Steamboat Springs If snowmelt in the Yampa River through Steamboat Springs has reached peak flows for 2008 - and that's no sure thing - then the river's peak would have fallen well short of a record.
The record snowfall of 489 inches on Mount Werner last winter didn't translate into record peak flows in the river. The Yampa has begun a steady slide this week, after nearly reaching 4,000 cubic feet per second on June 5. The river was running at 2,530 cfs Monday afternoon and was treading water at 2,740 cfs Tuesday afternoon.
After cool temperatures Monday, flows were rallying Tuesday afternoon behind a forecast high of 79 degrees. However, the overnight forecast called for a slight chance of rain mixed with snow and a return to the 50s today.
Routt County Emergency Management Director Chuck Vale said he conferred with other water watchers during a June 5 conference call and there was a consensus that the Yampa has at least moved beyond the threat of flooding, even if it hasn't peaked.
"My gut tells me we're past a crisis," Vale said. "From what I've seen and learned, we've peaked, but watch me be wrong."
Vale consulted with other county emergency managers, the National Weather Service and its River Prediction Service in Salt Lake City, Utah.
The Prediction Service uses mathematical formulas to translate known data about snowpack into a probability that individual rivers have peaked.
The only thing holding the experts back from certifying peak flows, Vale said, is the knowledge that there still are some deep pockets of snow moisture scattered around the Park Range and Elkhead Mountains.
A combination of cold, dry snowfall all winter and a protracted cool spring may have defused spring runoff this year, Vale agreed.
"This year it was cool, cool, cool," Vale said. "Mother Nature let it run down," gradually.
The all-time highest peak on the Yampa in Steamboat was recorded at 6,820 cfs on June 14, 1921. The record low peak was at 1,080 cfs on May 15, 1977. That was a pre-snowmaking ski season at the Steamboat Ski Area when the trails closed temporarily right after Christmas and opened in time for excellent spring skiing.
As recently as June 1, 2003, the Yampa peaked at 5,190 cfs. The river hit 5,310 cfs on Jun 3, 1997.
Hydrologists call the graph that describes the curve tracing the annual rise and fall of streamflows the hydrograph. The peak of runoff on May 30, 2002 - the year of Routt County's worst drought in 90 years and the Hinman Fire - was just 1,290 cfs.