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U.S. ARMY CORPS OF ENGINEERS NORTH CENTRAL DIVISION -Iwo- A C@o '2kTN' COASTAL ZONE :4.- U MFORMATION CENTER 77 Hel lg@ --l* 74- 7@ - 7A Yours If 11110 A discussion of erosion 4 problems on the Great Lakes a nd alternative methods of shore protection. GB 1627 G8 U580 GENERAL INFORMATION PAMPHLET 1978 1AINTED BY WADKINS Acknowledgements The U.S. Army Corps of Engineers, North Central Division, compiled and revised these data in cooperation with the Great Lakes States, as a public service. The Government does not guarantee that the methods for combating shore erosion as described herein will be successful in any specific application. ftw ty Of C 8C L"Waty COASTAL ZONE U - S - DEPARTMENT OF COMMERCE NOAA INFORMATION CENyER COASTAL SERVICES CENTER 2234 SOUTH HOBSON AVENUE CHARLESTON, SC 29405-2413 Page Introduction .......................... 2 CZIC COL"LECBOW Understanding Shore Erosion ......... 3 Initiate Action By Organization ........ 4 Permit Requirements ................. 4 Planning Considerations .............. 5 Great Lakes Shoreline ................ 6 A Guide for Selecting a Type This pamphlet has been prepared to provide owners of Of Shore Protection ................ 7 private property with technical assistance for the Construction Alternatives; Pros, protection of the Great Lakes shoreline from damage due Cons, and Costs ................... 8 to erosion. The sections of the pamphlet are arranged to;. Construction and Maintenance enable one to progress in a logical manner from Guidelines ......................... 14 understanding shore erosion to planning considerations Improper Solutions ................... 15 for erosion control, to then selecting a type of shore protection. A number of general shore protection designs Standard Designs .................... 16 and costs are presented, with discussion of construction Sample Specifications ................ 18 and maintenance guidelines, standard designs, and Shoreland Management ............... 19 sample specifications. It is recommended that each section of the pamphlet be read consecutively because Demonstration Projects ............... 20 Glossary Of Terms ................... 24 information presented in one section will be helpful in understanding material presented in the sections that follow. 1UZ NTRODUCTION 0@3 Shore erosion is a major water resource problem on the Great Lakes. Erosion is caused principally by storm induced wave action and associated alongshore currents. Shore erosion problems become critical. when'hi@h lake levels have submerged the beaches which protect the adjoining highly erodible upland areas. Raised above the /bekheg, wave forces can work directly on the toe of the bluffs and clunds, resulting in rapid erosion. The Corps of Engineers, as one of the Federal agencies concerned with bea6h erosion problems, has constructed many beach erosion @,cdhtrol projects along the shores of the Oceans and Great Lakes. The Co@,ps may undertake investigations of beach erosion problems under spe'6ific authorizations by Congress, or, for smaller studies, under s@eciAl_continuing authority given by Congress. Under present law, the Corps can provide assistance for protection of public shores, but has no authority to construct erosion control projects aimed solely at protecting private property. The problem which must be resolved is: How to protect an eroding property? This pamphlet is intended to help private owners evaluate their situation and decide on which course of action should be taken. In addition to the structural alternatives discussed in the pamphlet, "no action" and relocation should be considered. The benefits associated with no action are saving money and avoiding accelerated erosion on adjacent property with its potential liability problem; however, no protection from damages is provided by this alternative. If property is of sufficient width, homes may be moved back from the eroding shoreline. Long-term expense may be lower with relocation than installing several unsuccessful shore protection structures. IM CAUTM. This pamphlet is not intended as a substitute for professional engineering services that are needed to properly design shore protection works. The design of shore protection measures is complex and good engineering principles must be followed. A qualified engineer can help reduce the risk of failure by designing protection for the conditions at a specific problem area. Severe Erosion at Stickney Ridge, MI., in 1973. 2 UMIDERSMIMOMM SHORE ENOVOK SHOO MIE PRDCESSF@s LaKE The beach profile is a relatively small physiographic feature whose limits are Levels of the Great Lakes fluctuate from year to year and also from month to defined bythe effectsof waves. As waves approach the shore they react in special month during each year depending upon the volume of water in the lakes. The ways; they reflect, diffract and refract. The beach then acts as a natural defense source of the Great Lakes water is in the rain and snow which fall on the lakes againstthe attack from waves. The first defense againstthewaves isthesloping themselvesandon the land areas which drain them. When the net supply to one of nearshore bottom which dissipates the energy,or weakens the force of the the lakes exceeds the outflow, its level rises. When the net supply is less than the deepwater waves. outflow, its level falls. For example, the lake levels reached record highs in the The shoreline erodes from the force of wave action. The erosive energy of a wave early seventies because the precipitation, in those years, over the Great Lakes is a function of wave height and the depth of the water in which the wave acts. Basin exceeded the basin averages. Wave energy is strongest in deep water but its effect is greatestthru the surf zone, from the start of breaking waves to the limit of run up. Seasonal fluctuations, caused by the annual weather pattern are superimposed The amount of energy delivered to the beach depends on the level of the lake and upon the long-term variations resulting from extended periods of below or above the storm set up or storm induced temporary rise in lake stage. The offshore depth normal precipitation. During each year, the lake levels consistently fall to their is one of the most important parameters in the design of shore protection lowest elevation in the winter because most precipitation in the watershed areas structures. During high lake levels the typical shore becomes a narrow unstable during the winter is snow and ice. The lake levels then rise to their highest beach at the foot of a steep bluff or dune. Waves attack the toe of the bluff elevation in the summer wher. the temperature rises and there is substantial undercutting its face which falls on the beach. Waves wash out the fine bluff runoff dueto melting snow and ice. The probable maximum levels for the summer material, carry it offshore to deep water, or move it along the shore by littoral of 1978aregiven in thetable belowand aregenerally onetotwo feet lessthan the currents. recent record levels. High lake levels change the effects that waves have on the beach profile as shown below. The natural beaches are submerged and waves act directly on the highly erodible backshore. The increased wave action on the beach increases the rate of Lakes erosion of the bluff. In the new balance, a beach will reform its equilibrium slope, 1978 Lake Michigan- Lake Lake Lake but the foreshore would be moved landward. During high lake levels beaches may exhibit a steep and rather uniformly sloping profile and thus the effects of storm Superior Huron St. Clair Erie Ontario waves are greatly increased. End of Material is moved and redistributed along the beach by the waves and wave August generated currents. Long flat waves pick the sand up, move it forward, and Elevation 601.1 579.0 574.4 571.5 245.0 deposit it on the beach berm. Short steep waves acting on the beach carry End of May 600.5 578.9 574.7 572.4 246.5 UPI,ARID BEACH OR S @RE the sand lakeward. The direction of Low Water BREAKERS littoral transport depends on the OE direction of the wave generated Datum 6N.0 576.8 571.7 568.6 242.8 HORE OL HIGOHWATER LEVEL energy which impinges upon a ST RM SET-UP shore. Generalized data on storm TOE LOW WATER LEVEL water setup and the net direction of Because of the size of the Great Lakes and the limited discharge capacities of BAR littoral transport are shown on the their outflow rivers, extreme high or low levels and flows persist for considerable CREST OF BERM map of the Great Lakes on page 6. time after the factors which caused them have changed. Wherethe outflows from BOTTOM Short period fluctuations of the the lakes are controlled by regulatory works as isthe case with Lakes Superiorand lakes (Storm setup) result from me- Ontario, the releases of water are made in accordance with the plan for the RVATER tE-B teorological disturbances and may regulation of the lakes levels and outflows which maintain the lakes within a range last from a few hours to a few days. of water levels acceptable to all interests concerned. All regulation plans are WND STORK4 SETUP Wind and barometric pressure approved by the Governments of the United States and Canada. VALU cause the lake surface to tilt as STORM WATER LE@L shown to the left. The amount of storm setup depends on local con- UNDISTURBED (STL- R)LEVEL ditions. These values are shown in ( ) on the map for selected sta- tions on the Great Lakes on page 6. L The storm setup values are added to the projected lake levels to determine the design water level for the protective BREAKERS .'G. WATER LEVEL 'T.RM "_Up OF BLUE' WATER LEVEL BAR CREST OF BERM works illustrated in this pamphlet. This computation is described on page 16. NMA7E ACMM BV GRGAMEAMM PERM7 REQUREMEM7S Community organization is the key to successful Federal and State permits are required prior to District Engineer District Engineer emergency shore protection measures. There the construction of any work in, under, across, U.S. Army Engineer District, U.S. Army Engineer District are several good reasons for organizing groups or on the banks of navigable waters of the Buffalo Chicago 1776 Niagara Street 219 South Dearborn Street of property owners in a coordinated approach to United States. In general, both Federal and Buffalo New York 14207 Chicago, Illinois 60604 erosion control. Example has shown that where State permits are required prior to the initiation individuals have attempted to go it alone, the of construction of shore protection structures District Engineer results have often been ineffective, individual along the shores of the Great Lakes, lakeward District Engineer U.S. Army Engineer District protective structures have been damaged due to of the high water mark. The highwater mark is a U.S. Army Engineer District St. Paul Detroit 1135 U.S. Post Office and continuing erosion on unprotected adjacent specific elevation on each of the Great Lakes P.O. Box 1027 Customhouse properties (flanked) and failed. A well-planned, which establishes a plane above which Federal Detroit, Michigan 48231 St. Paul, Minnesota 55101 coordinated, and properly constructed system of permits are not required. State and Federal shore protection work extending for a consider- highwater mark elevations vary on some of the able distance will capture economy of scale in Great Lakes. As a result in some cases a Federal Information regarding the procedures for construction resulting in a lower cost per lineal permit may be required where a State permit applying for a state permit should be obtained foot of protection. may not. It is suggested that if there is any doubt from the following state agencies: as to the necessity for a permit the appropriate Chief Waterway Engineer Central Permit Agent The community, or a group of property owners, State and Corps district office be contacted for State of Illinois New York State Water should organize its resources to respond to the the determination. Federal permits are issued Division of Water Resources Commission existing situation. Civil defense directors can by the Corps of Engineers, only after a state Resource Management State Campus provide helpful hints on how to organize your permit or waiver thereof has been obtained. 201 West Monroe Street Albany, New York 12226 manpower and resources into a unit. An existing Upon receipt of application for permit, the Springfield, Illinois 26706 Staff Coordinator property owners association would provide a Corps District Office is required to issue a Chief, Division of Water Ohio Dept. of Natural basis for initial action. Public Notice describing the proposed work for Indiana Dept. of Natural Resources comment or objection by interested parties. Resources Ohio Dept. Building, The objective of organization is to prepare and The normal advertising period is 30 days; 605 State Office Building Room 815 Indianapolis, Indiana 46325 65 South Front Street implement a plan for shore protection. This plan however, where the applicant indicates urgen- Columbus, Ohio 43215 may consist of some or all of the following: cy for the work the advertising period can be Chief, Submerged Lands Chief Engineer reduced. Normally, if no objection is received, Unit Pennsylvania Department of � administration-delegation of responsibili- the District Engineer is authorized to issue the Division of Land Resource Environmental Resources ties, funding, and accounting. permit. A pamphlet, EP 1145-2-1, 1 November Programs P.O. Box 1467 � preconstruction plan n in g-assessment of 1977, entitled "U.S. Army Corps of Engineers Michigan Department of Harrisburg, Pennsylvania the existing situation, inventory of existing Permit Program, a Guide for Applicants", Natural Resources 17120 shore protection works and their effective- describing the procedures for applying for a P.O. Box 30028 Federal permit, may be obtained free of charge Lansing, Michigan 48909 Director, Bureau of Water and ness, maps of the shoreline area, and Shoreland Management establishment of surveillance points for from any Corps of Engineers' district office. Minnesota Dept. of Natural Division of Environmental photographs and surveying. Resources Protection Div. of Water, Soils & Wisconsin Dept. of Natural � with the aid of an engineer develop a plan of Minerals Resources protection, construction drawings, specifi- Centennial Office Building Box 450 cations, and a handbook for maintenance. St. Paul, Minnesota 55155 Madison, Wisconsin 53702 DEFINE THE PROBLEM: BUILDING PROTECTIVE WORKS The factors affecting shore erosion are the orientation of the shoreline, Timeliness is the essence of the successful construction of shore Anchorage and splicing details, particularly size, type, location, and offshore depth, and the resistance of the shoreline to wave action. An protection measures. The best time to build shore protection structures is method of connection. individual assessment of your situation should be described in terms of during low-water periods. Greater construction problems exist during backshore form, such as low bluff or high dune, offshore slope, and the high lake levels when many beaches are submerged making access Number and arrangement of cables and details of fastening members. existence or lack of a beach. Review the columns under type of shore on difficult, The lack of time precludes an in-depth study of the problem, Pile construction, the number of piles, length of piling, driving Paige 7 to determine what types of shore protective structures should be requiring a hasty solution. requirements, cut-off elevations, and framing details. employed for various situations. Construction alternatives, pros, cons and osts are shown on subsequent pages. The cost estimates given are only a Once the general plan of protection has been determined it should be The details of adjustable wire baskets (gabions) and the material to be guide and will vary with locality. discussed with the appropriate Corps of Engineer District, Permits used to fill the baskets. Branch. The permit application will require your plan, and information on SELECT@MG A PLAN OR PROTECTION any borrow or disposal sites and may require 90 days to process. Concrete specifications, materials specifications, placement instructions, quality control and description of payment items. The cost of a structure, the risk and consequence of failure, and the e final design of protective works can proceed once the general plan of materials available will decide the type of structure and its construction Th Start-up and completion time for the work. details. protection has been selected. The data herein describe the general plans. The final plan should include a layout drawing, construction details, and The primarydecision in contending with serious shore erosion problems is materials specifications. A complete alignment of the structure should be ENVIRONMENTAL COMSIIDERAT@OMS a choice of (1) relocation (2) armor the base or toe of the bank (3) build established as early as possible. Take advantage of the remaining beach Since installation of shore protection devices usually produces some beaches or (4) reduce the force of the offshore waves. Relocation requires and tie into adjacent shore protection works if possible. Provide enough change in the nearby shoreline environment, thorough planning and an alternative site for the home and a house-moving company. Armor room for the specified minimum slopes if you are building a revetment ' As design requires consideration of the f ull impact of the expected changes requires good foundation conditions and the availability of heavy stone or soon as the alignment is established, quantities can be estimated for on the ecological and aesthetic value of the area to be protected. If the other heavy material and access. Beach building requires artificial establishing equipment and materials requirements. possibility exists of adverse environmental or social effects resulting from replenishment or an area where large quantities of beach material move construction of a shore protection device, Federal and state law requires along the shore. Devices which retain placed sand or entrap the natural Access roads and borrow areas should be identified on the plan. Local consideration of alternatives to avoid or mitigate the effects. Possible littoral dritt are offshore breakwaters, groins or, in the backbeach area, contractors and local officials can provide information 'on sources Of adverse environmental effects of a shore protection device are considered vegetation. material and load restrictions on streets and highways. The use of heavy in the review process discussed previously under Permit Requirements. equipment on residential streets can result in severe damage to the Expected shoreline changes that might be produced by some shore There is no single type of permanent or temporary protection that should pavement. protection devices are discussed with other design aspects of the devices be used in all cases. The most suitable type for individual selection can equipment beginning on page 8. only be determined by consideration of specific information about the area Another important consideration is the selection of the proper to be protected, such as surveys, soil conditions, wave climate, set up, etc. to do the work. Utilize the contractor's experienceto establish the best use The cost of protection varies considerably, Low-cost emergency of equipment and the most efficient operation. SAFETY COMSIDERATOOMS protection can be provided for about $10 per toot, while permanent Common sense safety is necessary to reduce the chance of injury and Contracts for shore protection works delineate the responsibilities of both possible loss of life. Some safety considerations are listed below: protection might cost up to $500 per foot of shoreline. Because of varying parties, the owner and the contractor. The contract should be based on conditions of the shoreline around the various lakes, it is probable that the plans and specifications and include prices for the estimated quantities of Safe access and safe working conditions must be provided at all work best plan of protection would involve a wide range of designs, depending work. It is important that both parties fully understand the scope of work. areas. Unstable bluffs must be graded to a safe slope. on availability of materials and the severity of erosion. A number of these You should get "bids", i.e., prices, from a number of contractors,to insure A f irst-aid kit should be available. Everyone should be physically qualified alternatives are described beginning on page 8. obtaining quality work at the lowest price. to perform the work required. No one should expose themselves to injury. The availability of materials will dictate the type of structure and its cost. For example, the lack of stone within economic hauling distance would CONTRACT PLANS AND SPECIFICATIONS Protective clothing, such as safety shoes, gloves, goggles, and hard hats require the use of some other material. (TYPgCAL) should be worn'by persons engaged in work requiring this protection. t-or your protection, contract plans and specifications* should be provided Construction materials should be stored in an orderly manner on a solid, Some materials are very good, i.e., quarried stone, pre-fabricated concrete to or by your contractor. This should include some, if not all of the level surface. units, interlocking steel pile and creosoted wood timbers. Some materials following: are not acceptable such as junk cars, old tires, thin concrete slabs, and Waste materials should be removed from the work area daily. empty septic tanks, and may be against state law. In between these Location of the work with respect to the highway right-of-way and the extremes is a range of materials that can be used if care, discretion, and shore. INSPECTION CONSIDERATIONS ingenuity are applied to produce a more durable structure. Materials can Survey control and relation of elevations to lake levels and both expected Supervision of construction is very important. Close attention to detail is be used in conjunction with other materials, for instance, wire fencing and highwater conditions and low water datum (LWD). needed to assure the final design will perform as anticipated. Prior to and stones; or quarried stone, cloth bags and grout; or steel sheet piles and during actual construction make a complete review of the plan. A check list quarried stone. A typical cross-section indicating dimensions, slopes, arrangement and of the important items are described below. The desired life of the structure also dictates its type. Obviously, an connections. o Start a pictorial record with pictures of existing conditions. Continue untreated timber structure should not be installed where a structure is Quantity of materials (per lineal foot, per protection unit, or per job). this through all stages of construction. desired to last 50 years. Conversely, a permanent rubble-mound structure Relation of the foundation treatment with respect to the existing ground. o Establish elevations of known points, layout line, and grade for would not be required if the need for protection was of an expedient Relation of the top of the proposed protection to design high water and low nature. The durability of the structure and its ability to absorb wave energy water datum. construction. is also a factor. o Note changes in the terrain that may require a change in the plan or The limits of excavation and backfill as they may affect measurement and the layout of construction. The Corps prefers and recommends that permanent protective works be payment. built, but understands that private owners usually can't afford the large o Check material sources for compliance with plans. cost. This means there may have to be departures from the standard Construction details such as weep holes and pervious materials designs for permanent protective works to provide some degree of associated with them. o Inspect work to insure compliance with plans. protection against erosion. This will tend to decrease the first cost of Location and details of construction joints, cut-off stubs and end - Record dimensions, limiting heights and depths on as-built plans. construction; however, higher maintenance cost and reduced functional treatment. o Maintain pictorial record throughout the life of the structure, life will follow. The danger here is to underclesign the work and experience total failure. Close attention to the construction and mainten- Connections and bracing for framing of timber or steel. particularly after damaging storms. ance guidelines given later in this pamphlet are needed to minimize *Sample specifications are shown on page 18. losses. UPLAND SHORE TYPE AND DIRECTION GREAT LAKES SHORELINE I I 9,21@ OF NET LITTORAL TRANSPORT n PORT ARTHUR T-1 0. LIE (1.01 UQUGHTON DULUTH (1.0 Al SUPERIOR ID RQUETTE RAO LIL- 00"@N SA TE MARIE D Cb (9) ES NASA 0 ST. PAUL Ay 0 DISTRICT PE w w PE PE LEI) t- GREEN BAY OWEN SOUND U) (1.0) TORONTO LLJDIN.T.N (3.0) ei-NTAKI 'I ITATE LD 0 PAE@ LIE 1E OSWEGO BAY C ITY BE UIE 4-p,,4_L_ 0 "BE ROCHESTER MUSKEGON LIN BUFFALO MILWAUKEE PORT HURON (4 VC tCBE LAKE DETROIT DETROIT (l.q ST. CLAIR Is OVE \N DISTRICT 40 - (2.0) HIRE PEw A CHICAG (1.7) TOLEDO (1.9) L P E IN N. 0 A VELAND I L L . HAMMON ARY LIN LSE LORAIN niri-nu I N 0 1 A IN A 0 H 1 0 ro a (MUME FOR SELECTINQ ATYPE OF MORE Determine the shore type at the location to be suitable shore protection devices. Possible protected from the map on the opposite page solutions to erosion control are categorized or from an on-site inspection. The following below bythefunction theyservib, f6r6x&rnpIe: chart may be used as a guide in selecting bluff protection, beach accretion, and etc. FLAT OFFSHORE SLOPES MODERATE OFFSHORE SLOPES SYEFEP OFFSHORE SLOPES BEDROCK LAKE B0770M TYPE OF SHORE TYPE OF SHORE TYPE OF SHORE TYPE OF SHORE H BLUFF E IBLE > HIGH LOW EFRODING BLUFF NO BEACH WATER SURFACE WATER SURFACE LOW BLUFF NO BE- HIGH BLUFF E ERODIBLE> XI HIGH WATER SURFACE RODIBLE <X0 HIGH WATER SURFACE SOLIDROCK _j POSMOLIE SOLUMMS No 'EACH ERODIBLE BLUFF FIR OTECINOM BUF F WATER SURF@E LOW BLUFF WATER SURFACE WATER SURFACE NE No BEACH Flevellments LN __ ERODIBLE Lo 7 -R L-W .- EROD'.LE LOW PLAIN Stone N. RROW E.C. Gabion I I I I Bag-Grout filled FOOMMLIE SOLUMMS POWMIKE SOLUMMS RELOCATOOM BLUFF PR07EC700M HIGH BLUFF PR07ECTOOM Revetments .E NO BEACH Revetments Stone WATER SURFACE Stone Gabion Gabion Bag-Grout filled Bag-Grout filled Bulkheads Bulkheads Steel pile POSSIBLE SOLUMMS Steel pile Timber pile [BLUFF PR07ECTOOM Timber pile Timber cribs (stone filled) Revelments Timber cribs (stone filled) Wood pile wire mesh fence Stone RELOCA700M (stone filled) Gabion Beach Fill Bag-Grout filled BLUFF ZTABMXA790M Drainage BEACH ACCRETMM Bulkheads Sloping Offshore breakwater Steel pile Impermeable groin Timber pile Vegetation Timber cribs (stone filled) Wood pile wire mesh fence RELCCA7MM (stone filled) BLUFF STAB0MZXnGM Beach Fill Drainage SlEACH ACCRETOOM Sloping Offshore breakwater Impermeable groin Vegetation RELOCAT90M BLUFF STABOLOZATOOM Drainage Sloping No B ;H LL.F>F HIGH LOW M."". BLUFF WATER SURFACE W-1 R SURFACE SOU. RM@ I. HIGH W.'E. SUFF. IF CIDIM37RUC7MH ALTERIMA7MES- REVETNEWITS SLUFF Revetments are structures placed at the toe of bluff parallel or nearly parallel to the shoreline to protect against wave action. Three examples are shown below. STONE REVE7DREN7 GABMN REVMM7 GROUT FOLUED SAGS REVETMIEMT 16@'ESTABLISH VEGETATION TO EXISTING BLUFF .EXISTING SLOPE S NE FILLED GROUT FILLED BAGS GABIONS T- 3" TF STONE TOE PROTECTION REINFORCING BARS Q! DIA. h BACKFILL 1.1.o h DESIGN HIGH WATER @IN WOVEN OR a DESIGNHIGHWATER NONWOVEN@ WOVEN OR L,ASTIC NONWOVEN PL PLASTIC is J LAKE BED WOVEN FI@TER FILTER OR NONWOVU IV CLOTH \4 CLOTH FILTER PLASTIC PLASTld I FILTER CLOTH MATERIAL T1 FILTER CLOTH rT ESS T. -PILE WALL Stone revetment is the preferred method of shore protection. It is A gabion is a steel wire mesh basket available commercially. Hevetments Large grout-filled nylon bags (20' x 5' x 1 '6") may be used to protect economical and suitable for all types of erosion problems when stone is can be constructed from stone-filled gabions by groups of individuals eroding shorelines. This type of structure is adaptable to all types of available in sufficient size and quantity. The key design considerations, are without special construction equipment. Gabion structures can be built to slopes. Bags should be placed parallel to the shore with reinforcing bars the dimensions, foundation treatment, and stone size. Construction is not any height required. A step design is suggested to reduce wave runup. The installed both vertically and horizontally as shown in the section above. complicated and no special equipment, other than a Crane and trucks are manufacturer's instructions should be followed closely. The structure This type of structure may be applicable where access is limited and rock is needed. should rest on an 18" thick gabion mattress to protect against scour. This not readily available. No special material is needed otherthan the bags and NOTES: type of construction is applicable to all shore-protection problems. co instruction is not complicated. A grout pump is required to fill the bags. 1 . Slope should be compacted and graded to 1:2 or flatter. NOTES: Pr. ces in the table below were computed with the assumption that ready- 2. Place a gravel, small rock, filter blanket, and/or filter cloth on the 1 . Gabions can be filled with any stone material larger than the mesh. mix grout will be used but a concrete mixer could be substituted at the site. MAINTENANCE REQUIREMENTS prepared slope. 2. Gabion structures maintain theirstrength even ifthefoundation settles Remedial work on thistype ofstructure is not easily accomplished. Special 3. Place rock carefully with a crane; rock should be supported at three somewhat. attention should be given to toe protection. Uneven settlement or locations. 3. You should stagger the joints between baskets the same way you undermining might cause fracture or collapse. If excessive scour causes 4. Insure rock sizes are well mixed. Largerand smaller rock should not be stagger the joints between courses in a brick wall to make a stronger toe stone to settle, more material should beadded. Thistype ofstructure is visibly segregated. structure. readily adaptable to add-on construction. Additional structure height can MAINTENANCE REOUIREMENTS 4. You would be wise to anchor the lakeward end of the mattress with be easily accomplished if necessary. f the large stone or anchor screws. This structure is subject to displacement. The effectiveness 0 5. Your mattress should extend out as tar from the toe as one and one-halt structure will be impaired by thinning of the protective layer or settling of the structure. Restoration of the rock slope protection to the designed top times the design depth. elevation, equivalent thickness and reduction of voids in the facing should MAINTENANCE be accomplished when needed. The list of materials and general costs The life of gabion protection depends on the durability ofthe wire. Replace information is given in the following tabulation. broken wires with galvanized or plastic-coated wire. The baskets occasionally are moved during severe storms, but can often be replaced after the storm. Such movement indicates foundation failure or scour at the toe. Repair all storm damage as quickly as possible. Design depth of water 50' offshore (ft.) Design depth of water 50'offshore (ft.) Design depth of Water 50' offshore (ft.) Description 3-4 5@6 7-8 Description 3-4 5-6 7-8 Description 3-5 1 5-6 7-8 Dimensions Dimensions Dimensions Thickness (ft) 2 4 5 Height (ft.) 5 7 9 Height of structure (ft) 6.4 8.0 11.2 A@ rage wt of Stone (09 200-500 750-2000 2000 - 5000 Apron length (ft.) 2 5 7 (Bags) (5) (6) (8) H? 6 eight of Structure (ft) 4 8 Filter material Cloth List of materials (per ft.) Toe Protection Width (ft) 2 4 5 Fliter material Cloth Materials (per ft.) Grout (Yds.3) 1.5 1.8 2.4 List of Materials (per ft) Gabions (M 1 3 4 Reinforcing bars (lbs.) 10 12 16 1.89 Gabions-Stone filled (03) 0.2 0.7 0.9 Filter Cloth (sq. ft.) 21 26 Stone (tons) 4.94 7.36 18 Filter (sq ft) 13 19 22 Gabion type mattress yd3) 0.2 0.4 0.7 Cost $/Lin. Ft. 35 160 216 Cost$/ Lin. Ft. 50 130 230 Cost $/Lin. Ft. 40 90 12F I I I I A@VANTAGES DISADVANTAGES ADVANTAGES DISADVANTAGES ADVANTAGES DISADVANTAGES Most effective structure for absorb- Heavy equipment required for No special construction equipment Subject to rusting and deteriora- Moderate first cost. More subject to catastrophic fail- ing wave energy. construction. required, rated best 'do-it-yourself' tion unless wire baskets are plastic Adaptable to stage conStFUction. ure if the toe is undermined. Flexible-not weakened by slight Limits use and access to beach. type of protection. coated. movements. Flexible, easily repaired after storm Limits use and access to beach. Natural rough surface reduces Moderately high first cost. damage. Moderate maintenance costs. STO IN' FILL GAI I@NS I T' @KFI S @@h . @ES I i _.N OR N .T@ ,C s W L' OVN 'as OR 'L S C A MA R wave runup. Difficult to construct where access Low first cost, if do-it-yourself Lends itself to stage construction. is limited. project. Easily repaired-low maintenance cost. The preferred method of protec- tion when rock is readily available at a low cost. 8 F)RD'S9 cams amlo cas-re D'T [E Cr @ (a H BULKHEADS OR SEAUOALLS Bulkheads are structures placed at the toe of bluff parallel or nearly parallel slope failure. The secondary purpose is to provide protection against wave to the shoreline with the primary purpose of preventing the sliding of land or action. Examples of several different types of bulkheads are shown below. 67EEL BULKHEAD Mv BF-M U%U SULNHEAD 70DIMER CROB MUILMHEIRSO MRE FIEMCIE MULKNEM ESTABLISH ESTABLISH WIRE PROSE CAB VEGETATION .00 PILES VEGETATION GRANULAR CUT WASHER MIN 6 .6 TUFABUCKLE 6 .6 IILLSTOFIE NIAT EXISTING SLOPE FILTER 1ATERIAL REQUIR 3 WALES TIMBERS SMSHE @_AND 3 0 OC FOR TI18ER R STEEL CABLE SPLASH BACK FILLED WITH SAND A, FLA.. APRON BOLT ALTERNATE PILES. STONE I, FILL CK I I-IL E TIMBER IFT I'll DESIGN h GRANULAR DEA AN STONE ZIVAII.I.ED FILL WOR RFILTER WN SIDE LIT OFF LL ME HIGH WATER WATER NOE SLOPE 1- B NKET FILL DESIGN HIGH PL Ic 0CRIB F ECUP -UE F 11R WOOD HEETPILE S RE XISTI NK WOV EN 0" TOE STONE TIE ACK 3NX TOE PROTECTION 161 PION W. VEN STONE TOE CRRYPK TOE PROTECTION I Sh C NTINU SOCK FILL UNDER PLASTIC 0. WOVEN OR NONW E PROTECTIO 8L SH RLINE CRIB FOR UNDATION FILTER 'r H WOVEN OR NONWOVEN CLOTH TURNBUCKLE PLASTIC FILTER C Ill C1T___? % CABLE PLASTIC FILTER CLOTH WASH. STEEL PILING 3PLANK WALL ER CUT WASHER mr@ a , I I N T1 6 CUT WAS I-STONE I E., A, Ig ,FILL % c BOLT dill 11. A TIMEER :Ig@" APRON E. PLANK WALER Jf=Q_ @@3 WAUERW W FILTER @@ il ROD THREAD ONE END ICENTER EA SIDE AT HEAD 2 PER CRI. WOOD EIIANKET PILING OF STEELI HEAVY G UGE IR16 CUT WASHER EA SIDE DETAIL OF HEAD @NDUSTAITAL FE CING DETAIL OF HEAD WALES DETAR. DET,A OF HEAD STAPLE0PILES) I I II - I @ - I A steel bulkhead serves to armor the bank. The face Timber walls are constructed of plank sheeting with Heavy duty timber cribs can be used for bulkheads. Fence-type structures can be constructed oftimber, must be designed to absorb all wave energy. Severe round piles. They consist of two rows of 3-inch Timber cribs use log-headers and stretchers. or metal posts or piling, and wire fence or lumber. scour occurs at the bulkhead line. The sheeting plank sheeting and a row of round piling with heavy Headers must be long enough to integrate a stable The fences can be built of single, double, or triple depends upon penetration and tie backs for its horizontal walls between the planks and the piling. mass of backfill. Dimension lumber can also be rows. Posts should be driven below possible scour. stability. The structural design of sheet piling is They must be tied back to anchor piling. The most used. Backfill for cribs must be self-draining and Woven-wire fabric is preferred towelded wirefabric. highly specialized and not subject to standard common cause of failure of seawalls is undermining secure against erosion. The base of the toe must be This type of protection consists of fence, filled with plans. For this reason the service of a qualified of material from the bottom of the toe of the protected from scour. stone, and anchored to the embankment. The fence engineer is essential. Key design considerations are structure, resulting in inadequate penetration of NOTES: is used to hold small stones in place that would be foundation conditions, penetration of the piling, piling. The pressure of the soil and water on the displaced by wave action. height and alignment, and scour protection. back side can then tip the structure. The tie-backs Notch Iogs@ to reduce spacings between members. Sufficient access must be available for pile-driving provide additional strength to resist this force. Fill cribs with field stone up to 50 pounds. Provide a The more important design considerations include: equipment. Timber bulkheads also require positive toe pro- gravel bed foundation. Backfill area between bluff the piling length, the size ofthe wire fencefabric, the tection. and crib with bank run gravel. design of the compartment to hold the stone, and Piles shall be carefully located as shown on the the method of anchoring the stone-filled fence to drawings and driven in a plumb position, each pile The piling and sheeting are driven with the aid of a Place a storm splash apron on backfill. the embankment. interlocked with adjoining piles for its entire length, jet from a small pump. The use of this design is so as to form a continuous diaphragm, throughout controlled by subsurface foundation conditions. It the length of each run of wall. The Contractor shall is suitable for sand or sand and gravel shores where drive all piles as true to lines as practicable and shall the sand deposit is 12-15 feet below the lake bottom. provide suitable temporary wales or guide struc- Wooden structures must be securely fastened tures to insure that the piles are driven in correct together with bolts. alignment. Design depth of water 50' offshore (it.) Design depth of water 50'offshore (ft.) Design depth Of Water 50'offshOrs, (ft.) Design depth Of Water 50' Offshore (ft.) Description 3-4 5 - 6 7-8 Description 3-4 5 - 6 7-8 Description 3-4 S-6 7-8 Description 3-4 5 - 61 7-8 Dimension Dimension Dimensions Height (ft.) 5 0 Height 6 9 Diameter Of Piles (in.) 6 8 1 1 =0d piles (ft.) I Dimension I Height (ft.) 5 7 L-gth!w 153 5 23 Height (h) 5 8 10 Pile length 13 20 205 Width (ft.) 4 5 Not Diameter Wood pil- (in.) a 10 20 25 l P 6 9 Rac- S1-. fill Obs.) -50 -50 Piling length 13 Wat lank thickneas (in., 3 3 cut Off wall (ft ) 308 30 30-50 Toe Protection 2x2 4.4 5 .6 Toe Protection wt Obs.) 70 140 200 Cap som.,(,B, 1 10. "200 cap On. (Ibe.) IDO 200 300 ap= length List Of Materials Joe, ft.) St... fill t.5 10-50 -50 manded List of hatell.l. (par ft.) List of Materials (par ft.) Piling 5.3 8.0 9. Lin of Materials (Par ft.) Piling (Iinlft..) 17 20 30 Steel Piling (s.f.) 13 20 25 1 Water 1 1 13 T mber cribbing 6", 6") 20 24 S I 1 1 6 Rock fill (cu. yda.) 1.0 to- fill yd.) .53 .60 .90 Wall Plank (..f.) 11 9 Cap on. Vd.) .17 .17 .17 Fill material (ydR.) .9 2.0 3. Filter Blanket (..f.) 9 C.Fn Vd..) .2 Fencing (sq. ft.) 27 30 42 Wain (ft.) 2 12 16 '6 9 Cable (ft.) 2.3 2.3 2.3 Toe Protection (yd..) 15 .60 .95 Toe Stone (c.y.) 3 .7 .95 Sharing (sq. ft.) 81-0.1 Con $/Lin. Ft. 290 460 580 Fill Material (c.Y :9 2.0 3.0 Anchor rods (ft.) 16' - 0" 1 Toa Rock (11, YdJ 46 .53 [Ecira .1 150 Ft. 70 85 Lin. Ft. ID '2r ISO Lin. Ft. 70 95 ccaft $ 1 1E AND I ASUE VR.QED DES I.. R STEEL PILING *E Zt, RREE. HIGH WATER N 0. TOE STONE 'OVEN M._ N OVN LOT 61 Ei 9 ADVANTAGES ADVANTAGES DISADVANTAGES Provides substantial protection. Vertical walls induce severe scour at Lends itself to protecting short reaches. Structural integrity depends upon Maintains shoreline in fixed position. their base. Can be constructed of materials that adequate toe protection. Vertical walls Low maintenance cost. High first cost. are readily available. induce severe scour at their base. Materials are readily available. Pile driving requires special skill and Structure is easily repaired. Limits use and access to beach. heavy construction equipment. DISADVANTAGES Complex engineering design problem. Structural integrity depends upon 9 adequate toe protection. Limits access and use of beach. BOLUFF PROTECTNON(CONTINUED) BEACH BEACH FILL OR AR7MUAL MOUMSHNEM7 OFFSHORE BREAXVJA7En A beach fill artificially replaces The breakwater is placed offshore from material lost naturally to and usually parallel to the shoreline littoral processes. GASM BREAKWATER to protect a shore area from waves. LAKESIDE GASION shape of initial fill 3 DESIGN HIGH WATER 2-I'A' 3 GABIOLS ------- L'I 3' 7 profile adjusted by wave action ORIGINAL 8 @TONI STONE T E PROTECTION 0 BLANKET. (@TERNATIVE- WO ER NONWOVEN original bottom GARION TYPE, MATTRESS) PLASTIC FILTER CLOTH Offshore breakwaters are an acceptable method of shore protection for flat or Depending on the beach width and slope, a beach fill affords some storm moderate offshore slopes. The design wave is based on water depth 50 feet protection for the land area behind the beach by dissipating wave energy as the lakeward of the structure. waves break on the beach. Artificially placing suitable material (predominantly medium sand) on the shore to restore or create a protective beach directly Offshore breakwaters can be constructed of any material capable of withstanding replaces the littoral materials that are removed and not replaced by natural the wave energies impinging upon them, including stone, gabions, steel, wood, processes without inducing damage to shore areas beyond the project area. and concrete shapes. A toe protection blanket is essential. Offshore breakwaters When sand is placed on a beach, waves sortthe surface layerof thefill moving the may be low structures to allow passage of wave energy or they can be high finer particles lakeward while the coarser particles remain near the point where structures to completely block waves. They should be built in shallow water the waves break. This causes an adjustment of the beach fill profile as shown in nearshore for reasons of economy. They can be continuous for long distancesor the above figure. Theadjustment continues until the grain sizes on the beach are segmented with passages between them to allow exchange of water. compatible with the normal wave climate. Caution: Offshore breakwaters interfere with shore processes; their use demands Planning for a protective beach by artificial nourishment requires: knowledge of extreme caution to preclude major downdrift erosion. Consider them only in the littoral transport rate and direction atthe site; information on thegrain sizes of areas of substantial sand movement. Makethern low so they will be overtopped by the beach material at the site, as wel I as that of the material to be placed on the waves during storms. Offshore breakwaters are difficult and expensive to beach; and determination of the shape of the initial fill and how the beach profile maintain. will adjust when subjected to wave action. Although beach fill may often be the most environmentally acceptable solution to shore erosion control, the Design depth of water 50' offshore (ft.) preceding requirements make designing a protective beach difficult. Description 3-4 5-6 7-8 MAINTENANCE REQUIREMENTS Dimensions Beach fill often needsto be periodically nourished becauseof littoral transport. It Height (ft.) 1.5 2.0 may be difficult to find economic sources of borrow material with grain sizes Apron length (ft.) 10.0 10.0 similarto the existing or native beach material. However, if the borrow material is List of Materials Not much finer than the native material, large losses generally occur soon after Gabions-Stone filled (vd3) 0.7 0.7 Recom- placement of the material. Stone toe protection (yd3) ended COST 17C,,, $/Lin. Ft. 100 120 The cost of a beach fill varies with amountof initial fill, frequency and amount of nourishment required, and transport methods and distances. Initial costs may be ADVANTAGES DISADVANTAGES low if an adequate borrow source is nearby. Beneficial effect can extend over a May modify beach line and cause ero- ADVANTAGES considerable length of shoreline. sion in downdrift areas. Recreational area is provided if beach is of suitable dimensions. Maintains or enhances recreational Structure is subject to foundation and Beach nourishment benefits rather than endangers downdrift area. value of a beach. scour failures; floating plant and heavy DISADVANTAGES The structure is not subject t equipment may be required for con- o flank- ing-it can be built in separate struction. May be difficult to maintain in areas of rapid erosion or where no previous beach reaches. Gabions may be damaged by floating existed. Gabions can be constructed on shore ice or logs. and transported to site by ordinary Extremely difficult to repair. earth-moving equipment. Tends to build a natural beach between the breakwater and the shore V NO 10 ACCRETION IMPERMEABLE GROIN Offshore breakwaters also function as wave height Groins are usually constructed perpendicular to the shoreline reduction or attenuation devices on their landward side. and extend into the water far enough to effectively trap and An alternative design to the gabion breakwater on the retain littoral drift to build a beach or minimize erosion of an opposite page is shown below. Offshore breakwaters existing beach. GROUT FILLED NYLON BAGS Protection of the shoreline by groins assume along the shoreline. Groins can have the downdrift shores. The layout of groins is very low, only one foot above the expected high wa foot depth. Groins must be protected from fla bank. The maximum length of groins should: groins should be artificially nourished by placi groin. Caution: Groins are shore protection stru processes and entrap beach materials. Their preclude major downdrift erosion. Consider sand movement. Make them low so they wil storms. Groins should be constructed in stage end of the area to be protected. Study the ef before completing the layout of the groin fiel function by reducing the wave energy which strikes the Designes shore and by creating a quiet zone where sand istrapped. Description 3-4 5-6 7-8 The height, length and distance offshore at the Dimenions breakwater will control the size of the beach which Steal Piling (length) (ft.) 115 65 Not develops behind the structure. Steel Piling (wetted length) (ft.) 100 50 Recom- Depth (ft.) 15 15 mended Groin Spacing (ft.) 200 100 List of materials (per groin) Sheet Piling (tons) 27 16 Timber Walers (tons) 3 2 Stone Filter Blanket (tons) 90 90 Stone Rip rap (tons) 140 140 Cost $/Lin. Ft. 200 215 ADVANTAGES DISADVANTAGES Resulting beach protects up- Extremely complex coastal en- land areas and provides recrea- gineering design problem. tional benefit. Qualified coastal engineering services are essential. Groins Moderate first cost and low rarely function strictly as in- maintenance cost. tended. Areas downdrift will probably experience erosion. Unsuitable in areas of low littoral dirft. (Sand movement) Subject to flanking; must be securely tied into bluff. 11 LOR%CH Z%CQR[ET001M (CONTINUED) LOWER LIMIT DETERMINED BY LOCAL WAVE CONDITIONS AND ICE REGIME HIGH WATER ------------------------------------------------------ FUTURE LW ESTABLISH VEGETATION t TRAPPED SAND ........... VEGETATM Sandy beach areas lose sand inland accompanying figure, the vegetation through wind transport. Much of the sand actually helps form a sand dune system transported from the beach area can be and when storms occur, particularly trapped by planting and/or fertilizing during periods of high water level, this appropriate vegetation in the area above reservoir of sand serves to absorb wave the wave activity. As shown in the energy and slows shore erosion. Many factors affectthe efficiency of vegetation to trap sand. The availability the protective dunes. and volume of sand being transported from the beach, and a sand transport season that coincides with the vegetative growth season, are of prime COST importance in the Great Lakes area. When high wave action occurs, The cost of vegetative plantings could be as low as $10 per foot of shore particularly during high lake levels, the vegetation may be destroyed and front depending on plant species availability and area to be covered. the trapped sand redistributed to the beach. Therefore, the shorefront Information about plants and sources, site preparation, transplanting and owner should be aware that the life span of a portion of the planted or maintenance procedures is available from your local USDA Soil natural vegetation may be as short astheperiod between majorstormwave Conservation Service representative. attacks and periodic maintenance of the vegetation may be required, Also, the Great Lakes Basin Commission, in cooperation with other Federal Caution. Dune stabilizing vegetation is designed to develop the dry back and state agencies has prepared a publication entitled "The Role of beach area by trapping wind-blown beach material. Consider them only in Vegetation I n Shoreline Management" as a guide for Great Lakes shoreline areas of substantial sand supply. Direct wave attack will eventually destroy property owners. 12 BLUFF 8'Ta[MLMa70H BLUFF SEEPAGE PROBLEMS Bluff seepage problems are common for the clay bluff shoreline. Drainage should be provided where sloughing of banks caused by water seepage occurs through the upper relatively pervious strata to the impervious hardpan which underlies it. The saturated upper layer is unstable and sloughs off in large sections after which it is easily carried away by wave action. Whereverthe natural slopeof theground surface 0 UNSTABLE BLUFF behind the top of the bluff is toward the lake, drains paralleling the top of the bluff should be installed to collect the surface run-off. An open joint tile drain laid in a 0 trench about 2 feet deep located 10 feet back from the top of the bluff and backfilled 0 with crushed stone or gravel can be provided for this purpose. Paved gutters or tile 0 drains down the face of the slope are necessary to carry the water which is collected 0 by this drain to the lake. A tile drain along the foot of the slope just above the impervious strata with branches leading to the lake can be added to collect the seepage at this point and prevent softening of the toe of the slope. An alternative approach to the problem of steep and unstable slopes is excavation and slope protection. This plan consists of grading and landscaping the bluffs to a stable slope and the armoring of the toe of the slope as shown above. Revetments, beach accretion devices and bulkheads can be used for protecting the toe of the slope. The general cost of bluff treatment including excavationfill andseeding is$25 per foot. This cost does not include mobilization and demobilization costs for the SAND LENSES required construction equipment. The contractor should carefully plan his work to minimize the erosion damages CLAY BLUFF during construction. The work should be accomplished by reach. Toe protection for the graded slope should be provided as soon as possible after the excavation and filling operations are completed. HIGH WATER Bulkheads are considered as a method for armoring an erodible bluff. Bulkheads can also be used for retaining an unstable slope from sliding. The design of retaining walls is beyond the scope of this pamphlet. CAU71OM: Unstable bluffsshall begraded toasafeslope before anyone is allowed on the beach. M07E: CAUTIOM: This will not eliminate erosion due to wave action. Additional information on bluff stabilization may be found in "Harmony With the Frequently the combination of bluff seepage and wave erosion is responsible for Lake: Guide to Bluff Stabilization", distributed by the Illinois Department of continual bluff loss. In this case it will be necessary to protect the toe of the bluff in Transportation, Room 1010, Marina City Office Building, 300 North State Street, addition to the drainage work. Chicago, Illinois 60610. 13 Q31MS7RUCE`Tp0[M The following guidelines must be followed for any shore protection works built on the Great Lakes. If they are not followed the structure will inevitably fail after construction. Shore Relocation is an alternative that cannot be overemphasized. Erosion is a natural protection devices require varying degrees of maintenance depending on the type of geologic process that is extremely difficult to stop. Thealternatives to build shore structure and exposure to severe wave action. Establish familiarity with the symptoms of protection or to relocate must be weighed against the consequence of failure. failureand the action that should betaken to maintain the structure. Construction rulesand Depending on the type of structure you might consider, it may cost the same to relocate as it would to build shore protection. Should a protective structure fail, RULE 1 then your investment in the structure is lost and your home or cottage is still in Provide adequate protection danger. for the toe of the structure so that It will not be undermined EXISTING SLOPE A- I F. N ED RELOCATION 100' MINIMUM' TOE PROTECTION G NU . . . FIUL% HIGH WATER ToE 1. IN, CHECK FOR SIGNS OF FAILURE MAINTENANCE OR REPAIR PROCEDURE NEW FOUNDATION OLD FO N ON Most failures of shore protection works result from "toe Re-establish support by underpinning, tiebacks, sys- failure". or erosion under the lowest part of the structure. tems of anchor piling, wafers and tie rod. Place larger Failure of the bulkhead can be prevented with adequate stone or rock-filled mattress at toe of structure to toe protection. Toe protection must be substantial prevent scour. Backfill where necessary. HIGH BLUFFS enough to prevent the original ground under it from washing through the toe protection blanket, and extend far enough lakeward of the structure to prevent undermining. Check for signs of failure such as lakeward movement of the wall, erosion behind or at the RELOCATION toe, or at the end of the structure. NO BEACH RULE 2 Secure both ends of the shore protection works against flanking This alternative provides for the permanent relocation of homes subject to 4 FFAILMUNEORESUITS RO T-7 destruction by erosion-induced foundation failure. Relocation is accomplished STRUCTUREiNTO by home movers. The important planning consideration is the rate of erosion. Key TIE BLUFF design considerations are the condition of the home, foundation and utilities, access and obstructions, length of move, new foundation and utilities. A W11..ALL 1%UTft@0,F WINGWALL ..E LN. NOTE: Move 100' minimum or comply with state set back requirements. without wi.9,N., Home moving is a highly specialized activity requiring a qualified home mover. CHECK FOR SIGNS OF FAILURE MAINTFINIANCE OR REPAIR PROCEDURE This alternative may be more economical than the installation and maintenance Erosion will continue adjacent to your works. It an Place additional material at the ends and tie structure of shore protection. existing structure has been flanked, such as the one directly back into the bluff, shown to the right, correct it by placing additional RECESSION RATES material at the ends and tying your works directly into Long-term quantitative data on the rate of recession of a bluff or dune may be the bluff. Check for signs of failure such as lakeward movement of the ends and erosion at the end of the obtained from historic records of the area or the state. Early surveys and plat structure. The illustration to the right shows the result of maps may contain survey points and a plot of the bluff line and shoreline as of the not constructing wingwalls and tying the ends of the date of the survey. Utilizing these existing data, a new topographic map can be structure into the bluff. prepared showing the historic location of the bluff and shoreline and the present RULE 3 location. The distance between the old and existing location documents the Check foundation conditions amount of bluff or dune recession in the period of record. ILAX WARD DISPLACEMENT--,---___ 1A L.11EEOR11-11 I F. A The average cost of moving a typical home isabout $10,000, excluding the costof STONE FOUNDATION 11TERIAL land. This cost includes house moving ($4,500), new foundation ($4,500), and FILL TER utilities and service ($1,000). The cost of a new lot varies considerably depending RESULT OF on location. EXCEESIVE SETTILMENT ADVAHTAGES DISADVANTAGES It is permanent. In the long run it may Special skills and equipment required. CONTINUE ROCK FILL UNDER be the best method of protection. CRIB FOR FOUNDATION Area must be available for relocation of CHECK FOR SIGNS OF FAILURE MAINTENANCE OR REPAIR PROCEDURE Adaptable to short reaches of shore the house. Soft foundation material may result in excessive Re-establish support by constructing underpinning, line. settlement of the structure. Sofi underlayers may allow foundation protection and backfilling. If the structure Does not stop erosion. all or part of structure to slide. Check for settlement, and was impermeable such as a steel wall add or reopen Can be accomplished by the individual excessive displacement. Hydrostatic pressure due to weep holes. through contract with a house mover. groundwater seepage may cause lakeward movementof some types of impermeable walls. 14 MAINTENANCE GUIDELINES IMPROPER SOLUTIONS maintenance requirements are described below. Constant vigilance of all structures is necessary. Inspect your structure after every storm. Repair it immediately if it shows any Each of these IMPROPER SOLUTIONS sign of damage. Except forthe alternative of relocation, the various structures shown below violates two or more construction guidelines. are all subject tofailureifnot builtin accordancewith construction guidelines. Oncebuilt, Can you tell which construction guidelines they must be maintained in accordance with maintenance guidelines. each of these examples violates and how the RULE 4 structures will fail? Answers are provided Use material that is heavy and dense enough that waves under each illustration. will not move individual pieces of the protection VIOLATES RULES 1,2,4 and 6 VIOLATES RULES 1,4 and 6 CHECK FOR SIGNS OF FAILURE MAINTENANCE OR REPAIR PROCEDURE A cause of common failure isto use undersized material; Place additional stone at toe, restore to original waves have tremendous power and can move a lot of elevation, location and thickness, reduce excessive void VIOLATES RULES 1,2,4 and 5 VIOLATES RULES 1,2 and 5 material in a, short time. Small stones, or pieces of ratio, back fill behind structure; extensive upgrading in concrete, wil be moved around and carried away size of material may be required. by small waves. Larger waves will do it even faster. The VIOLATES RULES 1 and 4 unders ized stone that was carried down the slope by Iarge waves. Excessive settlement, increase in voids, loss of filter material, erosion behind or at the end of the structure can result due to the use of small stone layer. Filter material may be required between underlying ground and the prospective material. RULE 5 Build revetment high enough that waves cannot overtop It (spray overtopping Is all right, but not "green water") M any is it ures have happened because the structure was Restore to higher elevation, back fill behind structure, not built high enough and erosion could then continue add filter cloth, and splash apron. behind the, structure as it it were not there. Check for broken wire, excessive movement, and erosion behind or at ends of structure. RULE 6 Make sure that voids between Individual pieces of protection material are small enough that underlying material is not washed out by waves CHECK FOR SIGNS OF FAILURE MAINTENANCE OR REPAIR PROCEDURE A filter material such as plastic filter cloth must 'be Rebuild to original elevation, use at least two layers of placed on a highly erodible embankment to prevent the stone; use a stone filter or plastic filter cloth; fill fine material from washing through the voids in the behind structure. structure. The protection material must be thick enough to make a long passage for dissipation of wave energy prior to reaching the underlying materials. In the case to the right plastic filter cloth was not included. As a result fine bluff material was washed out by waves. ENAMPLE OF DE7ERNMNG DESM DEPTH A numberof general designs for shore protection various design water depths 50 feet offshore of The measured depth 50 feet offshore near Port Huron, works have been presented. These plans should the proposed structure which are shown so you Michigan is 2.1 feet. Information obtained from Detroit be adapted to the site by a qualified engineer. do not have to actually determine the wave District indicates the lake level on Lake Huron at the time Please note we have arranged the designs by height.) This offshore design depth is made up of you measured the depth was 578.0 feet above mean sea function: bank protection, beach accretion, wave three components: The actual measured depth level. From the table on page 3 the forecasted level for height reduction, and bluff stabilization. Since from existing lake level; the difference between the end of August can be found and is 579. From the this pamphlet is rather general it may not be the probable maximum lake elevation and the map on page 6, the approximate wind set-up value for applicable to unusual problems which may existing lake elevation; and an appropriate storm Lake Huron near Port Huron is found and equals 1.4 feet. require a different solution. set-up value. Measured Depth 50 feet offshore = 2.1 feet After selection of a general plan of protection Upon determining the measured Depth 50 feet Expected increase in lake levels from the information given in this pamphlet, the offshore the elevation of the lake surface in (579.0 - 578.0) = 1.0 feet 'next step in planning is concerned with the relation to sea level or low water datum must be extent of the works. Particular reference to determined. This can be done by contacting the Storm setup value = 1.4 feet dimensions of the structure, anticipated align- Corps District Office in your area. Design Depth = 4.5 feet ment, and analysis of foundation conditions will be required. The District Offices can tell you the approximate elevation of the lake surface at the time you Determination of the design wave height for a measured the depth 50 feet offshore. Then this given location is critical to the design of any can be related to the expected forecasted coastal structure subject to wave attack. The increase in level. The Great Lakes shoreline map wave height is in part regulated by water depths on page 6 shows values of storm set-up for over which the wave is passing. The design wave various points on the Great Lakes. Local height is equal to 3/4 the depth of water 50 feet variations of storm setup can be significant, lakeward of the water's edge. The structures particularly at the heads of bays. The determina- described in this pamphlet are located in very tion of the design depth for a typical situation is shallow water. As a result they are designed for illustrated in the diagram on the right. relatively small waves. Information on the height of the structure above the design water surface and its design specifications are given as a function of the anticipated offshore depth. (The specifications were developed based on wave heights for the 16 ILLD), IE 0 @ Q H a The general design of shore protection works Structures should also be designed and con- on, so that they can be incorporated into more and list of materials for various design depths structed in stages so that the first stage will permanent works. were given in the typical general designs become an integral part of more permanent illustrated on pages 8 to 14. These plans show protection. There is always the possibility that the dimensions and list of materials from a full the works you decide to build will not function as Protecting the lower portion of the structure is range of offshore depths and a table of materials you had intended. Supplemental construction extremely important. Toe protection should be that can be used for the elements of shore would then become necessary. The initial works provided to insure the integrity of the structure. protection structures. should be designed for the possibility of adding This protection should extend below anticipated scour or to bedrock. This can be accomplished by protecting erodible foundation material with heavy stone. The ends of the structure deserve careful considerations. If possible, structures should terminate at other protective works. Since this is not possible in many locations, the protective ---------- 580.4 ------------- DESIGN WATER SURFACE works must be returned securely into the bluff or bank. Extra materials are needed to tie into the 1.4 FEET WIND SET-UP bank. 579.0 ------------- FORCASTED LEVEL DESIGN DEPTH END OF MONTH-AUGUST 4.5 FEET 1.0 FOOT FORCASTED INCREASE Foundation design is another important con- 578.0- sideration. If bulkheads are considered, sub- surface investigations are needed to insure it is 2.1 FEET (MEASURED DEPTH) possible to drive the piling and to determine location of slippage planes. On the other hand, the lake bed materials may not have sufficient strength to support the protective works. A filter blanket consisting of small stones orfiltercloth is needed for structures to prevent loss of fine material such as sand from beneath the 50 FEET structure. 2.1 FEET The next step is the final design and layout of the protective elements. This is beyond the scope of this pamphlet and we again recommend you - - - - - - - - - - - - - - obtain the services of a qualified engineer; especially where the cost of the features exceed $100 per foot. 17 -SAMPLE SPECIFICA7MNS Sample government specifications covering the work illustrated in this pamphlet are provided below to assist in preparing contract plans and specifications should a contractor's services be required. S07E "MORK PLACEREM7 POL9MG 7MMER This work consists of performing all excavation and Stones shall be placed by equipment suitable for Wood piles shall conform to Federal Specification backfilling. All work shall be conducted in a manner handling material of the sizes required. The cover MM-P-371, Type 1, Class B, rough-peeled subject to to prevent damage to the structures which are to stone shall be placed a minimum of two layers thick. further limitation in this Section of the specifica- remain and to maintain or improve the aesthetics Stones shall be placed by means of a bracket or tions. The piles shall be treated in accordance with and ecology of the site. strip. End dumping will not be permitted. Stoneshall Federal Specification TT-W-571 with creosote by SYOMIE PROTECMM not be dropped from a height greater than three feet. the pressure process. The wood piles shall be The work required consists of furnishing and GRADIES treated to refusal with a minimum creosote content of ten pounds per cubic foot. The Contractor shall placing stone as indicated on the drawings and Cover stone and toe stone shall be placed to the make provisions for treating in the field, all cuts, herein. Surplus material other than stone shall be grades (neat lines) shown on the drawings, within a holes and abrasions in the creosoted piles. placed against the toe stone, as directed. All stone tolerance of 0.5 foot above grade and 0.5 foot below Abrasions and cuts in the piles shall be given two required shall be produced from quarries approved grade, measured perpendicular to the neat lines. brush coats of the creosote followed by a heavy coat by the owner. The intention is that the stone protection shall be of tar paint. The lengths of pilesshall be as called for FOUMBAYOOM PREPARA700M built to at least the neat lines, the outer surfaces on the drawings. To provide for "heading" and shall be reasonably even and present a uniform cutting off square after driving, piles shall be driven Areas on which cover stones and toe stones are to appearance and that extreme ranges in tolerance within one foot of the depths specified. be placed shall be trimmed and dressed as needed will not be allowed in surfaces of adjacent stones. to provide stable bedding and so that the stones PLAVMG AMD ORMMG NUMG may be placed within the allowable tolerances from NUMG: SHEIET S7EEL Driving equipment shall be a size and type required the neat lines. Where cover stone areas are below Shop drawings shall be submitted to the owner for to drive piling to the required penetration without the required depth, they shall be brought to grade his approval. The Contractor shall furnish two serious damage tothe pile. Piledriving leads shall be by filling with core stone. To the extent practicable, certified copies of all mill reports covering the marked so as to facilitate counting of the blows. A the larger sizes of core stone shall be placed in the chemical and physical properties of the steel used in protective pile cap of approved design shall be upper surface of the core stone. the work. employed in driving, when required, to prevent LM70MG MRAEM&OMS Steel for sheet piling shall conform to the damage to the tops of the piles. Spliced piles shall Cover stone and toe stone shall be in pieces requirements of ASTM Standard A 328. not be used. All piles shall be driven to the penetration called for where practicable to do so generally compact in shape and as nearly cubical as Piles, including special fabricated sections, shall be without damage to the piles. possible with the least dimension of any stone being of the types indicated on the drawings and shall be not less than one-third its greatest dimension. of a design such that when in place they will be QUALM COMTROL Stone shall consist of a well-graded mixture of sizes continuously interlocked throughout their entire The contractor shall establish and maintain a that will form a compact mass in place. The mixture length. All piles shall be provided with standard quality control system for all operations performed shall be well-graded within the limits of maximum handling holes located approximately four inches under this contract to assure compliance with and minimum as specified on the drawings. Where below the top of the pile. Eachsteel pileshall befree contract requirements and maintain records of his space does not permit the inclusion of the larger from any kinks and shall not possess camber, twist, quality control for all operations performed. or warp of a degree which will, in any manner, sizes of stone, these sizes shall be omitted from the prevent easy and ready driving of a pile. The mixture. interlock of each pile shall be straight throughout its entire length and shall be of such shape and dimensions as will permit free and easy threading. 18 3HORELMD RUHMEN ENT The Coastal Zone Management Act passed by the U.S. Congress in 1972 with Successful management of the coastal zone's resources also depends its 1976 amendments establishes a national interest in the effective upon local participation through development of a management plan or management, beneficial use, protection, and development of the coastal zone strategy by individual property owners when they consider shore by providing assistance and encouragement to coastal states to develop and protection. An individual's management strategy would consist of implement management programs. The addresses for the Great Lakes States evaluating the need for shore protection, selecting suitable techniques to coastal zone management offices are listed below. Questions concerning provide structural or non-structural erosion control considering other individual state programs should be addressed to the property owner's uses of theshore area, and formulating and then implementing a plan. This respective state office. pamphlet has presented information on techniques that may be used to provideshore erosion control. It must be understood; however, that some Illinois Indiana of these techniques alter littoral processes and may have eitheradverse or Division of Water Resources State Planning Services Agency beneficial effects on other shore uses. Illinois Department of Transportation 143 West Market Street For example, revetments and bulkheads protect only the land area behind 10th Floor Indianapolis, Indiana 46204 them and afford no protection foradjacent beach areas. Erosion in front of 300 North State Street Minnesota these structures may be increased, and if a recreational beach is to be Chicago, Illinois 60610 State Planning Agency maintained in front of them, additional beach erosion control devices may Michigan 801 Capitol Square Building be necessary. Coastal Management Program St. Paul, Minnesota 55155 Although groins or an offshore breakwater may provide additional beach Department of Natural Resources Ohio area at the structures, it is often at the expense of the downdrift shoreline. Division of Land Resource Program Department of Natural Resources Groins and offshore breakwaters may cause recession of the shoreline P.O. Box 30028 1930 Belcher Drive downdrift, because the supply of sand to the downdrift shoreline is Lansing, Michigan 48909 Columbus, Ohio 43224 reduced by the accumulation at the structures. In contrast, beach New York nourishment provides effective protection without altering the recrea- Division of State Planning Wisconsin tional values of the shoreline. State Planning Office Department of State B-130 One West Wilson Street 162 Washington Avenue Madison, Wisconsin 53702 Albany, New York 12231 Pennsylvania Division of Outdoor Recreation 3rd and Reilly Street Harrisburg, Pennsylvania 17120 19 PROJECTS The Corps of Engineers and several Great Lakes states below, with accompanying photographs, and the have been involved in a number of demonstration and locations are shown on the Great Lakes map on page research projects to develop low-cost practical means 6. Contact the agency listed for specific information. of shore protection. Demonstration sites are discussed In response to increased concern for the loss of public and private lands caused by shoreline erosion and the resulting environmental and economic damage, Con- gress authorized Section 54 of the Water Resources AUL Development Act of 1974, Public Law 93-251. This Section, also known as the Shoreline Erosion Control Demonstration Act of 1974, provides that a 5-year program be developed to demonstrate low-cost means to prevent and control shoreline erosion. Two sites were selected on the Great Lakes, one at Port Wing, Wisconsin, in the St. Paul District; and the second at Geneva State Park, Ohio, in the Buffalo District. The projects are scheduled for construction during the fall of 1978. Following that time, the projects will be available for the public to observe their effectiveness. The Port Wing project is shown in the illustration on the right and the Mft@ Geneva State Park project is shown on the following page. , * _R The types of structures proposed for Port Wing are steel QZ__ Rot.- H-piles with railroad ties placed and secured between the piles; a revetment of scrap tires filled with sand, backfilled with granular material; and three different sizes and types of concrete blocks laid on granular material. At each end of the protection and between each demonstration structure, rip-rap sections will be used to prevent possible failure of the structures due to flanking and to prevent 14 failure of one structure from influencing the adjacent structure. Vegetation will be used on the graded slope above the structural measures to stabilize the slope and prevent soil erosion. Demonstration project at Port Wing. 20 BE M\-/ (3H2'T[Ra7MH [PROJECTS (CONTINUED) Three experimental offshore stone breakwaters with beach fill placed behind the structures were constructed between May and Three types of offshore breakwaters of various construction are July 1978 by the Buffalo District on Beach 10, Presque Isle, PA; Lake proposed for the Geneva State Park site. The types of structures are Erie. The breakwaters were constructed to obtain information and gabions and two types of pre-fabricated concrete units. Also, data which can be used in determining whether breakwaters would vegetation will be incorporated into the project to assist in be the best permanent shore protection method for the eroding stabilizing a portion of the sand trapped by the structures. areas of Presque Isle. @'A IN, ......... '7 -777 7 A- Demonstration project of Geneva State Partr Brealarmters; at Beach 10, Presque Isle. 21 DEMONSTRATON PROJECTS (CONTINUED) Public Law 520, 71st Congress and Public Law 166, 79th A vegetative dune-building demonstration project was planted Congress, authorized the United States in cooperation with the in May 1977 west of Beach 10, Presque Isle, PA using American states, to study and report on means for the stabilization of Beach grass and prairie sand reed. The project was planted by beaches at shoreline areas. To demonstrate the effectiveness of the U.S. Army, Corps of Engineers, Coastal Engineering using beach grasses to build and stabilize dunes on the shores Research Center, Ft. Belvoir, Va.; in cooperation with the North of the Great Lakes to protect against erosion, a demonstration Central Division and the State of Pennsylvania. site was selected on the Pennsylvania and Michigan shorelines. The two sites are described in the following paragraphs. A vegetative demonstration project similar to the one at Presque Isle was planted in 1977 at Ludington State Park, M I by the Corps of Engineers in cooperation with the State of Michigan. -7 7 Vegetation site at Presque Isle Vegetation site at Ludington State Park 22 (CONTINUED) ".6 The Michigan Department of Natural Resources, Bureau of Water Management, implemented under the authority of Act 14 of the State Public Acts of 1973, a Demonstration Erosion Control Program in 1974 to demonstrate both innovative and conventional means of shore protection. All of the devices installed were intended to be low cost, and the costs varied from about $50 to $100 per foot. Reports have been prepared to describe the program and to report on the results achieved during the first three years of the study. The most A-, recent report is entitled "The Michigan Demonstration Erosion Control Program in 1976." Photographs of several of the demonstration sites are shown here. Gabion groin, 3 M1108 sough of Port Sanilac, 01. ond-fill3d Roca rovo@mznk ny�on tube groin 3 miles at To uYes Pt. 01. sough of Port S.Tniizc, 01. 23 -GLOSSARY OF 7ERMS ALONGSHORE - Parallel to and near the shoreline; same EQUILIBRIUM - A state of balance or equality of opposing PILE - A long, heavy timber or section of concrete or metal as LONGSHORE. forces. to be driven or jetted into the earth or lakebed to serve as a BACKSHORE - That zone of the shore or beach lying be- EXPEDIENT - A device used in an emergency such as a support or protection. tween the foreshore and the coastline and acted upon by structure intended to provide shore protection during the PILE, SHEET - A pile with a generally slender flat cross waves only during severe storms, especially when combined period of high lake levels. section to be driven into the ground or lakebed and meshed with exceptionally high water. FORESHORE - The part of the shore lying between the or interlocked with like members to form a diaphragm, wall, BEACH PROFILE - A side view of the zone along the crest of the seaward berm (or upper limit of wave wash) and or bulkhead. shoreline that extends landward from the water's edge to the the water's edge, that is ordinarily traversed by the uprush QUALITY CONTROL - A standard of comparison which toe of a dune or bluff. and backrush of the waves. assures a minimum of deviation from the standard. BREAKWATER - A structure protecting a shore area, FUNCTIONAL LIFE - The period of time the structure REFLECTED WAVE - That part of an incident wave that harbor, anchorage, or basin from waves. performs as intended. Performance can be expressed in terms is returned seaward when a wave impinges on a steep beach, BULKHEAD - A structure or partition to retain or prevent of benefits obtained versus the cost of maintenance. barrier, or other reflecting surface. sliding of the land. A secondary purpose is to protect the GROIN (British, GROYNE) - A shore protection structure REFRACTION (OF WATER WAVES) - The process by upland against damage from wave action. built (usually perpendicular to the shoreline) to trap littoral which the direction of a wave moving in shallow water at an CROSS SECTION - A vertical section (profile) of the surface, drift or retard erosion of the shore. angle to the contours is changed. The part of the wave the ground, and/or underlying material, which providesaside HEADS OF BAYS - In the approximate center of a bay advancing in shallower water moves more slowly than that view of the structure or beach (see beach profile). between the two points or headlands which form the bay. part still advancing in deeper water, causing the wave crest to CURRENT, LITTORAL - Any current in the littoral zone IMPERMEABLE - Not permitting passage of water. bend toward alignment with the underwater contours. REVETMENT - A facing of stone, concrete, etc., built to caused primarily by wave action, e.g., longshore current, rip LITTORAL - Of or pertaining to a shore. protect a scarp, embankment, or shore structure against current. LITTORAL DRIFT - The sedimentary material moved in erosion by wave action or currents. CURRENT, LONGSHORE - The littoral current in the the littoral zone under the influence of waves and currents. RIPRAP - A layer, facing, or protective mound of stones breaker zone moving essentially parallel to the shore, usually generated by waves breaking at an angle to the shoreline. LITTORAL TRANSPORT - The movement of littoral drift randomly placed to prevent erosion, scour, or sloughing of a in the littoral zone by waves and currents. Includes move- structure or embankment; also the stone so used. DATUM, PLANE - The horizontal plane to which soundings, ment parallel (Iongshore transport) and perpendicular (on- SEAWALL - A structure separating land and water areas, ground elevations, or water surface elevations are referred. offshore transport) to the shore. primarily designed to prevent erosion and other damage due Also REFERENCE PLANE. LITTORAL ZONE - In beach terminology, an indefinite to wave action. See also BULKHEAD. DEEPWATER WAVE - Waves which develop in water of zone extending seaward from the shoreline to just beyond SPECIFICATIONS - A detailed description of particulars, sufficient depth that they are not influenced by the friction the breaker zone. such as size of stone, quality of materials, contractor per- of the lake bottom. LONGSHORE - Parallel to and near the shoreline. formance, terms, quality control, etc. DIFFRACTION (of water waves) - The phenomenon by which energy is transmitted laterally along a wave crest. NEARSHORE (ZONE) - In beach terminology an indefinite STILLWATER LEVEL - The elevation that the surface of when a part of a train of waves is interrupted by a barrier, zone extending seaward from the shoreline well beyond the the water would assume if all wave action were absent. such as a breakwater, the effect of diffraction is manifested breaker zone. It defines the area of NEARSHORE CUR- UPDRIFT - The direction opposite that of the predominant by propagation of waves into the sheltered region within the RENTS. movement of littoral materials. barrier's geometric shadow. NEAT LINES - Lines on drawings which establish tolerances VOID RATIO - The volurpe of space or gaps to the volume DOWNDRIFT - The direction of predominant movement of for construction. of the area of the structure such as a stone revetment. littoral materials. PERMIT - A document issued by the Department of the WIND SETUP - (1) The vertical rise in the stillwater level on EROSION @ The wearing away of land by the action of Army expressing the assent of the Federal Government, so the leeward side of a body of water caused by wind stress natural forces. On a beach, the carrying away of beach far as concerns the public rights of navigation and the on the surface of the water. (2) The difference in stillwater material by wave action, tidal currents, littoral currents, or general public interest, for the accomplishment of certain levels on the windward and the leeward sides of a body of wind. works on or adjacent to navigable waters of the United States. water caused by wind stresses on the surface of the water. 24 4S p, Raw A# 0 AM UL IF, " A- lo*o A 'A QY - DEPARTMENT OF THE ARIV- NORTH CENTRAL DIVISION 3 6668 00000 5407