The Elk River west of Steamboat Springs was rushing along at 1,400 cubic feet per second late last week, nearly three times its normal flow before the weather began to change.
The cold snap that blew into the Yampa Valley during the weekend quickly dropped streamflows in area rivers that had been flowing well above their historical averages since late March.
Flows in the Yampa River in Steamboat returned to their historical average for the date Monday. But the Elk River at Milner had retreated only to 800 cfs, well above the normal of 450 to 500 cfs for this date.
Mark Oliver, a consulting hydrologist, said the trend early this spring could mean there will be less runoff to keep the river full later in the summer.
"There's only so much water in the snow," Oliver said. "If it's running down the river now, it won't be available in June, July and August."
As recently as April 9, the Yampa was flowing at 150 percent of average for this time of year.
The Yampa at the Fifth Street Bridge was flowing at just below 400 cfs Monday afternoon, just about where it belongs for April 12. But late Friday, it was at 600 cfs, 200 cfs more than 93 years of statistical data suggest it should be. The river had been running about 100 cfs above the median flow throughout the month.
Oliver pointed out that the early runoff primarily is attributable to lower level snowmelt -- the water stored on Buffalo Pass hasn't begun to fill the Yampa. However, he said the visible brown patches on the ski slopes of Mount Werner are signs of early water loss to evaporation and moisture soaking into the soil.
Oliver is seeing similar melting trends throughout the region.
"I've been looking at several stream gauges throughout the West," Oliver said. "The rivers are (flowing) way above the long-term average."
The data for the Elk River is based on 33 years of records. A measuring station upstream on the Elk at Clark is not yet operating for the season.
The temperature in the Yampa at Fifth Street remains cold. The river peaked above 50 degrees Fahrenheit on April 6 and 7. It dropped below 40 degrees on Sunday morning before reaching a daily high of 49 degrees.
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