SACRAMENTO (AP) — A federal agency has decided to boost releases of cool clean water into Northern California’s Klamath River to prevent a repeat of the 2002 fish kill that left tens of thousands of adult salmon dead.

“We have determined that unprecedented conditions over the past few weeks in the lower Klamath River require us to take emergency measures to help reduce the potential for a large-scale fish die-off,” U.S. Bureau of Reclamation Regional Director David Murillo said Friday from Sacramento, California.

Murillo added that fall chinook have been entering the lower Klamath River earlier than usual to spawn, and the severe drought has produced low and warm water conditions similar to those in the 2002 fish die-off. During that time, disease quickly spread through fish bunched together in low and warm pools before fall rains raised the river so they could move upstream. Some estimates put the toll at more than 60,000 adult salmon.

The Klamath River has long been subject to intense political battles over sharing scarce water between farms and fish. Three tribes depend on its salmon for subsistence and ceremonial needs, and a fourth is looking forward to the day that four aging hydroelectric dams are removed so they can once again harvest the fish.

When runs are low, sport and commercial salmon catches in the Pacific are cut to ensure enough fish survive to spawn.

In the 1960s, as much as 90 percent of the Trinity’s water was diverted to the Sacramento River for agriculture, but over time it became clear fish were paying the price. In 2000, a plan was adopted splitting the water about half and half on average.

Indian tribes have been pressing the bureau to change a July decision to hold off extra releases until significant numbers of fish start to die. Tribal members approached Interior Secretary Sally Jewell earlier this month when she was visiting firefighting facilities in Redding, California, and she sent bureau officials to the Hoopa Valley Tribe’s reservation to review conditions. Tribal members also demonstrated in front of bureau regional headquarters in Sacramento.

“We are very excited to have the releases we requested, however it’s just a Band-Aid when you look at the long-term solution,” said Danielle Vigil-Masten, Hoopa chairwoman. “We are praying that nobody does an injunction or anything on it so they can go ahead with the releases and save our salmon.”

Ultimately, she said the tribe would like to see a long-term commitment of enough water to maintain a healthy salmon fishery, even if it means reducing the water going to the Sacramento River.

To prevent the spread of disease, reduce the overall stress on fish from warm water, and inspire salmon to start moving upriver, extra water releases start Saturday morning from Lewiston Dam on the Trinity River, the biggest tributary of the Klamath. The releases run through the middle of September. A big pulse of water Monday is intended to flush out toxic blue-green algae growing in stagnant pools, and trigger the impulse in fish to move up river.

The major threat is a parasite known as Ich, short for Ichthyophthirius multifiliis, which attacks fish in stagnant water. The extra flows make it harder for the parasite to attack fish.

“This decision was made based on science and after consultation with tribes, water and power users, federal and state fish regulatory agencies, and others,” Murillo said. “We fully recognize that during this prolonged severe drought, every acre-foot of water is extremely valuable, and we are making every effort to conserve water released for fish health purposes to reduce hardships wherever possible.”

The bureau said the extra water for Klamath River fish would not reduce the amount of water diverted to the Sacramento River system, where much of it ultimately goes to irrigation for farms. The extra releases will mean less water carrying over the winter for next year, said operations manager Ron Milligan.

U.S. Rep. Jared Huffman, D-Calif., applauded the decision, but criticized the bureau for what he called the “shortsighted and irresponsible” diversion of water from the Trinity River to the Sacramento for agriculture