Constraints, Criteria & Standards

The design of the pond will be shaped by the following specifications:

Constraints

  • Design must stay within specified area
  • Adequate depth
  • Provide cover and habitat for various fish species and enhance biodiversity
  • Aesthetically pleasing
  • Minimize cut and fill
  • Pond is drainable
  • Provide system for water distribution to cattle
  • Water level stays below crest height (dam may not be overtopped)
  • Ability to drive over dam
  • Provide adequate water supply (volume) to account for drought periods
  • Design is cost-efficient

Criteria

  • 7-9 acres in size
  • Less than 100 ac-ft storage volume
  • Effective height must not exceed 25 ft
  • Storage * Effective height is less than 3000 ac-ft2
  • 12 ft in deepest areas (8 ft average)
  • Design for a peak flow of a 24 hour storm inflow
  • Riser must have a larger cross-sectional area than the conduit
  • Diameter of the principal spillway pipe shall not be less than 3 ft
  • Pipe conduits used solely as a supply pipe through the dam for watering troughs and other appurtenances shall not be less than 1-1/4 inches in diameter.
  • 12-15 gal/day/head
  • An adequate volume of water is defined as a minimum of 30,000 gallons (1.1 acre-inches) of pumpable impounded water or a minimum pump flow rate of 250 gallons per minute (gpm) without interruption for 2 hours.
  • 16 ft minimum top width of dam
  • Minimum of 2 ft of freeboard from top of dam to highest possible water surface elevation
  • embankment side slopes must not exceed a total of 5:1 (H:V)

Standards

  • NRCS CPS 378 Pond: For design and construction of low-hazard ponds, where dam failure will not result in loss of life, or significant property damage.

NRCS-NHCP. (2011a). CPS-378: Pond. National handbook of conservation practices. Washington, DC: NRCS.


  • NRCS CPS 399 Fishpond management: Provide sustainable habitat for fish and aquatic organisms.

NRCS-NHCP (2011b). CPS-399: Fishpond Management. National Handbook of Conservation Practices. Washington, DC: NRCS.


  • NRCS Agriculture Handbook Number 590: Ponds- Planning, Design and Construction: Requirements for embankment and excavated ponds, where dams are less than 30 ft. high.

USDA-NRCS (2016a). Ponds - Planning, Design, Construction (Agriculture Handbook 590). Washington, DC: USDA-NRCS. Washington, DC: NRCS.
  • NRCS TR-60 : For use in construction of low-hazard class dams with a product of storage times the effective dam height of 3,000 ac-ft2.

USDA-NRCS. (2016b). Earth dams and reservoirs (TR–60). Washington, DC: NRCS.
  • USDI-BR Design of Small Dams: Specifications and materials required for small dam construction.

USDI-BR. (1987). Design of Small Dams. Water Resour. Tech Publ. Washington, DC: United States Department of the Interior.
  • NRCS CPS 582 Open Channel: For design and construction of an open channel to convey water required to fill the pond.


NRCS-NHCP. (2015). CPS-582: Open Channel. Natl. handbook of conserv. practices. Washington, DC: NRCS.
  • NEH Part 628 Dams: Chapter 45 - Filter Diaphragms: For design of a filter diaphragm for earth fill structures.


USDA-NRCS. (2007). Part 628 Dams, Chapter 45 Filter Diaphragms. In Natl. Eng. Handbook (pp. 45ii -45C-10). Washington, DC: NRCS
  • Appendix B: Principal Spillways VA Stormwater Management Handbook: For design and construction of a principal spillway to regulate discharge from the pond


VADEQ. (2013b). Appendix B, Principal Spillways. Virginia Stormwater Manag. Handbook, Vol.I, Second Edition. Richmond, VA: VA Dep. of Environ. Qual.