Storms like the one that have doused arid California in recent days are cause for celebration, but also for better conservation. The Sierra Nevada mountains received nearly six feet of snow, which was especially welcome in a dry winter. Snowpack in the Sierras had measured a quarter of its historical average.

But precipitation that falls fast and furious is often wasted. Reservoirs in the north can’t store the excess runoff, which flows too rapidly into the Sacramento-San Joaquin River Delta to pump to the Central Valley and southern California. Regulatory protections for smelt and salmon also limit pumping. Hundreds of billions of gallons get flushed out to the ocean—rinse and repeat each winter.

Golden State voters in 2014 approved a $7.5 billion bond to expand water storage and improve flood control. Yet the California Water Commission, which doles out the cash, has tried to scuttle 11 water-storage projects. It says the projects would provide negligible public benefits as required by the law.

Seriously? The proposed Sites Reservoir, which would be located west of Colusa in Northern California, could store up to 1.8 million acre-feet of water. According to Republican state assemblyman Frank Bigelow, Sites could have captured more than 586 billion gallons of runoff between last October and February—enough to supply 13.3 million Californians for a year.

Then there’s the Temperance Flat reservoir northeast of Fresno, which would provide a more stable water supply for farmers in the Central Valley. The reservoir as envisioned could capture an additional 53 billion gallons of water each year. Commission staff deemed Temperance Flat ineligible for funding and offered the $5 billion Sites Reservoir only $660 million. Both projects scored low on public benefits, which the staff defined narrowly as improvements in the ecosystem, water quality, flood control, emergency response and recreation.

Yet the staff appears to have applied even these narrow criteria too conservatively. For instance, the Sites Reservoir would help California’s endangered Chinook salmon by increasing the amount of cold water in rivers available during droughts. Increasing surface storage could also reduce groundwater pumping in the Central Valley, which has resulted in land subsidence.

The real political problem, as always, is that environmentalists oppose dams as an article of faith. Meanwhile, the state Water Resources Control Board—in California, the more regulators, the merrier—recently proposed permanent restrictions on water use. But every storm that sweeps the state wastes more water than do millions of faucets left turned on.

View Original Publication: The Wall Street Journal