Fish fry: Endangered salmon pay for feds’ errors at Shasta Dam
Chinook return falls to second lowest in 20 years
The U.S. Bureau of Reclamation has blamed drought and technical failures at Shasta Dam for the second lowest return of endangered winter-run Chinook salmon in 20 years, but environmentalists say the federal agency has itself to fault.
Now, a species that historically consisted of hundreds of thousands of adult spawners each year in the Sacramento River is on the brink of extinction. Just 1,123 of the adult fish returned to the Sacramento River system to spawn in 2017, according to the California Department of Fish and Wildlife.
The population crash is hardly a surprise.
In the summer of 2014, virtually every egg laid and fertilized by that year’s generation of spawning fish was killed by warm water flowing out of Lake Shasta, the state’s largest reservoir. These conditions developed several months after the Bureau of Reclamation rapidly released cold water from the reservoir so it could be used by farmers. By the time the winter-run fish arrived to spawn, there was not enough cold water left to keep their eggs alive, which requires temperatures below 56 degrees fahrenheit. Scientists estimated at least 95 percent of the eggs died.
The agency received much criticism for its failures that year from fishery advocates who say the disaster was avoidable. Then, one year later, the Bureau of Reclamation did the exact same thing, flooding the spawning fish with warm water that cooked their eggs.
The feds claimed their temperature monitoring systems weren’t working.
There was also a problem with their temperature control device, or TCD—a building-sized steel box that is bolted to the lakeside face of Shasta Dam. This box is designed to allow dam operators to draw water from varying elevations of the reservoir. Opening the intakes near the top lets warmer water leave the lake, while opening lower intakes releases cold water. The lower intakes are meant to be opened during the salmon spawning months of summer and fall.
But the box leaks, making it less effective at preserving the lake’s cold water. The feds have been aware of this problem since 1997, the year the TCD was installed at a cost of $80 million. In 2015, the bureau even draped a huge tarpaulin over the face of the box to slow the leakage. Yet the bureau now says the device is supposed to leak.
“The TCD is not designed to form a complete seal,” said Erin Curtis, a Bureau of Reclamation spokeswoman. “The TCD is working properly.”
Jon Rosenfield, a conservation biologist with The Bay Institute, says the bureau knew everything it needed to know to protect Lake Shasta’s cold water pool in 2014 and 2015. He says the agency drafted a temperature maintenance plan in the spring of 2014 but later abandoned it.
“I wouldn’t let the Department of Fish and Wildlife and the State Water [Resources Control] Board off the hook, either,” he said. “They knew the bureau has a terrible track record when it comes to protecting these fish, but they just accepted the bureau’s assurances that they would protect the cold water supply.”
The current low fish numbers could result in a partial closure of the ocean salmon fishing season to protect the winter-run Chinook.
While many farmers saw their water allocations during the drought cut to zero, requiring them to pump it from the ground, those with senior water rights received as much as 75 percent of their contracted irrigation supplies, even as millions of salmon eggs died.
In a September 14 press release, Mike Aughney, vice chairman of the Golden Gate Salmon Association, a conservation group largely supported by fishermen, accused federal agencies of prioritizing agricultural water users over salmon.
“The economic damage to our salmon runs and ocean salmon fishery didn’t seem to match the concern federal water managers showed for other competing interests when drought forced hard choices,” he said.