California’s future water supplies depend on the outcomes of four intertwined battles

Since the earliest years of its history, California has been a political battlefield over divvying up the state’s water. The intensity of the multisided conflict, like water itself, ebbs and flows.

By happenstance this is one of the more intense and climactic periods in the eternal competition over water. It’s driven by uncertainty over the effects of climate change on precipitation and by looming decisions on how to cope with those effects.

What happens on four intertwined fronts in the near future will determine how water will be managed and allocated in the coming decades. In no particular order:

Colorado River

Decades of conflict over allocating Colorado River water, involving not only California but other Western states, are coming to a head. Runoff from snow in the Rocky Mountains has been declining, and the two major reservoirs on the Colorado, Lakes Mead and Powell, have been shrinking and rapidly approaching operational failure. Federal authorities have been pressing the states involved to agree on how the shortages should be managed, but it’s been a stalemate.

California is less dependent than Nevada and Arizona, which rely on the Colorado to serve their fast-growing urban centers. When the Bureau of Reclamation imposed some temporary operational rules recently, Nevada sued and Arizona is threatening to follow.

Sites reservoir project

An off-stream reservoir on the west side of the Sacramento Valley to capture and store water during years of high precipitation has been proposed for decades. But with projections of decreased snowpacks due to climate change, the project, called Sites, has gained momentum in recent years.

Gov. Gavin Newsom wants to nail down the project before leaving office in four months. Last week, the administration’s Water Resources Control Board issued a draft water rights decision for Sites. The project needs permission to draw water from the Sacramento River before it can secure financing for the 1.5-million-acre-foot reservoir.

Delta tunnel project

Newsom also wants to pin down another major project — a tunnel that would carry Sacramento River water around the Sacramento-San Joaquin Delta to improve deliveries to Southern California via the California Aqueduct. A conveyance of some kind has been proposed for more than 60 years but has never been able to clear political, legal and financial hurdles.

Advocates say the project would take pressure off the Delta, but it faces stiff opposition from environmental groups who contend it would worsen the Delta’s environmental problems. Putting together a package of regulatory permission and financing from water agencies that would benefit has been a daunting, and so far elusive, goal.

San Joaquin River diversions

While proposing the 45-mile-long tunnel to divert some Sacramento River water from flowing through the Delta, state water officials are simultaneously pressuring San Joaquin Valley farmers to reduce San Joaquin River diversions to increase flows into the Delta.

Supposedly reductions would be voluntary, but the state is also working on mandatory cutbacks if not enough water is voluntarily offered. Last week, Westlands, the largest water district in the valley, pulled out of the voluntary negotiations, saying the state was moving toward coercion. If the state issues mandatory cutbacks, it would probably become a legal battle over whether the state can interfere with long-standing water rights.

The conflict is exacerbated by reductions in water farmers can draw from underground aquifers with wells. There are projections that reductions in water supply, could take as many as 900,000 acres of farmland out of production.

That possibility drove major agricultural interests to successfully press the Legislature last week to make it easier to remove farmland from open space preserves, to replace crops with solar power arrays.