Upper Missouri Basin
August precipitation across the Upper Missouri Basin was below average. Basin precipitation summaries for the Missouri Basin include: Milk St. Mary, 96 percent; Milk Canada, 79 percent; Lower Milk, 35 percent; above Toston, 72 percent; Toston to Ft. Peck, 66 percent.
Of the four major irrigation reservoirs in Montana; Lima Reservoir had 48 percent average storage, Clark Canyon was holding 66 percent of average water, Gibson Reservoir had 28 percent of average stored water, and Fresno Reservoir had 34 percent of average stored water.
Yellowstone Basin
Precipitation during August ranged from below to above average. The upper Yellowstone River Basin received 127 percent of average precipitation while the Lower Yellowstone River Basin reported 80 percent of average. The Bighorn Basin received 191 percent of average precipitation while the Wind River Basin received 236 percent of average. The Little Bighorn - Upper Tongue Basin received 107 percent of average and the Powder River had 135 percent of average precipitation.
Monthend storage at Boysen Reservoir was 101 percent of average. Stored water in Buffalo Bill Reservoir was 104 percent of average. Monthend storage was 94 percent of average at Bighorn Reservoir.
Platte Basin
Precipitation during August in the Upper North Platte Basin was 84 percent of average. In the Lower North Platte Basin, precipitation was 194 percent of average. The North Platte Plains below Guernsy Reservoir had 55 percent. The South Platte Mountains had 109 percent whereas the Plains had 46 percent of average August precipitation.
Stored water in the South Platte Basin was 97 percent of average on September 1.
