Bayview Sand Mine - Sed Pond Berm with Overflow Baffle

Sediment Pond Sand Berm with Overflow Rock Baffle / Weir
Practice Standards and Specifications 6.87 – Check Dam with Weir
Bayview Sand Mine
Powells Point, NC
Currituck County

Definition: Small stone dam structure with a weir outlet with sediment storage area on the upper side, installed in sand
berm.
Purpose: To reduce erosion in overflow drainage outlet during major rainstorms by reducing velocity of flow, and
provide sediment control.
Siting: To be placed at lower end of sand mine disturbed area perimeter berm (8ft x 3ft sand berm).
Aggregate Size: NC DOT Class B stone lined with NC DOT #5 or #57 stone on upper side.
Construction Specifications: Keep center stone section 6 inches below top of sand berm. Place sediment control stone
minimum 1ft thick on upstream side of berm at weir. Provide 9ft long stone apron on lower side of berm to flush with
surrounding grade.
Maintenance: Inspect check dams weekly and after significant rainfall and repair immediately if needed. Clean out
limbs, sediment and other debris that could clog the weir. Add stones to check dam to maintain correct height.
Maintain vegetative ground cover on berm, repair berm erosion as needed.

Ken Elliott, consulting
December 3, 2017