Patrick Koepele isn’t sure the state’s plan goes far enough to save native fish in the Tuolumne and the other San Joaquin River tributaries. But he said it’s almost certainly better than the conditions that exist now, which have pushed native fish populations to the brink of collapse.
A Michigan native, he became a whitewater rafting guide on the Tuolumne while attending UC Davis and became entranced with the river. Now 47, he lives a few miles north of the river in Sonora and serves as executive director of the Tuolumne River Trust, an environmental organization.
Part of the attraction, for Koepele, is the Tuolumne is at the epicenter of the clash over how to share the state’s rivers, and always has been. One of the Sierra Club’s earliest crusades was its unsuccessful fight against the damming of the Tuolumne at Hetch Hetchy in Yosemite. Congress approved the project in 1913, a year before Sierra Club founder John Muir died.
“It’s really a world-class river in all respects,” Koepele said. “It starts in Yosemite .... It goes through the most productive agricultural valley in the world and it ends in this incredible cosmopolitan city, San Francisco. It ties it all together.”
The Tuolumne is one of the most overworked rivers in California. In most years, a mere 21 percent of its water makes its way to the ocean. In dry years, that can dip as low as 11 percent, according to state water board data.
Decades ago, before the dams were built, the Tuolumne teemed with 100,000 salmon swimming upstream and its wide flood plains provided rich habitat for tule elk, pronghorn antelope and other species. Today the fish number in the hundreds, and the elk and antelope have long since vanished.
“We’re trying to bring back a river corridor that could sustain some semblance of that,” Koepele said. “Obviously we’re not going to bring it all the way back.”
Opponents of the state’s plan say there’s a better way to revive native fish populations without shirking on water for human needs – namely, through habitat restoration. The Modesto and Turlock irrigation districts, in concert with the city of San Francisco, are pushing a plan to reshape portions of the river to make them more conducive to salmon spawning and less attractive to their main predators, the nonnative bass that thrive in warm, slow moving water. These habitat improvements could be augmented with periodic, well-timed “pulse flows” that would temporarily increase the volume of water coursing through the rivers.
But Koepele and other critics of the habitat-only approach say it won’t work by itself.
On a recent weekday, he met with two reporters at a spot outside Hughson, east of Modesto, and pointed to a section of the Tuolumne where similar restoration work was performed several years ago. The project created a small riffle where a deep warm pond once formed in a wide spot in the river channel.
Koepele said years later the project failed to do what it was supposed to: flush out the bass or improve salmon runs. The reason?
“It’s too warm, it’s too slow,” he said. “It’s going to need flow.”
He said he’s particularly disappointed that San Francisco, the bastion of liberalism and the ecomovement, has joined with the farm-irrigation districts in opposing the state’s plan to increase river flows.
“San Francisco really has an opportunity,” he said, “to step up and show a way to lead.”