San Francisco Teams Up with Trump on the Tuolumne River?
Did you know that the San Francisco Public Utilities Commission ("SFPUC") has been working with the Trump Administration to try to stop the State of California’s efforts to restore the health of the Tuolumne River? Despite San Francisco's iconic fishing industry in Fishermen’s Wharf, this weekend’s story in the San Francisco Chronicle highlights how the SFPUC has been working with the Trump Administration to undermine Federal agencies’ recommendations regarding how much water should remain in the Tuolumne river.
For the past 10 years, the State Water Resources Control Board has been working to update water quality standards for the Bay-Delta, including the Tuolumne River. The State’s proposal would require that a minimum of 40% of the unimpaired flow—the water that would flow downstream in the absence of dams and diversions—to remain in the Stanislaus, Tuolumne, and Merced rivers during the critical February to June months. As you can see from the graphic below, in 2015 there were a few storms that resulted in higher unimpaired flows, but those were all captured behind dams and diverted; the actual flows (red line) were a tiny fraction of those unimpaired flows.
On average today, farms and cities divert 79% of the Tuolumne River’s flow during the crucial winter and spring months, leaving less than a quarter of the water actually flowing downstream in the river. In the drier years, diversions by agricultural water districts and San Francisco divert nearly 90% of the river’s unimpaired flow, leaving only a tiny trickle behind.
The amount of water flowing downstream in these months is crucial for juvenile salmon to survive their downstream migration each year. For instance, a peer reviewed scientific study (Zeug et al 2014) demonstrates that the amount and variability of water in the Stanislaus River was the overwhelming factor explaining juvenile salmon survival from 1996-2009. Not surprisingly, the higher flows on the Stanislaus River as compared to the Tuolumne have led to higher salmon populations on that river. With so much of the Tuolumne River diverted, it’s not surprising that native salmon runs on the Tuolumne River have crashed.
The State Water Resources Control Board's proposal for increased flows on the Tuolumne River is already a compromise that is lower than what the California Department of Fish and Wildlife, other agencies, and conservation groups have stated is needed to restore healthy salmon runs. However, apparently San Francisco has been working with irrigation districts to lobby the Trump Administration to weaken or eliminate recommendations from the U.S. Fish and Wildlife Service, EPA, and National Marine Fisheries Service on how to restore the Tuolumne River and its native salmon runs. And that’s what happened a few weeks ago, when the Trump Administration formally withdrew the Fish and Wildlife Service’s prior recommendations for minimum instream flows in the Tuolumne River. The Fish and Wildlife Service’s recent letter admits that their prior flow recommendation was based on the best available science (page 6), including scientific studies in the Tuolumne River. And the agency did not withdraw those recommendations because of new scientific information, but instead these recommendations were withdrawn as a result of a “Policy Direction”—because increased flows would require farms and cities to divert less water.
I am disappointed by the San Francisco Public Utility Commission’s efforts to collaborate with the Trump Administration to weaken protections for the Tuolumne River. These efforts to undermine science are a slap in the face to the men and women in the fishing industry, who have made a home at Fishermen’s Wharf for generations and depend on healthy rivers to sustain their livelihoods. And they are inconsistent with the interests of San Francisco residents, who support restoring the health of the Tuolumne River and are willing to conserve water to do so. San Francisco can sustain its economy while diverting less water from the Tuolumne River, but there will not be a healthy Tuolumne River without significantly higher flows than today.
I hope and expect that the San Francisco Board of Supervisors will reject the SFPUC's efforts to collaborate with the Trump Administration to undermine science, and instead direct the SFPUC to work with all stakeholders on developing local and regional water supplies to sustain our economy while diverting less water from the Tuolumne River.