Sediment Basin / Trap Storage Volume
Settling storage a construction general permit requires per disturbed acre.
Example
You enter
- Disturbed drainage area (acres) 5
- Required storage per acre (cf/acre) 3600
- Usable settling depth (ft) 3
You get
- Required storage 18000
- Required (cy) 666.667
- Pond footprint at depth 6000 sf
Checked against published worked examples from: South Carolina DHEC.
Details, formula, and sources
ScopeRequired volume = disturbed acres x per-acre rule (commonly ~3,600 cf/acre wet storage), surface = volume / depth. A 5-acre disturbance needs 18,000 cf (667 cy), a 6,000 sf pond at 3 ft. Sizes settling storage only; the spillways are designed separately. Distinct from flood-control detention.
Formula or tablerequired_cf = disturbed_ac x storage_rule_cf_per_ac; required_cy = required_cf / 27; surface_area_sf = required_cf / basin_depth_ft.
Source and editionSediment-basin storage identity by name (per-acre wet-storage rule); first-principles volume arithmetic.
Free accessThe per-acre storage rule is set by the construction general permit or AHJ and entered here (no copyrighted table reproduced).
What governsEstimate. AHJ and licensed professional govern.
API field namesdisturbed_ac, storage_rule_cf_per_ac, basin_depth_ft, required_cf, required_cy, surface_area_sf
- Per-acre storage ~3,600 cf/acre wet storage default (doubled for wet+dry); the general permit / AHJ governsconstruction general permit / AHJ
- Scope settling storage only; spillways, dewatering device, and emergency spillway designed separatelysediment-basin design practice