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. 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. These geographic areas contain either the drainage area of a major river, or the combined drainage areas of a group of rivers. The Laguna–San Diego Coastal basin is approximately and includes the drainage into the Pacific Ocean from Moro Canyon near Laguna Beach to the international border between the United States and Mexico. 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. List of subbasins of the Laguna–San Diego Coastal basin See also South Coast hydrologic region Groundwater recharge Water in California Principal aquifers of California References Lists of drainage basins Water resource basins San Diego