stormwater, noun

Used attributively in Special Combinations
stormwater drain or stormwater pipe, a large cement pipe or cemented trench constructed (especially in urban areas) to carry rainwater off roads;
stormwater drainage, this system of drainage, or the infrastructure required for this system.
1965 A. Fugard Notebks (1983) 123She would never have reached her destination on foot that day...She said she knew it and would have slept in one of the stormwater drains.
1971 Cape Times 3 July (Mag. Sect.) 1To its credit, the Council has also energetically tackled the provision of basic services — gravel roads, stormwater drains and night soil removals in the slum parts.
1974 Barkly East Reporter 3 Dec. 2No stormwater drains are dug beside the sidewalks and the surface is left rough.
1979 Daily Dispatch 17 Apr. 9 (caption)Police carry the body of Jose J— who was drowned while playing in a Johannesburg stormwater drain with friends.
1980 C. Hope A Separate Development (1983) 97The municipal sweepers will come along with brooms and hoses and wash your blood and guts down the stormwater drains so the whole place is tidy again for the next day.
1982 Grocott’s Mail 25 June 1Why did they tar over the old cobbled stormwater drains instead of repairing the cobbles.
1986 Grocott’s Mail 14 Mar. 3Improvements will include laying drains, storm-water drains and water reticulation.
1994 Weekly Mail & Guardian 16 Sept. 26The problem is caused by heavy development and huge new stormwater pipes installed upstream, which the council allowed despite warnings of severe flooding.
1979 Quarterly Newsletter (George Municipality) 24 Sept. 1Stormwater Drainage — Again. The rather unusual downpour on Saturday, 15 September 1979, has again highlighted the necessity of an effective stormwater drainage system.
1982 Sunday Times 5 Dec. (Mag. Sect.) 4The services also had to be accommodated under the sidewalks..and there had to be provision for stormwater drainage.
1986 Sowetan 24 Sept. 7He said the council will also embark on the following projects: Improve the water pressure and distribution of water in the township; Upgrade roads; Improve stormwater drainage [etc.].