A high snowpack, a cool spring and recent storms have produced an unusual situation in Wyoming and Montana: way too much water.

As a result, Bureau of Reclamation officials are scrambling to balance the need to slow flooding down stream with the need to clear reservoir space in expectation of a huge run-off when the weather finally warms up.

The problem is especially acute for Big Horn Lake and Yellowtail Dam due to heavy inflows into the lake and flooding downstream in Montana.

Officials have been increasing outflows through the dam since early April, and had planned to raise them to as much as 8,500 cubic feet per second in anticipation of heavy inflow. However, last week’s precipitation resulted in flooding in tributaries below the dam, and Sunday releases were cut to 3,500 cfs, according to a release from Dan Jewell, manager of the Montana District of the Bureau, which manages Yellowtail Dam.

The release indicated that inflows into Big Horn Lake were running about 10,000 cfs, and were expected to rise. The combination of the storm and the reduction in releases had produced an increase of 40,000 acre-feet of water in Big Horn Lake, and the hope is that once flooding on the tributaries in Montana subsides, outflows can be increased again.

The average snowpack in Wyoming’s mountains is 227 percent of average for this time of year, and other basins around the state have snowpack levels ranging from 176 percent of average in the Upper Yellowstone to 350 percent of average in the Upper Bear River Basin in southwest Wyoming. The amount of water in the snowpack increased during the week in several drainages, including the Wind and Big Horn River basins that, along with the Shoshone River, feed Big Horn Lake.

John Lawson, area manager of Reclamation’s Wyoming District, said the situation hasn’t changed his office’s plans for Buffalo Bill Reservoir. Releases have lowered the reservoir to about 316,000 acre-feet, a little less than half its capacity, and he plans to have the level down to 300,000 acre-feet by the end of May in order to receive what promises to be an exceptionally heavy run-off once the weather warms.

“We have been drawing down Buffalo Bill,” Lawson said, “but we have not made large, exceptional releases. Our releases have been relatively low, but we will increase them sometime today (Monday) to get where we want to be.”

Lawson said both the North and South Forks of the Shoshone have come up in the last three days and he is increasing outflow through Buffalo Bill Dam to around 4,000 cfs in response. Based on experience in previous wet years, he believes he can account for the heavy snow-melt without resorting to huge increases later in the spring that would produce flood threats in Lovell.

Flows are also increasing from Boysen Reservoir south of Thermopolis following what Lawson called “dramatic changes on the Wind River” last week.

Managing reservoir levels is even more difficult in southeast Wyoming, where, according to Hackleman, “We have twice as much water in the Upper North Platte as we did last year.”

Last year’s thaw sent water over the dam at Pathfinder Reservoir north of Rawlins, and it is already flowing over the spillway this spring.

“I’ll be spending a lot of time on the North Platte,” Lawson said.

Lawson emphasized that his office makes no decisions without consulting with the Montana District and the Army Corps of Engineers as efforts to control flooding downstream continue.

More water may be on the way. The National Weather Service forecasts the possibility of more precipitation in the Absaroka Mountains this week, and has issued a flash flood watch for parts of the Big Horn Basin — including Powell, Lovell, Greybull, Basin and Worland — and Yellowstone National Park.