California is experiencing one of its driest stretches yet but San Diego County’s water agency isn’t alarmed.

In the weeks after Gov. Jerry Brown declared a drought emergency, the San Diego County Water Authority has repeatedly said past efforts to diversify its water sources and hold more H20 in storage mean our region can avoid the significant cutbacks others have seen.

The water agency’s board did vote Thursday to begin urging cities and agencies that rely on it to usher in voluntary belt-tightening. But that move is far less drastic than the 20 percent cuts the governor urged last month.

That relatively rosy outlook didn’t come without a major trigger.

In the early 1990s, San Diego relied on one major source for almost all its water: the Los Angeles-based Metropolitan Water District of Southern California, which draws much of its H20 from the Colorado River and the Sacramento-San Joaquin Delta.

Here’s what that looked like.

We Stand Up for You. Will You Stand Up for Us?

But a drought that hit its peak in early 1991 nearly stung the region when Metropolitan threatened to halve its allocation to San Diego County. Rain and snow ultimately saved San Diego, but business leaders and residents demanded that the county diversify to avoid a future disaster.

The County Water Authority responded. Today it only gets about half of its H20 from Metropolitan, relying on a handful of new sources to lessen that burden.

The percentage listed as “Conservation” isn’t an actual water source. It comes from the Water Authority’s assumption that efforts to save water since 1991 makes more available than there would have been without San Diegans cutting back.

San Diego water wonks want to diversify even more by 2020.

So where’s all this new water coming from?

Imperial County Farmers

The biggest chunk comes from a 2003 pact with Imperial County. It basically allows San Diego to pay Imperial County farmers for H20 they’d otherwise use to water crops.

Image via Shutterstock
Image via Shutterstock

The deal has already brought significantly more water to San Diego. By 2021, officials hope to get 200,000 acre-feet of water annually from the arrangement, about double what San Diego received from the Imperial Valley farmers last year. To put that in perspective, an acre foot is enough to serve about two households a year. So this means Imperial County water would service about 400,000 households in 2021.

Canal Linings

Image courtesy San Diego County Water Authority
Image courtesy San Diego County Water Authority

San Diego relies on two pathways to get much of its water: the Coachella and All-American canals.

For a long time, the region lost out on a lot of H20 while it was still on its way here. Hundreds of thousands of gallons of water seeped into dirt as it traveled through the canals.

That changed several years ago when construction crews laid these concrete linings along those two canals to save all that lost water.

The Water Authority can get as much as 77,700 acre-feet of water annually thanks to this relatively simple fix, which would serve about 155,400 households.


San Diego residents and business owners have cut back considerably in the last couple decades.

The region is using slightly less water than it did in 1991, when the county had roughly 2.5 million residents. The population is now closer to 3.2 million.

And since 2007 alone, Water Authority figures show total regional water use has fallen about 22 percent. The numbers below are presented in acre-feet.

Pushes for more efficient appliances and ideas from statewide task forces on conservation have also contributed to the drops in usage.

Recycled Water

Image courtesy San Diego County Water Authority
Image courtesy San Diego County Water Authority

The Water Authority and some of the cities and agencies under its umbrella are pushing a relatively new water source: extensively treated wastewater that can be used for irrigation or perhaps even refreshment.

The city of San Diego has conducted a handful of pilot studies on adding recycled water to the region’s general supply. Last year, 10 North County water agencies came together to increase necessary infrastructure to boost recycled water use for irrigation.

Some of these efforts are already paying off.

In 2013, the county had more than 27,000 acre-feet of recycled water in its supply. It hopes to almost double this amount by 2020.


Image via Shutterstock
Image via Shutterstock

San Diego can’t access groundwater supplies as easily as many parts of the state. But about seven water agencies in the county produce it. Camp Pendleton has been most successful, delivering about 7,000 acre feet of salty, brackish water a year. That makes up a sizeable chunk of the roughly 21,000 acre-feet of water that the county recorded from this source last year. Groundwater is processed and made drinkable before being added to the water supply.

Oceanside is one city that’s aiming to up its groundwater delivery. Late last year, the city installed a new pump station it projects will bring in about a 27 percent hike in usable groundwater H20.

San Diego Area Reservoirs

Image courtesy San Diego County Water Authority
Image courtesy San Diego County Water Authority
San Vicente Dam

Rainfall and runoff stored in San Diego area reservoirs make up the county’s largest local water source. These reservoirs hold enough water to fill more than 384,000 large swimming pools.

On average, these local surface water sources make up about 7 percent of the region’s annual water supply.

In recent years, the County Water Authority has tried to increase its storage, essentially to create an insurance policy for future droughts.

The Water Authority keeps tabs on 25 reservoirs. Two of the largest are El Captain and San Vicente, both owned by the city of San Diego.

Water in these reservoirs – as well as those outside San Diego – also accounts for the stored water that the Water Authority says makes it confident the region will have enough water to get through 2014 even if the drought continues.

Dana Friehauf, the Water Authority’s acting water resource manager, said the Metropolitan Water District’s storage reservoirs have also helped shield San Diego County from the water cutbacks necessary elsewhere.

Major Metropolitan water storage caches include Diamond Valley Lake near Hemet and Lake Matthews in Riverside County.

These H20 stockpiles act as a sort of an insurance policy for all Southern California water agencies, Friehauf said.

    This article relates to: California Drought, Community, Environmental Regulation, News, Science/Environment, Share

    Written by Lisa Halverstadt

    Lisa writes about San Diego city and county governments. She welcomes story tips and questions. Contact her directly at or 619.325.0528.

    Chris Klich
    Chris Klich subscriber

    San Diegans need to establish a dialogue addressing two important aspects that aren't covered in this article: recycled water for household use, and the use of grey water. The unfortunate moniker applied to the former, "toilet to tap," has stymied serious efforts to make use of this renewable resource. Overlooked in all of the rhetoric is the fact that, since we're at the end of the Colorado river, all of the water coming from the Imperial Valley is already recycled, having gone through the bodies of everyone upriver from us.

    As to the second item, laws need to be passed to make permitting of water from household drains, dishwashers, and washing machines ("grey water") easier. The availability of sophisticated pumps, filters, and storage containers makes us look foolish to let all of that water simply run into the ocean. It could easily sustain landscaping, if only landscape contractors could more easily install such systems. But the permitting process is lugubrious, and needs to be streamlined. A side benefit would be to create new jobs for the folks who would install these systems.

    jlhodges subscriber

    In addition to showing overall water use, it would be helpful to show water use by sector in order to inform the public about where there are the most opportunities for more efficient use of water: Residential, Agriculture, Thermoelectric, Livestock, etc.  Overall for California it looks like this:

    Of total water used in California:

    Agriculture = 80% (State Department of Water Resources)
    Of total California Gross Domestic Product: Agriculture = 3% (State Department of Finance)

    Number of water districts in California: 1,286 (Legislative Analyst's Office)
    Yes, 80% of California's water is used to support 3% of its economy

    Ranked by county, most water is used in counties with the largest Ag sectors, with Fresno just behind San Diego and LA.
    Today's water debates are often portrayed as Northern Cal residents vs Southern Cal lawns and golf courses.  But that is a red herring.  Even if every residential water user in Southern California let their lawns and golf courses die, that would not begin to solve California's water problems.  You have to go where 80% of California's water is used to support 3% of its economy: Agriculture.  And you have to get 1,286 water districts on board to address the problem.

    Carrie subscribermember

    Still, based on the 2014 pie chart, more than 3/4 of our water comes ultimately from the Colorado River and the Sacramento-San Joaquin Delta. If those sources decline, we can expect to feel it.

    Will Johnson
    Will Johnson subscriber

    Thank you VOSD.  Great article and must-read for every San Diegan to understand our water resources.  SD City Council took a path of least resistance in adopting the same water conservation measures back in 2009.  To bottom line this, there is no revenue stream in water conservation.  There is no leadership in the water districts....just nice pensions.  

    Michael Aguirre
    Michael Aguirre subscriber

    Another typical great piece of work by Lisa.  San Diego lives under a water Sword of Damocles. We need a deep and extensive change in our water consumption habits.  San Diego leaders worry that water conservation will be bad for development.  We see the issue put as green vs. water, while the opposite is true.  Reclaiming our water shed, decentralized recycling, and water conservation are immediate needs.  We need new leaders in control of San Diego/s water policies, the current group is giving us a false sense of confidence.  

    Susan subscribermember

    I completely agree with you Mike. We need some true leadership that will not hide behind a false reliance on temporary sources. Even if San Diego is currently better positioned than other cities, do you really think that LA won't come knocking on our water door when they run dry? We are all in this together. Taking a regionalist position is not particularly helpful.

    Mark Giffin
    Mark Giffin subscribermember

    Over the years San Diego Water authority has purchased and positioned Water rights. As the graphs show they have diversified those rights and purchases putting San Diego in a much better position.

    One of their Storage assets (30,000 acre-feet) was purchased from a local company back in 2008 who owned the rights to those assets.