It’s no secret that the Beaverhead Watershed is off to a dry start in 2015. The Centennial Valley snowpack in particular is alarmingly low. On March 31st, the Lakeview Canyon snow course just south of Lakeview in the Centennial Valley (elevation 6,930 ft) had only patches of melting snow cover no deeper than 2 to 3 inches. Water-year-to-date precipitation at the Lakeview Ridge automated SNOTEL site (7,400 ft) is a dismal 45% of average. There was no snow to speak of on the valley floor. Baldy Mountain (9,181 ft), Sheep Mountain (8,530 ft), and Mt. Jefferson (10,217 ft) were looking bare for this time a year as well. The Centennial Valley and the Lima Water Users could be in for a tough year if dry conditions linger into spring.
Water users below Clark Canyon Dam will likely feel the pinch of the dry conditions in the Centennial Valley as well, but the near-average snowpack in the Pioneer Mountains will provide some relief. On March 26th, the Elk Horn Springs snow course (7,800 ft) just north of the Elk Horn Hot Springs still had snow depths in the 18 to 22 inch range. Therefore spring runoff in Grasshopper Creek should help bring flows in the Beaverhead River a little closer to normal.
NRCS snow survey data is factored into the U.S. Drought Monitor, which currently has a portion of southwest Montana classified as D0: Abnormally Dry. The U.S. Drought Monitor factors into the USDA’s decision making process for distribution of drought relief aid.