Article Special Series Lester Snow

Meeting California’s Future Water Needs

Lester Snow is director of the state Department of Water Resources (DWR). For more about DWR, visit .

A clean and reliable water supply fuels California’s economy, landscape and population. The Golden State is the nation’s top exporter of computers, electronic products and food. With more than 36 million people, California is also the most populous state in the nation. Redwood forests, sandy beaches, wild rivers, mountains and deserts make up the state’s landscape, and this diverse natural environment is home to many endangered species.

In the past, California has met its water needs through storage and conveyance systems. Heavy rainfall and a generous snowpack in mountainous regions have reliably supplied the drier valleys and coastal plains where most of our water is used. Supply has generally kept up with demand, and the impacts of drought and flood have been mitigated. However, changing conditions are forcing an end to business as usual for water resource managers.

Scientists widely predict that climate change and population growth will severely challenge California’s ability to provide enough clean water for all of its needs. The state’s continued prosperity depends on a water plan and new investments that address these concerns.

By 2025, California’s population may increase to between 44 mil lion and 48 million people. Population is expected to increase most in inland Southern California, the San Joaquin Valley and Sacramento region. However, 60 percent of the population will remain in the coastal regions that are often hardest hit by water shortages (for more information, see “The Amazing, Changing California Population,” July 2007, Western City, online at

The projected dramatic population increases alone would strain California ’s water resources, but the effects of climate change will truly challenge the state’s ability to provide enough water for its residents.

Climate Change Adds to Water Supply Challenges

The “when” and “if” of the climate change debate has given way to “now” and “what next.” Scientists have already observed changes in natural systems that are impacting water resources. The average global temperature has risen more than 1 degree Celsius in the past 100 years. Since 1970, glaciers have been melting at an alarming rate, and the sea level is rising along with the water temperatures of lakes and rivers. Increased and earlier runoff has been observed in snow-fed rivers around the world.

Some of these same effects have been documented in California. In the past century, sea level has risen six inches at the Golden Gate Bridge. Since 1950, peak flows on California’s major rivers have been measured at levels higher than originally predicted possible. Because most levees were built before the 1950s, earlier 20th-century engineers didn’t anticipate the levels of flood protection now needed. Many rivers now flow at or above design capacity during storm events. These high flows are caused not only by more variable and extreme weather patterns but also earlier runoff from faster melting snowpack.

Two years ago, flooding in Northern California led to the discovery of major inadequacies in the strained levee system along the Delta rivers. Conversely, this past winter was very dry, with an abysmally low snowpack and dangerously arid conditions in every avenue of water supply in Southern California.

Anticipated Shortages

This year’s snowpack conditions are a window into future water expectations for the state. By 2050, scientists project a loss of at least 25 percent and up to 40 percent of the Sierra snowpack. The snowpack acts as a huge natural reservoir until the spring snow melt feeds reservoirs and rivers for summer agricultural, urban and environmental use.

With the predicted effects of global warming, much of the snow Californians have come to expect will not fall. Instead, rain will occur at higher elevations, causing raging winter rivers, immediate runoff and brimful reservoirs that must be emptied too early to make room for more rainfall. When the water is needed most, reservoirs won’t be replenished by runoff, and when storage is needed to preserve the integrity of levee systems, it will not be available.

If no changes are made to our current water management strate gies, it is likely that shortages will occur. Besides severe water shortages for urban and agricultural uses, fisheries will be im pacted. Changes in water temperatures will affect the ability of cold-water species to thrive. Rising sea levels would likely cause an inflow of saltwater into the freshwater Delta that currently provides drinking water for 25 million Californians. Salinity would negatively impact native species, ecosystems and habitat. As currently managed, more fresh water will be needed to repel seawater and maintain water quality standards in the Delta, especially during drier years.

Governor, Legislators and Voters Lay the Foundation for Change

There is no doubt that California must not only respond to the dual crises of climate change and population growth but also anticipate future impacts and water needs. Governor Schwarzenegger has been a national leader on these fronts. He signed an executive order in 2005 proclaiming California’s mission to anticipate and mitigate the effects of climate change and reduce the state’s contribution to greenhouse gases. With his support, Propositions 1E and 84 were placed on the November 2006 ballot and approved by voters. These measures provided $4.9 billion for flood management and $1 billion for integrated regional water management that includes wastewater recycling, groundwater storage, conservation and other water management activities.

This money lays the foundation for the steps that must be taken to address the effects of climate change on water supply and for solutions to the effects that have already occurred. By encouraging regions to work together, find new solutions and maximize water supply, Californians will continue their tradition of conservation and innovation that is needed to ensure adequate water into the future.

In January 2007, the Schwarzenegger administration proposed an additional $5.95 billion to bolster the existing funding through 2016. The new investments will specifically target population growth, climate change and environmental needs. [As Western City went to press, the budget was not yet final.]

The governor has proposed two new surface water storage facilities that would most likely be built at Temperance Flat on the San Joaquin River east of Fresno and sites on the west side of the Sacramento Valley. These facilities would provide additional storage areas for early runoff, easing flood conditions and supply concerns during dry summer months, improving water quality and supplying fisheries and wildlife refuges. Water supply from these reservoirs could provide up to 500,000 acre-feet per year.

But augmenting the traditional storage system is not the only solution. New means of water conservation encouraged through integrated regional water management would be funded by $200 million in general obligation bonds. This would be the state’s largest investment in water conservation programs. Investing in the sustainability of the Delta, the hub of California’s water delivery system, is also vital. The governor’s plan proposes another $1 billion in long-term improvements in the Delta.

State Water Plan Offers Roadmap

In concert with Gov. Schwarzenegger’s plan, the Department of Water Resources (DWR) is committed to ensuring sustainable water uses. In its California Water Plan Update 2005, a roadmap for water management through 2030 (online at, DWR defines its new vision of water use efficiency encouraged at the local level.

The plan advocates advanced levels of urban and agricultural water use efficiency by:

  • Increasing recycled municipal water programs;
  • Improving efficiency at water facilities;
  • Facilitating transfers to avoid shortages to the best environmental, economic and social ends; and
  • Eliminating groundwater overdraft.

By supporting integrated regional water management practices, communities can plan, invest and diversify their water portfolios and become more self-sufficient.

The measures that have been taken to find solutions to future water problems are crucial first steps. By working together at the state and local level with scientists, water managers and residents, California will better maintain its water supply and future prosperity.

About This Series

“How Should California Grow?” is a series of articles appearing in Western City through the end of 2007. This article is the third installment in the series.

The series presents a variety of perspectives on growth-related topics. The opinions expressed are those of the authors and do not necessarily reflect League policy.

To read past articles in the series, visit

This article appears in the August 2007 issue of Western City
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