RIVERS -- The spigot has been cranked down on the Spokane River at Post Falls Dam in the past four days in order to raise the level of Lake Coeur d'Alene, leaving the whitewater rafting season high and dry and fish managers in a sweat.
The full story is in The Spokesman-Review, but here are some highlights:
- 2015 is stacking up to be the record-setting low-water season since records have been kept.
- Spokane River flows, already dramatically lower than normal (see chart) have been curbed sooner and faster than normal out of Post Falls Dam because this season’s low snow pack may not otherwise provide enough water to fill the lake.
- Avista announced Thursday that the flows through Post Falls Dam would be reduced during the weekend from 3,600 cubic feet per second to 1,400 cfs.
- However, the flows continued to plunge on Monday down to 700 cfs.
- Area rafting companies say the flow reduction ends the Spokane River whitewater season, although other types of river trips will continue.
- “The snowpack is pretty much gone,” said Patrick Maher, Avista hydro operations engineer.
- The updated NOAA April-July water supply forecast for Lake Coeur d’Alene is 37 percent of normal.
- “Lost Lake up in the St. Joe drainage usually has snow into July, but right now it’s almost gone,” Maher said.
- Flows out of Post Falls Dam had been maintained at a minimum of 3,600 cfs through Thursday to maintain enough water to cover wild redband trout nests as required by federal dam relicensing guidelines.
- But the relicensing guidelines also require Avista to maintain the summer elevation of Lake Coeur d’Alene near 2,128 feet. The level had been raised to within three inches of summer pool in May, but the lake level has been lowered since then to maintain minimum flows for fish.
- Idaho and Washington fish managers approved Avista’s request to begin reducing flows two days earlier than is normally allowed. The trout fry appeared to be off their nests and swimming, said Randall Osborne, Washington Department of Fish and Wildlife fisheries biologist.
- Fish managers will keep track of river flows and temperatures and curtail fishing in some way if trout become too concentrated at aquifer recharge areas and vulnerable to anglers, he said.
- Rachael Paschal Osborn, the Spokane water-law attorney who led the 2008 effort to secure minimum flows for Spokane Falls, said she’s concerned that the cities and counties have not delivered a public message about municipal water usage.
“The river is fed by the aquifer,” she said, noting that the cold-water recharge is what keeps Spokane River trout alive when flows are low and warm. “When we pump from the ground, it lowers the aquifer and takes cold water from the river. We need to be conserving water during summer, especially this year.”
- Avista expects that Post Falls will operate at minimum discharge requirements of 600 cfs for a significant period this summer.
- “Were about 6 inches below summer level at the lake,” Maher said Monday. He expects the lake to be up to summer level in about two weeks.
- Once Lake Coeur d’Alene is at summer level, Avista will operate the gates at Post Falls Dam to maintain the level, he said.
- If the inflow into the lake, mainly from the Coeur d’Alene and St. Joe rivers, is not enough to maintain the lake level and still allow 600 cfs out of Post Falls Dam, the lake level potentially could be affected in order to keep an absolute minimum of 500 cfs flowing from the dam, Maher said.
- “If it came to that, we’d have to start drawing down the lake,” he said.