Why California Insists on Wasting Its Scarce Water Supply

Harvesting its abundant storm runoff would allow the state to leave the Colorado River alone

By Edward Ring. Mr. Ring cofounded the California Policy Center in 2013, served as its first president, and is a senior fellow. He is the author of “The Abundance Choice: Our Fight for More Water in California.” Excerpts:

"If California’s political leaders had the political will, they could solve the problem for every member of the Colorado River Compact by developing infrastructure to use untapped sources of water. But to do that, the state Legislature would have to stand up to a powerful environmentalist lobby that views humans as parasites and demands rationing as the only acceptable policy."

"in a single month, December 2021, well over 100 million acre-feet of rain fell during the one big storm that hit the state that year. If California had the capacity to capture more of that water, it would have been enough to supply full allocations to Golden State farmers and avoid rationing in cities."

There are two major projects that could unlock millions of acre-feet of new water for Californians. The first is to eliminate nutrient pollution in the San Francisco Bay, which feeds toxic algae blooms that kill aquatic life. The solution so far has been to dilute the nutrient loads in the bay by requiring massive diversions from the Sacramento-San Joaquin Delta—a little like flushing a toilet. But upgrading the urban wastewater-treatment facilities surrounding the bay would eliminate nutrient pollution, permitting more delta water to be directed to California’s farms and cities—a lot more water.

This rainy season started in October 2022. By the first day of spring, March 21, the net outflow (after pumping) from the delta into the bay was 11.6 million acre-feet but the state had only pumped 1 million acre-feet into the California Aqueduct, and the Federal Bureau of Reclamation had only pumped 826,000 acre-feet into the Delta-Mendota Canal. Despite record precipitation, the state had diverted only 13% of flood-level delta outflows into southbound aqueducts.

In late March and early April, as rain continued to pour in California and the biggest snowpack in decades began to melt, California’s water officials actually reduced pumping. Their reason? To protect endangered fish and maintain sufficient flow to flush out the nutrient pollution in the San Francisco Bay.

Even in a year with extraordinary rain and snow, California’s environmental extremists have done their utmost to prevent water managers from filling reservoirs, allow pumps to operate at capacity to fill the southbound aqueducts, and allow farmers to get their full water allocations so they can use runoff to irrigate instead of pumping already depleted groundwater. But even if California’s state government weren’t dominated by extremists, California’s water infrastructure would be stretched to the limit.

The second major project, then, would be for Californians to build new ways to extract and store water from the delta during atmospheric river events. A new technique, already demonstrated on the Tuolumne River, creates channels in some of the delta islands so that huge perforated pipes can be installed under a gravel bed. Fish aren’t endangered by such installations. This water could be rapidly transferred to aquifers south of the delta via surface percolation and deep injection. Unused aquifer capacity in the San Joaquin Valley is conservatively estimated at more than 50 million acre feet.

If Californians were willing to harvest additional millions of acre-feet from storm runoff in the Sacramento-San Joaquin watershed, and had the means to do so, they might not need any water from the Colorado River. This is how California can give back not only its share of Colorado River water, but cover its annual deficit of 2 million to 4 million acre-feet. Other states in the Colorado Basin might help fund these projects. Thinking big solves big problems. It’s time for California’s state Legislature permanently to solve the challenge of water scarcity in the American Southwest."