Water meant to cool and raise the lower Klamath River will begin coming down the Trinity River on Sunday.

The water will rise suddenly on the Trinity as flows jump from 450 cubic feet per second to 1,650 cfs. Flows will then slowly decrease until Sept. 13.

Some 36,000 acre feet -- almost 12 billion gallons -- will be released above the Trinity's normally scheduled flows over the three-week period.

Biologists hope the water will stave off diseases that in 2002 killed as many as 68,000 salmon.

Conditions on the lower Klamath River closely resemble those of 2002 -- though the fish run is projected to be only half the number of the salmon that migrated that year. The fish also have not begun to run up the river yet.

Klamath flows are slightly higher this year than in 2002, and in September, releases from Iron Gate Dam will increase the flow 230 cfs.

But steelhead and a few chinook salmon found dead on the river show signs of columnaris, and biologists and fishermen worry that if the fall salmon run begins to migrate before the Trinity water arrives, the fish could fall ill.

The U.S. Bureau of Reclamation bought the 36,000 acre feet of water from Central Valley water and power contractors.

The Six Rivers National Forest is reminding swimmers, boaters and fishermen that the increased flows can pose a hazard. Cold, strong currents can be stronger than they look. Children should always wear a lifejacket on or around the water and adults are advised to wear personal floatation devices when on a boat.