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Commentary: California can revive San Francisco Bay-Delta estuary

The Sacramento-San Joaquin Delta provides nearly half of Silicon Valley’s water supply. (File Photograph)

Starved of freshwater inflow from the Central Valley rivers that feed it, the San Francisco Bay-Delta is on the verge of collapse. This iconic estuary, which defines our region, has been neglected for too long.

Fortunately, the state Water Board is poised to provide relief by updating the Bay Delta Water Quality Control Plan. Phase 1 of the plan calls for requiring 40 percent of unimpaired flow (what would occur in the absence of dams and diversions) between February and June on the lower San Joaquin River and its three major tributaries. This amounts to a mere 14 percent increase in unimpaired flow over the course of a year, but it’s a start.

On average, less than half of the freshwater flow from Central Valley rivers reaches the Bay due to dams and diversions. in some years, inflows are less than 35 percent. This impacts the salinity balance of the Bay-Delta all the way up to the Delta pumps, which provide water for millions of Californians.

As the estuary becomes more saline, everything from plankton to sea lions is at risk.

Salmon, which depend on the Bay-Delta as a migration path, and rely on adequate river flows to migrate to and from their spawning grounds, have faced serious decline, and could be wiped out unless action is taken soon.

The Tuolumne River, which provides water for 2.6 million people in the Bay Area via the Hetch Hetchy Water System, is the largest tributary to the San Joaquin River. Before the Tuolumne was dammed, an estimated 130,000 salmon spawned in its waters. Tragically, over the past few decades the population has plummeted to just a few thousand, and in some years salmon number in the hundreds.

And it’s not just about salmon. The entire river ecosystem is facing collapse. Healthy salmon populations transport tremendous amounts of nutrients from the ocean to upland habitats where they fuel an entire food web.

Fortunately, we can have a healthy environment and a vibrant economy by using water wisely. We’ve already demonstrated we can do this. Over the past 10 years, water use in the Hetch Hetchy Service Area decreased by 30 percent, but during that same period, hundreds of thousands of jobs were created and our economy grew stronger than ever.

Unfortunately, there’s a lot of misinformation being distributed about the Bay Delta Plan by groups such as the Bay Area Council (Opinion, Feb. 9). Adrian Covert’s assertion that water supplies might be cut by up to 50 percent at the first sign of a drought is flat out wrong. With proper planning, we could survive an extended drought with no more than 20 percent rationing.

The San Francisco Public Utilities Commission (SFPUC), which owns and operates the Hetch Hetchy Water System, could accommodate its share of increased flow without suffering any water shortages that can’t be managed. This is because the SFPUC has so much storage capacity in its reservoirs (Hetch Hetchy is only one) that it’s well-positioned to withstand an extended drought.
On average, the SFPUC has the right to capture three times as much water from the Tuolumne as it delivers to its customers. Even after the recent drought, storage would have filled to capacity in January had releases not been required for flood control. This summer the SFPUC will have enough water in storage to last six years. Even with the increase in unimpaired flow recommended by the Bay Delta Water Quality Control Plan, we could survive the worst drought on record and still have water left in storage.

Saint Francis (San Francisco) – the namesake of our bioregion – is the patron saint of animals and the environment. Let’s do our best to live up to his convictions by reviving the Bay-Delta estuary – our own Garden of Eden.

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