The California water resource region is one of 21 major geographic areas, or regions, in the first level of classification used by the United States Geological Survey in the United States hydrologic unit system, which is used to divide and sub-divide the United States into successively smaller hydrologic units. These geographic areas contain either the drainage area of a major river, or the combined drainage areas of a series of rivers.
The California region, which is listed with a 2-digit hydrologic unit code (HUC) of 18, has an approximate size of , and consists of 10 subregions, which are listed with the 4-digit HUCs 1801 through 1810.
This region includes the drainage within the United States that ultimately discharges into the Pacific Ocean within the state of California; and those parts of the Great Basin (or other closed basins) that discharge into the state of California. Includes parts of California, Nevada, and Oregon.
List of California water resource subregions Subregion HUC Subregion Name Subregion Description Subregion Location Subregion Size Subregion Map 1801 Klamath–Northern California Coastal subregion The drainage into the Pacific Ocean from and including the Smith River Basin to and including the Stemple Creek Basin California, Oregon 1802 Sacramento subregion The Sacramento River Basin and drainage into Goose Lake California, Oregon 1803 Tulare–Buena Vista Lakes subregion The drainage into the Tulare and Buena Vista Lake closed basins California 1804 San Joaquin subregion San Joaquin River Basin California 1805 San Francisco Bay subregion The drainage into the Pacific Ocean from the Stemple Creek Basin boundary to and including the Pescadero Creek Basin, excluding the Sacramento and San Joaquin River Basins California 1806 Central California Coastal subregion The drainage into the Pacific Ocean from the Pescadero Creek Basin boundary to and including the Rincon Creek Basin California 1807 Southern California Coastal subregion Drainage within the United States that discharges into the Pacific Ocean from the Rincon Creek Basin boundary to the California-Baja California international boundary California 1808 North Lahontan subregion The drainage east of the Sierra Nevada and north of the Truckee River Basin, which includes the Lahonton closed basins that discharge into California California, Nevada 1809 Northern Mojave–Mono Lake subregion The Closed Desert Basins that discharge into South Central California, including Mono Lake, Owens Lake, Death Valley, and the Upper Mojave Desert California, Nevada 1810 Southern Mojave–Salton Sea subregion The closed desert basins in southeastern California, including the Lower Mojave Desert and the Salton Sea California
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See also List of California hydrologic regions List of rivers in the United States Groundwater recharge Water in California Principal aquifers of California
References