Temperatures are soaring in Jackson Hole, and the runoff is about to begin surging down the Snake River.

Last Thursday, Mike Beus of the U.S. Bureau of Reclamation gave an overview of the operation plan for Jackson Lake Dam. In the last few weeks, the bureau has been preparing for flood control, bracing for a second straight year of high runoff.

Beus projects that the Snake will peak around June 8 or 10, at a level comparable to last year. Releases from the dam should reach about 6,000 cubic feet per second, meaning flows likely will exceed 10,000 cfs in Grand Teton National Park and more than 20,000 in the Snake River Canyon.

Beus’ long-range weather forecasts suggest a greater chance of warmer-than-normal temperatures in the coming weeks.

The bureau aims to catch most of the runoff in Palisades Reservoir, which has been emptied to 38 percent of capacity.

Beus projects the releases at Jackson Lake Dam to drop to 3,000 cfs by July 2.

The water content of the snowpack in the Snake River basin measures 123 percent of average. At Lewis Lake Divide and Two Ocean Plateau, key gauges for the upper Snake, those figures are 122 and 158 percent of average, respectively.

Filed under: Watershed News on May 18th, 2009