Officials drain lake to prepare for rising flows from river

Officials have started to remove water from Jackson Lake for flood control in anticipation of a lot of water flowing in from the Snake River.

The Jackson Hole News and Guide reports the early season increase in Jackson Lake releases is intended to make space for the peak runoff that’s still likely six weeks or so away.

The Bureau of Reclamation’s plan is to draw 77-percent-full Jackson Lake down to about 65 percent. But bureau operations staffer Brian Stevens says nothing’s certain with a wet week forecast ahead.

Stevens says “base flows” are already higher than usual. He says the lake’s runoff volume at the first of the month was 114 percent of average, but the midmonth forecast is more in the range of 120 percent.

Across Wyoming’s portion of the Upper Snake River basin, it was 130 percent of normal as of Wednesday.