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Reduced river flow threatens Chinook By PAUL FATTIG TRAIL - Lower than anticipated river flows forced the U.S. Army Corps of Engineers to turn down the spigot Monday on the Rogue River at Lost Creek Dam. The change in flows from the dam, which had been fluctuated since late April to combat a salmon-killing disease, could harm some of the remaining spring chinook migrating up the lower reaches of the river between Galice and Agness. Beginning late Monday, the Corps began reducing water releases by 200 cubic feet per second (cfs) increments with a goal of dropping outflow to 1,400 cfs on Wednesday. The outflow at the dam Monday morning was roughly 2,600 cfs. Working with the Oregon Department of Fish and Wildlife as well as the Oregon Water Resources Department, the Corps began varying water releases from the dam in April to protect migrating spring chinook from epizootic disease, which spreads quickly in warm water. The releases are determined, in part, by air temperatures in Medford. More water is released when it's hot to reduce downstream water temperature. The outflow is reduced when the mercury drops. The Corps had hoped to continue altering releases through June 20, but had to change its plan because of decreased inflow, officials said. "Unfortunately, we do expect to have some losses in the lower river because the cooler water won't reach that far, so protection levels will diminish," said Russ Davidson, a Corps hydraulic engineer for the Rogue Basin. "We have to balance what we need to release now with requirements to conserve enough water for the summer and fall fish runs, however, and in this low water year we don't have all the options we'd like to have," he added. Since April 29, the outflow has varied from 2,000 cfs to 3,200 cfs. By the end of May, more than 15,000 spring chinook had passed Gold Ray Dam on their way upstream to spawn. That number is at the low end of what officials like to see, but it indicates that changing the water temperature has worked to prevent the disease, officials said. The change was based on a recommendation by the ODFW which noted that it had already used some 60 percent of the stored water allotted to help the fish. Spring chinook migrate upstream through early July. "If we were to continue that strategy, we would probably run out of water (stored for salmon) somewhere in the middle of June," said Mike Evenson, district fish biologist for the state. "Then we'd be forced to go to the inflow, which is expected to be around 1,100 cfs." Curtailing the variable release strategy early means there will be a higher constant outflow of around 1,400 cfs through the end of June, he said. The disease often strikes the lower section of the river during low-water years. In the drought years of 1977 and 1992, spring chinook died by the thousands along the lower Rogue by mid-May. "We also have fall chinook salmon migrating up in August and early September," Evenson said. "We have to allocate a certain volume of water to aid them getting upstream. "If we were to extend out any further for the spring run, we would take away from the fall chinook," he added. Because of drought conditions, dam managers must make choices among alternatives that all have down sides, Evenson observed. "There is a fair amount of risk," he said. "But if the weather cooperates, we may still be able to get through this in good shape." The disease isn't expect to affect salmon during current cool weather, he said. Reach reporter Paul Fattig at 776-4496 or e-mail him at [email protected] Mail Tribune Home | Ottaway Newspapers, Inc. | Dow Jones & Co., Inc. | Privacy | Contact Us Copyright � 2001 Mail Tribune, Inc.