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These Projects Can Solve the Water Crisis and Protect Farms

Despite seasonal rainfall at normal levels so far this year, the California Department of Water Resources on Dec. 1 announced an initial State Water Project allocation of 5% of requested supplies for 2023. Unless heavy rains or new policies change this decision, it will mark the third consecutive year that the State Water Project delivered only 5% to its customers.

This is an avoidable problem. By the end of December 2021, for example, only three months into the water year, two massive storm systems had already dumped more than 104 million acre-feet onto California’s watersheds. Almost none of it was captured by reservoirs or diverted into aquifers.

For nearly 40 years, the political consensus in California has been to cope with droughts by increasing conservation mandates. During that time, the state’s population has increased from 24 million to nearly 40 million, and farm production has increased in virtually every category. But due to conservation, agricultural water use has been constant, averaging about 34 million acre-feet per year.

Several factors are breaking this model despite a 40-year history of alleged success. Replacing flood irrigation with drip irrigation was a short-term solution. Flood irrigation in the fields downstream from the Sierra mimicked annual flooding prior to the construction of dams and levees—and replenished the aquifers.

Increased environmental requirements for less water diversion from rivers for agriculture have forced additional groundwater pumping at the same time as those aquifers were no longer being replenished by flood irrigation. As depleted aquifers collapse and percolation is no longer possible, the soil dies.

California policymakers have decided to prioritize river flow to protect salmon and other native fish, even though invasive striped bass have now been identified as a major cause of salmon losses. Those flow policies, combined with destruction of aquifers thanks to drip irrigation and a failure to construct any new facilities to capture more storm runoff have left Californians unable to cope with droughts.

Until a new consensus is reached on water policy, draconian rationing is the only option. Expect millions of acres of fallowed or ruined farmland and cities devoid of outdoor landscaping.

There is an alternative. Here are some water projects that ought to be moving forward in California:

• Build desalination at scale: Desalination has the unique virtue of being an inexhaustible supply of fresh water. But so far, there is only one major desalination plant in California, located just north of San Diego. The $1 billion Carlsbad Desalination Plant went into operation in 2015 and desalinates 56,000 acre-feet of water per year, enough to serve 400,000 people.

• Build off-stream reservoirs: The virtue of off-stream reservoirs is they are constructed in arid valleys and won’t disrupt the flow of natural rivers with a high dam. Instead, flood runoff is pumped into them during storm events.The largest proposed project, the $4 billion Sites Reservoir north of Sacramento, would store 1.5 million acre-feet. Its annual yield could irrigate more than 150,000 acres of farmland.

• Build wastewater recycling projects: The proposed Carson plant in Los Angeles County is planned to recycle 168,000 acre-feet of wastewater per year at a projected construction cost of $3.4 billion. This, however, is just a fraction of the total available wastewater stream in the Los Angeles Basin. If all urban wastewater in California were recycled, it would add an estimated 2.0 million acre-feet per year to the water supply, as well as improve the health of aquatic ecosystems.

• Support environmentally friendly Sacramento-San Joaquin Delta diversions to San Joaquin Valley aquifers: The draft “Water Blueprint for the San Joaquin Valley” proposes constructing channels inside delta islands where fresh water could be safely taken from perforated pipes beneath a gravel bed during periods of excess storm runoff, while at the same time continuing to provide fresh water in the Delta necessary for farming.

The Blueprint also proposes a new $500 million central canal in the San Joaquin Valley to transport water from the pipes in the delta to underground storage. Aquifer storage capacity in the San Joaquin Valley is conservatively estimated at 50 million acre-feet. Groundwater supplies could be greatly enhanced from this canal, which would include connections to Friant-Kern and Delta-Mendota canals and the California Aqueduct, as well as facilities to recharge and recover water from the aquifers.

These four project categories have the potential to eliminate water scarcity in California forever. If Californians are destined to endure decade-long droughts with minimal snow and only a few big storms each year, these projects will ensure that sufficient water is harvested and stored to keep cities and farmland healthy and green.

This commentary originally appeared in Ag Alert, a publication of the California Farm Bureau.

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