Ventura–San Gabriel Coastal water resource basin

Ventura–San Gabriel Coastal water resource basin (HUC 180701) is one of three hydrologic basins within the Southern California Coastal water resource subregion and is one of approximately 2,200 water resource basins in the United States hydrologic unit system. The Ventura–San Gabriel Coastal water resource basin is a third-level subdivision of the United States hydrologic unit system.

The Ventura–San Gabriel Coastal basin is approximately 4,530 mi2 and extends from Rincon Creek on the north to the San Gabriel Basin on the south. The Ventura–San Gabriel Coastal basin is composed of seven fourth-level hydrological units called water resource subbasins (formerly known as water resource cataloging units), each with its own 8-digit hydrologic unit code. Water in this basin is overseen by the Greater Los Angeles County Integrated Water Management Region, the Upper Santa Clara Integrated Water Management Region, and the Ventura County Watershed Protection District. This basin was part of an educational initiative by the University of California called Watershed U; modules focused on the Los Angeles River, Ventura River, Santa Clara River, and Compton Creek. The Los Angeles County Department of Public Works subdivides the water sectors of their county six ways, slightly differently from the federal subdivisions; they oversee the heavily channelized watercourses of the county in partnership with the U.S. Army Corps of Engineers.