In a ruling Wednesday, U.S. District Judge William Orrick ordered more water releases from dams on the Klamath River to flush out parasites causing deadly disease outbreaks in salmon.
In recent drought years, scientists have found extremely high rates of a disease caused by an intestinal parasite known as Ceratanova shasta in salmon populations protected under the Endangered Species Act.
"The disease rates are off the charts," said Patti Goldman, the EarthJustice attorney who represented tribal, fishing and conservation groups in the case. "Scientists looked at river conditions historically and disease rates, and the disease rates were far lower when there were more flushing flows in the winter."
But the U.S. Bureau of Reclamation denied requests from scientists to release more water from Upper Klamath Lake to help the fish, saying there wasn't enough water to go around.
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Several groups, including the Yaruk and Hoopa Valley tribes, sued the Bureau and National Oceanic and Atmospheric Administration, arguing the lack of water was likely to cause irreparable harm to protected species and asking the court to require protective flows.
Goldman said the judge's order will force the bureau to put the needs of fish before irrigators who also need water for farming.
“The problem has been irrigation allocations have been locked in and the bureau has not had enough water for fish when they’ve needed it,” she said.
Goldman said this year the Klamath Basin will likely have enough water for fish and irrigators, but that isn't always the case.
The court has ordered the bureau to release enough water in the winter to flush out the parasite causing the disease, and to reserve water for more flushing in the spring if a disease outbreak occurs.