Stormwater BMP Best Practices for Construction Sites

Perimeter and sediment controls should be installed and functional before the first significant land-disturbing activity occurs on a given area — not retrofitted after grading has already exposed soil to the next rain event.

Sediment basins, traps, and other capacity-based BMPs need to be sized to the actual contributing drainage area, accounting for how that area will grow as the site develops in phases — not just the conditions present on day one.

Sheet flow, concentrated flow, and channel flow each call for different BMP types. Using a sheet-flow control like standard silt fence at a concentrated flow point is one of the more common mismatches that leads to early BMP failure.

Routine periodic inspections combined with inspections following qualifying rainfall events — as required under the active NPDES CGP — catch problems while they're still cheap to fix, rather than after a discharge has already occurred.

On multi-phase sites, areas that reach final grade should be stabilized within the permit-required timeframe even if other parts of the project remain active — waiting for the whole site to finish before stabilizing anything is a common and avoidable compliance gap.