Water and Southern California: Past, Present, and Future

The history of Southern California has always been inextricably intertwined with the story of its water supply.  Southern California has a dry, Mediterranean climate with limited rainfall. While Southern California is more temperate than the hotter desert climes of Las Vegas and Phoenix, its relatively dry climate cannot sustain a large urban population base.

In the late 1800’s as Los Angeles and the surrounding region began to grow, the population relied primarily on the limited rainfall which fed the intermittent flows of the Los Angeles River and replenished the local groundwater basins. By the late 1890’s, the discovery of oil reserves in Southern California led to an economic boom and a growing population. It became clear to everyone that Southern California would need to supplement its local water supplies if growth were to continue.

Owens Valley (1900-1930)

By 1900, the head of the water department for the City of Los Angeles was a self-educated engineer named William Mulholland. Mulholland fully grasped that if Los Angeles were to grow, it would have to follow the model of Rome, another major metropolitan center built in a Mediterranean climate. Rome solved its water supply issues by importing water through a massive aqueduct system that transported water from wetter regions hundreds of miles away.

Mulholland began exploration for potential sources of water that could be tapped into and delivered to Los Angeles. One of the challenges in bringing water into Los Angeles is its terrain. Los Angeles is located on the coast of the Pacific Ocean in a broad coastal plain ringed by a mountain range that encircles the region. Any imported water supply must either go over or under these mountains.

Mulholland’s search led him to the Owens Valley. Owens Valley is located Northeast of Los Angeles and sits at an average elevation of 4000 feet. Owens Valley is flanked by mountains on both sides; the Sierra Mountains on its Western flank reach 14,000 feet and typically have a significant winter snowpack. That snowpack drains into the Owens River which flows into Owens Lake roughly 250 miles from Los Angeles.

There were several key aspects of the Owens Valley that attracted Mulholland for its potential as a water supply for Los Angeles. Foremost was its relatively high elevation in relationship to sea level Los Angeles. At 4000 feet above sea level, water from the Owens Valley could flow hundreds of miles by gravity towards Los Angeles. Using siphons, the water could gain enough velocity to go over the mountains ringing Los Angeles without pumping.

Finally, while there was an existing agricultural economy in the Owens Valley, much of the land and water rights could be acquired at relatively reasonable costs with the water redirected to Los Angeles. While Mulholland ultimately was able to accomplish acquisition of Owens Valley water rights, that acquisition has remained controversial to the present.

Construction of the Los Angeles Aqueduct was completed in 1913. Mulholland believed the Los Angeles Aqueduct would provide sufficient water for Los Angeles for the next fifty years, assuring its growth into a major city.

Colorado River (1930-1960)

By the early 1920’s, growth in Los Angeles and its surrounding suburbs was increasing exponentially. Orange tree orchards and the brand-new motion picture industry provided steady jobs and new economic opportunities for immigrants from other states. Mulholland realized that more water would be needed to meet the growing demands much sooner than 50 years and a new search for water to import was underway.

After several years of horseback exploration by Mulholland and his lieutenants, it was determined that the Colorado River was the most feasible source of new supply. The Colorado River is the largest river in the American Southwest. Starting in the Rocky Mountains, the Colorado River flows across seven states through the Grand Canyon to Mexico and on to the Sea of Cortez. At its closest point to California, the Colorado River passes about 250 miles east of Southern California. An aqueduct tapping into the Colorado River at that point would be slightly shorter than the Los Angeles Aqueduct from the Owens Valley.

But accessing the Colorado River would be significantly more challenging than the Owens Valley from both a physical and an institutional perspective. And it would be far more costly.

On the physical front, by the time the Colorado River reaches the California border it is at an elevation of only about 500 feet above sea level. It would not be possible for Colorado River water to reach Southern California absent pumping. Also, the Colorado River was prone to severe flooding and would require at least one major dam to control flooding and regulate the flow of the river.  A Colorado River Aqueduct would require major infrastructure investments with large dams, pumping stations, hundreds of miles of canal, all to be constructed in inhospitable desert terrain.

On an institutional level, seven states and multiple users within the states shared the water of the Colorado River. Before parties could commit to funding construction of these facilities, the states would have to agree on how to share the river. Federal and state laws would be needed to authorize such a project. Furthermore, the California parties would have to agree on how to share its portion of Colorado River and on how to finance the costly construction.

Ultimately, the seven states that use water from the Colorado River – Wyoming, Colorado, Utah, New Mexico, Nevada, Arizona and California – agreed to divide the river into an Upper and Lower Basin and share the flow of the river in an interstate compact signed in 1922. The California parties subsequently negotiated how to share California’s portion of the river among its urban and farming districts. And Congress blessed the sharing of the river by converting the various agreements into federal law.

Finally, Los Angeles and the surrounding cities of Southern California formed a new agency to finance, construct and operate an aqueduct to the Colorado River: the Metropolitan Water District of Southern California.

Metropolitan was created by Los Angeles and the surrounding cities of Pasadena, Glendale, Burbank, Santa Monica, San Marino, Torrance, Santa Ana, Fullerton, Anaheim, Beverly Hills, Compton, and Long Beach. Metropolitan was the governing mechanism for all the cities of Southern California to pool their resources to fund the building of two major dams on the Colorado River, Hoover and Parker Dams, and a 242-mile aqueduct with five pumping plants. It was the largest series of infrastructure projects ever built in its time, and it was funded almost exclusively by property taxes spread across Southern California during the Great Depression. 

Metropolitan’s Colorado River Aqueduct came online in 1941 and began delivering water into Los Angeles and Orange Counties. The end of World War II brought a huge wave of immigration into Southern California and the post-war economic boom continued throughout the 1950’s. Slowly but surely all Southern California annexed into Metropolitan to ensure access to a reliable water supply. By 1960, Metropolitan’s service area spanned southern Ventura County, Los Angeles County, Orange County, San Diego County, and the western portions of Riverside and San Bernardino Counties.  Once again, Metropolitan and its water planners were confident that with access to the Colorado River, Southern California’s water concerns were resolved for decades.

Northern Sierra Mountains and the State Water Project (1960-1990)  

The baby boom era of the 1950’s saw Southern California spawn endless suburbs replacing the orange tree groves planted in the 1920-30’s.  As Southern California continued to grow exponentially, Metropolitan realized by the mid-1950’s that a new source of water would be needed much sooner. 

After much internal debate over Metropolitan’s mission and role in Southern California’s growth, Metropolitan’s Board of Directors decided to expand its mission beyond the Colorado River. In 1960, Metropolitan voted to participate in the development of the State Water Project to bring water from the Northern Sierra Mountains to farmers in the San Joaquin Valley and to urban Southern California.

Metropolitan was the first public agency to commit to funding the State Water Project (SWP). Metropolitan agreed to pay for half of all the costs of constructing and operating the SWP for 75-years. The SWP is the largest public water delivery system in the nation consisting of ten storage dams, over 700 miles of canals, multiple pumping plants and extensive power facilities. The SWP provides water to 750,000 acres of irrigated farmland and to the urban Bay Area, Central Coast and Southern California.

The SWP was a massive undertaking by the State of California and by extension Metropolitan. The annual costs of the SWP are well over $1 billion a year. Two out of every three Californians get water from the SWP and much of California’s $4 trillion economy relies on the SWP.

With the completion of the SWP, Southern California received water from multiple sources. Local rainfall fed Southern California’s rivers and groundwater basins. Water was imported from the Eastern and Northern Sierra Mountains and from the Rocky Mountains via the Colorado River. These sources were all in different hydrological watersheds and this diversity of supply provided resiliency to Southern California from droughts in any one of these watersheds. An example of this resilience was a severe drought that gripped California in the late-1970’s. Metropolitan was able to maximize its pumping capacity on the Colorado River and allow its SWP supplies to be sent to Marin County in Northern California for drought relief.

Water Efficiency and Storage (1990-2020)

Throughout the 1970’s and 1980’s, growth in California continued unabated. By 1990, California had grown to nearly 30 million people with 14 million Californians residing in Metropolitan’s service area. When California went into another of its severe drought cycles in 1990-1992, the impacts of the drought were felt widely. For the first time in its history, Metropolitan was forced to ration water severely. 

In previous droughts, Metropolitan’s supply diversity meant a drought in one of its water sources could be covered by leaning more heavily on its other sources. But at 14 million people, Southern California demands meant that Metropolitan always needed a steady supply from all its sources.

In the past, when Southern California reached a water supply pinch point, Southern California would go and develop a new supply from far away to import. And indeed, many in the water community turned to look at the possibility of getting water from the Klamath River, the Columbia River, the Mississippi River or even the Great Lakes. But the world had changed significantly from 1960 to 1990 in how it looked at growth and its impacts on the environment.

Public expectations now extended to protection of the environment in conjunction with providing reliable water supply. Numerous environmental laws like the National Environmental Policy Act and the Endangered Species Act were passed by Congress along with California counterparts such as the California Environmental Quality Act and the California Endangered Species Act. Building new water projects now required years of planning, review and permitting. And new water project proposals typically generated significant opposition and litigation from environmental groups and concerned citizens.

Coming out of the 1990-1992 drought, Metropolitan conducted a broad two-year planning process and solicited input from its member water agencies, the cities and the communities in the service area, stakeholders and interested members of the public. This process culminated with adoption of Metropolitan’s first Integrated Resources Plan (IRP). The IRP is a living document that looks at Southern California’s water needs and demands 25 years into the future to guide Metropolitan’s planning and investment decisions. And because adaptation will always be necessary, the IRP is refreshed and updated every five years.

The IRP took a comprehensive review of all the local and imported water resources available to Southern California and used models based on projected growth to predict future needs and demands. The broad conclusions of the 1994 IRP was that developing new imported water supplies was not practical or feasible, and the best strategy was to focus on becoming more efficient in utilizing and maximizing Southern California’s existing available supplies.

Based on the conclusions of the IRP, Metropolitan’s Board adopted a two-prong strategy in the 1990’s. Metropolitan began to invest heavily in water conservation and efficiency along with water recycling to drive down per capita water usage in its service area. And Metropolitan also invested in building water storage to take advantage of the wet years in its existing water sources to have water in reserve for the inevitable dry years.

Over the next thirty years, this strategy has successfully shielded Southern California from drought impacts without having to build a new regional imported supply. In terms of water usage, Metropolitan systematically provided rebates for high efficiency plumbing fixtures while lobbying for tighter restrictions in plumbing codes. Per capita water usage in Southern California steadily dropped from over 300 gallons per day to about 100 gallons per day. 

In 1990, Metropolitan sold 2.4 million acre feet of water to satisfy demands for 14 million people. An acre foot of water is about 296,000 gallons and the rule of thumb in 1990 was that one acre foot of water provided a years supply of water for two households. Today, thanks to increased plumbing efficiency, one acre foot typically is enough water for three households per year. In 2019, Metropolitan sold 1.5 million acre feet to meet the demands of 19 million people. 

In effect, water efficiency has decoupled growth from demand in the water sector. Previously, growth in population always resulted in parallel growth in water demands. Over the past 30 years, Southern California has grown by 5 million people while demands for imported water have dropped nearly 40%.

From 1990 to 2020, Metropolitan alone invested over a billion dollars into water efficiency and over another billion dollars into water reuse projects. Much of this funding was matched with dollars from federal, state and local governments. These investments essentially created a fourth aqueduct into Southern California.

Water efficiency and water reuse, however, are not in and of themselves a water supply. They require an existing water supply to conserve against and to reuse. Southern California continued to need its baseline imported supplies despite increased efficiency and effective reuse. However, climate change has impacted the reliability and steadiness of existing water supplies. Climate change has made droughts longer, hotter, and deeper. Snowpacks have shrunk and snowfall has turned into rain. Climate whiplash has also resulted in larger, more intense storms in wet years punctuating the longer drought periods.

To deal with this reality, Metropolitan simultaneously invested in water storage to take advantage of these more intense wet years to provide a buffer during the longer drought cycles. In 1990, Metropolitan could only store approximately 300,000 acre feet – today Metropolitan can store over 5 million acre feet. 

In 2000, Metropolitan completed construction on Diamond Valley Lake. The largest reservoir constructed in California since the 1960’s, Diamond Valley Lake was constructed at a cost of over $2 billion and is connected to the SWP with a $1 billion high volume pipeline. The reservoir holds up to 800,000 acre feet and provides Southern California with over six months emergency supply.

In addition to building Diamond Valley Lake, Metropolitan invested heavily in groundwater banks in its service area and in California’s Central Valley. Finally, Metropolitan reached agreement with California’s Department of Water Resources and the United States Bureau of Reclamation giving Metropolitan the right to store water in Lake Mead and SWP reservoirs.

In the last twenty years, California suffered through three severe droughts. These have been three of the worst five droughts in over one hundred years of recorded history. According to tree ring data, the 2103-16 drought was the worst drought in California in the last 1800 years. Yet, during these droughts Metropolitan did not have to resort once to mandatory cutbacks, relying instead on calls for voluntary conservation. The strategy of reducing demands through efficiency and building a storage buffer to mitigate prolonged droughts provided Southern California with the resiliency to deal with prolonged droughts worsened by climate change.

Low Growth and Contraction (2020-?)

Since 1849 and the onset of the Gold Rush, California has always been a high growth state absorbing immigrants from east coast states and from abroad. But recently, California has begun to grapple with the reality of slow growth and contraction. From 2010 to 2020, California growth was flat at 1-2%. And that slight growth mostly occurred in the Central Valley region with virtually no growth in the high-cost urban areas of Southern California and the Bay Area. Overall, for the past decade Southern California’s population has remained flat. For the first time in 160 years, California lost a Congressional seat in 2020. 

Since 2020 when the COVID-19 pandemic ushered in teleworking and virtual meetings, Southern California and the Bay Area have been experiencing actual contraction.  Remote working allowed residents to keep jobs and leave high cost urban areas. Many jobs and residents left California for states with cheaper housing and lower or no state income taxes like Nevada, Arizona and Texas. Predictions are that California will lose three to four more Congressional seats by the next census in 2030.

This new reality will have significant implications in all of California’s urban sectors like education, transportation, infrastructure and housing. Water will not be immune from the impacts by this demographic shift.

The economics of water supply are that nearly 80% of the costs of water supply are fixed. These costs are bound up in long-term infrastructure like dams, canals, aqueducts and pumping plants. The remaining 20% of costs are for the marginal expense of energy for pumping water, chemicals to treat water and labor to maintain facilities. When less units of water are sold, the fixed costs of water infrastructure must be captured across the fewer amount of units sold resulting in rapidly rising costs. 

Southern California has been steadily growing more water efficient since 1990 and combined with the recent shrinking of the population base, demand for imported water has greatly contracted. In 2025, Metropolitan is projected to sell about 1.2 million acre feet – the least amount of water sold by Metropolitan in over 50 years.

Conclusion

There is a silver lining in this shift from rapid, high growth to flat growth or contraction. Southern California has invested in robust water infrastructure over the past 100 years. All that infrastructure worked well to prepare California to deal with the volatility of climate change. An easing of pressure to find new water supplies to handle growth frees agencies to focus on issues like aging infrastructure without the financial burden of developing new, expensive water supplies.

However, the financial pressure on water agencies will be immense for the foreseeable future. Affordability is a new political reality in all aspects of American life. Water will be no exception. Water agencies will need to be cautious in making new investments for the foreseeable future. The past mantra of building “all of the above” cannot be applied in an era of limited resources. All new investments and planning documents must be reevaluated through this lens. 

Every 30 years since 1900, a new generation of Southern Californians faced a distinct water challenge. The first three generations met that challenge by developing a new imported water source and transporting it to Southern California. The last generation used new tools to use water more efficiently and maximize the value of the existing resources. The challenge for this generation will be dealing with a need to face the impacts of climate change and modernize an aging system while managing in a shrinking economic environment. 

While this may be new to California, this is a normal part of how societies age and evolve. Japan and Europe have been managing an aging population and shrinking base for decades. The same is true for many cities in the eastern United States. As we enter this new chapter for California, water agencies will have to adapt and be ever more efficient in managing and safeguarding the one resource that is essential to all life – water.

Jeffrey Kightlinger was the Chief Executive Officer and General Manager for The Metropolitan Water District of Southern California from 2006 to 2021, the largest municipal water provider in the United States. He oversaw Metropolitan’s $1.8 billion annual budget and 1,800 employees, and was the lead on numerous landmark agreements and programs in western water development. Prior to becoming CEO, Mr. Kightlinger was Metropolitan’s chief legal officer and a known expert on California water law and the law of the Colorado River.