ASPEN, Colo. (AP) – Flows in the Roaring Fork River basin may have already peaked for the year, according to some hydrologists and forecasters with an eye on the watershed.
Still, there’s a chance that warm weather in the coming weeks could bring a second peak, pushing levels slightly higher than they were on May 27, when a gauge on the lower Roaring Fork River near Glenwood Springs recorded a flow of 3,394 cubic feet per second.
“Our model is showing right now that if it gets warm enough we can get as high as we were then, and possibly a little bit higher,” said Brenda Alcorn, senior hydrologist at the Colorado Basin River Forecast Center in Salt Lake City.
Each year, forecasters at the Colorado Basin center project the size of peak flows, but not when they will occur.
If May 27 does turn out to be the date of peak flows on the Roaring Fork, it will be one of the earliest since record-keeping began on the river in 1907. In only three years – 1964, 1967 and 1992 – did the Roaring Fork River peak before that date.
Rick Lofaro, executive director of The Roaring Fork Conservancy, a nonprofit river watchdog group, said the average date of peak runoff seems to be occurring earlier in general than it used to.
“Historically, people probably counted on runoff peaking sometime in the first or middle two weeks of June,” he said. “Now it seems like everything backs up considerably. In an average runoff year it is getting pushed back into May.”
Some owners of local rafting companies, who depend on decent flows in local rivers, said it was hard to tell whether runoff was trending earlier. In most years, peak runoff often occurs long before the bulk of their summer business arrives.
Evan Cree, manager of Blazing Adventures rafting company in Aspen, said his company’s business typically “ramps up throughout the summer,” starting around mid-June.
At this time of year, he said, most of the people on the river are locals who want to take advantage of high water.
Jim Ingram, who owns Aspen Whitewater Rafting, said that whether the river peaks again will depend on temperatures in the high country.
“If the weather stays in the 70s we are going to stay where we’re at, but if we get into a couple of 80 degree days in Aspen, we will see another peak,” he said. “The great thing is that unless it gets really hot, we are going to be able to raft the Roaring Fork straight from Aspen until July Fourth.”
Flows this year have been significantly higher than they were during the drought of 2012, when the river peaked in early June near Glenwood Springs at less than 2,000 cubic feet per second.
Still, water levels in the Roaring Fork watershed remain low for this date, according to Sarah Wood, the Roaring Fork Conservancy’s education and outreach coordinator.
“Flows are all significantly below historical averages,” she said, noting that the overall snowpack in the Roaring Fork basin peaked at 88 percent of average this year.
Low flows have consequences for the river’s ecology. Without high flows, sediment that has accumulated during the previous summer will remain in the river, and the growth of organisms like algae can result.
“The system needs a fresh start,” said Wood. “High flows are essential for the regeneration of riparian habitat.”
On the Fryingpan River, a tributary of the Roaring Fork, flows were averaging about 110 cubic feet per second on Monday. Engineers with the federal Bureau of Reclamation are required to release at least that much water from the Ruedi Dam this time of year to insure the health of fish and other organisms.
– By NELSON HARVEY, Aspen Daily News
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