Bighorn Lake
If things were perfect, with rain and snowfall adequate to every season, Bighorn Lake and the Bighorn River below it would be in a perfect balance. And all the people who manage them, use them and build their lives around them would be happy.
If you get 100 percent of normal snow pack and 100 percent of spring and summer rains, managing water is easy.
But, the real world doesn't work that way. In spite of statistics for its "normal" condition, the semi-arid West lives in a landscape of precipitation booms and busts. Lately, it's mostly been busts. These busts have left factions in Montana and Wyoming warring over water on the Bighorn in the waning months of 2006.
At the head of Bighorn Lake, Wyoming interests want more water for the lake to provide recreation and boost tourism dollars flowing into Lovell. Montana interests want to preserve the blue-ribbon trout fishery of the Bighorn River below Yellowtail Dam and the multimillion-dollar tourism industry there.
Caught in the middle are the water managers, trying to craft plans to satisfy as many people and competing interests as possible. The mixture of winter snow pack and spring and summer precipitation is what makes forecasting more difficult. Melting snow pack makes up 60 to 70 percent of the inflows to Bighorn Lake.
As of April 1 of this year, snow pack figures were 80 percent of normal for the Bighorn drainage, the latest in a long string of dry years. The Bureau of Reclamation made their predictions off that amount, figuring in average precipitation for spring and early summer. But then, almost no rain fell in the Bighorn River drainage.
BuRec reacted by reducing flows through Yellowtail Dam, but that wasn't quickly enough to keep water levels in Bighorn Lake high enough to use Horseshoe Bend's boat ramp near Lovell. BuRec performs a balancing act in managing the system, trying to provide needed waters and flood protection for a variety of users. Among the competing interests for water through Yellowtail Dam are flood control, lake recreation, reservoir and river fisheries, irrigation, power generation and industrial water for the power plants at Colstrip.
Complicating things further is Bighorn Lake's volatility. As it stands right now, lake elevations are above the forecasts. Predicted to be 3,609.5 feet elevation, Bighorn Lake was actually 3,611.7 feet because of better-than-expected inflows. Outflows through Yellowtail Dam down the Bighorn River at Fort Smith are holding at 1,500 cfs, and forecasts indicate that level should hold through winter if expected snows fall.
But that has always been the problem with managing this and other reservoirs in the West: You can never say for sure how much snow you're going to get. That's where problems on the Bighorn begin and the squabbling starts over who gets the limited amount of water available.
December 11, 2006 6:50 AM | Category: Drought