What is storm drainin construction?

A storm drain carries rainwater runoff from pavement and roofs to an outfall, pond, or municipal storm system, while a sanitary sewer carries wastewater to treatment. On US commercial sites they are separate piping systems with separate permits, and sanitary lines typically carry tighter joint, bedding, and testing requirements. Estimators keep them as separate scopes and separate line items even when the same utility sub digs both trenches.

On civil utility sheets, RCP means reinforced concrete pipe, the standard material for storm drains under traffic and at larger diameters. The same abbreviation means reflected ceiling plan on architectural and MEP sheets, which trips up estimators moving between disciplines in the same drawing set. Context resolves it: if the callout sits on a pipe run with a diameter and slope, it is reinforced concrete pipe.

Because the pipe itself is only part of the installed cost. A deeper run means more trench excavation, more imported bedding and backfill, slower production, and protective systems once the trench passes 5 ft, which is where OSHA requires a trench box, shoring, or sloped banks. Two runs of identical 18 in pipe can carry very different unit prices if one averages 4 ft deep and the other averages 10 ft.