Dismal mountain snowpack and hot temperatures have made water levels take a dive.
"River flows are the lowest they've been in 100 years," said Pat Maher, senior hydro operations engineer at Avista Utilities, which controls the levels of Lake Coeur d'Alene and the Spokane River with its Post Falls Dam.
"This is as bad as it gets from what we've seen in terms of history."
To capture the summer lake level of 2,128 feet, a condition of Avista's Federal Energy Regulatory Commission license, the company on Friday began closing the gates of the dam about a month earlier than most years. As of Tuesday, the level was 6 inches below the summer mark.
"Hopefully recreation won't be impacted a lot, but we'll see," Maher said. "It could be really dry. We just hope we can get some precipitation and users of the lake won't notice that much of a difference. Rafters won't be able to use the rivers as much because it's so dry in the mountains and there's not very much flow coming into the lake."
Flow on the Spokane River at Post Falls on Tuesday was at a 102-year record low of 708 cubic feet per second. The previous low for the date was 1,910 cfs in 1926. The median for the date is 11,000 and the high was 28,400 in 1917.
Phil Cooper, regional conservation educator for the Idaho Department of Fish and Game, said there are major concerns with the water conditions from a fisheries standpoint.
"The water flows are so low that we have concerns about the rivers being too warm for fish to survive in," Cooper said, adding that trout are the biggest concern.
Cooper said IDFG was planning to stock Spicer Pond near St. Maries for its first free fishing day there on Saturday, but has canceled the event because the water has topped 70 degrees.
"I think we're going to have a lot of issues as the summer progresses," Cooper said. "This certainly affects water temperatures and the ability of fish to survive."
Cooper said fish such as perch, bluegill and crappie can handle hot weather well, but Maher said small perch kills have already been reported this year on the south end of Lake Coeur d'Alene and in Lake Spokane.
Cooper said the hot weather could also bring on more algae blooms, which remove oxygen from the water and can kill fish.
Maher said there's generally snow in the mountains in the higher elevations into mid-July, but this year most of it was wiped out by mid-April. The dry conditions have agencies bracing for a rough fire season ahead.
Avista officials said the South Channel dam project at Post Falls is expected to be finished in late summer. A water filtration system in the adjacent parking lot is being moved, so the boat launch at Q'emiln Park is expected to open on Monday. The beach at the park is open.