Central Idaho river flows are returning to normal after unexpected—and in some cases, unprecedented—high flows following a low-snow winter.
The Middle Fork of the Salmon River, Idaho's premier commercial rafting destination, peaked at a gauge height at Middle Fork Lodge of 8.68 feet, about 16,500 cubic feet per second, on Saturday, June 5. Average flow for that date is 5,430 cfs. Historical maximum since the gauge was installed in 1973 is 10.8 feet, or 20,900 cfs, on June 16, 1974.
Middle Fork river ranger John Haugh said he received about 20 reports of flipped rafts, by both private and commercial parties, on the river during the week of high water, though he said some of those reports could be duplicates. He said several outfitters cancelled trips.
"Some flipped boats and some flew out their passengers and others stopped and waited for the water to go down," he said.
Haugh said one commercial passenger, injured when a raft flipped at Lake Creek rapid, was flown out at Indian Creek guard station.
He said a 59-year-old man from Ennis, Mont., named Michael Fitzgerald died while rowing a dory through Hancock rapid, about five miles above the confluence with the Main Salmon. However, he said, a coroner's investigation has not yet determined whether Fitzgerald died after his dory flipped or whether he collapsed while rowing.
"The river's calming down quite a bit now, which is a good thing," Haugh said Monday, when it had subsided to about 5 feet on the gauge.
The upper Main Salmon River also peaked on June 5, at about 8,000 cfs, measured below the Yankee Fork confluence. Average for that date is 3,450 cfs and historical maximum is 10,400 cfs, also in 1974.
Rivers rose quite a bit higher farther west in Idaho, which received two days of heavy rains on top of a still-substantial snowpack.
"It was warm enough that it was also melting the snow in upper elevations," said Tom Brennan, Idaho surface water data chief for the U.S. Geological Survey. "It was a huge event."
The USGS estimated that the South Fork of the Salmon River, east of McCall, hit a 100-year flood stage when it peaked at 11.07 feet on its gauge on June 5, more than a foot above the previous high mark. Brennan said the USGS didn't even have a cfs correlation computed for a gauge reading that high.
The North Fork of the Payette River, north of Boise, registered record high flows for both inflow to Cascade Reservoir and outflow from Cascade Dam. The U.S. Bureau of Reclamation reported an inflow of about 14,000 cfs on June 5 and a record release of 7,050 cfs on June 11. Bureau hydraulic engineer Brian Sauer said employees were walking the banks of the river downstream from the dam to make sure no properties were getting flooded.
The North Payette is well-known among river runners as an expert run even at relatively low summer flows. Kayakers were taking advantage of the unprecedented high flows last weekend as motorists on state Highway 55 stopped to stare and take photos of the raging river.
Boise kayaker Stacy McBain, 35, said her first high-water experience on the North Fork was intense, but felt safer than she had expected.
"I felt like I was climbing up the face of a wave and I just kept climbing higher and higher and then the wave fell out from under me and it was like dropping off a waterfall," she said. "It's so exciting to come out of a big rapid that when I hear people cheering from the road, I'm cheering back."
Greg Moore: firstname.lastname@example.org