The amount of water in the Snake River continues to decline, and as a result, Idaho Power is further reducing the minimum flows out of Hells Canyon Dam to 6,500 cfs (cubic feet per second).
Water flowing into Hells Canyon is stored in Brownlee, Oxbow and Hells Canyon reservoirs on the Idaho-Oregon border. The reservoirs generate a significant portion of the electricity used by Idaho Power's customers in southern Idaho and eastern Oregon, the company said.
With water levels in the Snake River across southern Idaho approaching record lows, it is essential that Idaho Power manage the resource carefully through the summer months, said Brad Bowlin, communication specialist with Idaho Power.
This means reducing flows to as low as 6,500 cfs below Hells Canyon Dam when power demand is low, so it's available when demand rises on hot summer days, he said.
The river is important to recreation as well as those who want air conditioning.
The stretch below Hells Canyon Dam is popular for whitewater boating and jet boating. It is so popular that permits, gained through a lottery, are needed to raft the section in the Hells Canyon National Recreation Area during the summer. Outfitters also offer trips in the canyon and lower flows aren't expected to be detrimental to the experience.
"It's a great float trip at those flows," said Jerry Hughes of Hughes River Expeditions in Cambridge.
Some of the smaller rapids in the canyon "become more snappy," Hughes said.
"Fishing also gets better with lower flows," Hughes said Tuesday during an interview.
Idaho Power typically sees its highest overall system demand during the summer when air conditioners and irrigation pumps are in heaviest use.
For perspective, the Snake River flow measured at Weiser paints a clear picture because it's just upstream from Brownlee Reservoir. It shows current flows near record lows and well below 2012 levels. Graphs for the Snake River at King Hill and at Nyssa, Ore., tell a similar story.
Flows in the Snake River above the Hells Canyon reservoir complex have been declining for about two weeks. Inflow is expected to continue declining through June and into July, Bowlin said.
It also will affect boat ramps for motor boaters in the reservoirs. Idaho Power plans to maintain the current water level at Brownlee Reservoir through June before drafting the reservoir.
Information about river levels and Brownlee Reservoir can be found at idahopower.com.