Report Summarizes California’s Water Year, Urges Better Water Management

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In 2023, California experienced whiplash weather events — successive atmospheric rivers at the beginning of the year, an epic snowpack and a rare summer tropical storm.

The year’s chaotic climate events are detailed by the Public Policy Institute of California (PPIC) in its latest water report, wherein the research institution urges more collaboration among stakeholders to improve water management during wet years.

“Californians are being asked to strike a strange balance between being prepared for both biblical droughts and unprecedented deluges. The happy medium—never a common experience for the state—is shrinking,” states Letitia Grenier, director of the PPIC Water Policy Center.

The best way forward, she said, is to design projects that bring broad benefits, such as:

• Recharging groundwater, which can aid growers, city dwellers, and wildlife simultaneously;

• Investing in infrastructure to protect communities at risk of flooding, which also could assist wildlife, farmers and community water systems; and

• Finding and exploiting synergies to make state and federal dollars go farther and help more people.

Improving how the state manages its water supply is a challenge Californians can and must rise to meet, Grenier stresses.

“California’s infrequent deluge years can be seen as a nuisance or as an opportunity that must be harnessed. Let’s seize them, prepare for them, and make the best use of them possible,” she said.

2023 Water Year

The 2023 water year, which ran from October 1, 2022 to September 30, 2023, continued the state’s overall trend of increasing seasonal and annual precipitation volatility and rising temperatures, mirroring changes across the United States and around the world, the report finds.

The chaotic weather of 2023 can be summarized by five episodes, each of which brought its own challenges:

• The 2020–22 drought continued. The fall of 2022 was exceptionally warm and dry, with low reservoir storage in California and record lows in the Colorado River’s main reservoirs, Lake Powell and Lake Mead. Seasonal forecasts—citing La Niña conditions—called for a continuation of drought conditions.

• A “winter in three weeks.” From late December to mid-January, California was hit by nine significant atmospheric rivers. Flooding affected 24 counties, and at least 22 people died. Much of the state received more than a year’s worth of precipitation in a matter of weeks; the Sierra Nevada snowpack in late January exceeded the April 1 average.

• A dry mid-winter. Very dry conditions then resumed, concerning water managers who were already worried about relatively low precipitation in the headwaters of the state’s two largest reservoirs: Shasta and Oroville.

• An epic snowpack. The dry spell broke with a series of strong, relatively cool late-season storms. Prodigious snowfall covered the Sierra Nevada and Cascades, setting a record for snowpack in the headwaters of the Tulare Lake region in the southern San Joaquin Valley. An unusually cold spring slowed the snowmelt and prevented widespread spring flooding in the San Joaquin Valley, but portions of the ancestral Tulare Lake refilled for the first time since 1997.

• A warm summer, with a surprise. A cool spring gave way to a very hot summer, mirroring conditions throughout the northern hemisphere. In late August, a rare tropical storm—the remains of Hurricane Hilary—made landfall in Southern California and hit interior deserts and much of the intermountain West. Precipitation records were set in many places, with numerous damaging flash floods and debris flows.

The water year was chaotic and underscored the urgent need for better water management.

“It highlighted our need to better navigate multiple imperatives: storing more water during intense wet periods to build water supply reliability, protecting communities and infrastructure against the threat of increasingly damaging floods, and taking better advantage of wet years to improve the health of freshwater ecosystems and native fish and wildlife,” the report stated.

Efforts to Store Water Faced Many Challenges

Water managers struggled to take full advantage of this wet year. Among the top issues the report cites are:

Insufficient opportunities to store water. Most surface reservoirs filled while there were still ample supplies in the system. The Central Valley Project (CVP) and State Water Project (SWP) had to reduce exports from the Sacramento–San Joaquin Delta due to limited surface storage capacity and insufficient access to groundwater storage sites south of the Delta. The PPIC estimates that the projects could have diverted and stored more than 600,000 additional acre-feet of water from the Delta while meeting environmental regulations. Another 1.2 million acre-feet of San Joaquin River flows could have been captured upstream of the Delta while meeting these requirements.

Incomplete preparation for recharge. Although interest has been growing in expanding recharge—especially in areas seeking to comply with the Sustainable Groundwater Management Act (SGMA)—many areas were not prepared to take full advantage of 2023’s wet winter. Efforts were hampered by a lack of coordination between surface reservoir and recharge operations, limited infrastructure to move water to suitable areas, time-consuming permitting requirements, and a dearth of landowners and local agencies sufficiently organized—or even willing—to take water.

Unrealized potential to improve community water wells. The abundance of water created an opportunity to improve drinking water wells affected by overpumping. Some strategic recharge efforts have begun—for example a partnership between Tulare Irrigation District, Self-Help Enterprises, and the community of Okieville. But for many reasons—including the constraints noted above and potential water quality concerns with recharge—community wells are unlikely to experience many benefits from actions in 2023.

Lack of strategic water storage for the environment. During wet periods, environmental flow and water quality standards typically are met by natural runoff conditions, so water for the environment gets little attention. Yet the relaxation of environmental standards during the past two droughts highlights the need to do a better job of setting aside more water during wet years that can be used to support vital habitat during dry periods. In some areas, recharge efforts can improve habitat conditions.


The PPIC notes that many advances have been made in tackling increasing drought intensity, but the state has a lot of work to do on improving management during wet years. Some areas suggested for improvement include:

Better planning for wet years: Water supply and flood management should be integrated at the regional level proactively before a wet year occurs, not reactively in the midst of one.

Infrastructure investment: New reservoirs, such as Sites (an offstream storage project west of Colusa in Northern California), may be built and existing storage facilities can be upgraded.

Regulation and permitting: Permitting of recharge, infrastructure and restoration efforts are still encumbered by frequent delays, high costs and changing regulations and policies.

To read the PPIC water report and full list of recommendations, click here.

Staff Contact: Brenda Bass

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Brenda Bass joined the California Chamber of Commerce on January 24, 2022 as a policy advocate specializing in water supply and storage issues. She came to the CalChamber policy team from the Sacramento office of Downey Brand, where she was a senior associate. She advised public agency and private clients on environmental review requirements, as well as applying for and complying with water quality permits. She has experience with California Environmental Quality Act (CEQA) litigation and groundwater quality issues for agricultural and water clients throughout California. She also advised clients on Clean Water Act matters, compliance with state and federal laws governing stormwater and wastewater quality, as well as assisted agricultural enterprises with rapidly changing irrigation discharge regulations. Before joining Downey Brand, Bass practiced at a California boutique environmental firm. She also externed for a federal bankruptcy judge in Sacramento. Bass earned a B.A. in linguistics at the University of California, Davis, and a J.D. with distinction from the McGeorge School of Law, University of the Pacific, where she was primary editor of the McGeorge Law Review.