[From the U.S. Government Printing Office, www.gpo.gov]




                                                                             I
                                                                             FY 1992 FINAL PRODUCT Task 34
                                                                                            Technical Assistance

































                                 UNREGULATED DAMS


                      IN CHARLES CITY AND NEW KENT COUNTIES





                                 Prepared by the
                  Richmond Regional Planning District Commission

                                  November, 1993



















          A Report of the Virginia Department of Environmental Quality's
                 Coastal Resources Management Program pursuant to
              National Oceanic and Atmospheric Administration Award
                                No. NA270ZO312-01


                This paper is funded in part by a grant from the
                 National Oceanic and Atmospheric Administration.
          The views expressed herein are those of the author and do not
                                      'r MW








            necessarily reflect the views of NOAA or any sub-agencies.












                                  ACKNOWLEDGMENTS

              The Richmond Regional Plainning District Commission staf f
        gratefully acknowledges the contributions of the staffs from the
        Virginia Department of Conservation and Recreation Bureau of Rivers
        and Shorelines, Charles City County Department of Planning, and New
        Kent County Department of Planning. Without them this study would
        not have been possible.











                                      TABLE OF CONTENTS


                                                                               Page(s)
          I.       INTRODUCTION   . . . . . . . . . . . . . . . . . . . .. .         1

          II,      STUDY PURPOSE                                                     3


          III.     INVENTORY PROCEDURE     . . . . . . . . . . . . . . . . .         6


          IV.      INVENTORY . . . . . . . . . . . . . . . . . . . . . . .           7
                    CHARLES CITY COUNTY    . . . . . . . . . . . . . . . . .         7
                      County Description      . . . . . . . . . . . . . . . .        7
                      Inventory Data     . . . . . . . . . . . . . . . . . .         7
                    NEW KENT COUNTY    . . . . . . . . . . . . . . . . . . .        10
                      County Description      . . . . . . . . . . . . . . . .       10
                      Inventory Data     . . . . . . . . . . . . . . . . . .        11

          V.       UNREGULATED DAM INSPECTIONS       . . . . . . . . . . . . .      14


          VI.      ISSUE IDENTIFICATION    . . . . . . . . . . . . . . . . .        is
                    REGULATORY PROGRAMS    . . . . . . .                            is
                      Virginia      Department      of    Conservation       and
                            Recreation   . . . . . .   * ' * * * ' ' *    * * ' '   is
                      Chesapeake Bay Local Assistance Department          . . . .   is
                      Local Code    . . . . . . . . . . . . . . . . . . . .         16
                    TECHNICAL ASSISTANCE      . . . . . . . ... . . . . . . .       16


          VII.-    CONCLUSIONS    . . . . . . . . . . . . . . . . . . . . .         18


          VIII. RECOMMENDATIONS        . . . . . . . . . . . . . . . . . . .        19


                                           APPENDICES


          APPENDIX A      DAM INSPECTION CHECKLIST


          APPENDIX B      CHARLES CITY SITE VISIT INSPECTION SUMMARY


          APPENDIX D      VIRGINIA DAM SAFETY REGULATIONS


          APPENDIX E      SAFETY EVALUATION OF SMALL EARTH DAMS











                                   I. INTRODUCTION

               Public awareness of dams is commonly rooted in the image of
          highly engineered, large concrete structures, impounding vast
          quantities of water. Structures such as these automatically bring
          to mind the great forces they contain, and the disastrous
          consequences that will occur should they fail. Most of these large
          dams were designed for the purpose of hydropower, water supply,
          and/or flood control, and were either built by agencies of the
          federal government or regulated by a federal agency. Some of the
          larger dams in Virginia include Smith Mountain Lake Dam, Lake Anna
          Dam, and Philpott Dam.   This regulatory scrutiny, beginning with
          design and construction, and on through the design life of these
          types of structures provides a high level of confidence in their
          integrity and safety.

               However, in the past not all dams were reviewed and inspected.
          The National Dam Safety Program was authorized by Congress in 1972
          and the purpose of the program was to inventory and inspect dams
          throughout the United States.     It was not until 1977 that the
          program was supported with significant funding.       This renewed
          interest in dam safety came about after the occurrence of several
          significant dam failures in the 19701s.    These failures included
          the failure of Teton Dam, a newly constructed 305 foot high
          federally design and built dam, but there were also failures of
          much smaller dams causing significant damage and loss of life.

               The Virginia Dam Safety Program was initially developed with
          the Army Corps of Engineers as part of the national program from
          1977 through 1981.    After this initial set up, the dam safety
          program became the responsibility of the Commonwealth.             In
          Virginia, dams are governed under the "Virginia Dam Safety Act" and
          the "Impounding Structure Regulations" (Appendix C) .       The dam
          safety program is administered by the Virginia Department of
          Conservation and Recreation's Division of Soil and Water
          Conservation.    Regulated dams, or "impounding structures", in
          Virginia are  those structures which are 11 ... equal to or greater
          than 25 feet in height and which create a maximum impoundment equal
          to or greater than 50 acre-feet ... 11. Dams which are not regulated
          included dams which are owned or licensed by the federal government
          and those dams which are less than 25 feet in height or that
          impound less than 50 acre-feet.

               Most unregulated dams do not pose serious problems to public
          health and safety, or property when they fail.            Typically,
          significant damage is limited to the dam owner with the loss of the
          dam and the lake. While the unregulated dams are not very high and
          do not impound a great deal of water, recent experience has
          demonstrated that the failure of unregulated dams       have caused
          significant problems and damage.



                                           I









               On July 1990, the Cockram Mill Dam in Patrick County failed
               under the pressures of rising flood waters. The 57 year old
               mill dam impounded 150 acre-feet of water, but it's height of
               20 feet was 5 feet under the state threshold for regulation.
               The Cockram Mill Dam failure resulted in 11 ... channel erosion,
               uprooted trees, debris pile-ups, uprooted road signs, mud
               flats, damaged lawn furniture, and some structural damage to
               the adjacent mill house. This dam failure left behind large
               concrete debris and a 20 acre mud flat that was once a full
               reservoirll.-@

               In March 1993, after a week of significant spring rains, there
               were two dam failures in Central Virginia investigated by DCR
               personnel. In Powhatan County, storm flows through a poorly
               maintained emergency spillway caused the spillway to erode
               back to the lake. This in turn, caused a sudden drawdown of
               the lake which lead to an upstream embankment slope failure.
               While not a complete failure, preliminary estimates to repair
               this dam are between $200,000 and $250,000. In Chesterfield
               County, a masonry dam failed completely when the pressure of
               the water overtopping the dam exceeded the structural capacity
               of the dam.    The owner has not rebuilt the dam because of
               financial constraints.

               In June 1993, while field work for this study was in progress,
               DCR personnel investigated the failure of Haynes Mill Pond Dam
               in Gloucester County. This failure was probably the result of
               improper improvements to the spillway.            This failure
               undermined the support structure of the Route 614 bridge
               immediately adjacent to the spillway and this caused the road
               span to collapse.     Fortunately no accidents occurred, but
               traffic was rerouted for over a week and the repairs to the
               roadway totalled over $90,400.

               Dams and the water they impound support numerous beneficial
         uses  which are often not fully recognized or utilized. Dams are
         always constructed initially with some beneficial use in mind.
         Many older dams were designed to impound water to drive mills to
         process grain and, while they no longer serve this purpose they
         have the potential to support other uses.         Other uses include
         agricultural water for livestock and irrigation, wash water for
         sand and gravel processes, fire suppression, erosion and sediment
         control, flood control, and recreation. Many dams and their lakes
         could be better utilized for the public good.






               'Gregory B. Secrist, "The Failure of the Cockram Mill Dam,"
         VLA NEWS, Issue No. 16, Winter 1991, p.l.

                                            2












                                  Il. STUDY PURPOSE

              Recent dam failures in other parts of the Virginia alerted
         Richmond's local officials to the need for more basic information
         on unregulated dams. Members of the RRPDC's Regional Environmental
         Committee from Charles City and New Kent requested RRPDC staff
         conduct a study of unregulated dams in their localities (Map 1).
         RRPDC staff applied for and received funding for this project under
         the Virginia Coastal Resources Management Program f rom the Virginia
         Council on the Environment (now absorbed into the Department of
         Environmental Quality, DEQ).

              The purpose of this study is to inventory and assess the
         condition of unregulated dams in Charles City and New Kent
         Counties, to provide a preliminary data base of information on
         unregulated dams in the counties, to identify issues related to the
         management, safety, and use of these structures, and to recommend
         alternatives to address these issues on a local, regional, and
         state level.

              Most Virginia localities lack the basic information necessary
         to understand the scope of potential benefits, problems and hazards
         related to unregulated dams. In 1981 the "Inventory of Dams" for
         the Commonwealth prepared by the Army Corps of Engineers and the
         Virginia Water Control ]Board (now the Water Division of the
         Department of Environmental Quality) was completed. This inventory
         listed approximately 1, 500 dams in Virginia. Approximately a third
         of the dams identified in this inventory are regulated under the
         Commonwealth's current program.     In Charles City, two dams were
         identified in this inventory, neither were of a size to be
         regulated. In New Kent 11 dams are listed on this inventory, and
         only one of which is regulated. Furthermore, the lower threshold
         for dam size utilized to develop the Corps/VWCB inventory meant
         that many other "small" dams were never included in the inventory.

              Localities need better basic information than what is
         currently available to understand any potential problems. while
         the Department of Conservation and Recreation has no regulatory
         authority over these smaller structures, the Department's Dam
         Safety Section elected to participate in this study in order to
         update the inventory and more importantly to evaluate potential dam
         safety problems and the magnitude of potential hazards in these
         counties.

              The needs of the owners of unregulated dams is also a concern.
         The dam owner is liable for any damage or destruction of life and
         property caused by a dam failure. The owner will also loose the
         use of the impounded water and may experience a potentially serious
         loss of income. Furthermore, the cost of replacing the dam can be
         extreme compared to the cost of proper care and maintenance. Dam
         owners can benefit from basic information on liability issues,
         proper dam design and construction methods, and basic operation and

                                           3









        maintenance procedures.

             The study was performed by Richmond Regional Planning District
        Commission (RRPDC) staff with technical guidance of staff from the
        Department of Conservation and Recreation's (DCR) Dam Safety
        Section and the assistance of Charles City and New Kent personnel.













































                                         4



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                                    IV. INVENTORY


         CHARLES CITY COUNTY

              Data f or Charles City County was developed f rom reviews of
         USGS 7.5 minute topographic maps, USDA Agricultural Stabilization
         and Conservation Service aerial photographs, and field inspections.
         USGS map coverage includes the quad sheets of Roxbury, Providence
         Forge, Walkers, Hopewell, Westover, Charles City, Brandon, and
         Claremont. This section describes the data developed for the study.

         County Description

              Charles City County is located in Virginia's coastal plain
         physiographic region.    This rural locality is relatively flat in
         the east with gently rising elevations in the central and west
         central sections of the County. Elevations range from sea level to
         150 feet above sea level. Some steep slopes can be found scattered
         throughout the County.

              Charles City is bordered on the south by the James River which
         is tidal along this   reach.   The Chickahominy River makes up the
         County's eastern and northern boundary. The Chickahominy is tidal
         up to Walkers Dam which blocks any further tidal influence
         upstream. Domestic,   commercial and industrial water demand for the
         County is met through groundwater sources. The County operates two
         water wells and associated distribution systems.

              Soils in the County are typically composed of silts, sands and
         clays originating from marine and alluvial deposits. The County is
         mostly forested with agricultural activity found primarily in it's
         southern half.

              Small community centers are scattered throughout the County
         and industrial development is located near Roxbury, a community in
         the County's northwest.        The County's 1991 population was
         approximately 6,3 002.

         Inventory Data

              In Charles City County there are two dams listed in the
         original 1981 inventory, but these structures are not subject to
         regulation. An additional dam on the county line between Henrico
         County and Charles City County is also listed in the 1981 inventory
         and this dam was included in this study.       Initially, a total of
         sixty-three impoundments were identified in Charles City County,
         including the three noted above.      Of those sixty-three, 33 were
         included in this study and inventory because they impounded a lake
         surface area of significant size.       The thirty impoundments not


              2Center for Public Service, University of Virginia.

                                            7




                                                Unregulated Dam Study Area
                                                              Richmond Regional Planning District





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                                       Legend                              Scale of Miles                             N
                                51.1 . ...... I M ri.dy A-                  NOOK-EMOV--i
                                Poe 15         E] C-ly I.-.,d.,,            0     20 40 60 80                                   Prepared by: Richmond Regional Planning Distric Commission, 1993.











                              III. INVENTORY PROCEDURE

              An inventory    of potential dam sites was developed by
         identifying impoundments shown on United States Geological Survey
         (USGS) 7.5 minute topographic maps. Recent aerial photographs of
         the counties provided by the United States Department Agriculture
         (USDA) Agricultural Stabilization and Conservation Service were
         examined for potential sites not shown on the USGS topographic
         maps. It was determined that the number of all potential dam sites
         noted on the maps and photographs was too numerous to be field
         inspected within the time frame of the study. Based on the best
         professional judgement of the DCR Dam Safety Section it was decided
         that the smallest impoundments (lake surface area of approximately
         5 acres or less) would not be inventoried nor field surveyed.

              A dam inspection checklist (Appendix A) was developed by DCR
         staff for the field survey.     The checklist was not a detailed
         inspection form but was developed to be used to assess the general
         condition of the dam including the embankment, principal spillway,
         emergency spillway, downstream channel, reservoir area, watershed
         area, and downstream area. Basic dimensions of the structure were
         estimated, and if available any dam history noted. Three days were
         spent in each county conducting field surveys of the dams
         identified using the maps and aerial photography during the months
         of June and July 1993.       For a variety of reasons, not all
         identified impoundments were surveyed.     Some access roads were
         barred to vehicular traffic with locked gates and chains while
         others were located far back in densely wooded areas with no
         apparent access road. Some identified impoundments were the result
         of beaver activity and were dropped from the study. Inventory and
         inspection data were then compiled and evaluated as a basis to
         identify issues related to the Counties unregulated dams.




















                                          6









         included in the inventory were determined to be very small with a
         lake surface area of less than 5 acres, and based upon the
         topographic mapping and aerial photography did not appear to pose
         a significant hazard to life or property downstream. Impoundments
         that. were the result of beaver activity were also not included in
         the inventory.

              Of the thirty-three inventoried impoundments, the inspection
         team was able to access fifteen. A total of eighteen is included
         in Table 1 under-the category of "Dams Inspected" since three were
         on the 1981 inventory. Three of these 18 dams had been breached
         and two of the 3 rebuilt. The third breached dam is included in
         the inventory as the remains of the dam might possibly be repaired.
         Table 1 contains the inventory data developed for this study. Map
         2 displays the location of the  inventoried dams and  those dams   that
         were inspec ted


                 .... . .. .. ... .




                                                                  ......    XX
                                                                 . I I I I I..  ....

                                                                 ... .......

              USGS      Impoundments       Dams         Dams          Dams
           7.51 Topo     Identified    Inventoried    Inspected    Regulated

             Brandon          11             5            3            0



             Charles          11             5            2            0
              city

           Providence         10             5            2            0
              Forge

             Roxbury          13             8            5            0


             Walkers          4              4            3            0



             Westover         14             6            3            0



              Total           63             33           18           0



         Note:      The area  of Charles City  County covered by the Hopewell
                    and Claremont topos contained no impoundments.

               For the eighteen dams that are listed above as inspected,
         their present and/or former uses were determined: eight are used
         for agricultural purposes (3 of which were former millponds)      eight
         were primarily recreational and habitat for wildlife; two


                                             8





                                        Inventoried and Inspected Dams
                                                                    Charles City County








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                                     Legend

                            Jufisdiction       Roa&


                            Hy&ogmphy          Dam                 Scale Of Miles        N
                                                                    Mff::@
                                                                    0    1    2
                            Highways           lmspecWd
                                                                                              Prepared by: Richmond Regional Planning District Commission, 1993
                                                                                                                                                       __j











         structures were associated with the Harrison Lake National Fish
         Hatchery; one is a water supply source for Newport News; and, one
         functions as an erosion and sediment control and storm water
         management facility. In addition to these eighteen structures, 3
         impoundments are associated with sand and gravel operations. Table
         2 contains data on dam uses of the twenty-one dams noted above.




                                 ..................... .........


                                              M

                pon   Agriculture  Sand and   Fire    Recreation Water Supp y
                       Livestock    Gravel   Control   Habitat    E&S Control

              (3)1         8          3       (1)         8           2

                Dual purpose included under agricultural purposes

         NEW KENT COUNTY

               Data for New Kent County was developed from reviews of USGS
         7.5 minute topographic maps, USDA Agricultural Stabilization and
         Conservation Service aerial photographs, and field inspections.
         USGS map coverage includes the quads sheets of Quinton, Tunstall,
         New Kent, West Point, Roxbury, Providence Forge, Walkers, and
         Toano. This section describes the study data.developed for New Kent
         County.

         County Description

               Like Charles City County to the south, New Kent County lies
         within the coastal plain physiographic region of central Virginia.
         The County is relatively flat with gradually rising and falling
         terrain. Some steep slopes are variously scattered throughout the
         County.    Elevations vary from sea level to 160 feet above sea
         level.

               The County's southern boundary is formed by the Chickahominy
         River and it's northern boundary by the York and Pamunkey Rivers.
         The County's eastern boundary runs along Ware Creek and the
         Diascund Reservoir, while it's western border is not defined by a
         discernable natural feature.      The York and Pamunkey Rivers are
         tidal in New Kent. The Chickahominy is tidal to Walkers Dam, which
         blocks further tidal action upstream.

               The Diascund Reservoir is a manmade 2.1 square mile body of
         water that provides pump over storage of raw water from the
         Chickahominy River at Walkers Dam.       The reservoir is owned and
         operated by the Newport News Waterworks as a raw water source for
         Newport News. For New Kent County the water supply for domestic,
         commercial and industrial use is met through groundwater supply.


                                           10









         The County owns a number of wells, and several residential
         developments are served by private central groundwater systems.

              Soils in the County are derived from a marine and alluvial
         deposits and are typically composed of sands, silts, and clays.
         The County is mostly forested with extensive agricultural
         production occurring along the Pamunkey River corridor to the
         north. Small communities are variously scattered throughout the
         County, with the county seat is located at New Kent Court House.
         New Kent's 1991 population was approximately  10,9003.

         Inventory Data

              In New Kent County there are eleven dams listed on the
         original 1981 inventory. Of these eleven dams, only Diascund Dam
         noted above is regulated by the Commonwealth.      Including these
         eleven, there were 83 impoundments in New Kent as identified from
         both USGS quad sheets and ASCS aerial photographs. Impoundments
         that were the result of beaver activity were not included in this
         inventory. Of the eighty-three identified, 39 were inventoried for
         this project. The remaining forty-four were determined to be too
         small to be inventoried and did not appear to pose a threat to life
         or property downstream. of the thirty-nine inventoried dams, 25 of
         the dams were accessible for inspection.      Table 3 contains the
         inventory data developed for New Kent County. Map 3 displays the
         location of the inventoried and inspected dams in New Kent County.

              For the twenty-five dams that are listed above as inspected
         their present and/or former uses were determined. Eleven dams were
         apparently used for milling operations, although none are presently
         used for that purpose.    Four dams were used primarily used for
         agricultural purposes, watering livestock and crops. Two dams had
         dry hydrants installed for the purpose of providing water for fire
         suppression, twenty-one were apparently used for recreation and
         habitat. of these twenty-five dams, 5 had state maintained roads
         over them. Table 4 list observed dam uses.

















              3Center for Public Service, University of Virginia.

                                          11



                                                                                                                                               i A


                                   Inventoried and Inspected Dams
                                                            New Kent County


















                                Legend
                   F]   Jufisdiedon  - Roa&

                        Hy&ogmphy A Dam                                     N
                                                          &We of Mfles
                                                                   F--1
                        H@&ways          lWected       0 1 2 3 4
                                                                                 Prepared by: Richmond Regional Planning District Commission, 19931















           ......... .. .... ....
                          ....             . .. ...... .


                                                       C.
                                     ...........


                 USGS        Impoundments           Dams            Dams             Dam
              7.51 Topo       Identified       Inventoried Inspected             Regulated

              New Kent               9                 3              2               0



             Providence              12                4              1               0
                 Forge

                Quinton              20                7              7               0


                Roxbury              3                 1              1               0


                 Toano               14                9              6               0



               Tunstal'l             13                8              5               0



                Walkers              7                 2              0               1*



             West Point              5                 5              3               0



                 Tot 1               83              39              25               1



                    Diascund Dam is the only        dam in New Kent      that is regulated
           under the Dam Safety       Program.




                                                        ... ..........
                 . . . . . . . . . .1. .............
                                                            .. ............



                      pon     Agriculture    Sand and      Fire      Recreation
                               Livestock      Gravel     Control      Habitat        oa

                    (11)1           4            0         (2)1          21          (5)

                    included in other categories         of this table.


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                                                     12











                           V. UNREGULATED DAM INSPECTIONS

               Inspections were performed for those inventoried dams that
         could be accessed by the inspection team. The inspections allowed
         a close up look at the design, construction, general structural
         condition, maintenance practices, and use of each dam. In general,
         the following conditions were the most consistently observed by the
         inspection team.

                    Tree growth on the top and downstream side of the
                    embankment.   Tree growth will undermine the structural
                    integrity of the dam by creating channels for water
                    seepage through the root system, especially when the tree
                    dies and the root system decays. Also, trees that are
                    uprooted will take with it a large amount of soil
                    integrated in the root mass leaving a large hole in the
                    embankment.

               0.   Lack of an emergency spillway, or an inadequate emergency
                    spillway.    This can result in dam failure when the
                    structure is overtopped during flood events causing
                    severe erosion, or through the unrelieved buildup of
                    water pressure greater than the dam can tolerate.

               0.   Erosion in the receiving stream around the outlet pipe.
                    This condition can result in the collapse and failure of
                    the outlet pipe, the undermining of the dam base, and
                    contributes to sediment loading of the receiving stream
                    during storm events.

               P.   Debris such as logs, sticks, and leaves that clog the
                    principal spillway. Debris can partially or completely
                    restrict the flow of water resulting in overtopping of
                    the structure.

               0@   Steep embankment slopes. Steep slopes can prohibit the
                    use of equipment used to maintain or repair the dam
                    structure.


               0.   Gates and valves at the principal spillway that have not
                    been maintained or checked for operation.        Gates and
                    valves can fail through lack of maintenance or through
                    nonuse.   Inoperable emergency valves can result in dam
                    failure during flood events, and can prohibit maintenance
                    and repair operations requiring drawdown of the pool
                    elevation.

               A dam inspection checklist (Appendix A) was completed for each
         dam visited.    A site visit summary for each dam inspected in
         Charles City County is included in Appendix B, and for New Kent
         County in Appendix C.


                                           14











                               VI. ISSUE IDENTIFICATION

               Unregulated dams present a variety of concerns to local
          governments and dam owners involving issues of management,
          construction, and operation and maintenance.      Local governments
          have a vested interest in ensuring that unregulated      dams do not
          pose a threat to public and private property, life and   health. Dam
          owners are interested in protecting investments, and either
          minimizing potential liability or insuring themselves against it.
          The following section identifies issues of concern to all local
          governments and to dam owners.

          REGULATORY PROGRAMS


               The   management,   design,    construction,   operation,     and
          maintenance of dams are addressed principally through the state
          regulatory programs, and/or through local programs. The following
          section briefly describes current state and local dam programs.

          Virginia Department of Conservation and Recreation

               Virginia Dam Safety Act Dams in Virginia are regulated by the
          Department of Conservation and Recreation (DCR), Bureau of Rivers
          and Shorelines, through the "Impounding Structure Regulations" of
          the Dam Safety Act, Article 2, Chapter 6, Title 10.1 of the Code of
          Virginia (Appendix D).

               Briefly, "Impounding Structure Regulations" (VR 625-01-00,
          Feb. 1, 1989) provide a permitting process for the construction,
          alteration, and transfer of regulated structures, and certification
          for dam operation and maintenance.         The regulations include
          procedures for inspections, enforcement, and complaints; grants the
          right of a hearing to an aggrieved dam owner, and defines
          procedures for consulting boards and dams in unsafe conditions.
          The regulations define design requirements for the dam structure,
          emergency spillway, principal spillway and outlet works, drain
          requirements, life of structure, plans and specifications,
          acceptable design procedures, and additional requirements.

               DCR concentrates it's efforts on regulated impounding
          structures, that is, dams that are greater than 25 feet in height
          and that impound an area of greater than 50 acre-feet. Budget and
          manpower limitations leave little time for other activities.

          Chesapeake Bay Local Assistance Department

               Chesalpeake Bay Preservation Act     The Chesapeake Bay Local
          Assistance Department (CBLAD) is responsible for the overall
          administration of the Chesapeake Bay Preservation Act (CBPA) . CBPA
          grants authority for administration of the Act to local
          governments. CBPA requires the designation of preservation areas,
          called Resource Protection Areas (RPA) and Resource Management

                                           15









         Areas (RMA)   Preservation areas are composed of RPA's, surrounded
         by a onehundred foot "buffer area", surrounded by an RMA.

              CBPA regulations generally prohibit the construction of dams
         in RPA's and their buffer area, although in certain situations
         exemptions may be granted.    Dams are permitted in RMA's if they
         meet regulatory criteria designed to maintain water quality.

         Local Code


              New Kent Co unty     Currently, New Kent County's Code permits
         water impoundments of fifty acres or more and a dam height of
         twenty-five feet or more.    Such structures require a conditional
         use permit issued by the County. Impoundments less than 50 acres
         or with a dam height less than 25 feet are not permitted in the
         County. The County historically has not enforced this ordinance,
         and recently developed a revised draft ordinance that allows,
         "Water impoundments for public or private use. 11 Water impoundments
         will require a conditional use permit issued by the County. It is
         expected the County will adopt this ordinance by the end of 1993.
         Neither the   current ordinance or the proposed draft ordinance
         specifically  address unregulated dams.

              Charles  City County Charles City County code contains no
         statutes that directly address the development of dams.

         TECHNICAL ASSISTANCE


              Unregulated dam owners, and those people wishing to construct
         dams that fall outside of State regulation, may find it difficult
         to obtain public sector technical assistance.

              Upon request, DCR staff will review design specifications for
         proposed structures that are not covered under the State regulatory
         program. DCR staff will also investigate unregulated dam failures.
         But these activities can only be performed as time permits and is
         not a formal agency program function.

              The Department of Conservation and Recreation published a
         pamphlet titled, "Safety Evaluation of Small Earth Dams", 2nd
         Edition, 1987, that is currently out of print. This informative
         publication is designed to assist dams owners in inspecting their
         dams and maintaining them in sound condition. The 2nd edition of
         the pamphlet requires revision before it is re-released to the
         public. No date has been set for this revision. A copy of the 2nd
         edition is included in Appendix E.

              The U.S. Soil Conservation Service has ceased the practice of
         providing technical assistance to farmers on the design,
         construction, and maintenance of dams.          This practice was
         discontinued as a result of liability issues associated with past
         failures of these structures.


                                          16








             Currently, persons seeking technical assistance on the design,
        construction, and operation and maintenance of unregulated dams
        have the option of private sector assistance, or their own best
        judgement.
















































                                        17











                                 VII. CONCLUSIONS

              After a review of the data developed from the inventory and
        inspections, and an assessment of identified issues, the study team
        drew the following observations and conclusions:

              1.   The number of unregulated dams in Charles City and New
                   Kent far exceeds those that are regulated; 146 to 1.
                   This alone underscores the need for local attention.

              2.   The great majority of dams do not pose a threat to life
                   or  property   downstream   either   because   they    are
                   structurally sound; they do not impound a volume of water
                   large enough to cause significant damage if the dam
                   fails; or, there are no hazards such as homes or other
                   structures, or property downstream that would be
                   threatened by a breach.

              3.   Privately owned dams that serve as a base for public
                   roads pose a high potential hazard to vehicular traffic.

              4.   In general, the most common problem     s observed with
                   inspected dams involve the growth of trees and bushes on
                   the dam's top and downstream slopes, and the lack of an
                   emergency spillway. Unwanted growth is relatively easy
                   to prevent through regularly scheduled mowing. Emergency
                   spillways are easily incorporated into the design of a
                   dam, and may be retrofitted on some existing structures.

              5.   Dam owners would benefit from information about dam
                   maintenance and repair, and individuals considering
                   constructing a dam would benefit from technical guidance
                   on new dam construction.

              6.   There are many dams that have the potential to support
                   beneficial uses that could serve the public.

              7.   Localities can benefit from tracking unregulated dams and
                   sharing information with staff from DCR's Bureau of
                   Rivers and Shorelines.
















                                         18











                               VIII. RECOMMENDATIONS


              Based on the conclusions above, the study team makes the
        following recommendations for consideration by local officials in
        Charles City and New Kent.

              1.   Utilize the data base developed and maintained by the
                   Virginia Department of Conservation and Recreation to
                   track unregulated dams in the Counties. A copy of the
                   data base has been provided to Charles City and New Kent
                   County staffs.

              2.   Develop a mechanism to keep the data base current through
                   the addition of information on new dams.

                   00.  New Kent County could require this information when
                        issuing    conditional   use    permits    for    dam
                        construction.

                   P.   Charles City should consider developing a program
                        to track new dam construction that will add to the
                        base of information on dams in the County.

              3.   To meet the information needs of dam owners and public
                   officials, it is recommended that Charles City and New
                   Kent copy and distribute the DCR publication, Safety
                   Evaluation of Small Earth Dams, Information Bulletin 549,
                   2nd Edition, 1987.    This information bulletin can be
                   found in Appendix E, and contains valuable information on
                   dam construction, maintenance, inspection, and other
                   resource publications.      Although the bulletin is
                   currently out of print and requires minor revision, DCR
                   staff encourages its use, and suggests that localities
                   make copies as needed for public distribution.

              4.   It is recommended that DCR revise and reprint the
                   information bulletin, Safety Evaluation of Small Earth
                   Dams, as a service to dam owners and local officials.

              5.   It is recommended that the Charles City and New Kent
                   consider potential beneficial uses of existing dams and
                   their impoundments in relation to identified public
                   needs. Two such uses include fire suppression and public
                   recreational amenities such as swimming, boating,
                   fishing, sunbathing, and picnicking.








                                         19




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                                            FIELD OBSERVATIONS


    DAM NAME:                                                 COUNTY:

    COORDINATES:  LAT.              LONG.                   DATE OF REVIEW:

    WEATHER:                             POOL ELEVATION:

    FIELD REVIEW TEAM:






                               DAM HISTORY AND RECORD OF INSPECTIONS



                                            BASIC DIMENSIONS


                Height (measured from downstream toe to top of dam):
                Surface area of take at top of dam (if known):
                Elevation of emergency spillway (if known):
                Surface area of take at emergency spillway crest (if known):
                Elevation of normal pool level (relative to top of dam):
                Surface area of lake at normal pool (if known):
                Width of crest of dam:
                Distance across emergency spillway:
                Upstream slope (for instance, 3 horizontal to 1 vertical, or 3:1):
                Downstream slope:


                                               DAM HISTORY


                                                                              Date

                Designed by:

                Constructed by:
                Date of completion:

                Has the dam ever failed,
                  either partially or totally?

                Has the dam ever been rebuilt
                  or modified?

                Has the dam been overtopped
                  by flooding?

                What is the maximum water
                  level observed?

                Other information relevant to
                  dam's history:
 







                                                              DAM INSPECTION AND MAINTENANCE CHECKLIST


       THE PRINCIPAL SPILLWAY                                                               THE RESERVOIR AREA.
       Yes No                                           Comments                             Yes No                                         Comments
                 Can water flow into the prin-                                        CI C] Oces the nature of the land sur.
                 cipal spillway without difficulty,
                 as intended when constructed?                                                                                       rounding the lake or its use
                                                                                            problems?
                                                                                                        present any



                 Is outlet pipe or discharge chan-
                 nel clear and open to allow the                                             40     is there any evidence of land-
                 free passage of the principal                                                          slides or instability an the slopes
                 spillway discharge?                                                                    around the reservoir?

                 Is the primary spillway structure                                           j8Z 40     Is seri= wave erosion ocvurring
                 in good condition (check con-                                                          along the shoreline?
                 crete, wood,and metal portions
                 for damage or deterioration)?
                                                                                       C] C:j   Is a let of sediment entering the
                                                                                                        impoundmem or has this haP-
                 can be used to lower it in an
                 emergency?                                                                             pened in the pasz?

                 0If there is an emergency drain, is
                 it known to be in working can-
                 dition? Note: If a drain has not
                 been used for a long time, it
                 may be possible to open it but                                                IJOWNST2RE8AM CHANNEL
                 not close it                                                                           Is the downstream channel free
                                                                                                        of obstruc,_;ons. so that water
      C:C      If there are other gares, valves.                                                      in a flood will not back up
                 or operating euipment, are these                                                      against the toe of the dam?
                 in working condition?






                                                                                               WATERSHED AREA
      THE EMERGENCY SPILLWAY                                                                   0M C!     Have- there been any majormcd-
                 C Can water flow into the emer-                                                       i8fications or significant changes
                 gency spillway without diffi-                                                          in tine -watershed drainage area,
                 uity, as intended when con.                                                           such as new urban developmerrm
                 truczed?                                                                              (shopping cwters, housing proi-
                                                                                                        ects), clear cutting of woodlands,
      C! 407      Is the discharge channel clear                                                         or other basic --j-:an4e:s in land use.
                 and open to allow t4he free pas-
                 sage of the emergency spillway
                 disc8har4ge2

                 Is the emergency spillway con.
                 structed in such a way that its
                 flows will net erode other 4pcr-                                               T
                                                                                                HE DOWNSTREAM AREA
                 tions of -die dam?
                                                                                                   200 If the dam should fail, would loss
                 Is the emergency spillway in                                                           of life cc extensive property
                 good cmnd2f2dan overall 2(c:2hec8k                                                          damage be likely?
                 for erosion within the channel,
                 adeuacy of 04gass cover, -8-,r-4)?
 






                                            DAM INSPECTION AND MAINTENANCE CHECKLIST


        THE EMBANKMENT                                                                          THE EMBANKMENT - continued
                                                                      - - - ---------

        Yes No                                           Comments                               Yes No                                           Comments

         -   -  Are there any surface cracks?                                                     -  - If there are any drains to collect
                                                                                                       and remove seepage, are they
                                                                                                       operating properly?
         -   -  Is there any unusual movement
                or cracking at or beyond the toe?                                                 -  - If there are foundation drain out.
                                                                                                       lets, are they clear and flowing?
        
         -   - Is there erosion on upstream
               face from wave action or changes
               in pool level?

         -   - Is there erosion from runoff,                                                      -  -   Are there wet spots or areas on
               either gullies or bare areas?                                                             the downstream face, at the toe,
                                                                                                         or beyond the darn? (Such spots
                                                                                                         are often indicated by a change
         -   - Is there erosion from traffic                                                             in color or type of vegetation,
               (people, animals, vehicles)?                                                              such as from grass to cattails.)
                  
         -   - Are there any animal burrows?                                                       -  -  Are there seeps or springs with
                                                                                                         flowing water? Look closely for
         -   - Are there depressed areas on the                                                          these at the ends of the dam,
               dam?                                                                                      around any pipes passing through
                                                                                                         the embankment, on down-
                                                                                                         stream face, at the toe of the
         -   - Is there any evidence of piping?                                                          dam and beyond, and at the base
               (This condition is evidenced by a                                                         of trees on, near, or below the
               muddy flow through the dam                                                                dam.
               and/or the formation of soil
               deposits beyond the dam and                                                           - - Is there swamp or marsh type
               depressions an its slopes.)                                                               vegetation on downstream face
                                                                                                         or beyond the dam (cattails. tall
          -  - Does the creats appear to have                                                            grass, etc.q)?
               shifted or settled excessively?
               (Look for cracks in the em-
               bankment and associated struc-
               tures. Compare alignment with                                                         - - Is the dam overgrown with, trees
               plans if they are available.)                                                             and/or underbrush?


           - - If the upstream face is protected                                                      - - Has the dam ever been overtop-
               by riprap is it in good condition?                                                         ped by water flowing over it?
               (Riprap is a layer, facing, or pro-
               tective mound of stone in ran-
               dom size pieces, randomly placed
               to prevent erosion scour, or                                                           - - Has there been any modifica-
               sloughing of an embankment or                                                              tion of the embankment, such
               structure.)                                                                                as raising the crest, changing
                                                                                                          the shape or size of the prin-
                                                                                                          cipal spillway or the emergency
           - - If there is riprap in discharge                                                            spillway, or changing the shape
               channels or in the plunge pool                                                             or size of the embankment?
               downstream, is it in good conn-
               dition?


           - - If drainage channels at ends of
               embankment are protected with
               riprap, is it in good c0ndition?

           - - If there is riprap in miscellaneous
               areas (an downstream slope, an
               crest.ect.) is it in good repair?




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                                    APPENDIX B
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                                 SITE VISIT SUMMARY


                                 CHARLES CITY COUNTY

         Field Trip 6/3/93
         Dameron, Fisher, Bragg


         (03901) Harrison Lake Dam

              Corps inventory. Structural height 12 ft. Hydraulic height
              -12 ft. Maximum capacity 210 acre-ft. Normal capacity 210
              acre-ft (?). Not field visited as part of this study. Last
              field visited spring of 1988. This structure provides water
              for the Harrison National Fish Hatchery.

         (03902) Charles Lake Dam

              Corps inventory. Structural height 12 ft. Hydraulic height
              -11 ft. Maximum capacity 359 acre-ft. Normal capacity 149
              acre-ft.   Access chained off and not visited.        Apparently
              recreational facility for Camp Weyanoke. Toe of dam tidal to
              James River.

         (03903) Hatchery Dam

              Not visited. This structure is associated with the Harrison
              National Fish Hatchery.

         (03904) Berkeley Dam

              Access chained off and not visited.

         (03905) Eppes Island Dam

              Private sand and gravel operation. Not field visited.

         Dam 001 (03906) Dogham Farm Dam

              Height of dam 8 to 10 ft. Toe of dam is at the tidal run of
              the James. Top of the dam is cleared but the side slopes are
              overgrown. All flow is through a concrete section possibly a
              sluice way for a mill. There is a pipe through the dam but
              its serviceability is unclear.        There is apparently an
              emergency spillway at the right abutment area but it is
              blocked with a fence line which is overgrown.

         Dam 002 (08704) Shirley Millpond Dam

              Corps inventory.    Dam height 23 ft.     Maximum capacity 920
              acre-ft.   This dam is on Turkey Island Creek which is the
              boundary between Charles City and Henrico Counties. The dam
              was assigned a Henrico Country inventory number. The dam was
              utilized as a mill pond with all flows through the concrete









              spillway. There is an auxiliary spillway towards the left of
              the dam. There is no emergency spillway. The dam has very
              large trees on the embankment.

         Dam 003 (03921) Bowens Store Dam

              This dam is approximately 6 f eet in height.    The width and
              crest elevation varies across the dam. The dam is apparently
              used for agricultural purposes. There is no apparent outlet
              pipe and the emergency spillway is an irregular low point at
              the right abutment area.

         Dam 004 (03922) Howard Farm Dam

              This dam is approx. 14 ft in height.       The embankment has
              recently been reworked with the side slope regraded to approx.
              3:1. Vegetation on the embankment has not become established
              as of yet. There is no trash rack on the principal spillway
              and debris is entering the riser. The emergency spillway is
              at the left abutment.

         (03929) Rustic Dam

              Access road chained off and not visited.

         (03930) Fairy Point Sand Dam

              Private sand and gravel operation. Not visited.

         Dam 005 (03931) Upper Hoffmyer Dam

              Dam height approx. 12 ft. Dam is overgrown. Trash rack is on
              embankment not on pipe.    No emergency spillway.     Backwater
              from lower dam up to toe of this dam. Dam probably used for
              agricultural purposes.

         Dam 006 (03932) Lower Hoffmyer Dam

              Apparently, between 1965 and 1980 Quad Sheet dates a dam was
              constructed and breached in this general area.      After 1980
              another dam was built down stream inundating this area and
              backing water up to the upper dam. Dam height is approx. 10
              to 12 ft. and has numerous small trees on the embankment and
              in the emergency spillway.









         Field Trip 6/17/93
         Dameron, Fisher

         Dam 021 (03928) Sod Farm Dam

               This dam is approx. 15 to 20 ft. in height, constructed some
               time between 1965 and 1980. Principal spillway is a CMP with
               a trash rack.     Emergency spillway is in the left abutment
               area.   Dam appears well maintained.      Recommend mowing this
               year. Dam.is used for agricultural purposes.

         Dam  022 (03926) Matahunk Neck Dam

               This dam is approx. 8 to 10 ft in height. This dam was a mill
               pond dam which failed through the concrete sluice way. The
               sluice way structure was recently rebuilt and all flows go
               through this rebuilt portion. There is no emergency spillway.
               The embankment is heavily overgrown.

          (03927) Walkers Dam

               This dam is approx. 5 to 8 ft. in height. The structure was
               not visited as part of this study but has been previously
               reviewed.     The dam separates the tidal flow up the
               Chickahominy River from the fresh water of the river. The dam
               is operated as part of the Newport News water supply system.
               There is a   fish ladder and boat lock in the dam providing
               passage for  tidal to non-tidal elevation.

         Dam  023 (03923) Holdcroft Dam

               This dam is  approx. 10 to 12 ft. in  height. The embankment is
               overgrown.   The principal spillway riser is partially clogged
               with debris and growth. The outfall is a concrete pipe and
               there appears to be a partial slope failure above this pipe.
               There is no emergency spillway.

          (03924) Binns Hall Dam

               Access to this dam could not be located and was not visited.









         Field Trip 7/30/93
         Dameron, Fisher, Bragg

         Dam 031 (03918) Wallace Dam

              This dam is approx. 22 to 25 ft in height. The reservoir is
              use for agricultural purposes.        A dry hydrant has been
              installed for fire fighting purposes. The dam has a CMP riser
              and outfall pipe and an emergency spillway.             This is
              apparently a designed structure and recently built. The woody
              growth at the lower portion of the dam needs to be cut.

         (03917) Stirling Dam

              Access to this dam not found and not field visited.

         (03915) Sandy Bottom Dam

              Private sand and gravel dam not visited.

         Dam 032 (03914) Chambers Dam

              This is a designed structure specifically used for erosion and
              sediment control for land disturbance at the landfill
              operation.     The structure is relatively new and well
              maintained.     I


         Dam 033 (03910) Ednas Mill Dam

              This structure has been breached and all flows go through the
              breached portion of the dam.       The original structure was
              approx. 8 f t. in height.    Embankment is heavily overgrown.
              Former mill.

         Dam 034 (03911) Roxbury Dam

              This dam is approx. 18 ft. in height. The principal spillway
              is a CMP riser and outfall pipe.         The structure has an
              emergency spillway.    The embankment is relatively clear of
              growth.     The purpose of the reservoir is apparently
              agricultural.

         Dam 035 (03908) Lower Hughes Dam

              This dam is approx. 10 to 12 ft. in height.             This is
              apparently a former, mill pond.      All flow is through the
              concrete sluice way.     The concrete has been significantly
              undermined by this flow. The in no emergency spillway. The
              embankment is overgrown.

         (03907) Upper Hughes Dam

              Access to this dam denied and not visited.         This dam is
              approx. 2000 ft. upstream of 03908.










        Dam 036 (03909) County Dam

              This dam is approx. 12 to 14 ft. in height.      The principal
              spillway is partially submerged. and the outlet pipe is also
              submerged. There appears to have been a slope failure above
              the outlet pipe.    Flow through the emergency spillway has
              caused erosion and a partial breach which has been sand
              bagged.     There is significant erosion at the right
              abutment /embankment interface. Trees should be cleared off of
              the embankment.


         (03912)  Nances Dam


              Not accessible and not visited.


         (03913)  West Run Dam

              Not accessible and not visited.




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                                    APPENDIX C
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                                SITE VISIT SU14KARY


                                  NEW KENT COUNTY

         Field Trip 6/11/93
         Dameron, Newton, Fisher

         Dam 001 (12723) Lilly Pond Marsh Dam

             Viewed from.road. Relatively new construction. Approx 6 to
             8 feet in height. No apparent principal spillway. All flow
             through the emergency spillway with debris.         Route 608
             downstream. On Lilly Marsh Creek.

         Dam 002 (12722) Lilly Point Dam

             No emergency spillway. original principal spillway failed and
             another culvert pipe installed.     Approx. 10 to 12 feet in
             height. Heavily overgrown. Pamunkey River approx. 1000 ft.
             downstream.


         (12724) Access to this dam was chained off and not visited.

         Dam 003 (12725) Cousaic Farm Dam

             Dam is in a pasture and is grazed.       No obvious emergency
             spillway but a low area in the left abutment area. Original
             principal spillway corrugated metal pipe (CMP) failed and is
             filled with concrete, and a new poly vinyl chloride (PVC)
             spillway was installed.    Approx. 10 to 12 feet in height.
             Cattle have caused erosion on upstream slope.      No hazards
             downstream pasture only. On trib to Mill Creek.

         Dam 004 (12702) Cooks Millpond Dam

             Corps inventory. Structural Height 15 ft. Hydraulic height
             11 ft.   Maximum pool 226 acre-ft.   Normal pool 74 acre-ft.
             No emergency spillway. Route 628 runs across the top of this
             dam and all flows go through the concrete structure beneath
             the bridge.     Heavily overgrown.    Dry Hydrant installed.
             Former millpond. Failure would take out route 628.

         Dam 005 (12728) Chesapeake Tree Farm Dam

             Dam has partially failed through the left abutment/emergency
             spillway (?) area.   Lake area is smaller than shown on quad
             last revised in 1986.      Thus, failure apparently occurred
             between 1986 and now. Height is approx. 8-10 ft but difficult
             to determine as dam is heavily overgrown with 2-6 in. trees.
             Approx 700 ft. downstream is Route 33 and then approx. another
             700 ft is a new structure (12726).

         (12726) Access to this dam was chained off and not visited.










         Dam 006 (12729) Eltham Marsh Dam

              Dam has at least 3 principal spillways; 2 through pipes and
              one stand pipe with make shift trash racks. Small "emergency
              spillway"    in left abutment area.     Dam is overgrown with
              trees. Dam is approx. 6 ft high. One house appears on quad
              approx. 600 ft downstream, but is probably above the breach
              elevation.   This lake is part of a subdivision.

         Dam 007 (12706)- Davis Pond Dam I

              Corps inventory. Structural height 10 ft. Hydraulic height
              8 ft.   Maximum capacity 412 acre-ft.     Normal capacity 196
              acre-ft.     Formally a millpond possibly constructed or
              significantly repaired August 15, 1938 (date in concrete).
              Used for irrigation and recreation. No emergency spillway,
              all flows through the sluice gate.       Severe erosion below
              sluice gate. Very little free board on dam, less than 1 foot.
              Dam is on Mill Creek.        Route 30 is approx. 3000 ft.
              downstream.

         (12710) Taylors Dam
              @ccess to this dam was chained off and not visited. This dam
              is on the Corps inventory.         Structural height 15 ft.
              Hydraulic height 15 ft. Maximum capacity 136 acre-ft. Normal
              capacity 68 acre-ft. On Mill Creek approx. 300 ft. upstream
              of Davis Pond Dam (12706).

         Dam 008 (12711) Goddins Dam

              Corps inventory.    Structural height 12 ft. Hydraulic height
              -12 ft. Maximum capacity 206 acre-ft. Normal capacity 120
              acre-ft. No emergency spillway. Route 600 runs across the
              top of this dam and all flows go through the bridge structure.
              The slopes are heavily overgrown including very large trees.
              Former mill pond. Dam is on Philbates Creek. Failure of this
              dam would take out Route 600.


         Dam 009 (12730) Philbates Dam

              No access to dam private property fenced off.      Viewed from
              road and appeared overgrown. Trib. to Philbates Creek.

         (12731) Mount Olive Dam

              Access to this dam was chained off and not visited. Trib. to
              Philbates Creek.

         (12733) Holly Forks Dam

              No apparent access to this dam and not visited. Trib. to Ware
              Creek.









         Dam 010 (09707) Richardson Millpond Dam

              Corps inventory. Structural height 13 ft. Hydraulic height 8
              ft. Maximum capacity 294 acre-ft. Normal capacity 86 acre-
              ft. This dam is on Ware Creek which is the boundary between
              New Kent and James City Counties.      The dam was assigned a
              James City County inventory number. No emergency spillway.
              Route 600 runs across the top of this dam and all flows go
              through the bridge structure. This dam is heavily overgrown
              with large-trees.    Former mill pond.    Failure of this dam
              would take out Route 600.


         Dam 011 (12717) Davis Pond Dam II

              The height of this dam is approx. 12 to 15 ft. No emergency
              spillway.   This is a former mill pond and all flows are
              through the concrete sluice. The concrete has had significant
              repairs. The dam is overgrown. This dam is approx. 4000 ft
              upstream of 12711.

         (12736) Tabernacle Dam

              Access to this dam was chained off and was not visited.


         Dam 012 (12734) Lower Ware Dam

              Dam is approx. 15-18 ft in height.     The top of the dam has
              been recently widened and reworked. No emergency spillway.
              The principal spillway is a 12 inch metal pipe which beavers
              frequently try to block up.       This pipe appears to be a
              replacement pipe for the original riser. The dam is overgrown
              with trees 6-8 in. The dam is approx. 400 ft from Ware Creek.

         Dam 013 (12735) Upper Ware Dam

              Dam is approx. 20-25 ft in height. The downstream slope is
              heavily overgrown with pipe saplings and height is difficult
              to determine. This dam is fairly recent construction (after
              1986) . The principle spillway appears to be a typical asphalt
              coated CMP riser and through pipe.      There is no emergency
              spillway. Lower Ware Dam is approx. 400 ft below this dam.









        Field Trip 6/17/93
        Dameron, Fisher

        Dam 020 (12709) Old Forge Pond Dam

             Corps inventory. Structural height 12 ft. Hydraulic height
             -12 ft. Maximum capacity S80 acre-ft. Normal capacity 232
             acre-ft. There is a principal spillway and a concrete sluice
             way section both of which pass flows. There is no emergency
             spillway. Dam is heavily overgrown with very large trees.
             Formally a mill pond.

         (12740) Forge Sand & Gravel

             Private sand and gravel operation. Not visited.

         (12738) Mountcastle Dam

             Not visited.

         (12739) Minitree Dam

             Access to this dam chained off and not visited.

         (12737) Trib. to Diascund Dam

             Access to this dam not found and not visited.








         Field Trip 7/21/93
         Dameron, Fisher, Newton

         (12721) St. Peters Dam

              Access to this dam not found and not visited.

         Dam 032 (12707) Groves Dam

              Corps inventory. Structural height 30 ft. Hydraulic height
              26 ft. Maximum capacity 73 acre-ft. Normal capacity 47 acre-
              ft. This dam meets the minimum regulatory standards. The dam
              operates under an agricultural certification since it is
              utilized for agricultural purposes and has less than 100 acre-
              ft. maximum capacity. Principal spillway is a 12(?) inch CMP
              riser with a CMP outlet pipe. The outlet area needs regrading
              and there is minor erosion at the toe. The emergency spillway
              is the parking lot/boat launch area near the left abutment
              area. The top of dam supports a private gravel road. A new
              dam (12718) is under construction immediately below this dam.

         Dam 033 (12718) Lower Groves Dam

              Currently under construction and not impounding water.
              Principal spillway is CMP. Emergency spillway channel cut in
              the right abutment. Height approx. 18-22.

         Dam 034 (12705) Cattail Swamp Dam

              Corps inventory. Structural height 20 ft. Hydraulic height
              16 ft.   Maximum capacity 344 acre-ft.     Normal capacity 134
              acre-ft. Private farm road runs across the top of this dam.
              Trees recently cleared off of the dam and under growth is
              coming up. Principal spillway has a square corrugated metal
              top and the riser pipe not visible.        Emergency spillway
              consists of 3-30 inch CMP culverts near the left abutment
              these are rip rap protected. The inlets to the pipes need to
              be cleared. Route 638 approx. 3500 ft downstream.

         Dam 035 (12741) Near Cattail Dam

              Dam height is 20-22 ft. Principal spillway riser with through
              pipe. Trash rack is wire and fence. Emergency spillway grass
              channel near right abutment. Good grass cover on dam.

         Dam 036 (12714) Higgins Swamp Dam

              This is a series of two dams, the lower dam built approx. 1988
              immediately below the upper dam.     Neither structure has an
              emergency spillway. The upper principal spillway is a pipe
              through the dam, the lower principal spillway is a CMP riser
              and through pipe.    The lower dam is approx. 6 to 8 f t. in
              height.









         Dam 037   (12712) Kamp Kentwood

              This dam is approx. 10    ft. in height.    It appears to be a
              former mill pond operation with all flows going through the
              concrete sluice way. The concrete channel of the sluice way
              has been partially undermined and has failed at the lower end.
              There is no emergency spillway. The dam is heavily overgrown.

         Dam 038 (12713) Lower Higgins Dam

              This dam was breached and is currently being rebuilt. This
              was apparently a former mill pond and all flow is being
              discharged through the concrete sluice way.            The only
              construction equipment present was a backhoe.         The f inal
              constructed height could not be determined at the      site. No
              new pipe or valving was noted and no emergency spillway was
              under construction. Route 613 is immediately below this dam.

         Dam 039 (1271S) Crump Swamp Dam

              Dam height approx. 10 to 12 ft.        Former millpond date in
              concrete mill race 1938. There is some undercutting of the
              concrete in this raceway.      The dam has trees on it, some
              large. No emergency spillway apparent. Beavers are blocking
              the concrete channel.

         Dam 040 (12720) Crumps Mill Dam

              Dam height approx. 1S ft. Flow discharges through 5 concrete
              pipes and the concrete sluice. This was a former mill pond
              now used for recreation. Dam appears reasonably maintained.

         Dams not visited but on the 1981 Corps inventory.

              12701 Kent Dam
              12703 Diascund Dam
              12704 Toms Brooks Dam
              12708 Fern Dam




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                                    APPENDIX D
I                        VIRGINIA DAM SAFETY REGULATIONS
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                                                                                                                                                                                                                                                                                                                                                                                                                   ir                                                                                               inia
                                                                                                                                                                                                                                                                                                                                                                         @Dam Safety
                                                                                                                                                                                                                                                                                                                                                                               Regulations

                                                                                                                                                                                                                                                                                                                     Virginia Department of Conservation and Recreation
                                                                                                                                                                                                                                                                                                                                                                                                  Division of Soil and Water Conservation
                                                                                                                                                                                                                                                                                                                                                                                                                                                      203 Governor Street, Suite 206
                                                                                                                                                                                                                                                                                                                                                                                                                                                                            Richmond,'VA 23219-2094
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                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           ReprintOd 1992
                                                                      darnregs-pnIA






                                               Virginia Soil and Water Conservation Board
                            Title of Regulation: VR 625-01 -00. Impounding Structure Regulations.
                                                                   Effective Date: February 1, 1989




                                                                    TABLE OF CONTENTS


                      Section


                                                                               CHAPTER ONE - GENERAL
                      1.1 Authority          .................                                                                                                      .........  1
                      1.2 General Provisions                ....................................................................................................................1
                      1.3 Definitions          ...................................................................................................................................1
                      1.4 Classes of Impounding'Structures                       ..........................................                             ...................... 2
                      1.5 Performance Standards Required for Impounding Structures                                        ..................... .............................. 2
                      Table I       ..............................................................................................................................................3


                                                                  CHAPTER TWO - PERMIT REQUIREMENTS
                      2.1     Required Permits ..                                                                                                                              4
                      2.2     Construction Permfts*****          ...                                                                                                           4
                      2.3     Alterations Permits           ....................................................................................................................5
                      2.4     Transfer of Permits           ....................................................................................................................6


                                                            CHAPTER T14REE - CERTIFICATE REQUIREMENTS
                      3.1     Operation and Maintenance Certificates                        ....................................................................................6
                      3.2     Operation and Maintenance Certificates For Newly Constructed Impounding Structures                                                  ............ 6
                      3.3     Operation and Maintenance Certificates For Existing Impounding Structures                                           ............................ 7
                      3.4     Existing Impounding Structures Constructed Prior to July 1, 1982                                   ..............................................7
                      3.5     Existing Impounding Structures Constructed After July 1, 1982                                  ..................................................8
                      3.6     Conditional Operation and Maintenance Certificate                            .....................................................................8
                      3.7     Additional Operation and Maintenance Requirements                                ................................................................8
                      3.8     Transfer of Certificates             ..............................................................................................................8


                                                                          CHAPTER FOUR - PROCEDURES
                      4.1     Inspections        ................................................................................................................................8
                      4.2     Right to Hearing           ........................................................................................................................8
                      4.3     Enforcement          ..............................................................................................................................9
                      4.4     Consulting Boards           ...................................................................................................................... 91
                      4.5     Unsafe Conditions           ......................................................................................................................9
                      4.6     Complaints          ................................................................................................................................9

                                                                  CHAPTER FIVE - DESIGN REQUIREMENTS
                      5.1     Design of Structures             ..................................................................................................................9
                      5.2     Design Flood         ............................................................................................................................ 10
                      5.3     Emergency Spillway Design                    .................................................................................................... 10
                      5.4     Principal Spillways and Outlet Works                      ....................................................................................... 10
                      5.5     Drain Requirements               ................................................................................................................ 11
                      5.6     Life of the Impounding Structure                   .............................................................................................. 11
                      5.7     Additional Design Requirements                     ..............................................................................................*11
                      5.8     Plans and Specifications               .......................................................................................................... 11
                      5.9     Acceptable Design Procedures and References                               ...................................................................... 11

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                                                          CHAPTER ONE - GENERAL

                      1.1 AUTHORITY
                            This regulation is promulgated by the Virginia Soil and Water Conservation Board in accordance with
                      the provisions of the Dam SafetyAct, Article 2. Chapter6, Title 10.1 (ï¿½10.1 -604 et seq.) of the Codeof Virginia

                      1.2 GENERAL PROVISIONS
                            A. This regulation provides for the proper and safe design, construction. operation and maintenance
                      of impounding structures to protect public safety. This regulation shall not be construed or interpreted to
                      relieve the owner or operator of any impoundment or impounding structure of any legal duties, obligations or
                      liabilities incident to ownership, design, construction, operation or maintenance.
                            B. Approval by@the board of proposals for an impounding structure shall in no manner be construed Or
                      interpreted as approval to capture or store waters. For information concerning approval to capture or store
                      waters,see Chapter 8       ï¿½ 62.1-107) of Title 62.1 of the Code of Virginia, and other provisions of law as may
                      be applicable.
                            C. In promulgating this regulation, the board recognizes that no impounding structure can ever be
                      completely "fail-safe," because of incomplete understanding of or uncertainties associated with natural
                      (earthquakes and floods) and manmade (sabotage) destructive forces; with material behavior and response
                      to those forces; and with quality control during construction.
                            D. Any engineering analysis required by this regulation such as plans, specifications, hydrology,
                      hydraulics and inspections shall be conducted by and bear the seal of a professional engineer licensed to
                      practice in Virginia.
                            E. The official forms as called for by this regulation are available from the director.

                      1.3 DEFINITIONS
                            The following words and terms, when used in.this regulation, shall have the following meaning, unless
                      the context clearly indicates otherwise:
                            "Acre-foot" means a unit of volume equal to 43,560 cubic feet or 325,853 gallons (one foot of depth over
                      one acre of area).
                            "Agricultural purpose dams" mean dams which are less than 25 feet in height or which create a maximum
                      mpoundment smaller than 100 acre-feet and certified by the owner on official forms as constructed,
                      maintained or operated primarily for agricultural purposes.
                            "Afteration permir'means apermit required forchangesto an impounding structurethat could afteror
                      affect its stnuctural integrity. Afterations requiring a permit include, but are not limited to: changing the height,
                      increasing the normal pool or principal spillway elevation, changing.the elevation or physical dimensions of
                      the emergency spillway or rernoving the impounding structure.
                            "Board" means the Virginia Soil and Water Conservation Board.
                            "Conditional operation arid maintenance certificate" means a certificate required for impounding
                      structures with deficiencies.
                            "Construction permit" means a permit required for the construction of a new impounding structure.
                            "Design flood" means the calculated volume of runoff and the resulting peak discharge utilized in the
                      evaluation, design, construction, operation and maintenance of the impounding structure.
                            "Design freeboard" means the vertical distance between the maximum elevation of the design flood and
                      the top of the impounding structure.
                            "Director" means the Director of the Department of Conservation and Historic Resources or his
                      designee.
                            "Height" means the structural height of an impounding structure. If the impounding structure spans a
                      stream or watercourse, height means the vertical distance from the natural bed of thestrearn or watercourse
                      measured at the downstream toe of the impounding structure to the top of the impounding structure. If the
                      impounding structure does riot span a stream or watercourse, height means the vertical distance from the
                      lowest elevation of the outside limit of the barrier to the top of the impounding structure.
                            "Impounding structure" means a manmade device. whether a dam across a watercourse or other
                      structure outside a watercourse, used or to be used to retain or store waters or other materials. The term
                      "impounding structure" includes all dams which.are equal to or greater than 25 feet in height and which create
                      a maximum impoundment equal to or greater than So acre-feet, except (i) dams licensed by the State
                      Corporation Commission that are subject to a dam safety inspection program; (ii) dams owned or licensed
                      by the United States government; (iii) dams constructed, maintained or operated primarily for agricultural


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                                                                  TABLE I


                   Class     Hazard Potential                                                                  Spillway
                     of      If Impounding               SIZE CLASSIFICATION                                    Design    b
                    Dam      Structure Fails        Maximum Capacity(Ac-Ft)"          Height (Ft)s           Flood(SDF)
                       I     Probable Loss of       Large > 50,000                    > 100                      PMFO
                             Life;Excessive         Medium > 1,000 & < 50,000         > 40 & < 100                PMF
                             Economic Loss          Small > 50 & < 1,000              > 25 & < 40           1/2 PMF to PMF

                      11     Possible Loss of       Large > 50,000                    > 100                       PMF
                             Life; Appreciable      Medium > 1,000 & < 50,000         > 40 & < 100          1/2 PMF to PMF
                             Economic Loss          Small > 50 & < 1,000              > 25 & < 40         100-YR to 1/2 PMF

                      III    No Loss of Life        Large > 50,000                    > 100                 1/2 PMF to PMF
                             Expected; Minimal      Medium > 1,000 & < 50,000         > 40 & < 100        1 00-YR to 1/2 PM F
                             Economic Loss          Small > 50 & < 1,000              > 25 & < 40         50-YR  d to 1 00-YRe

                      IV     No Loss of Life        > 50 (non-agricuftural)           > 25 (both)           50-YR to 100-YR
                             Expected; No"
                             Economic Loss          > 100 (agricultural)
                             to Others



                    a. The factor determining the largest size classification shall govern.

                    b. The spillway design flood (SOF) represents the largest flood that need be coinsidered in the evalu-
                  ation of the performance for a given project. The impounding structure shall perform so as to safely pass*
                  the appropriate SDF. Where a range of SDF is indicated, the magnitude that most closely relates to the
                  involve'd risk should be selected. The establishment in this regulation of rigid design flood criteria or
                  standards is not intended. Safety rrxist be evaluated in the light of peculiarities and local conditions for
                  each impounding structure and in recognition of the many factors involved, some of which may not be
                  precisely known. Such can only be done by competent, experienced engineering judgement, which the
                  values in Table 1 are intended to supplement, not supplant.

                    c. PMF: Probable Maxirnum Rood. This means the flood that might be expected from'the most severe
                  combination of critical meteorologic and hydrologic conditions that are reasonably possible in the region. The
                  PMF is derived from the current probable maximum precipitation (PMP) available from the National Weather
                  Service, NOAA. In some cases local topography or meteorological conditions will cause changes from the
                  generalized PMP values, therefore, it is advisable to contact local, state or federal agencies to obtain the
                  prevailing practice in specific cases.

                    d. 50-Yr: 50-Year Flood. This means the flood magnitude expected to be equaled or exceeded on the
                  average of once in 50 years. It may also be expressed as an exceedence probability with a 2 percent chance
                  of being equaled or exceeded in any given year.

                    e. 1 00-Yr: 1 00-Year Flood. This means the flood magnitude expected to be equaled or exceeded on the
                  average of once in 100 years. It may also be expressed as an exceedence probability with a 1 percent chance
                  of being equaled or exceeded in any given year.










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                          the particular impounding structure and specific site conditions, including when required by the
                          director, a plan and profile of the inundation zones.
                                12. Erosion and sediment control plans to minimize soil erosion and sedimentation during all
                          phases of construction, operation and maintenance. Projects shall be in compliance with local
                          erosion and sediment control ordinances.
                                13. A description of the techniques to be used to divert stream flow during construction.so as
                          to prevent hazard to life, health and property.
                                14. A plan of quality control testing to confirm that construction materials and methods meet the
                          design requirements set forth in the specifications.
                                1 S. A proposed schedule indicating construction sequence and time to completion.
                                16. Plans and specifications as required by section 5.8 of these regulations.
                                17. An emergency action plan on official iorms and evidence that a copy of such plan has been
                          filed with the local and state Department of Emergency Services. The plan shall include a method
                          of providing notification and warning to persons downstream, other affected persons or property
                          owners and local authorities in the event of a flood hazard or the impending failure of the impounding
                          structure.
                                18. A proposed impoundment and impounding structure operation and maintenance plan on
                          official forms certified by a professional engineer. This plan shall include a safety inspection schedule
                          and shall place particular emphasis on operating and maintaining the impounding structure in keeping
                          with the project design, so as to maintain its structural integrity and safety during both normal and ab-
                          normal conditions which may reasonably be expected to occur during its planned life.
                       C. The director or the applicant may request a conference to facilitate review of the applicant's
                  proposal.
                       D. The owner shall certify in writing that the operation and maintenance plan as approved by the board
                  will be adhered to during the life of the project except in cases of unanticipated emergency requiring departure
                  therefrom in order to mitigate hazard to life and property. At such time, the owner's engineer and the director
                  shall be notified.
                       E. If the submission is not acceptable, the director shall inform the applicant within 60 days and shall
                  explain what changes are required for an acceptable submission.
                       F. Within 120 days of receipt of an acceptable design report the board shall act on the application.
                       G. Prior to and during construction the owner shall notify the director of any proposed changes from
                  the approved design, plans, specifications, or operation and maintenance plan. Approval shall be obtained
                  from the director prior to the construction or installation of any changes that will affect the stability of the
                  impounding structure.
                       H. The construction permit shall be valid for the construction schedule specified in the approved design
                  report. The construction schedule may be amended by the director for good cause at the request of the
                  applicant.
                       1. . Construction must commence within two years after the permit is issued. If construction does not
                  commence within two years after the permit is issued, the permit shall expire' except that the applicant may
                  petition the board for extension of the two-year period and the board may exte;@ such period for good cause.
                       J. The director may revoke a construction permit if any of the permit terms are violated, or if
                  construction is conducted in a manner hazardous to downstream life or property. The director may order the
                  owner to eliminate such hazardous conditions within a period of time limited by the order. Such corrective
                  measures shall be at the owner's expense. The applicant may petition the board to reissue the permit with
                  such modifications as the board determines to be necessary.
                       K. The owner's professional engineer shall advise the director when the impounding structure may.
                  safely impound water. The director shall acknowledge this statement within 10 days after which the
                  impoundment may be filled under the engineer's supervision. The director's acknowledgement shall act as
                  a temporary operation and maintenance certificate until an operation and maintenance certificate has been
                  applied for and issued in accordance with section 3.2 of these regulations.

                  2.3 ALTERATIONS PERMITS
                       A. Application for a permit to after an impounding structure in ways which would potentially affect its
                  structural integrity shall be made on official forms. The application shall clearly describe the proposed work
                  with appropriately detailed plans and specifications.
                       B. Alterations which would potentially affect the structural integrftyof an impounding structure include
                  but are not limited to changing its height. increasing the normal pool or principal spillway elevation, changing
                  the elevation or physical dimensions of the emergency spillway or rernoving the impounding structure.

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                3.3 OPERATION AND MAINTENANCE CERTIFICATES FOR EXISTING IMPOUNDING STRUCTURES
                      A. Any owner of an impou riding structure other than a Class IV impounding structure which has already
                filed an inventory report that does not have an operation and maintenance certificate or any owner renewing
                an operation and maintenance certificate shall file an application with the board.
                      B. The application for an operation and maintenance certificate shall be on official forms and shall
                include:
                                1. A reinspection report for Class I and 11 impounding structures. The reinspection report shall
                          include an update of conditions of the impounding structure based on a Phase. I or Phase 11 inspec-
                          tion as established by the U.S. Army Corps of Engineers, a previous reinspection report or an as-built
                          report.
                                2. An inventory report for Class III impounding structures. The inventory report shall include:
                                         a. The name and location of the impounding structure and the name of the owner.
                                         b. The description and dimensions of the impounding structure, the spillways, the
                                  reservoir and the drainage area.
                                         c. The history of the impounding structure which shall include the design, construction,
                                  repairs, inspections and whether the structure has been overtopped.
                                         d. Observations of the condition of the impounding structure, reservoir, and upstream
                                  and downstream areas.
                                         e. Any changes in the impounding structure, reservoir, and upstream and downstream
                                  areas.
                                         f. Recommendations for remedial work.
                                3. An impoundment and impounding structure operation and maintenance plan certified by a
                          professional engineer. This plan shall place particular emphasis on operating and maintaining the
                          impounding structure in keeping with the project design in such manner as. to maintain its structural
                          integrity and safety during both normal and abnormal conditions which may reasonably be expected
                          to occur during its planned life. The Phase I Inspection Report should be sufficient to serve as the
                          basis for the operation and maintenance plan for a Class I and Class 11 impounding structure. For
                          a Class III impounding structure, the operation and maintenance plan shall be based on the data
                          provided in the inventory report.
                                4. An emergency action plan and evidence that a copy of such plan has been filed with the local
                          and state Department of Emergency Services. The plan shall include a method of providing notifi-
                          cation arid warning to persons downstream, other affected persons or property owners and local au-
                          thorities in the event of a flood hazard or the impending failure of the impounding structure.
                      C. The owner shall certify in writing that the operation and maintenance plan approved by the board
                 will be adhered to during the life of the project except in cases of emergency requiring departure therefrom
                 in order to mitigate hazard to life and property, at which time the owner's engineer and the director shall be
                 notified.
                       D. If the director finds that the operation and maintenance plan or emergency action plan is deficient,
                 he shall return it to the owner within 60 days with suggestions for revision.
                       E. Within 60 days of receipt of an acceptable application if the board finds that adequate provision has
                 been made for the safe operation and maintenance of the impounding structure, the board shall issue an
                 operation and maintenance certificate.

                 3.4 EXISTING IMPOUNDING STRUCTURES CONSTRUCTED PRIOR TO JULY 1, 1982
                     ' A. Many existing impoundment structures were designed and constructed priorto the enactment of the
                 Dam Safety Act, and may not satisfy current criteria for new construction. The board may issue an operation
                 and maintenance certificate for such structures provided that:
                                1. Operation and maintenance is determined by the director to be satisfactory and up to date;
                                2. Annual owner's inspection reports have been filed with and are considered satisfactory by
                          the director;
                                3. The applicant proves in accordance with the current design procedures and references of
                          section 5.9 to the satisfaction of the board that the impounding structure as designed, constructed,
                          operated and maintained does not pose an unreasonable hazard to life and property; and
                                4. The owner satisfies all special requirements imposed by the board.
                       B. When appropriate with existing impounding structures only. the spillway design flood requirement
                 may be reduced by the board to the spillway discharge at which dam failure will not significantly increase the
                 downstream hazard existing just prior to dam failure provided that the conditions of section 3.4.A of these
                 regulations have been met.


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                 4.3 ENFORCEMENT
                      Any owner refusing to obey any order of the board or the director pursuant to this regulation may be
                 compelled to obey and comply with such provisions by injunction or other appropriate remedy obtained in a
                 court proceeding. Such proceeding shall be instituted by the board or in the case of an emergency, by the
                 director in the court which granted approval to the owner to impound waters or, if such approval has not been
                 granted, the proceeding shall be instituted in any appropriate court.

                 4.4 CONSULTING BOARDS
                  '   A. When the board needs to satisfy questions of safety regarding plans and specifications, construc-
                 tion oroperation and maintenance orwhen requested bythe ownerthe board may appoint a consulting board
                 to report to it with respect to those questions of the safety of an impounding structure. Such a board shall
                 consist of two or more consultants, none of whom have been associated with the impounding structure.
                      B. The costs and expenses incurred by the consulting board, if appointed at the request of an owner,
                 shall be paid by the owner.
                      C. The costs and expenses incurred by the consulting board, if initiated by the board; shall be paid by
                 the board.


                 4.5 UNSAFE CONDITIONS
                      A. No owner shall have the right to maintain an impounding structure which unreasonably threatens
                 the life or property of another person. Theownerof any impounding structure found to have deficiencies which
                 could threaten life or property if uncorrected shall take the corrective actions needed to remove such
                 deficiencies within a reasonable period of time.
                      B. Imminent danger. When the director finds that an impounding structure is unsafe and constitutes
                 an imminent danger to life or property, he shall immediately notify the state Department of Emergency
                 Services and confer with the owner. The owner of an impounding structure found to constitute an imminent
                 danger to life or property shall take invnediate corrective action to remove the imminent danger as required
                 by of section 10. 1 -608 of the Code of Virginia.
                      C. Non-imminent danger. The owner of an impounding structure who has been issued a report by the
                 director containing findings and recommendations for the correction of deficiencies which threaten life or
                 property if not corrected, shall undertake to implement the recommendations for correction of deficiencies
                 according to a scheduleof implementation contained in that report as required by section 10.1 -609of the Code
                 of Virginia.

                 4.6 COMPLAINTS
                      A. Upon receipt of a complaint alleging that the person or property of the. complainant is endangered
                 by the construction, maintenance or operation of impounding structure, the director shall cause an inspection
                 of the structure, unless the data, records and inspection reports on file with the board are found adequate to
                 determine if the complaint is valid.
                      B. If the director finds that an unsafe condition exists, the director shall proceed under the provisions
                 of sections 10.1 -608 and 10.1 -609 of the Code of Virginia to render the extant condition safe.

                                      CHAPTER FIVE - DESIGN REQUIREMENTS


                 5.1 DESIGN OF STRUCTURES
                      A. The owner shall complete all necessary investigations prior to submitting the design report. The
                 scope and degree of precision required is a matter of engineering judgement based on the complexities of
                 the site and the hazard potential classification of the proposed structure.
                      B. Surveys shall be made with sufficient accuracy to locate the proposed construction site and to define
                 the total volume of storage in the impoundment. Locations of center lines and other horizontal and vertical
                 controls shall be shown on a map of the site. The area downstream and upstream from the proposed
                 impounding structure shall be investigated in order to delineate the areas and extent of potential damage in
                 case of failure or backwater due to flooding.
                      C. The drainage area shall be determined. Present, projected and potential future land-use conditions
                 shall be considered in determining the runoff characteristics of the drainage area. The most severe of these
 E.J             conditions shall be used in the design. All hydrologic assumptions shall be included in the design calculations
                 which shall be submitted as part of the design report.
                      D. The geotechnical engineering investigation shall consist of borings, test pits and other subsurface


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                 prevent significant erosion or damage to the impounding structure or to the downstream outlet or channel.

                 5.5 DRAIN REQUIREMENTS
                       All new impounding structures regardless of their hazard potential classification, shall include a device
                 to permit draining of the impoundment within a reasonable period of time as determined by the owner's
                 professional engineer, subject to approval by the director.

                 5.6 LIFE OF THE IMPOUNDING STRUCTURE
                       Components of the impounding structure, the impoundment, the outlet works, drain syst             em and
                 appurtenances shall be durable in keeping with the design and planned life of the impounding structure.

                 S.7 ADDITIONAL DES        IGN REQUIREMENTS
                       A. Flood routings shall start at or above the elevation of the crest of the lowest ungated outlet.
                       B. All elements of the impounding structure and impoundments shall conform to sound engineering
                 practice. Safety factors, design standards and design references that are used shall be included with the
                 design report..
                       C. Inspection devices maybe required by the director for use by inspectors, owners or the director in
                 conducfing inspections in the interest of structural integrity during and after completion of construction and
                 during the Iffe of the impounding structure.

                 .5.8 PLANS AND SPECIFICATIONS
                       The plans and specifications for a proposed impounding structure shall consist of a detailed engineer-
                 ing design report that includes engineering drawings and specifications, with the following as a minimum:
                       1. The name of the project; the name of the owner; classification of the impounding structure as set
                 forth in this regulation; designated access to the project and the location with respect to highways, roads,
                 streams and existing impounding structures and impoundments that would affect or be affected by the
                 proposed impounding stnx;Wre.
                       2. Cross-sections, profiles, logs of test borings@, laboratory and in s'Ru test data, drawings of principal
                 and emergency spillways and other additional drawings in sufficient detail to indicate clearly the extent and
                 complexity of the work to be performed.
                       3. - The technical provisions, as may be required to describe the methods of the construction and
                 construction quality control for the project.
                       4. Special provisions, as may be required to describe technical provisions needed to ensure that the
                 impounding structure is constructed according to the approved plans and specifications.

                 5.9 ACCEPTABLE DESIGN PROCEDURES AND REFERENCES
                       The following are acceptable as design procedures and references:
                       1. The design procedures, manuals and criteria used by the United States Army Corps of Engineers.
                       2. The design procedures, manuals and criteria used by the United States Department of Agriculture,
                 Soil Conservation Service.
                       3. The design procedures, manuals and criteria used by the United States Department of Interior,
                 Bureau of Reclamation.
                       4. The design procedures, manuals and criteria used by the United States Department of Commerce,
                 National Weather Service.
                       5. Other design procedures, manuals and criteria that are accepted as current, sound engineering
                 practices, as approved by the director prior to the design of the impounding structure.















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                                    APPENDIX E
I                     SAFETY EVALUATION OF SMALL EARTH DAMS
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                                       Safety Evaluation
                                  of Small Earth Dams











                                                                                        Pogo"


















                                        The Virginia Department of Conservation
                                                   and Historic Resources
                                         Division of Soil and Water Conservation
                                                 Richmond, Virginia 23219


                                                       2nd Edition 1987


                                                       Previously issued as
                                                    information Bulletin 549 by
                                                The Virginia Water Control Board







                                          Safety Evaluation
                                       of Small Earth Dams




                                                   ONSERVA









                                                                          col








                                                      w





                                  The Virginia Department of Conservation
                                           and Historic Resources
                                   Division of Soil and Water Conservation
                                          Richmond, Virginia 23219





                                                Previously issued as
                                             Information Bulletin 549 by
                                          The Virginia Water Control Board








                                               2nd Edition 1987













                                             TABLE OF CONTENTS

                                                                                      Page

                                Acknowledgements     ..................................   iv

                                Foreward  .............................................   v

                                Introduction .........................................    vi

                        CHAPT ER

                        I       Types of Dams    ......................................   1

                        11      A Typical Dam and Its Principal Parts  .................  3

                        III     Is Your Dam Really A Hazard   .........................   5

                        IV      Inspecting Your Dam    ................................   7

                        V       Dam Inspection and Maintenance Checklist     ...........  9

                        vi      Maintenance Priorities  ..............................  21

                        Vil     Dam History and Record of Inspections    .............. 22

                        Vill    Where Can You Get Additional Help?     ................ 24

                        ix      Conclusion   .........................................  25

                                Bibliography   .......................................  25


                                                LIST OF PLATES



                        PLA TE

                        1       Types of Earth Dams    ................................   1

                        2       Typical Small Earth Dam   ..............................  2

                        3       Foundation Drains   ...................................   4

                        4       The Problem Dam     ...................................   6

                        5       Dam Failure!   ........................................   8

                        6       The Sound Dam     ....................................  20








                                                     ACKNOWLEDGEMENTS


                        The subject of dam safety has attracted a great deal of attention in recent years, and
                     in preparing this pamphlet information from a number of sources was used. The
                     National Dam Safety Program, instituted in response to several major dam failures in
                     the early 1970's, focused on the problem nationwide. Under this program the U.S. Army
                     Corps of Engineers and the Virginia State Water Control Board worked together to
                     inspect many dams in the Commonwealth and to lay the groundwork for eventual state
                     responsibility for this activity.

                        This responsiblity was accepted on October 1, 1981, at the conclusion of the
                     National Dam Safety Program. On July 1, 1986, the Dam Safety Program was
                     transferred to the Division of Soil and Water Conservation of the Department of
                     Conservation and Historic Resources.


                        The assistance and training provided by the Corps over the four year period of the
                     National Dam Safety Program is reflected extensively in this publication. Additional
                     opportunities for the training of state personnel in this area of expertise have been
                     provided by the Soil Conservation Service of the U.S. Department of Agriculture and
                     the University of Virginia School of Engineering and Applied Science. Other states have
                     freely shared their experience in this area, as well as their publications. Those of the
                     Kentucky Department for Natural Resources and Environment Protection have been
                     particularly useful.

                        The members of the Dam Safety Advisory Committee, serving at the request of the
                     Virginia State Water Control Board, have given generously of their time and wisdom to
                     provide guidance in establishing an appropriate role and level of activity for this
                     agency's Dam Safety Section.

                        The cooperation of the owners of dams within the Commonwealth is of course
                     essential to the success of the State's dam safety effort. The agreeable and helpful
                     response of most of the owners, both public and private, with which this agency has.
                     come in contact in the course of its dam safety activities has been most gratifying. The
                     ultimate purpose of such a program is the protection of the lives and property of citizens
                     of the Commonwealth, and the ready acceptance of this goal by the majority of the wide
                     range of individuals and groups bearing the responsibility for the safety of dams is very
                     much appreciated.





















                                                                   iv








                                                             FOREWORD



                         This pamphlet presents a basic discussion of how to evaluate the safety of a small
                      earth dam. Its intent is to inform the dam owner or operator of general aspects of
                      preventive maintenance that he should be aware of and enable him to recognize certain
                      unsafe conditions that may be associated with such structures.               Once unsafe
                      conditions are recognized, professional services may be obtained to assess the
                      problem and to take appropriate remedial action. The Division of Soil and Water
                      Conservation cannot provide consulting engineering services, but it does maintain a
                      list of private firms that have performed this in the state. This brief discussion provides
                      general guidance on some of the more common problems, but it is not intended to cover
                      every type of condition, situation, or emergency that could possibly cause a dam to
                      become unsafe or fail.


                         It should be noted that the condition of a dam depends on many internal and
                      external conditions that may be constantly changing, causing the overall health of the
                      dam to evolve over time. It is incorrect and unwise to assume that the conditions of a
                      dam at any given time will continueto represent itscondition at some time in the future.
                      Only through continued care and evaluation can there be a reasonable chance that
                      unsafe conditions will be detected.


                         The design of an earth dam is the task of an experienced professioani engineer.
                      Likewise the implementation of major remedial measuresfora dam generally requires a
                      consultant. The application of trial-and-error "home remedies" to dam problems is not
                      recommended, and such an approach will likely prove to be far more costly than
                      obtaining and acting on professional guidance. Thetextand p lates of this pamphletare
                      not intended to serve as a design guide either for the construction of new dams or for
                      extensive remedial measures for existing dams. Rather they are intended to serve as a
                      source of information which the owner can use in his regular maintenance and
                      inspection activities and as a general guide as to when professional services are needed
                      to insure the safety of a dam.



























                                                                     V








                                                    INTRODUCTION



                   This pamphlet was written to assist you in inspecting your dam and maintaining it in
                a safe and stable condition. The focus of any dam safety effort is, of course, safety: the
                protection of lives and property in the area downstream from the impoundment. Every
                owner should be aware of the potential hazard that his dam might pose to the down-
                stream area and of the need to properly maintain the dam in such a way as to reduce
                this hazard as much as possible. The liability for damages resulting from a dam failure
                rests with the owner of the dam.

                   A good inspection and maintenance program is important. Your dam represents a
                considerable investment. Replacement costs would be high. Loss of the dam would
                probably mean the loss of a water source, recreational facility, flood protection, or
                other assets.


                   Dams are products of our technology and, like automobiles, provide us with many
                benefits. Like autos, however, they may not be thoroughly understood by persons who
                own them. Consequently, their maintenance is often neglected, and their potential for
                doing great harm and damage-and costing large amounts of money as a result-is often
                not appreciated until an accident occurs.

                   As is the case with buildings, highways, and other works that we construct, dams re-
                quire an on-going maintenance program to insure their continued useful life. This fact
                has not always been fully appreciated. Often there is a tendency to neglect them once
                construction is completed.


                   There are many ways an earth dam can fail. These include but are not limited to
                sliding, piping (internal erosion of soil particles from the embankment), overtopping
                during periods of high water, erosion, liquefaction of earth materials (which may occur
                when embankment material is poorly drained and loosely compacted), structural fail-
                ures -resulting from excessive seepage or other causes, and failures of the foundation
                upon which the structure rests. Problems associated with outlets and spillways can also
                be contributing factors.

                   Like most works of man, dams should not be considered to have an unlimited use-
                ful life. Ernest E. Wahlstrom, Professor of Geological Sciences at the University of
                Colorado, states in Dams, Dam Foundations, and Reservoir Sites: "The ultimate fate
                of all dams and reservoirs, unless they are carefully constructed and maintained, is
                deterioration and failure or filling by sedimentation. Every reservoir that impounds
                water behind a dam is a real or potential threat to those who live and work in flow
                channels below it, and, in some locations where earthquake shocks, movements along
                bedrock faults beneath dams, or collapse of large volumes of earth materials into reser-
                voirs are distinct possibilities, even the most skilled design and continued maintenance
                may not preclude failures that are disastrous to life and property." So, many events
                and circumstances can threaten the safety of a dam, including floods, landslides, earth-
                quakes, and-less dramatically but just as surely-neglect and the deterioration which
                inevitably occurs through neglect.







                                                               Vi









                                                             CHAPTERI


                                                          TYPES OF DAMS



                          Before discussing some of the procedures for inspecting a dam, it is appropriate to
                        make a few general comments about such structures. In simplest terms, a dam is a
                        barrier constructed across a watercourse for the purpose of storing water. Perhaps the
                        most common type is the earthfill dam, and this pamphlet deals with small dams of
                        this mode of construction. There are also concrete dams (gravity, arch, multi-arch, and
                        buttress types) and dams constructed of masonry, timber, rockfill, steel, and combina-
                        tions of these materials.

                          Earth dams may be further classified as simple, core, and diaphragm (Plate No. 1).
                        The simple embankment type consists of reasonably uniform material throughout,
                        sometimes with a blanket of highly impervious material placed on its upstream face.
                        Core embankments employ a central zone or core of carefully chosen material which is
                        less pervious than the rest of the dam. Clay soils are often used for the core, as this
                        type of material is particularly suitable. Diaphragm type dams incorporate a relatively
                        thin section of concrete, steel, or wood-sometimes referred to as a cut-off wall-in the
                        central portion of the embankment, which forms a barrier to the flow of water perco-
                        lating through the dam. Occasionally an earth dam is constructed with both a central
                        core and a diaphragm.








                                                           (a    simpl e








                                            111ol,AY11ANN'



                                                              W     core










                                                          (c) diaphragm

                                                         TYPES OF EARTH DAMS


                                                                                                   PLATE NO. 1


















                                                                                      outlet
                                                                                      pi pe
                 emergency drain
                            riprap/               crest      foundation
                                                             drain pipes            stilling
                principal spillway                                                    basin
                intake structure                                                      (rip-
                with trash rack                                                       rapped)





                                     '*T"emergency spillway




                                                  PLAN



                  emergency drain

                      principal spillway
                      intake structure
                     with trash rack                      crest
                           ri prap                                         bankment
                                                                                     outlet
                                                                                     pi pe


                                     core                 foundation drain
                                cutoff trench.,@          (blanket type)        stilling
                                                                                basin
                                                ELEVATION                       (riprapped)
                                                                     ..4-,embanki





             L                         TYPICAL SMALL EARTH DAM                   PLATE NO. 2

                                                      2








                                                            CHAPTERII


                                          A TYPICAL DAM AND ITS PRINCIPAL PARTS


                          As stated earlier, a dam is essentially a barrier constructed across a watercourse for
                       the purpose of storing water. There are certain features of such structures, such as the
                       principal spillway, which perform vital functions and are common to practically all
                       small earth dams. Understanding the purpose of these is essential to any evaluation of
                       a dam's condition.

                          Such principal parts include the embankment itself, the principal and emergency
                       spillways, the intake structure, outlet works, and stilling basin. Other common features
                       often but not always found are riprap slope protection and foundation drains. Brief
                       definitions of some of these principal features follow, and others are indicated on
                       Plate No. 2, "Typical Small Earth Dam."

                          Spillway. A channel or conduit for an impoundment's overflow. The main such out-
                       let is designated as the principal spillway. Usually there is an additional outlet at a
                       somewhat higher elevation, known as the emergency spillway.

                          Emergency spillway. The purpose of the emergency spillway is to safely pass the dis-
                       charge of major floods, thereby preventing the dam from being overtopped and pos-
                       sibly washed out. Because the ability to handle major floods is so critical to a dam's
                       safety, an adequate emergency spillway is one of the most important features of any
                       dam.


                          Intake structure. That part of the principal spillway through which water enters.

                          Outlet works. Pipes or culverts below the spillway crest and generally near the base
                       of the downstream toe of the dam, which serve to release water through the dam.

                          Stilling basin. A basin or pool area at the toe of a dam into which the outlet works
                       discharge, designed to dissipate the energy of the flow so as to -prevent downstream
                       scour or erosion.

                          Foundation drains. Various types of systems employing pipe, gravel, etc. within an
                       embankment which serve to collect seepage water and move it to a point where it can
                       be safely discharged without deterioration of the dam. Typical foundation drains are
                       shown on Plate No. 3.


                          Core. The central portion of a zoned earth dam, composed of impervious material.

                          Cutoff trench. An excavation in the foundation of a dam for the purpose of con-
                       struction of a vertical barrier to seepage.

                          Riprap. A layer, facing, or protective mound of stone in random size pieces, ran-
                       domly placed to prevent erosion, scour, or sloughing of an embankment or structure.

                          Trash rack. A screening device located at an intake structure to prevent the entry of
                       debris.









                                                                  3


















                                      (a)  toe drain











                                      (b) toe drain,
                                           clay core










                                     (c) blanket drain











                                     (d) chimney  drain,
                                            clay core



                                        FOUNDATION DRAINS

                                                                      PLATE NO. 3



                                             4







                                                             CHAPTER III


                                               IS YOUR DAM REALLY A HAZARD?


                          Every dam represents a potential hazard to the area downstream from it, simply
                       because of the inherent amount of destructive energy that would be unleashed if the
                       stored water behind it was suddenly releases. Thus a dam is generally classified as to
                       the degree of hazard it poses simply on the basis of its location, without regard to the
                       type of structure or the condition it is in. Hazard class I dams are those whose location is
                       such that in the event of a failure there would be probable loss of life and excessive
                       damage. Hazard class 11 are those where loss of life is possible and damage would be
                       appreciable. For Hazard class III dams no loss of life is expected, and damage would be
                       minimal.


                          In view of the fact that a dam owner is legally liable for damages resulting from the
                       failure of his dam, it is a good idea for every owner of a dam to pauseand considerwhat
                       lies below it. Several questions need to be asked.

                          What is the nature of the land use downstream: wooded or agricultural land,
                       scattered homes, roads, villages, urban areas? How many structures are located within
                       a half mile, a mile, several miles of the dam?


                          How are downstream structures located with regard to the watercourse or
                       floodpiain, with respect to both distance from the watercourse or river and elevation
                       above it? Think about the first-floor elevation of the homes located downstream. Are
                       they only afewfeet above the level of thewatercourse, oraretheyon bluffs high above it
                       and out of danger?

                          Is the valley below the darn characterized by steep hills forming a narrow gorge, or is
                       there a broad floodplain? This is an important consideration, as it determines whether
                       water released in a dam failure would soon spread out and lose its force or whether a
                       destructive wall of water would travel a long distance downstream.

                          An awareness of the state of development of the downstream area should be a
                       continuing concern, as conditions below a dam often change appreciably over the
                       years. Thus a dam which posed little hazard when constructed may represent a
                       formidable hazard later as the downstream area develops. When this is the case, it is
                       imperative that an emergency warning plan be prepared for the structure, with
                       adequate provision for alerting those in the affected area in the event the dam's safety is
                       threatened. The Division of Soil and Water Conservation in conjunction with the
                       Department of Emergency Services, can provide guidance on the establishment of
                       such plans.










                        - ----------I







                                   4






                                                                                          no trash rack;  principal
                                                                                          spillway intake structure
                                                 o4                                       partially blocked with debris
                                                                                                          emergency drain
                                                                                                   Oki    damaged and
                                                                                                          inoperable

                emergency spillway                                                      sett ement
                too small

                                                                                                sloughed    I
                                                                                                area
                                 V,
                                    animal                              (4         trees and
                                    burrow               ck@                       underbrush
                                                         JA'       springs and
                                                                         sive seepage     A
             emergency spillway                                    exces
             partially blocked                                                      -4          ruts from traffic
                                                        At,
                                                                         ijA                    with gullies forming

             obstruction
             in downstream
             channel
                                                                                                TIIE PROBLEM DAM




                                                                                                                PLATE NO. 4








                                                               CHAPTERIV


                                                        INSPECTING YOUR DAM


                            The matter of inspecting    your dam should be given the time and consideration it
                          deserves in view of the impoundment's value to you and the possible consequences of
                          its failure. Try to set aside enough time for the project to do a thorough job.

                            Before taking a close look at the dam itself, it would be a good idea to review all of
                          the material (plans, specifications, construction history, records of operation, repairs,
                          major floods, maintenance, etc.) that you may have on it or can locate. Once assem-
                          bled, this material should be kept together in one place for future reference.

                            Sometimes a dam is so overgrown that it is difficult or impossible to evaluate. If
                          this is the case, the underbrush should be cleared off before doing anything else.

                            The following checklist outlines an approach to the actual inspection. The wording
                          of the questions is general so as to apply to as wide a variety of dams as possible. Walk
                          over the structure, examine it closely, and try to answer the questions. Use the "com-
                          ments" space to write down additional information or observations, and study the
                          "remarks" and "maintenance tips" related to each topic.

                            Completing the questionaire should give you an idea about what areas of your
                          dam require attention. The "Maintenance Priorities" section which follows the check-
                          list will be useful in setting up an ongoing program to take care of these in the order
                          of their importance.

                            Some of the common problems associated with dams and covered in the checklist
                          are indicated on Plate No. 4, "The Problem Dam." Plate No. 5, "Dam Failure!",
                          dramatizes the worst possible consequence of neglecting to maintain a dam.





























                                                                     7







                            Your dam is gone, your lake is gone
                            property and possibly lives downstrLam
                            are gone.



            But your liability for damages resulting from t e
            failure of your dam remains, as well as the expense
            of restoring your own facility.                                       Dam failure--don't let it
                                                                                       happen to youl
                                                                                                                        ON



      03























                                                                                                        DAM  FAILUR
                                                         is gone
                                                         lown  str La@a)























                                                                                                                       Yr  Kin
                                                                                                                    PLAI E. I'M








                                                                          CHAPTER V


                                              DAM INSPECTION AND MAINTENANCE CHECKLIST


         THEEMBANKMENT


         Key things to-look for: Anyevidenceof movement, either within the dam itself, at its ends, or in the material on which itrests.Exces-
         sive surface erosion or orher damage to the embankment, or excessive seepage. Is the dam overgrown with underbrush or -rees?

         Yes No                                            Comments            Remarks                                 Maintenance T`ip

         ZI C)     Are there any surface cracks?                               May indicate movement with-             Should be evaluated by a
                                                                               in the dam.                             professional engineer.

                   Is there any unusual movement                               Dam or its foundation may               Should be evaluated by a
                   or cracking at or beyond the toe?                           be unstable.                            professional engineer.
         C3    0   Is there erosion on upstream                                If severe or rapid, a serious           If severe and progressive, pro-
                   face from wave action or changes                            problem.                                tect upstream face with rip-
                   in pool level?                                                                                      rap or other form of wave
                                                                                                                       protection.

         0 0       Is there erosion from runoff,                               Erosion of any sort is a prob-          Improve grass cover; reshape
                   either gullies or bare areas?                               lem, as it tends to get worse           embankment       to     improve
                                                                               with time if not corrected.             drainage pattern.

                                                                                                                       Try to keep all types of
          J    0   Is there erosion from traffic                               Any erosion is serious, as it
                   (people, animals, vehicles)7                                will get worse with time if             traffic to a reasonable level.
                                                                               not corrected.                          Keep vehicles off dam, Stab-
                                                                                                                       bilize crest roads to prevent
                                                                                                                       rutting. Prohibit recreational
                                                                                                                       vehicle traffic on slopes. Keep
                                                                                                                       livestock off dam. Fill in ex-
                                                                                                                       isting ruts or eroded areas
                                                                                                                       and reseed.
         M C3 Are there any animal burrows?                                    May provide passageways for             Fill burrows with earth or oth-
                                                                               water into or through the               erwise block entry.Try to keep
                                                                               dam.                                    woodchucks, muskrat and
                                                                                                                       beaver away from the dam.
                   Are there depressed areas on the                            May have resulted from slope            If pronounced or progres-
                   dam?                                                        failures or settlement, or even         sive, should be evaluated by
                                                                               piping.   .                             a professional engineer.
         C3   C3   Is there any evidence of piping?                            Piping   is  internal    erosion        Piping is always a serious
                   (This condition is evidenced by a                           within an embankment, or                condition, which can lead to
                   muddy flow through the dam                                  the progressive removal of              failure of the dam. A piping
                   andlor the formation of soil                                soil  particles   adjacent to           condition should be evalu-
                   deposits beyond the dam and                                 leaks through a soil mass.              ated by a professional engi-
                   depressions on its slopes.)                                                                         neer.
         0 13      Does the crest appear to have                               Crest movement may indicate             Should be evaluated by a
                   shifted or settled excessively?                             a stability problem. How-               professional engineer.
                   (Look for cracks in the em-                                 ever, some settlement of a
                   bankment and associated struc-                              new fill, such as an em-
                   tures. Compare alignment with                               bankment dam, is normal.
                   plans if they are available.)




                                                                                      9



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                               NOTES
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                                  10
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         THE EMBANKMENT -continued

         Yes No                                             Comments              Remarks                                   Maintenance Tip

                    If the upstream face is protected                             Effectiveness is lessened if rip-         Restore riprap as necessary;
                    by riprap is it in good condition?                            rap has slipped out of place,             keep free of trees and bushes.
                    (Riprap is a layer, facing, or pro-                           has been undermined, or has
                    tective mound of stone in ran-                                become      overgrown         with
                    dom size pieces, randomly placed                              brush.
                    to prevent erosion, scour, or
                    sloughing of an embankment or
                    structure.)

         7    El    If there is riprap in discharge                               Has riprap stone been dis-                Restore riprap as necessary;
                    channels or in the plunge pool                                placed or overgrown?                      keep free of trees and bushes.
                    downstream, is it in good con-
                    dition?

         0 C3       If drainage channels at ends of                               Drainage along abutments of-              Riprap or other forms of
                    embankment are protected with                                 ten causes gullying if there is           slope protection should be
                    riprap, is it in good condition?                              no protection.                            restored as necessary.

         13    0    If there is riprap in miscellaneous                                                                     Restore as necessary.
                    areas (on downstream slope, on
                    crest, etc.) is it in good repair?

         7     [2   If there are any drains to collect                            Check plans for the presence              Keep drains clear of any
                    and remove seepage, are they                                  of drains, or search the dam              blockages      and      operating
                    operating properly?                                           to see if any are present.                property.

         0 'ZI      If there are foundation drain out-                            Foundation drains serve to                Open outlets   to such drains if
                    lets, are they clear and flowing?-                            collect     seepage        passing        they have become covered or
                                                                                  through the dam and conduct               damaged.
                                                                                  it away from the embank-
                                                                                  ment.


         C3 0       Are there wet spots or areas on                               Some seepage is normal for                Observe seepage areas periodi-
                    the downstream face, at the Toe,                              an earth dam. Be concerned                cally to detect changes in the
                    or beyond the dam? (Such spots                                if it appears to be excessive (a          amount of moisture, new
                    are often indicated by a change                               lot of standing water: very               flows, or muddy flows. If the
                    in color or type of vegetation,                               soft and marshy areas; evi-               upper limit of seepage is fair-
                    such as from grass to cattails.1                              dence of a seepage line high              ly high on the downstream
                                                                                  on the downstream face).                  face, the dam may be un-
                                                                                                                            stable.


         C 0_       Are there seeps or springs with                               Flowing seeps or springs      may         Monitor seepage closely for
                    flowing water? Look closely for                               indicate problems, and should             any changes in amount, rate,
                    these at the ends of the dam,                                 be observed periodically for              extent, or clarity. Excessive
                    around any pipes passing through                              changes in rate of flow or                or turbid seepage, or marked
                    the embankment, on down-                                      muddy flow. Creation of an                increases in rate of seepage,
                    stream face, at the toe of the                                impoundment often causes                  should be evaluated by a pro-
                    dam and beyond, and at the base                               changes in the water table                fessional engineer.
                    of trees on, near, or below the                               nearby.
                    dam.


                    Is there swamp or marsh type                                  Swamp type vegetation indi-               Cut frequently to make ob-
                    vegetation on downstream face                                 cates the presence of seepage.            servaTion of the area easier.
                    or beyond the dam (cattails, tall                                                                       Such growth can hide pro-
                    grass, etc.)?                                                                                           blems.



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                       NoTEs
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                                                 1
                         12                      1
                                                 I







        THE EMBANKMENT -continued
        Yes No                                            Comments            Remarks                                Maintenance 'rip


            0 Is the dam overgrown with trees                                 One of the most frequent               Keep embankment faces free
                   and/or underbrush?                                         probl@ms, and highly un-               of tren and underbrush by
                                                                              desirable. Roots may damage            periodic mowing. Remove ex-
                                                                              the embankment and allow               isting trees and saplings, and
                                                                              water to pass into or through          establish and maintain a good
                                                                              it. Trees may be uprooted in           grass cover on the dam.
                                                                              a storm and breach the dam.

        0 El Has the dam ever been overtop-                                   Past overtopping may have re-          Restore eroded areas or ot@er
                   ped by water flowing over it?                              sulted in erosion of the crest         damage done to the dam by
                                                                              and downstream face of the             overtopping. Consider enlarg-
                                                                              dam. Overtopping indicates             ing the emergency spillway,
                                                                              that the emergency spillway            lowering the normal pool level
                                                                              is probably too small.                 to allow more storage capa-
                                                                                                                     city during floods, or perhaps
                                                                                                                     raising the height of the em-
                                                                                                                     bankment to decrease the
                                                                                                                     possibility of future over-
                                                                                                                     topping.


        CJ 0       Has there been any modifica-                               Inappropriate or unsuitable            Dams that have been appre-
                   tion of the embankment, such                               modifications can drastically          ciably modified since con-
                   as raising the crest, changing                             affect the safety of a dam,            struction should be evaluated
                   the shape or size of the prin-                             even one that may have                 for stability by a professional
                   cipal spillway or the emergency                            originally been properly de-           engineer.
                   spillway, or changing the shape                            signed and constructed.
                   or size of the embankment?








        THE PRINCIPAL SPILLWAY


        Yes No

        C1 0       Can water flow into the prin-                              7-he riser, intake structure, or       Install a trash rack if one is
                   cipal spillway without difficulty,                         channel should be free of trash        not already in place. Periodi-
                   as intended when constructed?                              or o d7er blockage.                    caily clear trash racks of any
                                                                                                                     accumulated debris.


        C3 0       Is outlet pipe or discharge chan-                          Flows passing through the              Keep outlet pipe, plunge pool,
                   nel clear and open to allow the                            spillway should not erode or           and all other outlet works
                   free passage of the principal                              otherwise damage the dam.              clear and in good repair.
                   spillway discharge?


                   Is the primary spillway structure                          Such dam features as the               Repair and maintain as ap-
                   in good condition (check con-                              principal   spillway     require       propriate to insure the con-
                   crete, wood, and metal portions                            continued maintenance like             tinued useful life of the dam.
                   for damage or deterioration)?                              any other structure.

        C3 C]      Does the lake have a drain that                            Lowering a take may be                 Check plans or search dam
                   can be used to lower it in an                              necessary if the dam begins            for emergency drain system.
                   emergency?                                                 to develop problems.


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         THE PRINCIPAL SPILLWAY -continued

         Yes No                                          Comments            Remarks                               Maintenance Tip


         C1 0       If there is an emergency drain, is                       Drain   valves    and     other       Maintain system so that it can
                    it known to be in working con-                           mechanisms should receive             be used in an emergency. Nor-
                    dition? Note: If a drain has not                         sufficient maintenance to in-         mally,  the pool behind an
                    been used for a long time, it                            sure that they remain in              earth    embankment        dam
                    may be possible to open it but                           working order.                        should  not be lowered at a
                    not close it.                                                                                  rate of more than 6 inches a
                                                                                                                   day.


         C3   C3    If there are other gates, valves,                        Such devices are vital to the         Repair  and restore if neces-
                    or operating equipment, are these                        effective and safe operation          sary, and maintain in an oper-
                    in working condition?                                    of the dam.                           able condition.








         THE EMERGENCY SPILLWAY

               0    Can water flow into the emer-                            To be effective, aliporrions of       The approach channel should
                    gency spillway without diffi-                            the spillway channel should           be kept free of trash, under-
                    culty, as intended when con-                             be clear and unobstructed.            brush, or other blockage.
                    structed?


         0 C3       Is the discharge channel clear                           Spillway flows must be ef-            Clear as necessary.
                    and open to allow the free pas-                          fectively  conducted      away
                    sage of the emergency spillway                           from the dam.
                    discharge?

         0 C3       Is the emergency spillway con-                           A berm is often constructed           Reshape dam if necessary to
                    structed in such a way that its                          to keep spillway flows from           take care of this problem.
                    flows will not erode other por-                          flowing down the embank-
                    tions of the dam?                                        ment.

         13 C3      Is the emergency spillway in                             Spillway erosion is a common          Restore any erosion gullies or
                    good condition overall (check                            problem.                              eroded areas. Provide channel
                    for erosion within the channel,                                                                protection (riprap, concrete,
                    adequacy of grass cover, etc.)?                                                                etc.) if necessary to eliminate
                                                                                                                   recurring erosion problems.







          THE RESERVOIR AREA


          0     C3  Does the nature of the land sur-                         Intensive agricultural ordevel-       Problems of this nature are
                    rounding the lake or its use                             opment activities in the water-       often complex and may be
                    present any problems?                                    shed may precipitate problems         beyond the owner's direct
                                                                             associated with surface runoff        control.
                                                                             or other difficulties.


          C3    C1  Is there any evidence of land-                           A large landslide into a lake         Suspected or evident pro-
                    slides or instability on the slopes                      can subject a dam to over-            blems of this type should be
                    around the reservoir?                                    topping or other damage.              investigated by a professional
                                                                                                                   engineer or engineering geolo-
                                                                                                                   gist.




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         THE RESERVOIR AREA -continued


         Yes No                                           Comments             Remarks                                 Maintenance Tip


         M 0       Is serious wave erosion occurring                           Some minor erosion along a              Critical shoreline areas can be
                   along the shoreline?                                        shoreline is to be expected.            protected with vegetation or
                                                                                                                       in some other manner.


         M 0       Is a lot of sediment entering the                           This may occur as a result of           Dredging may be required to
                   impoundment, or has this hap-                               construction or agricultural            restore the lake.
                   pened in the past?                                          activity in the watershed.








         DOWNSTREAM CHANNEL


              0 Is the downstream channel free                                 The channel below a dam is              Clear downstream channel if
                   of obstructions, so that water                              often a neglected area.                 necessary.
                   in a flood will not back up
                   against the toe of the dam?








         WATERSHED AREA


                   Have there been any major mod-                              Intensive agricultural or de-           Problems of this nature are
                   ifications or significant changes                           velopment activities in the             often complex and may be
                   in the watershed drainage area,                             watershed may precipitate               beyond the owner's direct
                   such as new urban developments                              problems     associated      with       control. Appeals to existing
                   (shopping centers, housing proj-                            greater   surface    runoff or          regulations dealing with eros-
                   ects), clear cutting of woodlands,                          other difficulties.                     ion    prevention,      pollution
                   or other basic changes in land use.                                                                 control, etc. may be helpful.









         THE DOWNSTREAM AREA

         10 0      If the dam should fail, would loss                          Consider the number of oc-              Personally inspecting the area
                   of life or extensive property                               cupied homes or businesses              that would be affected will be
                   damage be likely?                                           downstream, their distance              useful in determining who
                                                                               from the dam, and their dis-            needs to be alerted in an
                                                                               tance from and elevation                emergency. Topographic maps
                                                                               above the streambed. Con-               prepared by the U.S. Geolo-
                                                                               sider also potential losses in          gical Survey are also useful
                                                                               property and disruption of              for this purpose.
                                                                               facilities, i.e., roads, railroads,
                                                                               or utilities.





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                       0 0 Do you have on file the current telephone numbers of any persons living or
                       working in areas downstream from the dam, as well as the telephone numbers of those
                       responsible for facilities that would be affected, such as highways or public utilities?
                          Do you have on file the current telephone numbersof local authorities who would be
                       informed if the dam is endangered, such as the sheriff, county administrator, or
                       emergency services coordinator?
                          Prior planning for an emergency is invaluable in terms of mitigating losses. When a
                       dam failure is imminent, it is too late to begin wondering who is located downstream
                       and how they can be reached.
                          The Division of Soil and Water Conservation and the local Emergency Services
                       Coordinator can offer guidance for preparing an emergency warning plan, if needed.
                       Such a plan should be filed with local authorities, because in an emergency certain
                       functions, such as compelling the evacuation of an area, can be performed only by
                       those with the legal authority to do so.
                          The Emergency Action Plan Information Statement (Forms DS-2EAP) available
                       from the Division of Soil and Water Conservation provides a basic format which is
                       generally appropriate to smaller dams as wells as larger ones. To be effective, the plan
                       should be appropriate to the structure it is prepared for. A simple prearranged plan can
                       be very effective in mitigating damage downstream in situations where the failure of a
                       dam would create a hazard.
                          Any list of phone numbers or other information to be used in an emergency should
                       be checked for accuracy and updated periodically to insure that the information
                       remains current.










































                                                                  19



















                                                                                                  emergency drain in
                                                                                                  good condition



                                                                                          trash rack on
                                                                                           intake structure



                     adequate                                    embankment clear of
                     emergency                                   trees and underbrush
                     spillway        IL riprapped drainage                                       'Zo/
                                       ways at abutments                                                  traffic restricted
                                                                                                          from dam



                                                                                    p,
                                              outlet works and
                                               toe drains in good
                                               condition                 A


             stilling basin
             protected by riprap




                                                               THE SOUND DAM

                                                                                                                 PLATE NO. 6







                                                            CHAPTER VI


                                                   MAINTENANCE PRIORITIES


                          Maintenance is an ongoing process which should never be neglected during the life
                       of a dam. If a dam has not received much attention for a long time, there are often a
                       number of areas that require attention. Some of these are more pressing concerns than
                       others. The following outline indicates the relative priority that should be given to
                       certain problems or conditions.


                          What Needs To Be Done At Once:


                          The following'conditions require immediate attention:

                          1. Dam is being overtopped or nearly overtopped.
                          2.Dam is about to be breached (by progressive erosion, slope failures, fallen trees
                       whose root masses have left gaps in the embankment, or by other circumstances.)
                          3. Dam evidences a piping or internal erosion condition.
                          4. Spillways are blocked or otherwise inoperable.
                          5. There is evidenceof excessive seepage, the embankment appears to be saturated,
                       or the upper edge of the seepage is high up on the downstream face of the dam.

                          Although the remedy to some critical problems may be obvious (as in clearing a
                       blocked spillway, for instance), the problems listed above generally require the services
                       of a professional engineer familiar with the construction and maintenance of dams to
                       determine the best means of achieving a solution.


                          What Needs To Be Done Within The Next Year


                          1. Removal of all underbrush and trees and establishment of a good grass cover.
                          2. Restoration and reseeding of eroded areas and gullies as soon as possible.
                          3. General repairs to spillways, gates, valves, and other features of the dam other
                       than the embankment itself.
                          4. Establishment of an emergency action and warning plan, in conjunction with the
                       Virginia Department of Emergency Services and the Division of Soil and Water
                       Conservation if dam's location makes it a hazard to life or property.

                          What Needs To Be Done On A Continuing Basis:

                          1. Routine mowing and general maintenance.
                          2. Periodic observation of all springs and areas of seepage.
                          3. Periodic inspection of dam (at least annually).
                          4. Monitoring development which may take place in the downstream area and
                       updating the emergency warning plan to include new homes or other occupied
                       structures within it.


                          Plate No. 6, "The Sound Dam," illustrates some of the features of a typical well
                       maintained small earth dam. Like other examples in this pamphlet, "The Sound Dam"
                       sketch is not intended to show every feature that my be required on a particular dam,
                       but it should serve to illustrate some of the primary considerations, such as an adequate
                       emergency spillway and the absence of underbrush on the embankment.





                                                                   21











                                                         CHAPTER VII


                                       DAM HISTORY AND RECORD OF INSPECTIONS


                          It is a good idea to keep a record of a dam's history, and the following table may be
                      used. Your record of inspections will serve to keep this history current. Also, it is
                      desirable to record a few basic dimensions of the dam.


                                                     BASIC DIMENSIONS


                      Height (measured from downstream toe to top of dam):
                      Surface area of lake at top of dam (if known):
                      Elevation of emergency spillway (if known):
                      Surface area of lake at emergency spillway crest (if known):
                      Elevation of normal pool level (relative to top of dam):
                      Surface area of lake at normal pool (if known):
                      Width of crest of dam:
                      Distance across emergency spillway:
                      Upstream slope (for instance, 3 horizontal to 1 vertical, or 3:1):
                      Downstream slope:                 DAM HISTORY
                      Designed by:                                                         Date
                      Constructed by:

                      Date of completion:

                      Has the dam ever failed,
                        either partially or totally?

                      Has the dam ever been rebuilt
                        or modified?

                      Has the dam been overtopped
                        by flooding?

                      What is the maximum water
                        level observed?

                      Other information relevant to
                        dam's history:












                                                              22












                                             RECORD OF INSPECTIONS


               Date   Summary of Findings Recommendations    Evaluated By  Summary of Actions



















































                                                       23






                                                             CHAPTER VIII


                                            WHERE CAN YOU GET ADDITIONAL HELP?



                          The Divison of Soil and Water Conservation can offer general guidance on many
                       aspects of dam safety. It also can suggest other agencies that may be able to assist with
                       specific problems, such as the preparation of an emergency warning plan. It cannot
                       provide consulting engineering services, but it does maintain a list of private firms that
                       have performed this work in the state. The Division of Soil and Water Conservation's
                       regulatory program with regard to dams is outlined in its regulation, "Impounding
                       Structure Regulations." Copies are available on request.

                          You may wish-to do some additional reading on dams and their maintenance, and, of
                       course, more detailed treatments than can be included in this brief pamphlet are
                       available. Many books discuss these matters, and a few basic references are listed in
                       the bibliography at the end of this pamphlet. Of these, Dams and Public Safety and
                       Design of Small Dams are relatively inexpensive publications by the Bureau of
                       Reclamation, which may be ordered from the Superintendent of Documents, U.S.
                       Government Printing Office, Washington, D.C. 20402. Dams and Public Safety
                       presents many case studies of dam failures and has particularly informative chapters on
                       "Kinds of Problems" and "Preventive and Remedial Engineering." Design of Small
                       Dams contains a wealth of information on the subject, and, although technical
                       considerations of dam design are covered in depth, the clarity of the text and the
                       abundance of illustrations give it more than average appeal to general readers.

                          Standard textbooks and references on water resources, which may be found in
                       engineering school libraries, sometimes contain general discussions of spillways,
                       embankment construction materials, and other subjects which may be of interest to the
                       dam owner. An example of these is Water Resources Engineering by Linsley and
                       Franzini. Professor Ernest WahIstrom's Dams, Dam Foundations, and Reservoirs is
                       primarily concerned with the geological aspects of dam location, construction, and
                       maintenance.


                          "Ponds-Planning, Design, Construction," is published by the U. S. Department of
                       Agriculture. Designated Agriculture Handbook Number 590, this useful publication
                       contains a great deal of information of general interestto anyone concerned with dams.
                       Copies of this booklet and of the "Impounding Structure Regulations" may be obtained
                       at no charge by contacting the Division os Soil and Water Conservation, 203 Governor
                       Street, Richmond, Virginia 23219.


















                                                                   24







                                                             CHAPTER IX


                                                            CONCLUSION



                         As stated in the Introduction      the purpose of this pamphlet is to assist you in
                      inspecting your dam and to make suggestions for a continuing maintenance program
                      to keep it in a safe and stable condition. It is not intended to be a complete checklist for
                      every type of dam, but it should suggest areas with which the dam owner should be
                      concerned.
                         No dam can ever be declared completely and perpetually safe, as a large volume of
                      water in storage always represents a potential hazard. However, a reasonable amount
                      of care and attention to an impounding structure (assuming that its original design and
                      construction was adequate) can generally make the possibility of a failure fairly remote.

















                                                               BIBLIOGRAPHY


                        Design of Small Dams, Bureau of Reclamation, U. S. Department of the Interior,
                        Revised Reprint, 1977. Stock No. 024-003-00199-8.

                        Jansen, Robert B., Dams and Public Safety, Bureau of Reclamation, U. S. Department
                        of the Interior, 1980. Stock No. 024-003-00138-4.

                        Linsley, Ray K. and Joseph B. Franzini, Water Resources Engineering, McGraw-Hill
                        Book Company, New York, 1979.

                        WahIstrom, Ernest E., Dams, Dam Foundations, and Reservoir Sites, Elsevier Scientific
                        Publishing Company, New York, 1974.


















                                                                    25





                                                                                                                          NOAA COASTAL SERVICES CTR LIBRARY



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