For many years, advocates of more dams being built in California by the federal, state, and corporate governments have touted cold water discharges from rivers provided through higher water dams as a key tool to “save” suffering salmon and rainbow trout populations.
However, recently published through the UC Davis Watershed Science Center, Dams Ineffective for Cold-Water Conservation – 08/25/21, found that dams are useless in keeping the bloodless water needed to keep salmon, rainbow trout, and trout in jeopardy.
“Prey mimics the temperature patterns California streams want for the state’s local salmon and trout, more than three-quarters of which are in danger of disappearing,” according to the study published in the journal PLOS ONE at the University of California, Davis. . ” Bold action is needed to oppose extinction trends and protect cold water currents that are resistant to global warming. “
The examination identifies where high-quality cold water habitat is located for managers to prioritize conservation efforts.
“It’s no longer a smart investment to put all of our cold water conservation eggs in a dam-regulated basket,” said lead writer Ann Willis, a senior researcher at the UC Davis Watershed Science Center and a member of the John Muir Institute. of the Environment. ” We want herbal processes to be able to take place again. “
“Understanding where bloodless water is most likely to remain bloodless is for conservation,” according to the study. “But ‘bloodless’ is more than a number on a thermometer. The term represents the many points that mix to create bloodless water capable of sustaining aquatic ecosystems.
Water managers supply bloodless water from reservoirs to streams to aquatic life, however Willis said this assumes all bloodless water is the same, “like donating blood to another user without understanding their blood type and fitness. “
“While previous studies have advised that dams can be exploited to succeed at ideal temperatures, few have proven this speculation opposed to the temperature models that aquatic ecosystems need,” the examination reveals.
The UC Davis exam evaluated knowledge of river temperatures from 77 sites in California to design and classify their “thermal regimes” or annual temperature styles. He found that the state’s reservoirs did not adequately reflect the thermal patterns of grasses, making them unable to water cold water well. species. The exam states:
“In stretches of waterways that are not resistant to global warming, cold-water, bloodless habitats are highly unlikely to succeed by regulating dams. In particular, the solid bloodless regimen may pose the biggest challenge to bloodless water conservation because it regularly lacks cooler winter temperatures due to unregulated variable bloodless regimes. A notable result was the classification of the outlet of the Shasta Dam (SHD site), the only reservoir that produces a solid thermal regime without blood. Lake is California’s largest reservoir and helps keep your pond blood-free through bloodless water inlets, cooling that occurs during the winter, thermal stratification, and operational decisions [38]. California), this, or any other dam included in this analysis, was unable to produce a solid bloodless regime upon its exit.
Reacting to the study’s publication, Barbara Barrigan-Parrilla, executive director of Restore the Delta, said, “We feel validated when top-notch educational science systems turn out to be what our network science researchers find. in the capacity of the dam. But expanding dam capacity won’t provide the fresh, blank water we want to repair the delta. Climate change demands ambitious new responses for water control and a calculation of the amount of water we allocate to commercial services. agriculture.
“Empty dams and a dry tunnel will solve our problems. We predicted in 2014 that the Proposition 1 budget for dams would be painted and that lawmakers would listen. We hope that budget will be reallocated to meaningful water projects that serve all Californians,” Barrigan concluded Parrilla.
The study’s publication may have come at a darker time for endangered salmon and rainbow trout in California. The California Department of Fish and Game (CDFW) has predicted that nearly all winter juveniles were born in the Sacramento River this year. it may die before snowing, due to disease caused by warm water situations downstream of keswick dam.
An unprecedented winter run of 18,000 spring Chinook salmon on Butte Creek, a tributary of the Sacramento River, also turned into a disaster, as 14,500 fish died before spawning. These fish also died due to the onset of the disease in warm, low-water conditions.
The only smart news is that the death rate dropped after more water was released despite everything that was released through PG.
As adult Chinook salmon return to the Sacramento River and its tributaries, they will face warm water situations and low flows, which can cause an outbreak that would kill many fish before they can skin.
The crisis hit the Klamath River, where nearly all of the autumn Chinook salmon juveniles perished before reaching the ocean on their downstream adventure this spring and summer, due to an eruption of disease C. Shasta and Ich in fish, according to scientists from the Yurok and Karuk Tribes.
Ann Willis, lead author of the study, says creating a cold-water habitat to prevent the extinction of salmon and trout populations is removing dams and restructuring water control in California.
“I’m an engineer; I think we can succeed, but science doesn’t do that,” Willis said. “The question is not whether we remove a dam, but what dam and how we want to restructure our water management. We have to be willing to take up the duty for being the generation that says, “Okay, we’re letting this ecosystem go extinct. “