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Virginia Department of Conservation & Recreation

Virginia Department of Conservation & Recreation. Virginia Dam Safety & Floodplain Programs William G. Browning, Director Dam Safety & Floodplain Management. Dam Safety & Floodplain Organization. Department reorganization effective November 1, 2003

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Virginia Department of Conservation & Recreation

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  1. Virginia Department of Conservation & Recreation Virginia Dam Safety & Floodplain Programs William G. Browning, Director Dam Safety & Floodplain Management

  2. Dam Safety & Floodplain Organization • Department reorganization effective November 1, 2003 • Merged Dam Safety and Floodplain Management Programs • Purpose is to reduce risks and hazards to the Commonwealth from dam failure and floods.

  3. Dam Safety & Floodplain Organization

  4. Dam Safety Program

  5. Virginia Dam Safety Act of 1982; Amended July 1, 2002 • Provides for the proper and safe design, construction, operation and maintenance of impounding structures to protect public safety. • No impounding structure can ever be completely fail-safe, because of • incomplete understanding of/or uncertainties associated with natural and man-made destructive forces • material behavior and responses to those forces • quality control during construction

  6. Code of Virginia Requirements: The law regulates impounding structures including dams used to retain or store waters or other materials. With a few exceptions, the following structures are regulated: > Impounding structures 25 feet or higher with a maximum impoundment capacity of 15 acre-feet or more > Impounding structures 6 feet or higher with a maximum impoundment capacity of 50 acre-feet or more

  7. Dam heightis the vertical distance from the streambed at the downstream toe to the top of the dam. Maximum Impounding Capacityof a dam is the volume capable of being impounded at the top of the dam. Acre-foot is a volume of one foot of depth over one acre of area Definitions: 50 acre-feet 6’-25’ high 15 acre-feet 25’ or higher

  8. Impounding structures are classified by hazard potential and size Hazard potential relates to downstream losses that may occur if the dam fails Classifying Regulated Dams

  9. Classes of Hazard Potential If Structure Fails Class I Probable loss of life Excessive economic loss II Possible loss of life Appreciable economic loss III No loss of life expected Minimal economic loss IV No loss of life expected No economic loss to others

  10. The required spillway design flood is based on the combination of : hazard classification size classification Performance Standards Required for Impoundments* * 4 VAC 50-20-50

  11. Spillway Functions • Prevents dam overtopping • Prevents erosion at base of dam

  12. Classifications of Dams

  13. What are the Responsibilities of Dam Owners?

  14. Documents Required For Certification: Operation and Maintenance Application – I, II & III Emergency Action Plan - I, II & III Re-inspection Report – I & II Inventory Report – III & IV Note: Class IV inventory report can be completed by owner

  15. Frequency of Submittal

  16. In addition… Owners of Class I, II, III and IV structures shall perform an annual owner’s inspection and submit the report in years when a professional re-inspection is not required.

  17. Dam Safety Regional Engineers: Review submitted materials May inspect structure Make recommendations to the Soil and Water Conservation Board Upon Submission of Forms…

  18. The Soil and Water Conservation Board Issues: • Regular Operation And Maintenance Certificates • Conditional Operation And Maintenance Certificates • Construction Permits for new dams • Alteration Permits to repair and/or upgrade dams • Transfer of Ownership

  19. Regional Engineers Also … • Review new construction and alteration applications • Advocate dam safety to local governments • Respond to emergencies • Provide training

  20. Number Of Impoundments In Database *May need permitting based on regulation criteria change July 1, 2002

  21. Types of Non-Regulated Dams

  22. At least 18 declared flood or hurricane disasters since Hurricane Camille in 1969 Timberlake dam failure killed 2 people Flooding is the most costly and frequent Virginia natural hazard Why Does Dam Safety & Floodplain Management Matter?

  23. Hurricane Floyd – September 1999 • 13 dam failures in eastern Virginia • Devastated Southampton County and Franklin • Floodwaters did not receed for 11 days

  24. Through Proper Dam Maintenance Build At or Above The Base Flood Elevation Elevate, Relocate or Demolish Flood-prone Structures Conserve Floodplains for Habitat, Open Space, Flood Capacity and Storage How Do We Prevent Damage From Floods and Hurricanes?

  25. Dam Safety & Floodplain Management Programs Need Your Help…

  26. Please Contact Us Regarding • Use of Downstream Inundation Zones • Training In Floodplain Management & Dam Safety • Floodplain Ordinance Review • Technical Assistance For Dams & Floodplain Construction • Floodplain Management Community Assistance Visit • Dams 6 Feet or Higher That Are Not Properly Maintained

  27. Contact Information Department of Conservation & Recreation Dam Safety and Floodplain Management Programs 203 Governor Street, Suite 206 Richmond, VA 23219 804-371-6095 www.dcr.state.va.us

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