Laguna–San Diego Coastal water resource basin

Laguna–San Diego Coastal water resource basin (HUC 180703) 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 Laguna–San Diego Coastal water resource basin is a third-level subdivision of the United States hydrologic unit system.

[1] The tiers of the classification system, in order from largest to smallest, are regions, subregions, basins (formerly accounting units), subbasins (formerly cataloging units), watersheds, and subwatersheds.

[2][1] The Laguna–San Diego Coastal basin is approximately 3,860 sq mi (10,000 km2; 2,470,000-acre) and includes the drainage into the Pacific Ocean from Moro Canyon near Laguna Beach to the international border between the United States and Mexico.

[3] The Laguna–San Diego Coastal basin is composed of five fourth-level hydrological units called water resource subbasins (formerly known as water resource cataloging units), each with its own 8-digit hydrologic unit code.