The Yurok Tribe and two fishing organizations have asked a federal judge to reject the 2019 biological opinion for Klamath Project operations and send it back to the National Marine Fisheries Service to do-over.

Filed in U.S. District Court on July 31, Yurok Tribe et al. v. U.S. Bureau of Reclamation et al. also challenges the U.S. Bureau of Reclamation’s environmental assessment and finding of no significant impact, and asks the judge to require an environmental impact statement for operating the Klamath Project.

The Yuroks, the Pacific Coast Federation of Fishermen’s Associations and the Institute for Fisheries Resources say they filed the lawsuit to protect coho—listed as threatened under the Endangered Species Act—from “severely diminished Klamath River flows” caused by irrigation withdrawals. Higher instream flows would also help ensure abundant Klamath River Chinook to aid endangered southern resident killer whales, the lawsuit says.

The Bureau of Reclamation has primary management authority of the Klamath Project, which includes 185 miles of diversions, canals and pumping stations that provide irrigation water to about 200,000 acres of agricultural lands and to four national wildlife refuges. According to the lawsuit, Reclamation determines the level, timing and rate of water flow in the Klamath River below Iron Gate Dam, the first dam on the lower Klamath River and one of four dams on the lower Klamath operated by PacifiCorp and proposed for removal.

According to the lawsuit, a status review of coho found that Ceratonova shasta—a parasite which infects both coho and Chinook juveniles—is one of the most significant threats to Klamath River coho and is more prevalent under low flow and warm water conditions. In 2017, a federal judge issued an injunction requiring added flows, called “dilution” flows, under certain conditions.

The lawsuit alleges that NMFS’ 2019-2024 biological opinion fails to require dilution flows, allows for too little rearing habitat, and approves an unacceptable incidental take of half of the juvenile coho during outmigration.

The biological opinion does provide for a surface flushing flow in most years—34 out of 36 of the past water years—and gives Reclamation the discretion to decide whether to provide dilution flows when conditions warrant.

In addition to rejecting the biological opinion, the plaintiffs are asking the judge to reinstate the 2017 injunction or require Reclamation to provide sufficient flows to prevent irreparable harm to coho and orcas while NMFS completes a new biological opinion.

K.C. Mehaffey covers fish issues for Clearing Up, and is editor of the NW Fishletter. She joined the NewsData writing team in February 2018. From lawsuits to scientific studies, she is enjoying the deep dive into the Columbia Basin's many fish topics.