SACRAMENTO, California’s Department of Water Resources has signed off on its largest renewable energy contract ever, a 105-megawatt solar installation in the Tehachapi area that will power the pumps and infrastructure behind the State Water Project rather than feed electricity to the grid.

The Pastoria Solar Project, located near the Tehachapi Mountains, breaks new ground for the agency that moves water across more than 700 miles of canals, pumping stations, and reservoirs to serve about 27 million Californians. The department has long relied on outside electricity sources to run that system. This project changes that equation.

Water. Solar. They don’t always come up in the same sentence in California policy circles, but state officials are increasingly treating them as inseparable problems. The State Water Project is one of the largest single consumers of electricity in California, burning through power at a scale most utilities would envy, and the cost of running it lands directly on water ratepayers across the state.

The 105-megawatt contract, first reported by LA Times, represents the department’s push to cut those energy costs while meeting California’s aggressive decarbonization targets. The logic is straightforward: if you’re going to pump billions of gallons of water over a mountain range, you might as well do it on sunshine.

That mountain range matters here. The Tehachapi area sits just north of where the State Water Project tackles its most energy-intensive stretch, the lift over the Tehachapi Mountains through the Edmonston Pumping Plant. That single facility uses more electricity per year than many mid-sized California cities. Putting solar generation near that chokepoint isn’t an accident.

The Department of Water Resources has been working to diversify its energy mix for years, signing smaller renewable deals and experimenting with solar on canal covers in the Central Valley, a program that generates power while cutting evaporation losses. The Pastoria project is a different scale. At 105 megawatts, it dwarfs those earlier efforts and signals that the department is serious about owning a larger piece of its own energy supply.

California’s State Water Project serves a sprawling network of contractors including urban water agencies, irrigation districts, and environmental water accounts. Rate pressures on those contractors have climbed sharply over the past decade as energy prices rose and infrastructure maintenance costs compounded. Reducing dependence on the spot electricity market gives the department more predictability on one of its biggest operating line items.

Environmentalists have tracked this space closely. Solar projects in the Tehachapi region have drawn scrutiny before over impacts on the California condor, desert tortoise habitat, and migratory bird corridors. The Pastoria project will need to satisfy review under the California Environmental Quality Act, and environmental groups in the region have not been shy about intervening in past solar approvals near similar terrain.

The Department of Water Resources didn’t disclose the full contract value in publicly available documents reviewed for this story, and the department had not responded to a request for comment by publication time. The project’s operational timeline wasn’t confirmed either, though utility-scale solar installations of this size typically move from contract signing to commercial operation within two to four years, assuming permitting clears without significant delays.

What’s clear is that the state is doubling down on the idea that water infrastructure and energy infrastructure need to be built together, not procured separately on the open market. That thinking shows up in Governor Gavin Newsom’s broader infrastructure agenda and in the Department of Water Resources’ energy and climate programs, which have prioritized self-sufficiency as a hedge against grid instability and wildfire-related outages that have knocked out pumping capacity in the past.

For cannabis cultivators in the San Joaquin Valley and the broader agricultural south, the State Water Project’s cost structure feeds directly into irrigation water pricing. Growers on State Water Project contracts have watched energy surcharges creep into their water bills as the department passed along electricity costs. A major solar contract that holds down operating expenses doesn’t guarantee lower rates, but it removes one variable that has consistently pushed them higher.

The Pastoria project won’t solve California’s water-energy puzzle by itself, and no one at the department is claiming it will. But at 105 megawatts, it’s the clearest sign yet that the state is treating its biggest water conveyance system as an energy consumer that needs its own generation strategy, not just a utility bill to pay every month.