WORK O~U1ER NO. 0 CORPS Of ENGINEERS, 611 SOUTH COBB ORIVE, MARIETTA. GA. 30061 Req. No. SAUcC-77-20 U. S. STANDARD SIEW OPENING IN INCHES U.S. STANDARD SIEVE NUMBERS HYDROMETER 6 43 2 3 46IS2 3 10 14 16 20 30 4( 50 70 100 140 200 100 r f t I _ _ 0 ___ - - LL , _ ______. - .._.- _ _. .. 4. __ t-i___ __ I ti I~~~~-- .-- iitri ___--_ . 0 30 20 - - I: , 0 ti 100~~~~~~~:f_:i--I 500 too 50 to 5 I 0.5 01 0.05 0.01 0005 0.001 GRAIIl SIZE IN MILLIMETERS COBE GRAVEL ISAND SILT OR WLY COSELES ~~COARSE fINE FINE - _______ _________ Sample No. j Elev or Depth v.S clesmcaon Nat LL PL P1iL~~.~ T -, rr j -ach gr c ,d:6lrLI (S' w~ijt -a - Lb ___o. 74,'2313 _ _ __ _ _ __ _. _____ ---~ - tr:cc o)f g size ald_ - - ""4 Area - j j ____ all J r �: tI Ln ~~~~~GRADAT!,ON CURVES ________DOI 2 Cl 1977 EN G MF 'A' R me, 2087 DEPARTMENT OF THE ARMY, SOUTH ATLANTIC DIVISION LABORATORY WORK ORDER NO. 3449 CORPS OF ENGINEERS, 611 SOUTH COBB DRIVE. MARIETTA. CUA. 30061 Req. No. SACFC-77-20 U. S, STANDARD SIEVE OPENING IN InCliES U. S STANDARD SIEVE NUMBERS HYDROMETER 06 43 21L1 -4 6 I 110 01416 20 33 40 50 70 100140200D 100 0f~~f'i 7717' iTT II 90 - ~--------- . 70~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~0 50 - 0 0 ti 30 70 10 ~~~ L- - - 90- 20 too----- I ��--�-- 500 la, so 00 50 0 5 0 5 0.1 06T--- Ob1 O.W5 DOW1 GRAIN $IZE IN MILLIMETERS COBBLES GRAVEL r SAND COARSE F INE jCOwS1 J77 EiININE I~ '11 Sample No. * Elms or Depth -Visual ClxsfcaKron Nat V, % L Pp P 17.1 I T ii! C77T=TT7T .ac= 4 & 4 Greenish g.-ay poorly gradc"! P I - -y-UBeadh S - ________- silty s-rnd (S -ib,-SI Nv-4.. I2339.,Z323- m race of coirse.-mied iu -d -Atr __________ size sh-ll fragaluLnts. - joa __________ Shcli~lroY iraly'~l% - - .9!AinK No. H010 No4 Snmple No. 4 GRADATION CURVES r.0 2 -arch 1977 ENG I : 2087 OEPARTMENT OF THE ARMY, SOUTH ATLANTIC DIVISION LABORATORY WORK ORDER NO. 0449 CORPS OF ENGINEERS, 611 SOUTH COBB DRIVE, MARIETTA, (A. 30061 Req. No. SACEC-77-20 U. S. STANDARD SIEVE OPENING IN INCHES U. S. STANDARD SIEVE NUMBERS HYDROMETER 6 4 3 I+ I 4 1416 20 30190 50 70 100 14020D 0 too~ 711 i19{ 47< ___~ I. I __-- ____ ____I I N __ __ - _ _ - -- -- -- - ..I 70 r~~~~~~~~~~~~~~~~~~~~~RI sZ INMLIMTR COBLE GRAVEL-- ______- ________ SAD___________- SIT OR_: ClAY1 T-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~7 5 _0 - 1�..- -T T tab.Nr 14 -9 -- 40 _ -- I 60_ 1 4 30 - 70~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~i- 0 P-L - 0.00105O.1 500 100 50 10 51 05 0.1 6.5 .6 DD GR.'-IN W!E IN NIRLIMETERS GRAVEL C2 ENG C~tCOBBLES 2087;K~;;KT~!m~nsr uiolvu I nlrE SILT ORCII~LRL sample No. Elev or Depth : L Li ;t Ca"";fj'al'on N'tu: LL PL pI c i FL) I IV c ~~~~~~~sanld Lab. NoI~ j __~ _rtl~r.. 71(:1~~22,f1 . m Arej GRADB-ION~ CLJRVE:S 2,..- .;s.- ENG MF(A`76, 2087 DEPARTUENT OF THE ARMY, SOUTH ATLANTIC DIVISION LABORATORY WORK ORDER NO. 0449 CORPS OF ENGINEERS, Gil SOUTH COBB DRIVE, MAR IETTA. GA. 30061 Beg. NO. SAUCc-77-20 U. S. STANDARD Sl' VI OPEING IN INCHES U. S. '~TANDAFID SIEVE NUMBERS HYDROWETERt 6 4 3 2 3 4 6 8 10 1. 16 20 30 40 50 70 100 14D 2DO 70- -- 4 __ .~~~~~~~~~~~~~~~~~xzz4~~~~LK, T 30 S260 _ _ _ I _ __ _ _- _ __ _ 40- -- 1 - - - - -- 4 - _ _ _ _ 350 Lj __ ~ ~ ~ ~ ~ ~ ~ ~ ~ __ 30 _ _ _ _ _ _ 500 50 s 10 5 1 0.5 01 0.05 0.01 O~05GC01 COBBLES GRAVEL IS.%ND SILT Oil CLAY COARSE F INE C4300SE MECIUM F I N E ________ -ii Sample No. Elev of Depth jV;sis Classification - Nat W_% jLL P i CHRULESTONDS'{C Folly Beach - ._______ ~~~~~~~~~tr,-ce of rc,�Jjua sa-a-:1 -- --__32_232 mr size shell1. f a:-ns --I- S __f _ - ~~~~~~~~~~~~Shell app-txi :LLSt~y 1'/ J_ -F IBrn l .tSampJ esI3 & 2L a, ~~~~~~~~~~~~~~~GRADATION__CURVES 2 MLarch 1 97 7 ENG, MA 2087 DEPARTMENT OF THE ARMY, SOUTH ATLAIII'IC DIVISION LAECRATORY WgRIK ORDER No.* 0449 CORPS OF ENGINEERS, 611 SOUTH COBB DRIVE, M~ARIETTA, GA. 39001 Req. NO. S;ACI-2-77-*20 U. S. STANDARD S!EVLf OPENINGZ IN 12FIES U. S. STANE'ARD SILVE NUMBERS I-f;OPOAE1ER MO A~~ 4 21+1~ 3 4 6 8 1O ?.4 1 20 3) 10 !-O 70 100 14C 2CO ---4---.-.-~~~~~~~~~~~-FT-i ZZT- .,41 ---- ..,.2 -.�.j --T 0 60 _ - 77 - -20 70 .- A 30 10---. -- - ..__ _ I- .j . a 500 10( 50 1_ _ I C. . .5(0I _ _00 _ _ _0 ____.~~~ ~ ~~~~RIN 51 -- IN MU_ LETT A 3~~~_ ---- S i l t ) - cl yv: __ _- _____~~~~~~t a __ t- r-Li.-iT ofK.17L~ ~~~~~~~~GRAAION CSIZVE IN MI 2 METRcS 1 9 7 7 ______ EN~~~~~~~~~~~~~~~~IGRAE 2087_ ___ SA~ DEPARTIENT OF THE ARtY. SOUTH ATLANTIC DIVISION LABDIATORY 10j1K ORDER NO. 0449 CORPS OF ENGINEERS, 611 SOUTH COBB DRIVE, MARIETTA, ~A. 30061 Req. No. -;ACEC-77-20 U.S. STAND .RD SEVE OPENING IN IIKVEfS U. S STANDARD SIEVE NUMBERS HYDRCIETER 6 4 3 21 If -+ 3 4 6 110 :4116 20 30 90 50 70 O 140 200 - 90'--- I I I I I- -- -- tT-1 8011 ~ t-I __ L{{ j- --_ -20 70 - 30 -- - --i .ii_--- 70-- -- -4 ___A 360 4- 7 20 I - --- --------- so B 60--- I---- I Y ~ ~ ~ ~ ~ ~ ~ ~ ~~ __ -_____ ____ - � -50 __ -- z - .. i~~-tt-zx -"-_..L- 77iIIII77- -~~~~~~~~~~ - __ 500 100 50 10 5 1 0.5 0.1 C.05 0.]0) C0C 0 301 GF!AIN SIZE IN MILL METERS COBBLES G RAVEL SAND SILT OR CLAY Sa~mple No. Elv or Depth Vi -;'- j_________ Nat 'y % IL Pl PL:4.I W [i 7777-77 T, 1"oy ii]e-acci 4 &5 r. ___ aro_2o r v Ed '-iiIty -IL.. - -cFroS.C. ;Po L- m~~~~~~~~~~~~_ ___ _ _ ___ M~~- ________~~~~~~~~~~~~~~~~~~~~' F-,n No. ILI., LS N ri 5x-u - awpOcs 4&5 GRADAT ION CU R/ES 2 March 1977 ENG MF'y"o 2087 *~~~~~~~OBE DEPARTNENT OF THE ARMY. SOUTH ATLANTIC DIVISION LABORATORY WOAX ORDER NO. 0449 CORPS OF ENGINEERS, 611 SOUTH COBB DRIVE, MARIETTA, GA. 30061 Req. No. SACEC-77-20 U.S. STANDARD SIEVE OPENING IN INC;HES U.S. STANDARD SIEVE NUMBERS HYDRO)ETER 6 43 '2 if 1 3 46 a 10 1416 20 30 40 50 70 100 140 200 100 I ii T----- II 0 70_ - -- -- - 30 1~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~1 r ..I_~______ .1 I 1 z 50 10 70 --..-.-. -- - ____ .1 30----- - 40 60. 20 S D . --i~~~~~~~_ - .-.--- t- -60 500 100 so to 1 Us5 0.1 0.65- 0.01 0.005 &.001 GRAIN SIZE IN MILLIMETERS COBBLES GAESNDSILT OR CLAY ~U(U I rll~t FINE Cr Pa JAI(" ' FINE - Sample No. Elev or Depth S U-q Cl asisifkabon N a Nt %v % LL PL Pi ')SCiCT Fly ec I 2 -va'r~y ckayey il'or;'_~~..irLanic Bea-ahFa~ SC. .: c ~~~~~~~~~~~ ,Ti 2 i Lab. No. 74,123'29, 2330 C1 rag~~~~~~~~~~~~~~~~lellts h ~~~~~~~~~~~~~~~~~~~Are, Shrl!. s~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~oring No. 6. Saniples I 21 GRADAITIONV CL)RVES Date- 2 fit rch I S17 ENG M'A"Y"'-, 2087 DEPARTIENT OF THE ARVY. SOUTH ATLANTIC DIVISION LABOrATORY WORK ORDER NO. o644 CORPS OF ENGINEERS, 611 SOUTH COBB DRlIVE, MARIETTA, PA. 30061 Req. No. S�ACEC-77-20 U. S. STANDARD SIEVE OrENING IN INCIIES U. S. STANDAFID SIEVE NUMBERS HYDROMETER 6 4 3 2 if I j-t-4 34638 10 1416 20 30 4050 70 100140 .00 100 I I~~~~~~~~~~~~~~~~~~~~~~~~~~r~ I I I 0 70 - -- --- __ _ I_ _ I 30 T 40~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~,0 3 0 - -- -- -- - - - 70 20_-_---~~.~~ o __-___ __ - - ___ L~~~~~~ - 7T 5w ~~~100 50 10 5 1 0.1 DES O.5 t( 0.005 - 0AI1 GRA:N SIZE IN MILLIMETERS COBBLES GRAVEL ISAND SILT OR CLAY I F.mINEL Id3I L FINE II Sample No. Elev or Depthi clossication INst w LL PL p I (i~. -SI, - I , jo.Y -~~~~~~~~~~~~~~~~~~~~,7 Ch___ tracersi.i I. * c L~ n..N 741/--31 M ~~~ - - - -- - -_1Ares S~~i 1 ~ rI~'-r.IQZPI y t~~~ Borioj ~ 6, ",ample 11o. 3 N ~~~~~~~~~~~~~~~GRADATION CURVES Prelli 19;77 EN G 1MY32087 1~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ DEPARTVENT OF THE ARMY, SOUTH ATLANTIC DIVISION LAB3RATORY WORK ORDER NO. 0449 CORPS OF ENGINEERS, 611 SOUTH COBB DRIVE, MARIETTA, GA. 30061 Req. Ng. SACEC-77-20 U. S. STANDARD SIEVE OPENING IN INCHES U. S. STANDARD SIEVE NUMBERS HYDROMETER 6 43 2 1+1 + 1 6 110 1416 20 3040 50 70 100140200 100 k -~ ii ii 0 9of- 10 80 __ 20 -d+-1--------- 80 160 iI 0 S 2 6 0 _ _ _ _ _ _ _ _ _ 10 _ _ _ _ I 30 20I-i -- 1~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~t -' -1 0 I - -VT t oo 500 100 50 10 5 I 0.5 0.1 0.05 001 0.005 0001 GRAIN SIZE IN MILLIMETERS GRAVEL SANDSILTORCLAY I9 C0iA6E I I ____________I nat SILT DR CLAY J _171 Sample No. Elwe or D-pth 7'iUjI Cwizhlation Not . %9 LL PL PI . ..5oN )i SfLCT, Foily '.each C3 4 & 5 GrayPoorl y gradrPeled, - (S?- C _ _ with a traco of coarse-mrcdia Lab. No. 74/2332, 2333 m sand size shell, fragments jshcil approxin~tu~y37 I -- o~Area 4ft. 6, ';_--n~j~'tly3:. --I--1 `~1~les 4 & 5l~;l;ls~_& GRADATION CURVES DINt 2 "arch 1977 ENG IMAY 6, 2087 DEPARTEENT OF THE ARMY, SOUTH ATLANTIC DIVISION LABORATORY WORK ORDER NO. '1449 CORPS OF ENGINEERS. 611 SOUTH COBO DRIVE, MARIETTA, GA. 30061 Req. No. SACI:C-77-2O -U.S. STANDARD SEYE OPENIFS III IN-CHES U. S. STANDARD SIEVE NUMBERS HI1OIEETER 6 4 3 1L 34 6 8 L 14 16 20 30 50 70 100 1411 2M too_ _T__T - 7--- ---a so 2 70---- - - -3 60' - ---- -4-2__ _ E j --I_ __- to U Ii ___ __ ___ I--I--- too_ 10 i-If 1I~ f .i- 4k- 47 io & 1+--111~-- ----- - -1GANSIE0l0m-.4 500 100 50 t o 5 I 0.5 0.1 005 0.01 0.005 0.30 GRAIN SIZE IN MILLIMETERS COBBLES GRAVEL I SAND I arnsr I H~~~ ( CMHY ( YL~~~lllu- 1 nnL . ~SILT OR WYY COARSE nNE I M~~~~~~~~~~EDIUFIJM Sample No. Elev or Depth V-sual Cinsircawn Naet wI IL f Pi j7TRJcr, 7'1y BEach I 1&2 __ sa gray y sa af' - -(SC)Prolect SU n" y_-1 ____ - ___________ ____ - I - L~~~~~~~~. No. ~74 /23 314 , 233 -5 __ _____ 1 1 i7-- -- -- - - ---I. 7- Ar---A ---1--t- --- ________ I I I~~ --~ ~ ~~~ * - ~ t`- ~t - --t-~~f- Boring No. 8, Samples 1 & 2 GRADATION CURVES Dite 2 1-arch 1977 ENG , ~ 2087 *",. .. - .~~~~..i.. . -~~~~~~~~~~~I---..-~~~~~~~~~~.. .-~~~~~~~--------------�-�- ---~~~~~~~~~~~~~~~~~~~~~~~ DEPARTMENT OF THE ARMY. SOUTH ATLAN1TIC DIVISION LABORATORY WORK ORDER Ng. 04,49 MAOPS OF ENGINEERS, 611 SOUTH COBB DRIVE. IARIETTA, GA. 30061 Req. No. SACFC-77-20 U. S. STANDARD SIEVE OPENING IN hfIC'HES U. . STANDLARD SEVE NUMBERS HYDmalMETER 6 432i!fIj4~ ~_ 3 4 S 1 i :t6 23 10 40 50 70 10 141 200 7 0 - - - ---�--- ------- -___ ---- ---- ---__ � - 4 _____ I _____ , 1 I ~ -.-.- ---,-- 53 90-- - _ . * .I D i V A.-.~~ so,1 s 50- -- ---------- ----- --_::: --_ -Ir- --------- --f------ t-------' -6 2-0__ _ j -- - 70 40 9 2~~~~~~~~~~~GANSZ -0. - -___ 8 0~~~~~~~~~~~~~~~~ --toot~.-. . L. -__~0 w 0 10) 50 t o 5 I 0.5 0.1 0,05 0~c 0005 (30 G3AIN S2iE IN MILLIMETER3 COBBLES GRAVEL I SAN D I SILT OR CLAY I *"'t I ruiE I mUT~ I ucrcluu jc FINNErAUM Sample No. Eley or Dept hI: 1 C$ific~ti-i Tr F P1 II c. L AJ . .Jj 'i C 1. , 'S ii. I.y ii N--A 2 3,-- - r ny snay if , ci lt i - 7 c --au -v ar S ?r-t. rr4 L _ _ - . - r j III. No. 4 /2 32,3_2337, 2-;'S, 2339 rri~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Re Boring No.9, S-lilples 1, 2, 3 &4 ~c' I GRADATION CURVES D ate 1 Search 1977 ENG IMAY 0, 2087 DEPARTUENT OF THE ARMY, SOUTH ATLANTIC DIVISION LABOtATORY WORK ORDER NO. '0449 CORPS OF ENGINEERS. 611 SOUTH COBB DRIVE, MARIETTA. Gh. 30061 Req. No. SACEC-77-20 U. S. STANDARD SIEV OPENING IN INCHES U. S, 5ANOARD SIEVE NUMBERS YDROmETER 100 6 4 3 2 3 . 34 6 8 10 !416 20 3040 7 7100 140 2100 100~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~-1 r ~ T- J-- --I -r- T T.- 4--- 70-- -- . P"~~~~~~~~~ll- __r'~ _ w I 50 ~~~~~~~~~- --� ---- ---- ---- - -- -4 -90 30 100 -70 500 100 50 10 5 1 0.5 0.1 0.05 0.01 0.005 0301 GrMN SIZF IN MILLIMETERS COBBLES GRAVEL I AILT OR CLAY I COA.RS FINE W~rt I5OU _____ FI________ Sample No. 1Elv or Depth CLossifictubn That w% LL PLfl Pi CH1A1LL-L1- DlShicR, Vollyeach 1, 2 Gray an d n-.oorly graded - - - - - - r t ,E'c1.1y.Wea 1S.C. ____ __ Graysand _____c~ ~ -_____ (S'") ___ I. Nq._~ ,24�E~12 /3A4S _3 __~~~~~~~~~~~~~~~~~~~~~~~~~. 21 __4_0 J --____ 0:0toE No. L Sample s 1& 2 _ GRADATION CURVES flts 2 March 1977 FOR"~~~~~~~~~~ o ENG 1MAY83 2087 @1no 1 DEPAnTIEUT OF THE ARMY, SOUTH ATLANTIC DIVISION LABORATORY WORK ORDER NO. 6449 CORPS OF ENGINEERS, 611 SOUTH COBB DRIVE, MARIETTA, FiA. 30061 Req. NO. SACEC-77-20 U S. STANDARD SIEVE OPEN:NG IN INCHES U.S. STANDARD SIEVE NUMBERS HYDROMETER 1 A 63 2 43 f + i 346 16 2 0 3040S0 7010014020D __- I'-'-'- i -----_ It ~~LO__ I - I -----.-I-j-.--3 00 ___ __ .__ ___ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~40; z 50 -- - 30 - . 70__ i _ _ __ ._ GRAINP( SIZE IN MILLIMETERS COBLSGRAVE I SAND COBBLES I FINE I cOA IU M FINE SILT OR CLAY Sample No. Efev or Depth VisUal Cist4iraIn Natw% pi i2L'luNDI S FAUL k-oily btach 3 - 3 Cray poorly groped sity__ 1 -- portFoIYy-R La 70 sand 'S" Lab. Nl. 74/2342 m~~~~~~~~~~~ [.lJ_ 3 ___ ~b~nr~__ Sampl ge_ No._3~ GRADATION CURVES cute 2 1larch 1977 ENG F 2087 DEPARTHENT OF THE ARMY, SOUTH ATLANTIC DIVISION LABOIlATORY WORK ORDER NO. 44-9 CORPS OF ENGINEERS. 611 SOUTH COBB 03IVE, MiARIETTA, GA. 30061 Req. No. S;ACEC-77-2O U. S STANDARD SiE OPENING IN INCHES U. S. SIANDIRD SIEVE NUMBERS HYDRO1ETER ID 6 43 2 l-11 I A 10 :1416w 30 45070 I(D140 20) 0 lw~~~~~~~ In Ir __ Ii - -..- ---1- --P -- -- -.. - _ _ 90 �- -- IC --------- ~ - ---- �- -1 �0 70 --� ti' Ir~~~~~~~~~~~~~~----1 I R_____ 70 zo --.--�--- ----- 501 T~~~~~~~~~~~ F-'----~~~~~~_ __ ~i tl -- .-.20 I~~~~~~~~~~ ____. I. -____I -�- ___C.-- -7 0 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~30 so0 150 5 0 5 1 05 051 0.5 0.01 0.005 OC(l Sample No GRAV'EL SN OR' Sampl No. Elte or Oeplh Vjsua ~L Calcto alus IBIL LIP I~:IJT::~'.'::2, ly Beach I-a _ _ _ _ _ -- CLOSS'Acrti~ �ori i; 7 ' I- __~ l~ tS~ :rrI~ i3 t ;l~ !~ l 40 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~~~4 G, ~~~~~~~sand__(S"-S:*:) �Iiti+ a tr~lc.1j 20~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ I ;a ~ ~ ~ ____- rledjulll saad size: ~Iiht:I frZ'0f:lct3 Shell ap~prTOxi~lacei~ iL% Ionp ____az~1_ ___ wf~ GRADATION CSRIZES ua 2 MIIrch ET77 E NG MDIM FI 2087 *~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~- ..234 DEPARTUENT OF THE ARMY, SOUTH ATLANTIC DIVISION LABOIATORY WORK ORDER NO. 6449 CORPS OF ENGINEERS. 611 SOUTH COBB DRIVE, IIARIETTA, GA. 30061 Req. No. SACEC-77-20 U. S. STANDARD SIEV OPENING 1N INCHES U . i STANDIRD SIEVE NUMBERS HYDKNCETER 6 A 2 I I 3 4 6 810 1416 29 W 10 50 70 100 14L 200 100 I I 0 _______ I ?~~ -. i~ ii ii r - ~- -- - - - ----- - - - - - _ _ _ _ 90 I__ 10 70 ____- 20 70------ ~~~~I ------ ---___ ____ I 3)----- 70- --- --------- - - - _ _ --.- -- ---- I- F---- 6; _0 Q 40l 60t~ I ~~~~~~~~~~30 70 - F~~~~~~~~~~~~~~~~~~l to~~~~~~~~~~~~t 0--H~~~~~~~~~~~~~~ -1 I---------- -- __ __- ____ I .. - 1 i i _ _ _ _ _ 0 100 s o 10 7 I. 1.1 0.05 0i'1 0.005 GqAIN SIZE IN MILLIMETERS COBBLES GRAVEL I SAND SILT OR CLAY mORSE I FINE IOSE M-ZI MEL Sample No. Eev or Depthi Visual Cassiftabon NatI% LL PL F11CIUCKL :STL)I D RCT F'olly Beach ___3 & 4 Gr__ poorly g-_,Actd sand(SP: e S u I Fl -1 with a trace of sand size Lab. No. 74/2345, 2346 r 3 _______ shell fragnlenzs O ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Area �P -1- ~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~orn$?V---LO San~nles 3 C. 4 ID GRADATION CURVES O'at 2 Search 1977 ENG ,I MFAR 2087 DEPARTVENT OF THE ARMY. SOUTH ATLANTIC DIVISION LABORATORY VORK ORDER NO. 0449 CORPS OF EliGiNEERS. 611 SOUTH COBB 0OIVE, MARIETTA, GA. 30061 Req. No. SACEC-77-20 U. S STANDkRD SIEVE OPENING IN INCHES U. g STANDARD SIEVE NUMBERS IMRtOMErER 6 43 21+ I I 'J 34 6 910 :416 20 30 40 50 70 10014020 20 100 - IIj-i F-r-T' 7 I I I ___ 90 -- --I ____ _ IjI__~ ;t- - - 83--------- V - _ _ i...i ---C~ ~~-1 7, 50 ----.--------0---- --- t ~o 9D _ _ -V _ _ _ _ ~~~__ __-- ------- *-*A- - .--.--1---.--- 2~~~~~ __ H __--- - 40 t_ ___ to~~~~~~ 4L- i-2.__zxIzzz- 30 500 t o o 50 10 5 1 6.- 0.1 0.05 0.01 0.005 _01___ GRAIN SIZE IN MILLIMETERS COBBLES GRAVEL I SAND I SILT OR CLAY COBBLES~~~~~~~ ~FN I camm--7- MED'um FINEll~ Sample No. Elev or Depth Visual Clssilicion p lat % L. PL Pi CiLkiLIESTU", D1.1 RICT Folly Beach 5 Gray silty ,-ind (S_) _____ F .. v Beach. S.C. C, - .- ----___ -.-lab. ND3. 7412:347 ____ ____ _______ __ I _ L a . N D _7__4 0 .Bor!~ng .Np lkL.. ample No . 5 GRADATION CURVES Dote 2 Ma;ch 1977 ENG MAY 0 2087 DEPARTMENT OF THE ARMY, SOUTH ATLANTIC DIVISION LABORATORY WORK ORDER NO. 0449 CORPS OF ENGINEERS, 611 SOUTH COBB DRIVE, MARIETTA, SA. 30061 Rfq. No. SAcEC-77-.:0 U.S. STANDARD SIEVE OEN:NG IN INCI&FS U.S TAEIlDARD SIEVE NUMBERS HYDROMR 100 6 4 3 2 Ii 1 3 9 - 6 810 1116 210 30 431 50 70 ICOD 40 1.N 10- I --iI II77--- I I ii -'I----~ ~~~~- - ---------3 ___-- L - -- - __ - - - 2.. -.-L L.___ 70___ . . -__ --.30 I ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~a -30 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ .-...- __ - .----.---5 240 SD 30------ I ---- -I--~~~~~~~~~~~~~~~~~~~ -~~~~-~~I +---~~~~~~~~~~~~~~~~~~.-. -10 to z -90 10 - -.----- iit ii__- - .LA--:. ___ - _ _ ..-~---------.. 2 -. -- .f V..I 4L__too 500 100 50 10 5 1 05 0.1 0015 0.01 0.005 0.01 GEAIN SIZE IN MILLIMETERS CCEILES GRAVEL SAND SILT OR MY OrSE FINE IMOUSE MEDIUM F1INE T1 Sample No. -EIe or Depth Visuil Cllassrfiation Not a% IL PL Pi CUiARLESTON DI TRI(,'T Folly 3each 6 ___ __ _Gray clavcys ,,nd -- Project iuryeyepI)rttiEl~ahs.. __vth 0 tr.lc.2 O! IJold ____ I Lab. No. 74/2348 m ___________ I .------ ___--.----.---.- ~~~~~~~~~~~~~~~~~~~Area V______I - 1 - orin No.-. I t Safnile No. 6 GRADATION CURVES Dato 2 1,1,trch 1977 ENG P Oc~1RM EG IMAY 03 2087 DEPARTMENT OF THE ARMY, SOUTH ATLANTIC DIVISION LABORATORY WORK ORDER NO. 0449 CORPS OF ENGINEERS. 611 SOUTH COBB DRIVE, MARIETTA, GA. '0061 Req. No. SACEC-77-20 U. S STANDARD SiEE OPENING IN INCHES U. S. S-ANDARD SIEVE NUMBERS HYOROMEYER 100 6 4 3 2 1+ Ii + 6A 3 j 6 11 10 1416 20 30 45 50 70 100140000 900 _ _ _ _ - - - . - -o I ____ ____T- I --2 _0 __ 5 I __ 0 730 so~~~~~~~~~~~~~~~~~~~~~~1 -i--- i ~~~~~60~~j~~_ _ ___~ COBBLES GRAVEL I SAN _SLT R LA CO_ --.---. ----- E-_ -IN-E-I -I___ N 30 - - f . - - - _ _ - - - - -7 *~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~25 351- >{44.52, < __~~~~sz _,-.'hz I_~I fvam I 50O 100 50 10 0 o 0.05 0.01 0005 -0.30i GRA:N SIZE IN MILLIMETERS GRAVEL M A SND COBBLES II I ICUMP 1SILlO CLAY Simple No. Eley ey Depth Vrsual O. Ca;ion w% Le a I CHRLL'i 1)PiLC Fol jPac n1 1 2 31L -- C!"vepaorr~rnd~dsilty -- __ Proienur~r~ijriL 'x' H 4' --~- --I------ _------ 4T4 2%O0 2351, 2352, r, 5 &________ sand (S"'-SiM) w~.th a trace .4f __ __ No. _ _______ -o 1 snd size ~.hi~l fi~-aglints Ara_________ m I- ___ I P i I ~~~~~Shell approximlately 1% 1 Bo~�riegN 2, Saples 1, 2, 3, 4, 5 & 6� U, - ~~GRADA~TION CURVES Date 2 E:rch 1977 ENG , T.~ 2087 DEPARTMENT OF THE ARMY, SOUTH ATLANTIC DIVISION LABORATORY WORK ORDER NO. 0449 CORPS OF ENGINEERS. 611 SOUTH COBB DRIVE, MARIETTA, GA. 30061 Req. No. SACEC-77-20 U. a STANDARD SIEV OPENING IN INCHES U. S. STANDARD S;EVE NUMBERS HDROMETER 6 4 3 21~_ I . A 63 10 1416 2 330 40 50 70 100140 220 100 - - I 0 _ _ _ I _ . YZ 40 t -7 -- - - _- - - ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~30 7 20 __ _ ti~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -~~~~~~~~~ __B,~~~~~~~~~~~~~t 10 _____ 1 .-- 500 100 50 10 5 1 0.5 0.1 0.03 100~~~~~~~~~~~~~~~~~~~~~~1 20 501) 100 5 10 5 1 0.5 0.1 0.05s DIIIO 0.005 0.051l GRAIN SIZE IN MILLIMETERS COBBLES GRAV EL SAND SILT OR CLAY I I i~~~~~~~t~~~II4 I ~~~~~~FINE I Sample No. -Elev o Dpth vi:-11:1 Claue-ic--n a tiwx I LL PL Pi CHDARLESTOll L)iCT, Folly Beach 1. 2, Gray )~~~~~~~~~~~~~~OicS~~~lcort.,E~~e'31,~t ~1 . 2I~LL ______- 0rayand tan poor lygraded - - - s a n 'ILs n~0f74it3ia ce of 13 2 3 5 _____ ___ _________ siznd size s!hlai fr1 -- ______ ~ I I 1 -___ -- *.lnIpjNoS. 13, Sznu les 1, 2, & 3 GRADATION CURVES __ _ to 2 Marzh 1977 ENG IMAY a, 2087 DEPARTMENT OF THE ARMY, SOUTH ATLANTIC DIVISION LABORATORY, WORK ORDER NO. 0449 CORPS OF ENGINEERS, 611 S01-11 COBB DrIun, NNAIETTA, GA. 30061 REQ. NO. SACEC-77 20 U. S STANDARD SIEVE OPENING IN INCIIES U. S. STANDARO SIEVE NUMBERS HYDROMETER 1oo 6 A43 2 1-T I 34 6 810 I16 0 304050 70 130140 20 - - - --I 7f~~ --- --*-- t Z Ti i it I t i Tii ,__ _ ___ -I t> * ----- __ ~~~~~~~~~~~~~~~~~~~~~~4 ~ - j __ -- - : 1-H-,r~i-i~--` i -Lii--- x 70 30------------ ---f- -] -+-I - ~60 4 0 __. .-.1 4 0 - -60" t~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ IA I-- - 3-0 70 T -----.----.------ 20 150 90_ 50 D 100 50 io 5 1 0.5 0.1 0.05 0.01 0.005 0001 GRAIN SIZE IN MILLINETERS SGRAVE I SAND S - ~ ~ ~ mR __N 4 _____ I 7717U ~ IT ___SIS09C ~~~~~~CASFIN I CORENDU IN II-4 Sarnple No. Elev or Dept Visu~al casnification N at W' % U- PL PtP C-IARL~l~SfU'.~ Lll!iK LR- o I ly Bench @ 4 p~~~0~~e~e~~t _S wr ~~Cay nnt - p.~ 1-y-F,,- h S-u ~-�-C- 20~~~~~~~~~~~__zol ___<(S"-urL-i M with some g-vav~l 4A.!;e and Lab. No. 74/215S shcll fra,,:liMM~ms __ ShcX1. n~,p;�;,�:ir;:nrShel 5% Boring No._ I 3 s__-Sa --. No. 4 GRADAT10t4 CURVES LDat 2' Harch 1977 ENG :~ 2087 DEPARTIENT OF THE ARMY. SOUTH ATLANTIC DIVISION LABOATORY WORK ORDER NO. 0449 CORPS OF ENGINEERS. 611 SOUTH COBB DRIVE, MARIETTA, SA. 30061 Req. No. SACEC-7,7-20 U- S. STANDARD SIEVE OPE14ING IN INCHIES U. S. STANDAlOD SIEVE NUMIBERS HYDROPIETER 6 Al3 2 I 3 4 6 810:4 1.6 2 )30 40 50 70 10I140 200 ____ _+ 'it _ __1 I_____~ 4 - ---- 52-.-___ 60---- V. 70 - 30-- __ i{. ---- --.-- -t _ 70 --'-4 -- -6 30 S2 :50-- 4 - 40 -- ___. i -I 30 7 I 1Sm N. Ev ep0ls o 90 ...-100___ 1y1 5w 10 5010 5 1 0 5 0.1 0.05 0.01 0.005 .0 GRAIN SIZE IN- MIIMETERS C0813LES GRAVEL S A _ ND _ SILT OR CLAY I..u .x COARSE I -FINE1 I _____FINE__ _n Sample No. -Elev r Depth Clasnil brslolsn Nat w LL PL Pi '~R~STON D IISTU~CT, Folly Bf~ach i LL~~~~~~~~~~~~~~ m ____ ____ ~~of shellfr-j:l---kn - Cn Shell. a;pr~:ii :.-ite:~ C B~rog Np. 13 Sxinle to. 5 GRADATION CURVES Date 2- "ar-ci 1977 ENG , MAY 6 2037 DEPARTMENT OF THE ARMY, SOUTH ATLAUTIC DIVISION LABOR-ATORY, WORK ORDER NO. 0449 CORPS OF EN(;INEERS , 611 souril COBB DRIVE., NIAJIETrA , (A. 31H)61 REQ. NO. SAC---X:-77-20 i S. S7ANDArD SIEV~ OPWN W; IN INC'EsS U, 1 STA NDARD SIEVE NUM3F )[-1 H1'3f('MCT ER 5 4 3 2 1-I- I - -3- 3 4 6 B 10 14 1 -,O 3K4I 4950'I10( 14!)201X 90 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~IC 70 - C 50~~ ~~~~~~~~~~~~ - I 30~~~~~i Ii - 7 -- 60 I 9i)- r~~ * 0 1 1 - GAI S I ZEINILMTR GRVE I ~ SILORCA _ _~~ ~~CAS FI R I CAS EI FINE_ saild s-Al fr -2 n'I j i8 (JrI S h e l npprum!:-ue~y oring No 13, SirplI No.I ~~~~~~~~~GAAI O C UVE _ _ _0 2 M a rc 1977 EN 0 MF"Y"O 208 __ I ~--------- ---7) DEPARTVENT OF THE ARMY, SOUTH ATLANTIC DIVISION LABORATORY 9ORK ORDER NO. 0449 CORPS OF ENGINEERS, 611 SOUTH COBB DRIVE, MARIETTA, GA. 30C61 Req. No. SACEC-77-20 U.S. STANDARD SIEVE OPENING IN INCHES U. S. STANDARD SIEVE NUMBERS KYDROMEE 5 3 2i I1 j+ 3&6S 10 1416 20 33 40 50 70 100140 200 100 0 w----------------- --I lo~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~I_ so ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~20 70 --__ . -41 : ~.1.~- - 30 "---~ ~~ ~_ - ------ -1- -.I_ t44i ---.--_ _ __- ~~ _ _ _ _ - - - - - - - - - _ _ _ _ -- 4O- - 500 ~~40 --- '2 ~~~~t-t4-11- U:i ;lo~~~t _ _._~.LI h7 71 30 20~I __- . - -1.-- so -1--- .i ____ ___ m----------- ~ ~ ~ ~ ~ : -- 5 1 0-- ---o _ _ _ - - ' } -0- - - - . 70 - H- 500 100 50 10 5 1 05 (11 0.05 0.1 0.005 0.OX1 GRAIN SIZE IN MILLIMETERS COBBLES GRAVEL I SAND EOAASE ~FINE NO E I litklU FINE S I L T __ _ _ __ _ _ __ _ _ __ _ _ _ ORCA l-A Sample No. -Eley or Depth ViSU:t- CLis-ifyiation Ilat wI ILL PL Pi CI{\ LISLy N ~ c L2,L 2.3 -,-Gray poorty __&p.-ne S?) san!F -. - 6& 4 - With a tracyl of shell fr~i&. l 1 .. ~ i q..7Lilbl 2 51$1 23.64 --- --- +------- ------t�------ ------ --- ______- '- --- Arc ___ _______________ I -- - 14o-.njo. , S amplecs 1, 2, 3, & 4 GRADA'1'1(:)N CUFIVES 2 1--I 9 ENG MAY 6, 2087 ,.---..-- DEPARTUENT OF THE ARMY, SOUTH ATLANTIC DIVISION LABORATORY WORK ORDER NO. 0449 CORPS OF ENGINEERS, 611 SOUTH COBB DRIVE, MARIETTA. GA. 30061 Req. No. SACEC-77-20 U. S. STANDARD SIEVE OPENING IN INCHES U. S STANDARD SIEVE NUMBERS HYDROMER 6t4o3?IAj3 2If I 34 Ri6 Ir3 i 20 30 40 50 70 100140230 _ _ _ -- - - - _-- 7_ 90 10 iI�-I;, _ _ _ ~~~~ V ' _ m~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 20 S2 ______ ______ ______~~~~-tL --.______ ______ B 60 I- i T- --- Jo~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~6 20 to ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~90 C.)o 10 I-- - - - - _ _ _ - -- D *.9 500 100 50 10 5 1 0.5 0.1 005 0.01 0.005 0.l00 GRAIN SIZE IN MILLIMETERS GRA~~~fL SITONtA COBBLES GRAVEL SANDOR OARSE INNE I Z[3 uM nE __ Sample No . Ei orDeth IVisualI cawl~ason ILNLtw I PL Pt. Pl Cl\rLE1UN I):ISfRLCT Folly Ea'ch G, 5 I-Gray poorly graded sand (SP - -e- -Sur R e p Foil Beach, S.C. with a trace ot sand size Lab. No. 74/2365 rn _ _ _ _ she 11 fragments - 4 - -- _ __ _ _ _ _ _ _ 1 Sneii apprS?:llP aftely No. 5 _ _ GRADATION CURVES Data 2 MIarch 1977 ENG 2087 *.~- -*0 SECTION E ESTIMATED BENEFITS ESTIMATED BENFFITS TABKE OF CO,.TENTS ITEM PAGE ALTERN!ATIVE PLANS F-I RECREATIONAL BFEFITS E-3 BEACH USF F-4 SEASONAL VAR!ATIQJ' IN PFACH USF E-7 PROJECTIOSR OF FIIT!RPF DEMAND F-9 AVAILABILITY OF BEACH RECREATION It' THE VICINITY OF CHAPRLESTOj, S, C. F-lO BENEFITS FROM INCREASED RECPFATTIO1AL USF F-l1 EROSION CONTROL. BENEFITS E-J3 GENEPAL F-13 LANI LOSS PREVENTFED F-.LL BUILDING DAMAGE PPFVfLNTFP E-15 LAND ENIHA!'CEMEIT E-1.7 HURRICANE !AVE D/AMAGE PP[VEP. TION FENEFITS F-17 ASSWUPTI O'S F-18 GENERATIO! OF STAGE DAMGE CUPVFS E-20 ANNUAL DAMAGES AND BE!EFITS E-20 TABLE OF CONTENTS (CONVTD) ITEM P~~~~AGE SUMMARY OF BFrIFFITT E-22 LIST OF TA FS iJIL ~~~~~~TITLE F91 1.01WI!G PAGF F-I PEPTV'!Fr!T P/\TA ell Pi TF P'ATJIVF PIP.11S (O!1!) F-2 E-2 TOTAL RESIPFr!T ANP N1ON'-RFSIDFENT PRMPflf FOR BFAC', USER OCCASIONS - SUB PTG IO P11 -5 II CH!pRLF-T.Nl CNINITY BEACI'FS E-3 1980 BEACH UISE IN Clf'PPLEST.W CL'T (PP~) FE- E-4 REGION IT BEACH U'SE OCCASION'S (BY SEASON) 1.972E- 53 AVERAGE NIT- PEAK U'SE OCCASI10"S, -1972., . RrEGION II P[ACPFS F-6 PROJFCTFD AVERAGE ANNUAL PEACH DEMAND E-9 E-7 FOLLY BEACH DEM~A.ND FOP EACH TYPF OF PEACH [-9_ 1"SE 'PAY E-8 DAILY FOLLY PEFACHP CARRYI-NG CAPACITY F -12 F.-9- PEACH USE RPLCPFATIONAL. Vf4LLFS., ltIJTJI PROJEFCT (PLAN A-I) F-1 2 F-10 BEACH USE RECREATIONAL. VALUES 1'ITH!PUT PROJECT F-1.2 * TABLE OF CONTFNTS (coNT'D) rC!,, TITLE FOLLO0ING PAGE F-l1 RECREATIOr\AL P'FrIFIT.Q RESUL-TU"IG FROr- VARIOUS ALTERNATIVF PLANS OF IMPROVIMR"fT E-13 E-1.2 ESTIMATES OF VALUES OF LA.! A?~ PJIL-PINGS TO PE LOST WITHOUT SHORF STARII-I7ATION IN THE 16,860 FOOT REACH INTENDED FOR PROTEC- TION UNDER PLAN;S P-O THROUGH A-3 (ON) E-l4 E-13 ESTIMlATES OF VALI'ES OF L-8ND A ND BUILDINGS TO BE 1.OST WITHOUT S'ORF STAPJI7IZATION. IN TPE 25,960 FOOT PEACH 1ITENDED FOR PROTECTION UNDER PLANS A-4 & A-5 AND B-1i THROUGH B-3 E-14 E-14 ASSUMED STRUCTURAL VALUES FOR DERIVATION OF FOLLY BEACH DEVELOPMEN'T AWi GROWTH FACTORS E-16 E-J.5 ESTIMATION OF GROIPTH AND) DEVELOPMENT FACTOR E-16 E-36 ESTIMATE OF ANNUAL COST OF SEAWALL PROTEC- TION! AT FOLLY REACH AlS ANl ALTERNATIVE [EANS OF PREVE.TI G LOSS OF PRIVATE LAND AND STRUCTURES [-16 [-17 PHYSICAL DAMAGES EXPPFSSED IN PERCENT F-20 E-18 DAMAGES IN DOLLARS E-20 [-19- AVERAGE ANNUAL DAMAGE COMPUTATION1, WITHOUT * PROJECT, REACCH NO. 2 E-21 TABLE OF CONTFN'TS (CONT'D) .L TITLE FOLILOVWI'r PAGE E-20 AVERAGE ANNUAL DAMAGE COMPI!TATITON, WITH PROJECT (12-FOOT DP'D'E), RFACP NO, 2 E-21 E-21 AVERAGE AN.NUAL DAMrAGF COIPI-!TATIOn!, WITH PROJECT (15-FOOT DUNrE), REACH riO. 2 E-2). E-22 AVERAGF .ANF!UAL PDAMAGE COMPUITATIPN, WITH PROJECT (18-FOOT DUL!E), REACH NO. 2 E-21 E-23 AVERAGE AN!"IUAL DAMAGE COMPUTATIOr!, WITH- OUT PROJECT - RFACH Nn, 3 E-21 E-2L4 AVERAGE AN:lNJAL DAMAGF COMPULTATION, WITH PROJECT (12-FOOT DUNl!E), REACH NO, 3 E-21 E-25 AVERAGF AN~!UAL DA.1AGE COMPUTATION, WITH PROJECT (15-FOOT DUN1!E), RFACY MO, 3 E-21 E-2E AVERAGEF A NUI,UAL DAMAGE COMPUTATIONT, WITH PROJECT (18-FOOT DU.E), REACH Nn, 3 E-21 E-27 SUMMARY OF HURRICAIE WAVE DAMAGF PRFVFNTION BEN!EFITS E-21 E-28 SUMMARY OF TOTAL A.NNPIAL BEIPEFITS E-22 LIST OF FIGURES NO. TITLE FOL.LOWINIG PAGE E-1 LFFIGTHS OF ALTERNATIVE PLANS OF IMPPROVE- MENTS E-]1 TABLE OF CONTFNTS (CONT'D) TITLE FOLLOWING PAGEP E-2 SOUTH CAROLINA STIATE COMPRFPENSIIVE OUTDOOR0P RECREATION PLAN SUPREGION II, CHAPLESTON AREA E-5 E-3 CHARLESTON ARE? PEACHES E-10 E-4 STAGE W,1AVE DAMAGE, PEACH 2 E-20 E-5 STAGE W1!AVE DAMAGE, REACH 3 E-20 SECTION E ESTIMATED BENEFITS 1. The purpose of this section of the report is to estimate the bene- fits which would result from various plans of improvement for comparison with associated costs. This will allow a determination of the economic feasibility of the various plans of improvement and aid both in iden- tifying those measures which will economically contribute to planning objectives and in sizing them to maximize their output. Alternative Plans 2. Derivation of benefits for the six "Beach Development" plans and the three "Beach and Dune Development" plans which best meet the planning objectives are presented in this section. The Beach Develop- ment plans are designated as A-0 through A-5 and the Beach and Dune Development plans as B-1 through B-3. Figure E-1 shows the locations of these-plans of improvement. These lengths and the average recre- ational beach widths, between 5-year nourishment periods, are given in Table E-1. Figure C-5 in Section C of this appendix is a typical APPENDIX I E-1 WWTm ~~ C~~AROLINA IC A~~~~~~~~~~~~~~~~~~~~~~ 0~~~~~~~~~~~~~~~~~~~~~ _______________ C OCTO VICINITY MAP~~~~~~~~~~~~~~~~~~~~4 N-~~~-e,4 . So ,~~~~~~~~~~~y ~~LENGTHS OF ALTERNATIVE PLANS OF IMPROVEMENTS o r ~~~~~FOLLY BEACH SCALE IN THOUS FEET SOUTH CAROLINA section of the combined beach and dune development plans. Three different dune heights were evaluated: +12 feet, +15 feet and +18 feet, measured from mean sea level. The beach development, only, plans would have the same beach slope, 30 to one, as the beach and dune plans. Berm elevation of the beach would be set at +4 feet MSL. Beach widths (measured from the back edge of berm to mean high water on the beach slope) were analyzed in 50-foot increments up to 150 feet in order to optimize designs. The most promising alternative plans are described below and discussed in greater detail in Section G, "Project Formulation". Table E-1 PERTINENT DATA ON ALTERNATIVE PLANS Average Width of Recreational Beach (in feet) Provided for Different Reaches.1/ Total Dune Critically Less Serious Project Height Recreational Eroding Erosion Length Plan (feet, MSL) (5,200 ft.) (11,700 ft.) (9,100 ft.) (feet) BEACH DEVELOPMENT A-0 -- 50 50 0 16,900 A-1 -- 100 50 0 16,900 A-2 -- 150 50 0 16,900 A-3 -- 150 100 0 16,900 A-4 -- 100 50 50 26,000 A-5 -- 150 100 50 26,000 BEACH AND DUNE DEVELOPMENT B-1 12 123 123 123 26,000 B-2 15 125 125 125 26,000 B-3 18 128 128 128 26,000 I/See Figure E-1 for reach locations. APPENDIX 1 E-2 3. There are two types of benefits to be derived from the solutions considered. The first category stems from prevention of the loss of real property. Houses, land, public utilities, etc., are, in the case of a beach development project, saved from destruction by ordinary erosive forces or in the case of a combination beach and dune project, from destruction by direct wave attack during a storm. The second category of benefits, recreation benefits, result from increasing the carrying capacity and recreational quality of the beach. 4. Recreation benefits usually account for the majority of benefits attributable to beach restoration and nourishment projects; conse- quently, the economic justification of any plan will be largely dependent on them. For this reason, the economic analysis of the various plans will begin with an examination of recreational benefits. Following this, the benefits resulting from protection of real prop- erties will be examined. Recreational Benef its 5. Improved quality and increased capacity are two objectives of a beach protection project (restoration and nourishment). The bene- fits derived from meeting these objectives are heightened enjoyment and increased recreational use of the improved beach. To determine the economic benefits which would be derived from increasing the APPENDIX 1 E- 3 carrying capacity of a particular beach, it is necessary to de- termine the amount of increased beach usage which will result from0 the improvement. This is a function of the physical capacity and value of the beach with and without the improvement, the demand for beach use in the area and the availability of competing beach resources in the vicinity. The first quantity which must be determined is the demand for beach use in the area both present and projected. Next, the supply available can be evaluated and compared with the demand to determine the need for additional beach. If area needs for this type of recreation are met, there would be little justification for increasing the supply. On the other hand, if there is a deficiency of supply, some expenditure to improve the supply might be justified. The difference in the projected demand and supply would also give some indication of the amount of improvement needed. There are reports available which examine the supply and demand situation for beach use in South Carolina. This study will begin with an examination of those reports. BEACH USE 6. There are two readily available sources from which the demand for beach recreation in the Charleston area can be estimated. These are (1) The South Carolina State Comprehensive Outdoor Recreation Plan (SCORP) and (2) a consultant study Beach Access and Recreation in South Carolina, conducted by the firm of Hartzog, Lader and Richards for various state and Federal Resource Management agencies hereafter referred to as the "HLR Study". APPENDIX I E- 4 7. SCORP Report. In the SCORP report, existing demand for 10 different types of activities in 14 subregions were estimated: participation rates were determined from resident and non-resident surveys, user occasions were calculated by multiplying participation rates by resi- dent population and non-resident visitation respectively. Demand forecasts for South Carolina residents are based solely on population projections; disregarding shifts in income distribution, increases in leisure time, etc. Beach activity demand for Subregion II (Charleston County Beaches) is shown in Table E-2. Location of Subregion II is shown in Figure E-2. APPENDIX 1 E-5 TABLE E-2 TOTAL RESIDENT AND NON-RESIDENT DEMAND FOR BEACH USER OCCASIONS-SUBREGION II- (CHARLESTON COUNTY BRANCHES) (As given in SCORP Report, 1974) YEAR AVG. PEAK AVG. DAILY YEARLY DAILY DAY PEAK SEASON TOTAL RESIDENT NON-RESIDENT 1972 8,731 68,129 14,617 3,186,716 1,650,759 1,535,957 1975 9,136 71,294 15,297 3,334,776 1,653,347 1,681,429 1980 9,504 74,161 15,912 3,468,875 1,698,755 1,770,120 1985 9,869 77,009 16,523 3,602,068 1,741,675 1,860,393 (With necessary revisions to SCORP Report)1 1972 8,866 69,184 14,843 3,236,074 1,700,1172 1,535,957 1975 9,244 72,139 15,478 3,374,291 1,692,8622 1,681,429 1980 9,656 75,345 16,166 3,524,254 1,754,1342 1,770,120 1985 9,900 77,250 16,575 3,613,389 1,752,9962 1,860,393 (Projections beyond SCORP Report) 1990 10,6033 82,7384 17,7535 3,870,114 1,921,7946 1,948,3207 2000 11,3743 88,7514 19,0435 4,151,351 2,062,0556 2,089,2967 2010 12,0563 94,0724 20,1845 4,400,232 2,170,5446 2,228,6887 2020 12,6193 98,467 21,127 4,605,832 2,252,8006 2,353,032 2030 14,6773 114,5304 24,5745 5,357,156 2,883,7406 2,473,4167 1. For the years 1972, 1975, 1980, and 1985, the "average daily", "peak day", and "average daily for the peak season" have been increased (revised) in the ratio of the annual user occasions (revised) to the annual user occasions, SCORP. 2. The SCORP estimates of S.C. Population are at variance with Census Bureau estimates appearing in the 1977 "City-County Data Book". Hence "Residential User Occasions" have been increased in accordance with the following factors. YEAR SCORP POP. CENSUS BUR. POP. FACTOR 1972 2,590,516 2,668,000 1.0299 1975 2,750,000 2,815,800 1.0239 1980 2,914,000 3,009,000a 1.0326 a-From "Summary of 1985 3,129,200 3,149,500a 1.0065 Projections..." 3. Annual User-Occasions x 0.0027398, which is the ratio: 9,900/3,613,389. 4. Annual User-Occasions x 0.0213788, which is the ratio: 77,250/3,613,289. 5. Annual User-Occasions x 0.0045871, which is the ratio: 16,575/3,613,289. 6. South Carolina Population x 0.58296, which is (for the year 1980) the ratio of the Resident User-Occasions to the South Carolina Population. 7. The United States Population (in millions) x 7,920, which is (for the year 1980) the ratio of the Non-Resident User-Occasions to the U.S. Population (in millions). * ~ ~ ~ ~ ~ O_ - -- co U, IIFI~ ~ ~ ~ ~ ~ ~ ~ ~~~~~~~~MRL BEACHL o ~ ~ ~ ~~~~~~~~~~~~~~EREO P m CH 0x0* > n0 3D~ ~ ~ ~ ~ ~ ~ ~~~~~~~~~~~~~~~~MRL BEAF- ~>m 'ii x .m 8. Demand for Beach Use at Folly Beach. A study of the relative popularity and demand for various South Carolina beaches entitled "Public Beach Access and Recreation in South Carolina" was completed in 1976 by the firm of Hartzog, Lader and Richards for the South Carolina Department of Parks, Recreation, and Tourism, et. al. This (hereinafter "HLR') report employed a gravity model to determine market demand for beach recreation in South Carolina, and to distribute this demand to the various beaches. 9. The HLR report estimated the day use demand for Charleston County beaches in 1975 to be 2,805,400; the resident vacation user demand to be 103,300 user occasions per year; and the non-resident vacation beach user demand to be 621,700 user occasions per year. Or a total 1975 demand for beach use in Charleston County of 3,530,400 user occasions, comparing rather closely with the SCORP estimate of 3,334,778 user occasions for the same year (Table E-2). 10. The HLR report gave the following estimates of 1980 beach user occasions for the following Charleston County beaches (all figures are in thousands of beach-user occasions): TABLE E-3 HLR ESTIMATES OF 1980 BEACH USE IN CHARLESTON COUNTY VACATION USE BEACH RESIDENTS NON-RESIDENTS DAY USE TOTAL % Isle of Palms 14.6 83.6 911.7 1,009.9 27.5 Sullivans Island 13.4 83.6 1,298.1 1,395.1 38.0 Folly Beach 71.2 417.8 563.7 1,052.7 28.7 Kiawah 12.3 69.6 130.7 212.6 5.8 TOTALS 111.5 654.6 2,904.2' 3,670.3 100.0 The above figures are from Pages 132, 140, and 146 of the HLR report. They show a total number of beach user occasions of 3,670,300 for Charleston County in 1980, and may be compared with the figure of 3,468,875 given on Page 3-97 of the S.C. SCORP Report, or with the figure 3,524,254 shown in Table E-2. APPENDIX E-6 . ~SEASONAL VARIATIONS IN BEACH USE 11. The South Carolina SCORP report was based on 1972 survey. It gave the seasonal distribution of beach use for non-residents of South Carolina using South Carolina beaches, but for residents it noted only whether such occasions were in one of the following cate- gories: Vacations, weekend trips, or outings. Thus it is necessary to estimate the seasonal distribution of resident beach use. For this purpose the year has been characterized as: Peak season--98 days, between and including Memorial Day and Labor Day, and basically the summer months of June, July, and August; within the peaks season there is a peak day (4th of July), and two lesser peak days (Memorial Day and Labor Day), 24 peak season weekend days, and 71 peak season week- days. Transition season-55 days; that is 30 days of May and 25 days of September, which includes, on the average, 16 weekend days and 39 weekdays. Off season--October through April, has 212 days. The latter season is one of low beach use, and while weekend day use may be somewhat greater than weekday, only the average daily for this off season has been used. 12. It will be noted (Table E-2) that in 1972 the South Carolina SCORP report gives an average daily beach use of 14,617 during the peak season. This, however, cannot be reconciled with similar data in the SCORP report. For instance, on p. 3-46 the number of summer beach use occasions for Region II beach is given as 1,201,249 for 1972 (see also Table E-4, line 1); but this when divided by 98 gives an average daily number of user occasions of 12,257. This, it should be noted is for Appendix I Rev. non-residents alone, and they account for 48 percent of the total number of user-occasions (see Table E-4). Thus we would expect the average daily beach use for Region II for 1972 to be on the order of 24,000 rather than the 14,617 figure given. Thus the SCORP report data is not only erroneous; it lacks internal consistency. Table E-4 attempts (in the absence of reliable SCORP data) to derive a reasonable seasonal distribution of total Region II beach use for 1972. It will be noted that Table E-4 ultimately derives a summer (peak season) use of 2,174,642 beach user occasions for 1972, which is 67.2 percent of the annual total, and which if divided by 98 gives an average daily peak season usage of 22,190 user occasions. 13. We are now in a position to estimate number of user-occasions associated with each type of day described in paragraph 11; and the results are shown in Table E-5. In line 1 of this table, the figure 8,866 will be found in Table E-2, and 3,236,074 will be found in that table as well as E-4. The average for the peak season (22,190) is derived as stated above; the peak day (69,184) will be seen to have come from Table E-2 (that is, from the SCORP report). For the other types of days data was generally scant; data on weekly beach use at Hunting Island Beach State Park was generally available. The lesser peak day (of which there are two) is assumed to have 75% of the user-occasions of the peak day, or 51,888. Each of the 24 peak season weekend days is about 70% of the peak day, or 48,428. This accounts for 1,335,232 of the 2,174,742 summer user occasions, leaving 839,410 for the remaining 71 weekdays, or an average of 11,822 user occasions for each such day. Assuming the daily average use in May is about 80 percent of the daily average for the peak season, there are 532,560 users; and assuming the daily average in September is about 50 percent of the peak season average, Appendix I Rev. E-8 17 Oct 79 there are 277,375 uses; or a total of 809,935 for the 55-day transition period, which is a daily average of 14,726. This leaves 251,497 for the 212-day off season, or a daily average of 1,186. In the transition period there are 16 weekend days. If these are assumed to be about 50 percent of the summer weekend days, each represents 24,214 uses, or a total of 387,424, leaving 422,543 uses for the remaining 39 days, or a use of 10,834 for each of such days. The results of these estimates and assumptions appears in Table E-5. PROJECTIONS OF FUTURE DEMAND 14. The projected future demand for beach use in Charleston County and Folly Beach is shown in Table E-6. The derivation of the projections for Charleston County are explained in Table E-2, and its footnotes. The projections for Folly Beach's share of the total will continue to be the 28.7 percent estimated in the HLR report (Table E-3). In terms of daily beach use occasions, the projections for Folly Beach are as given in Table E-7. Appendix 1 Rev. E-9 17 Oct 7 TABLE E-4 REGION II, BEACH USE OCCASIONS (BY SEASON) 1972 USER TYPE SPRING SUMMER FALL WINTER TOTAL NON RESIDENTS OF STATE1 244,420 1,201,249 29,928 60,360 1,535,957 RESIDENTS: 2 Vacation Beach Use Occasions 3 18,039 234,508 6,193 10,500 269,240 Week-End Trips , User Occasions4 92,118 106,291 81,489 74,403 354,301 Outings (1 day), User Occasions 221,879 599,895 168,464 36,980 1,027,218 TOTAL5 576,456 2,141,943 286,074 182,243 3,186,7165 SEASONAL PERCENTAGES 18.1 67.2 9.0 5.7 100.0 TOTAL6 585,729 2,174,642 291,247 184,456 3,236,074 NOTES: 1. From SC SCORP Report, p. 3-46 (which gives the seasonal beach user occasions for non-residents). 2. Total resident vacation beach use is given in Table 3-36 (SCORP); it has been assumed that seasonally the number of beach user occasions is proportional to the number of resident vacations for each season. (p. 44). 3. The total (354,301) is from SCORP, Table 3-36; it has been assumed that seasonally the number of such beach user occasions is proportional to occupancy figures for hotels, motels, etc., as given in SCORP, Table 3-14. 4. The total (1,027,218) is from the SCORP report, Table 3-36; seasonal allocation has been made on the assumption that the number of user occasions associated with one-day outings is proportional to seasonal camping figures as shown in p. 3-16 and p. 3-15, SCORE. 5. The total (3,186,716) is the 1972 figure as used in the SC SCORP Report of 1974. 6. The total (3,236,074) is the figure that must be used to reconcile the SC SCORP Report of 1974 (which used 1972 population figures that were later revised by the Census Bureau) with the true population figures (see Table E-2, third column from right). This line should be considered the final result of this table. The figures for each season are derived from the total via the seasonal percentages shown in the line above, which were derived as indicated. Rev. 17 Oct 79 TABLE E-5 AVERAGE AND PEAK BEACH USE OCCASIONS, 1972, REGION II BEACHES (CHARLESTON COUNTY, S.C.) AVG. NO. USES NO. OF SUCH TOTAL BEACH USE PERCENT OF TYPE OF DAY PER DAY FACTOR1/ � DAYS FROM SUCH DAYS ANNUAL USE Each day of the 8,866 1.0 365 3,236,074 100 year Peak Season: 22,190 2.5 98 2,174,642 67.2 Peak Day 69,184 7.8 1 69,184 2.1 Lesser Peak Day 51,888 5.8 2 103,776 3.2 Weekend Day 48,428 5.5 24 1,162,272 35.9 Weekday 11,822 1.3 71 839,410 26.0 Transition Season: 14,726 1.7 55 809,935 25.0 Weekend Day 24,212 2.7 16 387,392 12.0 Weekday 10,834 1.2 39 422,543 13.0 Off Season 1,186 0.13 212 251,497 7.8 -/The average number of beach use occasions for the type of day indicated divided by the average (annual) daily number of beach uses (8,866). TABLE E-6 PROJECTED AVERAGE ANNUAL BEACH DEMAND (VISITS PER YEAR) YEAR CHARLESTON COUNTY FOLLY BEACH 1975 3,374,291 968,421 1980 3,524,254 1,011,460 1990 3,870,114 1,110,722 2000 4,151,351 1,191,437 2010 4,400,232 1,262,866 2020 4,605,832 1,321,873 2030 5,357,156 1,537,503 TABLE E-7 FOLLY BEACH DEMAND FOR EACH TYPE OF BEACH USE DAY DAY TYPE 1980 1990 2000 2010 2020 2030 Total Annual Visits-1/ 1,011,460 1,110,722 1,191,437 1,262,866 1,321,873 1,537,503 Peak Day2/ 21,624 23,745 25,471 26,998 28,260 32,870 (1) Such Day 21,624 23,745 25,471 26,998 28,260 32,870 Lesser Peak Day 16,218 17,808 19,103 20,248 21,195 24,652 (2) Such Days 32,436 35,616 38.206 40,496 42,390 49,305 Peak Season Weekend Day 15,136 16,621 17,829 18,898 19,782 23,009 (24) Such Days 363,264 398,904 427,896 453,552 474,768 552,216 Peak Season Weekday 3,919 4,304 4,616 4,893 5,122 5,958 (71) Such Days 278,249 305,584 327,736 347,403 363,662 423,019 Transition Season Weekend Day 7,856 8,310 8,914 9,449 9,890 11,504 (16) Such Days 125,696 132,960 142,624 151,184 158,240 184,066 Transition Season Weekday 3,386 3,718 3,988 4,227 4,425 5,147 (39) Such Days 132,054 145,002 155,532 164,853 172,575 200,750 Off Season Day 274 325 349 370 387 449 (212) Such Days 58,137 68,911 73,972 78,380 81,978 95,277 1/Table E-6 2/28.7 percent times peak days Charleston County beaches, Table E-2. *s Is AVAILABILITY OF BEACH RECREATION IN THE VICINITY OF CHARLESTON, SOUTH CAROLINA 15. There are five barrier islands in the Charleston vicinity which are accessible by road (see Figure E-3). Three of these islands: Sullivans Island, Isle of Palms and Folly Island serve as the primary day-use destinations for Charleston area residents. Kiawah Island and Seabrook Island are primarily resort areas which serve mostly non-resident vacationers and are used little as day-use destinations. 16. Isle of Palms, located approximately 11 miles northeast of Charleston, has about 7 miles of ocean front beaches and is open to the public. Parking is available to commercial areas, while on-street parking near the beach is restricted. Isle of Plains is mostly residen- tial with 1,000 of the 1,800 homes on the island occupied year-round. 17. Sullivans Island, located adjacent to Charleston Harbor on the north side, is mostly residential. Beach access is available all along the 4 mile ocean front but is restricted by the lack of avail- ability of parking. 18. Folly Island, 12 miles south of Charleston, has about 6 miles of ocean front beaches. Folly Beach is a shore town with a small (1,200) permanent population and a large number of modest summer cottages. Only 32 percent of Folly's 1,329 housing units are occupied year-round. The influx of summer residents brings the peak season population of Folly Beach to about 4,500 persons. On the 4th of July 1973, the Folly Beach Police Department reported 20,000 persons on the beach by 3 p.m. APPENDIX E- 10 BULL ISLAND CAPERS ISLAND ~DEWEES ISLE OF PALMS SULIAN0L 0~~~~~~~~~~~~~~~~~~~ILN CHARLESTO S~~AEA BEACHE FIGURE E-i '?with more to come"f, as published in the Charleston News and Courier on 5 July 1973. Perhaps as many as 30,000 visitors come to Folly Beach on a peak summer day. Folly Island's beaches are the most easily accessible of all the Charleston area beaches. On-street parking is allowed along the beach front and back roads. Conspicuously marked public beach access points are located every couple hundred yards along the entire beach front. Although the beach is accessible, it is in poor condition for recreation use due to erosion. At high tide, there is little or no dry beach area. As a result of this condition, many area residents travel to other more distant beaches or stay home. A survey of beach goers at Edisto Beach State Park revealed that 64% of the vistors were from the Charleston area. The presence of so many Charlestonians at a beach 60 miles away indicates that there is, for one reason or another, a large surplus of demand for suitable recreational beaches in the Charleston area. BENEFITS FROM INCREASED RECREATIONAL USE 19. The benefits attributable to recreational use of an improved beach are the differences between the recreational values to be realized by the improved beach less those to be realized by the beach as it will exist without improvement. Annual values of each of these have been estimated, and examples are given in Tables E-9 and E-10. This analysis is for "Beach Protection" Plan A-1. 20. The unit recreational values (values per user occasion) without * a project (existing conditions) have been taken as $0.60 for the amusement APPENDIX I E-1 1 center frontage (the 5,170 feet between Stations 27 + OON and 24 + 70S) which is, in effect, dedicated to public usage, and $0.40 for the remainder of the beach frontage, the usable beach, in total, is 28,600 feet. The "1with" project conditions involve the improvement of two reaches of 16,860 and 25,960 feet, the former (from Station 143 + 90N to 24 + 70S) being included in the latter (Station 180 + 90N to 78 + 70S). To the 25,960 feet is added 1,320 feet (one-fourth mile) on each end of the beach, assumed to be within walking distance from access points, yielding the total beach length of 28,600 feet. The unit recreational value with project conditions has been assumed as follows: For the amusement center area, $1.00 per user occasion, as it will be well developed with regard to facilities and amenities, essentially dedicated to public use, and enhanced by widening. For the remainder of the improved beach (11,690 or 20,790 feet, depending on the project), $0.80 per user occasion, because of improvements in effective public access, particularly through parking improvements to be required of the locality, and amenities improvements. This beach, with frontage technically in private ownership, has always been available for public use, and with nourishment, the increment of dry beach area will, under the laws of South Carolina, belong to the state. The remainder of the unimproved beach, which will be either 2,640 or 11,740 feet, depending on the project, is assumed to have a value of $0.40 per user occasion, as in the "without" project condition. 21. The procedure was as follows. Projections of daily demand were made, as in Table E-7. Estimates of daily carrying capacity were made, as in Table E-8. Footnotes generally explain the assumptions. Estimates of the realizable recreational values with a project were APPENDIX1 E- 12 TABLE E-8 DAILY FOLLY BEACH CARRYING CAPACITY (visits) Alternative Structural 1980 1990 2000 2010 2020 2030 Plans Without Project: 6,248 1,780 1,627 1,627 1,627 1,627 With Project: A-0 19,736 17,713 17,713 17,713 17,713 17,713 A-1 24,886 22,963 22,963 22,963 22,963 22,963 A-2 30,036 28,113 28,113 28,113 28,113 28,113 A-3 41,746 39,823 39,823 39,823 39,823 39,823 A-4 32,166 31,460 31,460 31,460 31,460 31,460 A-5 49,020 48,320 48,320 48,320 48,320 48,320 B-1 64,714 64,008 64,008 64,008 64,008 64,008 B-2 66,150 65,444 65,444 65,444 65,444 65,444 B-3 67,636 66,986 66,986 66,986 66,986 66,986 REMARKS: Carrying capacity is for all of the beach, whether improved or not. It is the dry beach area divided by 100 sq. ft. per use, times 2 uses per day (turnover rate). Along the reaches not protected by project improvements, it is assumed that erosion will continue but the dry beach area will not completely disappear. As the beach erodes lands, homes, and other structures may be lost but some constant width of dry beach area will remain after the year 1990. It is assumed that without bulkheads, seawalls, or revet- ments, this width of dry beach will be reduced to and remain at about 5 feet; and with these bulkheads, etc., the width of dry beach will be only about 2 feet. TABLE E-9 BEACH USE RECREATIONAL VALUES, WITH PROJECT (Plan A-l)1/ DAY TYPE (NO. OF DAYS) 1980 1990 2000 2010 2020 2030 Carrying Capacity 24,886 22,963 22,963 22,963 22,963 22,963 Peak Day (1) 21,624 22,963 22,963 22,963 22,963 22,963 Lesser Peak Day (2) 16,218 17,808 19,103 20,248 21,195 22,963 Weekend Day, Peak Season (24) 15,136 16,621 17,829 18,898 19,782 22,963 Weekday, Peak Season (71) 3,919 4,304 4,616 4,893 5,122 5,958 Weekend Day, Trans. Season (16) 7,856 8,310 8,914 9,449 9,890 11,504 Weekday, Trans. Season (39) 3,386 3,718 3,988 4,227 4,425 5,147 Day, Off Season (212) 274 325 349 370 387 449 Annual Uses: 1,011,411 1,109,929 1,188,945 1,258,891 1,316,642 1,523,004 Recreational Values: ($) @ $0.84Z/ 849,585 932,340 998,713 1,057,468 1,105,979 1,279,323 1/ Beach use limited by demand. 2/ This is an area-weighted figure for each user occasion for the 28,600 ft. of usable beach, including the unimproved beach, 11,740 feet of beach lying on both sides of the 16,860 feet to be protected. TABLE E-10 BEACH USE RECREATIONAL VALUES WITHOUT PROJECT DAY TYPE (NO. OF DAYS) 1980 1990 2000 2010 2020 2030 Carrying Capacity 6,248 1,775 1,627 1,627 1,627 1,627 USE: Peak Day (1) 6,248 1,775 1,627 1,627 1,627 1,627 Lesser Peak Day (2) 6,248 1,775 1,627 1,627 1,627 1,627 Weekend Day, Peak Season (24) 6,248 1,775 1,627 1,627 1,627 1,627 Weekday, Peak Season (71) 3,919 1,775 1,627 1,627 1,627 1,627 Weekend Day, Trans. Season (16) 6,248 1,775 1,627 1,627 1,627 1,627 Weekday, Trans. Season (39) 3,386 1,775 1,627 1,627 1,627 1,627 Day, Off Season (212) 274 325 349 370 387 449 Annual Uses: 737,055 340,475 322,919 327,371 330,975 344,119 Recreation Values (@$0.43)/ 316,933 146,404 138,855 140,769 142,319 147,971 1/ - This is an area-weighted figure for each user occasion for the 28,600 ft. of usable beach, and assumes a value of $0.60 per user occasion for the 5,170 ft. fronting the amusement center, and $0.40 for the remaining frontage; that is: (0.60 x 51,700 + 0.40 x 207,900 + 0.40 x 52,800)/312,400 = $0.43. Dimensionally, this is $/sq. ft., but it is also $/visitor, since, if each term had been multiplied by visitors/sq. ft. (constant), it would have been cancellable between the numerator and denominator. CD -4 made as in Table E-9; and those without a project as in Table E-lO; the differences being the recreational benefits for each of the dicennial years. The equivalent average annual recreational benefits were com- puted by a computer program that interpolated benefits for each year between those shown, giving, by summation, the total present worth of benefits for all years; then multiplied this by the capital recovery factor to give the equivalent annual benefits. The interest rate used was 6-7/8%, and the period of analysis was 50 years. A summary table (Table E-11) gives these annual benefits for all project configurations analyzed. This analysis assumes development of adequate associated facilities such as parking, bath houses, etc. Erosion Control Benefits GENERAL 22. These benefits consist of the value of the land loss prevented by beach stabilization, of the value of the various structural improvements that might be expected to be lost in the absence of a project, and land enhancement. The land referred to is privately owned land, presently landward of the mean high water shoreline. Counting the prevention of its loss as a benefit does not amount to a double-counting of recreational benefits previously estimated, as the latter are predicted on values yielded by land oceanward of the present mean high water line. These benefits are limited (cannot be greater) than the cost of their prevention by means other than the shore protection project, and the most economical alternative means. This has been assumed to be by means of a seawall, which presumably the property owners would construct if it were cheaper * ~than suffering the losses. APPENDIX I E- 13 TABLE E-11 RECREATIONAL BENEFITS RESULTING FROM VARIOUS ALTERNATIVE PLANS OF IMPROVEMENTS PLAN AVERAGE ANNUAL RECREATIONAL BENEFITS BEACH DEVELOPMENT A-0 $681,500 A-1 $748,060 A-2 $771,820 A-3 $760,640 A-4 $760,630 A-5 $760,640 BEACH AND DUNE DEVELOPMENT B-1 $738,130 B-2 $738,130 B-3 $738,130 Rev. 17 Oct 79 LAND LOSS PREVENTED 23. Tables E-12 and E-13 give estimates of the value of the land that would be lost along the two applicable reaches of oceanfront in the absence of protection, and this is equal to the loss prevented by a properly maintained project. These generally show the assumptions made, and indicate that the annual value of land loss prevented along the 16,860 foot project shore would be $119,200 and that along the 25,960 foot project shore would be $177,200. TABLE E-12 ESTIMATES OF VALUES OF LAND AND BUILDINGS TO BE LOST WITHOUT SHORE STABILIZATION IN THE 16,860 FOOT REACH INTENDED FOR PROTECTION UNDER PLANS A-0 THROUGH A-3 ITEM ANNUAL LOSS ($/yr.) LAND: Frontage (within project area) not presently protected by structures is 9,350 ft. Land loss at 5 ft/yr is 46,750 square feet, and at $2.55 per square foot this amounts to... $119,200 BUILDINGS: The present value of structures along the 9,350 ft. not protected by a seawall is $2,332,000. Erosion of some 250 ft. in 50 years would destroy all these first row structures, at the rate of about $46,640, and this time the growth factor (1.19) is... $ 55,500 APPENDIX I E-14 TABLE E-13 ESTIMATES OF VALUES OF LAND AND BUILDINGS TO BE LOST WITHOUT SHORE STABILIZATION IN THE 25,960 FOOT REACH INTENDED FOR PROTECTION UNDER PLANS A-4 & A-5 AND B-1 THROUGH B-3 ITEM ANNUAL LOSS ($/yr) LAND: For the 9,350 feet of shore previously mentioned... $ 119,200 For the 9,100 feet beyond the limits of Plans A-0 through A-3, the land loss at 2.5 ft/yr is 22,750 square feet, and at $2.55 per square foot this amounts to... 58,000 TOTAL VALUE OF LAND LOSS: $ 177,200 BUILDINGS: For the 9,350 feet of shore previously mentioned... $ 55,500 For th 9,100 feet beyond (as above), at a rate of 2.5 ft/yr (125 ft. in 50 yrs) is assumed that about � the value of the present structures, valued at $2,269,700 will be destroyed, an amount of $1,134,850 at $22,697 per year, which, times the growth factor (1.12) amounts to... $ 25,400 TOTAL VALUE OF STRUCTURES LOST: $ 80,900 BUILDING DAMAGE PREVENTED 24. There are 259 structures along the developed 25,960 feet of beach along which erosion is to be controlled. Counting only the value of the building itself, these have an average value of $25,000, or a total of $6,475,000 or $249 per linear foot of beach. Table E-14 shows these building values by reaches. Tables E-12 and E-13 give estimates of the values of buildings that would be lost along the applicable reaches of oceanfront in the absence of protection, and this is equal to the building loss prevented by a properly maintained project, It should be noted that the economic life of a project is assumed to be 50 years, and that losses have been estimated on this basis. 25. Growth and Development Factor. The value of damageable property in constant dollars is expected to increase during the project life. It is desired to have a factor by which we may multiply annual damages estimated on the basis of present values by which to obtain the annual damages on the basis of the value of such property over the life of the project. The assumed values of damageable property for certain years is shown in Table E-14. The growth and development factors have been derived as illustrated in Table E-15. 26. Limitation on Erosion Control Benefits. The total of the benefits shown in Table E-12 and E-13 are limited by the cost of the most economical protective means to prevent them. This 'has been assumed to be a seawall, and the estimates of annual costs of protection by means of such a seawall are given in Table E-16. This shows the annual cost of seawall protection APPENDIX I E- 15 for the 16,860 foot frontage to be about $218,900, which exceeds the potential land and building loss of $174,700; and it shows the annual cost of seawall protection for the 25,960 foot frontage to be about $400,000, which exceeds the potential land and building loss of $258,100 for this frontage; and thus the appropriate benefit values are those shown in Table E-12 and E-13. APPENDIX 1 E-16 Table E-14 ASSUMED STRUCTURAL VALUES FOR DERIVATION OF FOLLY BEACH DEVELOPMENT AND GROWTH FACTORS Reach Length Year Value of Structures in Reach ($1979) (see note) (ft) to be 1980 With 38 New Structures 2000 2010 bulkheaded 1990_/ Upgraded 19902/ A 7,510 1980 1,873,200 2,148,000 2,276,7003/ 2,276,700 2,276,700 B 9,350 1990 2,332,100 2,674,300 2,674,300 2,834,5004/ 2,834,500 5/ C 9,100 2000 2,269,700 2,602,700 2,602,700 2,602,700 2,758,8005/ TOTAL 25,960 6,475,000-6/ 7,425,000 7,553,700-/ 7,713,900-6/ 7,870,0001-/ Remarks: -/At present there are 259 oceanfront structures at an average value of $25,000 each ($6,475,000, or $249.42/LF); by 1990 it is estimated that there will be 38 more at same value; that is, $7,425,000, or $286.017/LF. --/Assumes that in the period 1980-1990 ten percent of the structures in Reach 1 (protected) will be upgraded to an average value of $40,000. (The ratio of $40,000 to $25,000 is 1.6) 3-/$286 (7,510)(0.90 + 0.10(1.6)) = $2,276,732 -/Assumes that in the period 1990-2000 ten % of the structures in Reach 2 (protected from 1990) will be upgraded to an average value of $40,000: $286 (9,350) (0.90 + 0.10(1.6)) = $2,834,546 --/Assumes that in the period 2000-2010 ten % of the structures in Reach 3 (protected from 2000) will be upgraded to an average value of $40,000: $286 (9,100)(0.90 + 0.10(1.6)) = $2,758,756 --/These are the values used in derivation of the development and growth factor. NOTE: (1) Reach A is the shoreline presently protected by bulkheads, seawalls, or revetment; all of which is within the 16,860-foot reach of critically eroding shoreline (Figure E-1). (2) Reach B is the remainder of the 16,860-foot reach (16,860'-7,510') = 9,350 ft. (3) Reach C is the remainder of the developed shoreline (25,960'-16,860') = 9,100 ft. TABLE E-15 ESTIMATION OF GROWTH AND DEVELOPMENT FACTOR Total value of Structures ($ Millions) 7,870 _...-U] 17,713.9 7,553.7 | I_ 16,475 I , i i l Ow Od O � O O -- ~ 0 0 0 0 Present Worth of Future Structures 00~~~~~~~ Definition: G & D Factor =Present Worth of Future Structures Present Worth of Present Structures Present Worth of Present Structures: (i=6-7/8%) ($ Millions) 14.021949 (6,475) = 90.79 (That is, P.W. of I) Present Worth of: II: 3.500736(7,553.7 - 6,475) = 3.78 III: 13.527608(.514326) (7,5537 - 6,475) = 7.50 IV: 3.500736(.514326)(7,7139 - 7,553.7) = 0.29 V: 12.566465(.264532)(7,7139 - 7,5537) = 0.53 VI: 3.500736(.264532)(7.870 - 7,713.9) = 0.14 VII: 10.697723(.136056)(7,870 - 7,713.9) =0.23 Present Worth of Future Development: 103.26 103.26 Growth and Development Factor = 903.76 = 1.14 90.79 NOTE: The above is for the entire 25,960 feet of developed beach (see Table E-15). The factors for reaches B and C are 1.19 and 1.12, respectively. TABLE E-16 ESTIMATE OF ANNUAL COST OF SEAWALL PROTECTION AT FOLLY BEACH AS AN ALTERNATIVE MEANS OF PREVENTING LOSS OF PRIVATE LAND AND STRUCTURES ITEM ANNUAL COST FOR THE 16,860 FOOT FRONTAGE: (Plans A-0 through A-3) Additional 9,350 ft. of seawall: First Cost: 9,350 x $218/ft. = $2,038,300 Interest and amortization on above (6-7/8%; 50 yrs.) $ 145.365 Maintenance (at 2% of first cost/yr.) ($4.36/ft.) 40,766 Maintenance of existing 7,510 ft. seawall (@ $4.36/ft.) 32,744 Total annual costs for the frontage: $ 218,875 FOR THE 25,960 FOOT FRONTAGE: (Plans A-4 through B-3) Additional 18,450 ft. of seawall: First Cost: 18,450 x $218/ft. = $4,022,100 Interest and amortization on above $ 286,844 Maintenance on the above (@ $4.36/ft.) 80,442 Maintenance of existing 7,510 ft. seawall 32,744 Total annual costs for the frontage: $ 400,030 ~~~~~~~~~~~~~~~~~$400,3 LAND ENHANCEMENT 27. In some cases in the initial restoration of the beaches, sand will be added on private property and landward of the property holding line. Strictly speaking, legal opinions of the law of South Carolina hold that the riparian owner owns naturally accreted land (above the Mean High Water Line, but it 'has been held that the state owns artificial accretions. Here, however, it is assumed that private property owners benefit from sand placed landward of the property holding line, and that this benefit is the value of the acreage added measured along the Mean High Water Line. For the projects embracing 16,860 feet of beach, it is estimated that 4.4 acres will be so added; and for the projects embracing 25,960 feet of beach, it is estimated that 5.8 acres will be added. This results in estimated enhancement values, annually, in the amounts of $34,800 and $45,900, respectively; that is 4.4(43,560) x $2.55 x 0.071317 $34,800, and 5.8 (43,560) x $2.55 x 0.071317 = $45,900. In these figures, the value of the land is taken as $2.55 per square foot, as before, and 0.071317 is the capital recovery factor, 6 7/8%, 50 years, which assumes that the enhancement is provided once and for all initially, and is hence amortized over the life of the project. Hurricane Wave Damage Prevention Benefits 28. The following analysis is a method of calculating the benefits that would accrue to the establishment of a dune capable of providing structures at Folly Beach protection from wave damage due to hurricane storm surge. Hurricane storm surge is the increase in water level O ~from the norm due to the action of the storm. APPENDIX I E- 17 29. Flood protection, it must be stressed, is not afforded by the presence of a dune. Thus, flood damages are not a consideration in this analysis. 30. Four conditions are analyzed: (1) existing conditions, present dune configuration; (2) post construction of 12-foot msl dune; (3) post construction of a 15-foot msl dune; (4) and post construction of an 18-foot msl dune. Each dune provides protection from storms of increasing severity to one whose severity corresponds to a certain return period. 31. The method of analysis consisted of: (1) finding the number of structures on the ocean front (259); (2) classifying the structures according to foundation type; (3) calculation of damages accruing to each foundation type, combining them at hurricane tide stages (eleva- tions above mean sea level); (4) from graphs of damage versus hurricane tide stage and frequency/return period versus hurricane tide stage finding total damages for each condition in each reach; and (5) cal- culation of benefits (or the difference in damages between existing conditions and the various proposed dunes). ASSUIMPTIONS 32. Certain key assumptions must be made at this level of study before proceeding with computation of wave protection benefits. APPENDIX 1 E-18 33. Hurricane wave damages are generally believed to occur only to those structures on the ocean front. For the purposes of this analysis, these are the only structures considered. Groins, bulkheads, and paved areas were omitted. Also, the commercial structures (Arcade) and the fishing pier located between Station 3+70 North and Station 11+55 South were omitted from the analysis. 34. From a representative sample of structures on the ocean front, it was assumed that foundations could be grouped in three classifications. Structures had either slab foundations, were constructed on piles less than 8 feet in height, or were constructed on piles 8 feet and greater. 35. All structures above their foundations were treated as having the same capacity for resistance to wave damage. Some damage to piles, in the uppermost 2 feet, was assumed to occur. Complete destruction of structures, 5 feet above the foundation, and damages in the first 5 feet of building height (above the foundation) increasing non-linearly was also assumed. 36. Finally, while an average dune elevation is given, dunes at Folly Beach are not at all regular and are not existent in a large portion of the northeastern most reach analyzed (Referred to as Reach No. 2 on Fig. E-1). APPENDIX1 E- 19 GENERATION OF STAGE DAMAGE CURVES 37. Stage damage curves relate stillwater elevation (hurricane tide stage) to damage due to wave action. Their generation is the first step toward finding possible annual damages due to existing conditions and annual benefits due to the establishment of a dune. 38. The three dune heights under study: 12, 15 and IS feet lmsl; will provide protection against storms with return periods of 25, 50, and 100 years, respectively. 39. Upon classification of the various foundation types, it is neces- sary to compute each' s percent of the total, the percent contribution of each type to total damages at specific elevation intervals, and the total damages at these same intervals. (Tables E-17 and E-18). 40. These damages (total damages at various elevation intervals) are then plotted on a graph (stage damage) versus their elevation plus the average building elevation (relative to mean sea level - average building elevation is the existing condition) and/or the elevation plus the stillwater elevations corresponding to the various hurricane return periods. (Figures E-4 and E-5). ANNUAL DAMAGES AND BENEFITS 41. Tables E-19 through E-26 present the total average annual damages for each condition in Reaches 2 and 3 (see Figure E-1). These APPENDIX I E- 20 Table E-18 DAMAGES IN DOLLARS/ WAVE ELEVATION ABOVE FOUNDATION REACH NUMBER 1' 2' 4' 8' 10' 12' 13' 1 $145,000 $340,000 $660,000 $1,075,000 $1,180,000 $1,390,000 $1,630,000 2 400,000 930,000 1,800,000 2,940,000 3,230,000 3,800,000 4,460,000 -/Average value of structure taken to be 25,000 dollars (Sample size of 87 structures - Total Number of structures - 259). Table E-17 PHYSICAL DAMAGES EXPRESSED IN PERCENT WAVE ELEVATION ABOVE FOUNDATION 1' 2' 4' 8' 10' 12' 13' Foundation Classification % of Total A B A B A B A B A B A B A B Slab 56.23 0.15 .0843 ~ 0.35 .1968 0.65 .3655 1.00 .5623 1.00 .5623 1.00 .5675 1.00 .5623 Piles (Less than 8') 17.24 0.00 .0000 0.00 .0000 0.10 .1720 0.20 .0395 0.40 .0690 0.80 .1379 1.00 .1724 Piles (8' or greater) 26.43 0.00 .0000 0.00 .0000 0.00 .0000 0.10 .0264 0.20 .6232 0.40 .1058 0.80 .2099 .0893 .1968 .3827 .6232 .6842 .8060 .9496 Notes: A. Fraction of individual structural damages per classification. B. Fraction of structural damages per classification. _~~~~ . *.. I::I .� ,..* * . I ..IK. I I~~~~~~~~~~~~~~~jli 7. * .1 ; i iiti S.:~~ ~ ~~~~~ * .Tt :-I~i.LL 'F.WT.r:~~dETt..i, ~~1...... '. IFJ-2~EPJ ��-����V. .1 /�- F:D/,�L~ / 2 . . . *1. : 1:72427 f�� F ---V-r---- : -.....: _-r-~~::r::_rrl:~: ;~-.1 -~�-...- -....-. ----. __________ .--.~ - ._ .... .. ..... -..2> :l . ft- -27-21 7:SI 2tL-7 7 *- /--�-- ~ ~~~~~ F ----I- I . l__i .,... . .......-i . 4 --...- 1 ~~..~e--. ::::___- ___::: LII H 7 2:2 -t' . __ _. - . b T~~ ~~~~ _._ ..._1 .1- t~~~~~~~~~~c-~ZIR~ *I . ~V* . . * 5r4� i t .Md * ' --wz .,.- .I-~~~~~~~~~~Fgr B- 4 7TmTTTT1~ . ... ...... ...... '77~~~~~~~~~~~. / IT * . I * ;I IT : 7 .... . -1-::1.....-/ I/ d~ ...~~~~~~~~~~... ..... � -- - . H ---PT 4.~:::1 : : i : : e -l o. ........ .... ....... . 7 7 -77 7 7 7,7. i .7 . -ri. . TT-.- ' '~' i Figure -. . . ..:: . I� 'Iit_ I 71.l li_1:: , /:. .~~~~~~~* , .I---7L~~~~ F-.- .... . . . . ~~ ....i.A P-I-mj:c0~3'-~O - .. L~1 __-__1 __~__[ Y~I.:t ... �-i----;- : : :Ir: : : : ____ 4. -4 tt_-i-~~ If Ci-1-_iT..I~1; _ -~~ - . - ~; ~f;47~p '--tL.-V -----!---- ///'-A PY6t .-� - ~~u~~d i - � --i- ---t----~~~~~~~ I - I- 4 �-- ---1----1 +__t__!:: l-~ ..~~~ ~ 4 .1-~. I, �---~ ~ ~ ~ t: i~~~i__ ____ � -- : :_:~771:--(~_-~- -::~ __ - -- ~~~~~~~~~~-- 1. ..� -.-tA-I Z r2-E - a/YCsC-C. -_ .:I:::1~~~~~~~~~~4 4 . I t---� � h ..I..'.I . 4 . . . . * ---'- ~~~ LJZ..~~~~~..L..L.~~~ .... ..,VtAC//3.:::; � ::rA ~ ..1. - t : : : : : : -- : i~~igur E- nO NUJ.tC.J',lt l.W. ,,~nfI4lflLJflO -l�tII' totals represent the area under a damage-frequency curve (not shown). The computations within the tables represent a numerical method for summing the area under a damage frequency curve. 42. Table E-27 is a summation of average annual damages and annual benefits when each dune project under study is compared to existing conditions. 43. Summary of Hurricane Wave Damage Prevention Benefits. Equivalent annual damage under existing conditions amounts of $73,400. The ana- lysis shows the relative inefficiency of an established 12-foot dune at Folly Beach. The dune will yield only $11,300 in equivalent annual benefits. Considerating future development, this would be increased to $12,900. 44. The 15-foot dune affords greater protection than the 12-foot dune with an annual benefit of $42,400 for existing development and $48,400 including future development. 45. Finally, the 18-foot dune affords the greatest protection, yielding an annual benefit of $58,800, increased to $67,100 with future devel- opment included. APPENDIX E-21 Table E-19 AVERAGE ANNUAL DAMAGE COMPUTATION Type of Damage W/tRt/ C14YE /4/tz'E Damage Stage? 5 '4L Reach Numbers -agea Location E/'ZL Z//f6 . Condition W/,>/ -r - r7-CTr Elevation Fr.equency Probable Incremental of WS Damages in Damage in years Occurrence Probability (msl) $1,000 - Average ,Increment $ O. CC2C Zoos I tw . 27 _3 /7s< i.. 9C./ 2J9 5'!q 7 C.T- 054, vk2/ S. 20 4/2 6/65 - -. ,', -, " -' ^ s^r l'�, .1 1/ "C 0./7 /65� C '<�� I ,'f7o � g6czzc /24 /Sf !I � _____ ___ /0 __ _| ._ O. oc2! I i 4I /c' SAN 120, 4/26/65 Table E-20 AVERAGE ANNUAL DAMAGE COMPUTATION Type of Damage#/46(,/-Yff /l<4 Damage Stage P2 '7-SL Reach Number 2 --g-Location ~e44 CC. Condition < i-rA3c7 //2' &6-) Elevation Frequency Probable Incremental of WS Damages in Damage in years Occurrence Probability I (msl)I $1,000 Average Increment $ Z'. cle ze~97 ~~~5 ~ ~ 6.~2C 297� 66( Ie Ir2928 I/G d. ." "Ss' ~~I 2 7ec~ /. 6~/7 41 6:5-- 6e t'/ds SAN1i 120 4/26/65 C� rZ~rr I // I ('- D'�32 I I 4s c?.~~~~~~~~ a I3 L- _____ %�- ~7 I lI _ zS~ C.~~~r 626'I i4 __ d.~~~ ~~ 4Z/4/ 9) 2o. (~ (. *7~-~0 TOTAL SAN l2g), 4/26/65 Table E-21 AVERAGE ANNUAL DAMAGE COMPUTATION Type of Damage /bqA ft~rE Damage Stage /:/9 /9SL Reach Number 2 -Gage-Location A~,L/z564Ch4 56C Condition 4,P r.-'1 Elevation Fr~equency Probable Incremental of WS Damages in Damage in years Occurrence Probability (ms1) $1,000 - Average Increment $ 6~ edd 2 b 3 5~7 e. V,:5Y2,d 17,4 2 6 35 - IC.6'4d5 ~SS/2F2 460 a. 003~~- i. 9 2496' ~~. dabZ90/b a. ~~c /77 ~~~~d~~ d __________~ 9z eel 77s i / ?$ g ~~~sa d. 0.�'Z5- /2.4~~~~~~~~~~~~~~~~~- LI. . Z%, e-21g 4 4i~~~~~~~~ ~~~~~ IaaZ _______ 6. eOi 7 22, 7 97 a441 TOTAL 4'22,c92 SAN.120, 4/26/65 Table B-22 AVERAGE ANNUAL DAMAGE COMPUTATION Type of Damage /A/dt/CA VVf/149rC Damage Stage /30 - ASL Reach Number g age Location F4LC/ 564cW .5,�6 Condition 0ri Pcoxccr (isoor OsA'5) Elevation Fr~equency Probable Incremental of WS Damages in Damage in years Occurrence Probability (msl) $1,000 - Average Increment S 0.0020Z /950 3906 4S~ !I, 10,020 /7.4 51-;9' d~~~~dddg ~ ~~~~~lze102 - 0. 0005 927~~~~~~~MO - 0.002 /6/Q /zZ7S5 b~~dd~~S~~ 42L8 2446 /00D 0 ./00 /50 0. C. 002� AO ~~/2.4 I call~~~,.41 1 I e. Lie .0 24:20/& L7 e 0.00501I _ _ _ 40~~~~ O0 ~7 SAN.1219, 4/26/6 5 P 22. 7 03.044/ 9/ 2'.3 0. 04C9 gq8 SAN 120, 4/26/65 Table E-23 AVERAGE ANNUAL DAMAGE COMPUTATION Type of Damage AaWRI/$4~ oV6kR5 Damage Stage 83'4$Z Reach Number 3 -Gge Location P'r2L '/ V � d Condition jTU J-Cr Elevation Fr~equepcy Probable Incremental of WS Damages in Damage in years Occurrence Probability (msl) $1,000 r Average Increment S 6. e0Z I /,&A 41 /~~~~~~~$9 ///6~~~~~~~~~~ I15 4/3~~ b. d~~6 ZV. goo 4- e. 4ve 4 / IT '7Z f~ 64/T, /// I 2 za~~~~~~~~5 /6/I /.I/ I~ si 6)02 -O 6~r95- i / 727 F/I D.6'/z~ I2.'?- D. bOC I ~Y8 I 5/ d~~~ ood ~ ~~ ~ ~ ~ I /AI I oP 422 6OZ60 //1 475~I ___ ___ Lal_s~_~ ___ _ _~ 13 1/6 I 0~83 ~E OL 2698 3S 1.20303 i iI 2s466 d. Oc3G7I /98 /Sz 7 25a6~ I 9,2 2/I.~3~ 6'6�1/ I 6-6 /~~~~~4d 6�57 I7 _ /d ~~~~~~~. OCL7~~6. TOTAL 2,e7 SAN 12Q), 4/26/65 Table E-2A AVERAGE ANNUAL DAMAGE COMPUTATION Type of DamagellUeotIC415' A*We-I Damage Stage IZ I Al .5 Reach Number 13 -Gee-Location A -01-Z. Condition 0$ 2-Al Pl ' 7~ C (2/D e') Elevation Frequency Probable Incremental of WS Damages in pamage in years Occurrence Probability I (msl) $1,000 - Average Increment S /Za 19'.5 5~~ 4 D, sat 0. 6'e'/7 9~37 C'. B ibe 7 eI3Y d~1d /2.4 550 I ~I~ 6.0/6-7 //53 _ _ _ _ I I 2 4 *, Ib /0. I~ 2./' __ ~~~~~~7~666 I I4 401 10 s lid?'95 LO. al3L 2,~~~7 &.C~4c'e I 3 /9 eV zd5- ~ 4 L715_ 4n d. ~~~~Z~b IP. e 1 * ~d ,dc~7 6..3 i 1/8 i/ 4c: 0. 63n .98 0. C'e04 TOTAL SAN 120, 4/26/65 Table E-25 AVERAGE ANNUAL DAMAGE COMPUTATION Type of Damage 4/aPA'CAa &, 4s'C Damage Stage 2/C - Reach Number 3 -Gage-Location F-'ec 3 C s.d Condition A/1,I? PoR,96J5C r (4Sec2r z e%/C) Elevation Fr~equency Probable Incremental of WS - Damages in Damage in years Occurrence Probability (msl) $1,000 r Average Increment $ o~vZc 0 210 C06O. 0.00� /79 9z6 0, ev.AAO I 7~s 400 0. cc zs i6487' 3~~n C. ~7'33 /6 g 89/0 a- ecci 740 /14,5 A~ corc S 252 �i /60/3 0.Z. �2 0C/3 6. 402<E 2,$70 AC 0,iizs~ /2,4 6.40642 I /40 588 /�6~~~~~~~~~:~ C..o/6 /15 0 ctCDOs3 I 5c �60.Cc;7n /1. 0 I ___ 4n 6'. _ _ _I _ _ _ *20 Z'.7i .2(3~~~~~~~~ 002 I2-n I /74� 0. 0gy5 8.3II /2~~~~0 A. /o4 TOTAL X', ISO SAN.121, 4/26/65 Table E-26 AVERAGE ANNUAL DAMAGE COMPUTATION Type of DamageW/UAV1 / ;C4'// /rAVsF Damage Stage /-O //sL Reach Number 3 sage Location ROLL / e'-ACg .. Condition V//r,/ P/,oj-cr (/,' t/or ~ ,A/) Elevation Frequency Probable Incremental of WS Damages in Damage in years Occurrence Probabilitv (msl) $1,000 - Average Increment S :D. taps Z / b , 9 /--3 /~0. /0o02 /. _7,i D O. 0r ., R3 LIZ 460 , c:r /6. ,- 0. oo /7 I, 7" zoo o. o C- /5 35 d. o.o _. 8 /4o o. o/a 15. o D d. 67'2 7.< o. /-ZS /Z. / ,4 CO. 1 _ A g. C/3,7 SAN 12d, 4/26/65 CC 0. O Zoo f/ O ___._ 4o o.$02.-so ___ _ /0* .___ 0. 0d7001.I /74 0. S7S 8 I AC o. /A' 7 TOTAL t 2<6 SAN 12S, 4/26/65 Table E-27 SUMMARY OF HURRICANE WAVE DAMAGE PREVENTION BENEFITS Average Annual Annual Damage Benefits Without With Existing Future 1/ Reach Location Project Project Development Development- 12-foot Dune 2 Sta 75+54.81 - Sta 0+00 $22,975 $16,193 $ 6,782 3 Sta 0+00 - Sta 180+00 50,402 45,849 4,553 TOTAL $73,377 $62,042 $11,335 $12,922 15-foot Dune 2 Sta 75+54.81 - Sta 0+00 $22,975 $ 8,130 $14,845 3 Sta 0+00 - Sta 180+00 50,402 22,802 27,600 TOTAL $73,377 $30,932 $42,445 $48,387 18-foot Dune 2 Sta 75+54.81 - Sta 0+00 $22,975 $ 3,863 $19,112 3 Sta 0+00 - Sta 180+00 50,402 10,674 39,728 TOTAL $73,377 $14,537 $58,840 $67,078 I/Future development was computed by multiplying benefits to existing development by the factor 1.14. Derivation of the future development factor is discussed in Paragraph 25 of this Section. g Summary of Benefits 46. A summary of total annual benefits which would result from the various plans of improvements is shown in Table E-2F. S. APPENDIX 1 E-22 TABLE E-28 SUMMARY OF TOTAL ANNUAL BENEFITS PLAN TYPE OF BENEFIT RECREATIONAL LAND-LOSS BUILDING LAND HURRICANE TOTAL PREVENTION DAMAGE ENHANCEMENT WAVE-DAMAGE ANNUAL PREVENTION PROTECTION BENEFITS A-0 $ 681,500 $ 119,200 $ 55,500 $ 34,800 $ 0 $ 891,000 A-1 748,000 119,200 55,500 34,800 0 957,500 A-2 771,800 119,200 55,500 34,800 0 981,300 A-3 760,600 119,200 55,500 34,800 0 970,100 A-4 760,600 177,200 80,900 45,900 0 1,064,600 A-5 760,600 177,200 80,900 45,900 0 1,064,600 B-1 738,100 177,200 80,900 45,900 12,900 1,055,000 B-2 738,100 177,200 80,900 45,900 48,400 1,090,500 B-3 738,100 177,200 80,900 45,900 67,100 1,109,200 Rev. 17 Oct 79