Letters From the West

Two dry months likely means lower river flows this year

The Twin Springs water monitoring station on the Middle Fork of the Boise River

The Twin Springs water monitoring station on the Middle Fork of the Boise River (USGS Photo)

You might notice that the Boise River through town remains low, a sign that dam managers are more worried about filling reservoirs than flooding.

The dry conditions are not limited to the Boise Basin according to the Natural Resources Conservation Service.

“The snowpack is lagging from below normal precipitation in January and February,” said Ron Abramovich, Idaho NRCS Water Supply Specialist. “If March is dry that will affect streamflow forecasts,”

Right now the agency is predicting flows of 70 to 90 percent of average. That will affect irrigation, hydropower production and whitewater sports like rafting and kayaking.

“We’ve learned from the past that when we get two dry winter months in a row, negative impacts on the water supply start to occur,” Abramovich said. “Abundant March precipitation would help but short of that, preserving the snow that already exists is the best we can hope for.”

The snowpack is average in the high elevations and would be adequate. But the snow at lower elevations will melt out quickly as the spring warms up.

“Knowing what elevation your water supply comes from will help you prepare for this season’s water supply,” Abramovich said. “Lower elevations will melt out sooner and runoff will be low translating to a decreased water supply.”

So if you like to float the Bruneau or the Owyhee rivers you had better get there sooner.

Remember NRCS’s predictions this year are based on the last 30 years, which have been dryer than the 30 previous years. That means flows of 70 to 90 percent are more like flows of 60 to 80 percent based on forecasts of the last few decades, a new normal, officials call it.

Rocky Barker is the energy and environment reporter for the Idaho Statesman and has been writing about the West since 1985. He is the author of Scorched Earth How the Fires of Yellowstone Changed America and co-producer of the movie Firestorm: Last Stand at Yellowstone, which was inspired by the book and broadcast on A&E Network. He also co-authored the Flyfisher's Guide to Idaho and the Wingshooter's Guide to Idaho with Ken Retallic. He also was on the Statesman’s team that covered the Sen. Larry Craig sex scandal, which was one of three Pulitzer Prize finalists in breaking news in 2007. The National Wildlife Federation awarded him its Conservation Achievement Award.

Posted in Letters from the West