BEsT MANAGEMENT PRACTICEs HANDbooK - Tahoe BMP

4.3.1.5 DRAIN INLETAlternate Names: Catch Basin, Curb Inlet, Drop InletBMP DESIGN APPROACHPollutant SourceControlHydrologic SourceControlStormwater TreatmentSCALE OF APPLICATIONAll SFR and MFR < 1acreMFR 1-5 Acre andCICU < 5 acresMFR and CICU > 5acres and all WQIPsTYPE OF APPLICATIONTemporaryPermanentA drop inlet collects stormwater from a parking lot.DESCRIPTIONDrain inlets collect water from roads and parking lots and convey it to anunderground storm drain system. Drain inlets incorporated into a curb andgutter systems are called curb inlets.Drain inlets have minimal water quality benefit alone; however, in a developedwatershed they are often a necessary component of a drainage system that as awhole has a water quality benefit. There are design elements that can beincorporated into a drain inlet to achieve some water quality benefit.APPLICABILITYDrain inlets are suitable along paved roads, parking lots, paved swales, or rocklinedditches where permanent storm drain system are currently installed orplanned to be.Advantages• Prevents discharge of degraded runoff water from roadside ditches andadjacent slopes.• Reduces discharge velocity from culverts/curbs by dissipating energy.TRPA BMP HandbookChapter 4: BMP Toolkit2012 4.3.1.5-Drain InletPage 1