Northern California receives more annual rain and snow than Southern California, with 75 percent of the state’s precipitation falling in the watersheds north of Sacramento. Yet amid a drought, it seems people in the north are conserving water by letting their lawns turn brown and taking shorter showers as districts and municipalities impose mandatory water-use restrictions, while urban areas of the arid south are lush and green with well-watered gardens and lawns.
Gov. Gavin Newsom asked Californians in early July to voluntarily reduce their water consumption by 15 percent in response to the state’s shrinking reservoirs after two consecutive dry winters. Recent data from the state showed that in July the North Coast reduced water use by 17 percent compared with July 2019 and the Bay Area cut back 8 percent, while the South Coast region that includes Los Angeles and San Diego increased use by 0.1 percent.
Southern California’s urban areas have a more robust and varied water supply than those in Northern California and are generally better prepared for drought conditions. Roughly half of Southern California’s water is transported from other places through a vast system of aqueducts drawing from water rights agreements that go back decades. The other half draws from local sources, such as groundwater basins and recycled water.
There’s also the Metropolitan Water District of Southern California, the regional wholesaler that’s the largest supplier of drinking water in the country. Importing water into the region from the Colorado River and Northern California’s Sacramento-San Joaquin Delta, Met sends water to the region’s most heavily populated places. It serves more than 19 million people in Los Angeles; Orange; Riverside; San Bernardino; San Diego; and Ventura counties.
Jeanine Jones, the interstate resources manager for the Department of Water Resources, explained that the Metropolitan Water District supplements local agencies’ stores that mostly pull from groundwater.
“When you move outside Southern California, what you don’t have in the Bay Area is one overarching large wholesaler that brings in water from multiple sources,” explained Jones, who is managing the state’s drought response. “You have San Francisco with its water supplies from the Hetch Hetchy System, you have East Bay MUD [Municipal Utility District] with its Mokelumne River Aqueduct and much of the Peninsula and the Bay Area does not have ground water resources.
“They’re in an area where Mother Nature was just not favorable for groundwater so they rely more heavily on those surface sources.”