CODY, Wyo. — The Bureau of Reclamation has increased outflows from Buffalo Bill Reservoir in recent weeks to make room for what officials believe will be rapid inflows this spring.
Water levels in the reservoir have dropped 1 foot over the past month, as BuRec releases water down the Shoshone River, making room for inflows that could reach 127 percent of average.
“On April 1, the snowpack we use for our forecast was 107 percent of average in the Shoshone basin,” said John Lawson, BuRec’s Wyoming area manager. “It went to 110 percent on April 4 and (Wednesday) it was at 114 percent.”
The snowpack is expected to increase again after Thursday’s spring storm, which is expected to deliver heavy snow across the Shoshone River basin and eastern portions of Yellowstone National Park.
Flows into the reservoir are projected to be 127 percent of average this spring with an infill estimated at 840,000 acre-feet of water.
Lawson said that last year the reservoir saw an infill of 674,000 acre-feet. The snowpack for the Shoshone basin was just 64 percent of average.
“This is quite a difference from last year,” Lawson said. “We’re taking action early so if we get the spring moisture that we don’t always get, we’ll be prepared for it.”
Lawson said the agency was looking to avoid large releases in June and July, as happened in 2009 when the reservoir saw an infill of 954,000 acre-feet of water.
That year, Lawson said, the snowpack looked to be down, but heavy snows late in the season prompted large releases, which had consequences downriver.
“We were making releases out of Buffalo Bill of around 7,000 cubic feet per second and we spent the month of June working with emergency management in Lovell,” Lawson said.
“This year, we’re moving water out and making space early. If the snow drops off, we can decrease what we release this summer, but if we get higher infill, we’ll be prepared.”
The reservoir is 66 percent full and 29 feet from what’s considered full pool.