Forecast calling for unusually dry summer

BONNERS FERRY — While much of the East Coast and Great Plains suffered their worst winter in decades, with record snowfalls followed by torrential floods, Idaho was largely missed by the season’s winter storms, and that could bode an unusually dry summer.

According to the Natural Resource Conservation Service, Washington, D.C,. received its highest snowfall since records have been kept there, going back to 1884 and the presidency of William McKinley. Conversely, Idaho’s Upper Snake River Basin, a watershed critical to many, had the third lowest snow seasons since records have been kept here, which date back to 1919.

If the El Nino pattern that shaped the odd winter doesn’t relent and the area doesn’tt receive hoped-for April showers, NRCS experts warn that much of Idaho face water shortages this year and May flowers might be drying up earlier than usual.

Here in the Panhandle, a few streams have been flowing at 75 percent of average, but most of the state is seeing streams at 30  to 55 percent of average. But the surface water supply index, an indicator of water availability within a watershed for the spring and summer water use season, looks fairly dismal.

On a scale where plus four equals an abundant supply and negative four means extremely dry, the Idaho Panhandle comes in at minus 3.2. Only the Clearwater, Henry’s Fork, and the Owyhee are expecting drier summers, each with a surface water supply index of negative 3.4.

According to the NRCS, the seasonal stream flow volume on the Kootenai, Moyie and Priest rivers and Boundary Creek are expected to run at about 70 to 75 percent of average, while the St. Joe, Spokane and North Fork of the Coeur d’Alene Rivers might run half of normal. There was hope that precipitation in March would help improve the outlook, but rain and snowfall stayed below normal.

At Libby Dam, plans are going forward to conduct a week-long spring spill operation to test whether additional flows will meet habitat attributes required for the Kootenai River white sturgeon, but those plans could be scrapped if the water supply forecast doesn’t improve.

According to the Army Corps of Engineers, the spill is slated for sometime between late May and late June, but we’re already experiencing a low-water year and the overall volume of precipitation appears likely to further decline. If the spill can’t be accomplished, sturgeon recovery efforts will focus on water temperature management.

The corps will hold two public meetings later this spring to provide more details on 2010 Libby Dam operations; one in Bonners Ferry on May 17, the other in Libby, Mont., on May 20.