de686747_inとは___goo_Wikipedia__ウィキペディア___American_English
[0] Storm sewer [British English] See surface water sewer or surface sewer. [Comments] Only stormwater [American English] 
A sewer designed and intended to carry only storm waters, surface runoff, street wash waters, and drainage.[2]
Storm drainとは - goo Wikipedia (ウィキペディア)
American English