Check dams

From LID SWM Planning and Design Guide
Revision as of 18:15, 27 September 2017 by Jenny Hill (talk | contribs)
Jump to navigation Jump to search
The printable version is no longer supported and may have rendering errors. Please update your browser bookmarks and please use the default browser print function instead.

Check dams are small dams or weirs constructed across a drainage ditch, swale, or channel to lower the speed of concentrated flows for a certain design range of storm events and to promote infiltration.

Check dams:

  • may be constructed of any resilient and waterproof material, including: rock gabions, earth berms, coarse aggregate or rip-rap, concrete, metal or pre-treated timber. Rocks used in check dams should have median diameter 25-75 mm.
  • for enhanced swales may be up to 0.6 m in height; the maximum design depth of ponded water should be ≤ 0.6 m.
  • designed for higher flow velocities should have spillways incorporated into their profile, to direct water to the centre of the swale.
  • are usually installed between 10-20 m along the swale. The spacing of dams should not exceed the horizontal distance from the toe of the upstream dam to the same elevation on the downstream dam.
  • should have energy dissipation and erosion control measures installed in the 1 - 2 m downstream. Examples include large aggregate or turf reinforcement

Sizing[edit]

Check dams: Sizing