Utility Plans to Reduce Flows Below
by Eric Barker
Flows below Hells Canyon Dam could drop to as low as 7,000 cubic feet per second next week, according to a news release from Idaho Power Co. Water flowing into the company's three-dam complex at the upper end of Hells Canyon has dropped to low levels typical of late summer. But the hot weather recently boosted demand for power from the dams. So company officials are reducing nighttime outflows from Hells Canyon Dam and saving the water to be released through power producing turbines during the day when demand is higher.
"We are trying to put quite a bit of water and resulting energy into the daytime. As a result we are having to lower flows at nighttime," said Roger Fuhrman, water manager for Idaho Power Co. at Boise. "It's really a pretty simple equation."
Water released from the dam can take about 20 hours to reach Lewiston. That means the flows far below the dam could be at their lowest during the day instead of at the middle of the night. Low flows can expose hazards, such as rocks, to jet boaters navigating the canyon's many rapids. It can also leave boats high and dry if they are beached at higher flows or cause them to float away if they are beached at low flows without being securely moored.
Fuhrman said the company is communicating with jet boat tour operators to let them know they may experience low flows during outings. However, the low flows should be mitigated below the mouth of the Salmon River, which was running at 7,300 cfs on Friday afternoon.
Fuhrman said the company will make decisions about nighttime flows from the dam on a week-to-week basis depending on weather and demand. But the low nighttime flow scenario can be expected to last a month or so. People who would like to get the latest information on flows can visit the company's Web site at www.idahopower.com and then click on the water information link under the heading "rivers and recreation."
The low nighttime flows are scheduled to start on Monday.
Dworshak's Cool Outflows Hit Maximum with Hopes of Keeping Lower Snake Below 68 Degrees, Columbia Basin Bulletin, 7/31/9
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