January 16, 2009

Corps officials: Mountain snowpack near normal

Corps officials: Mountain snowpack near normal

There’s still plenty of winter to go yet, but U. S. Army Corps of Engineers officials predict Lake Sakakawea should peak at about 1830 mean sea level (msl) this summer – approximately six feet higher than the present level of 1824.6 msl.

Corps officials base their predictions on the amount of snowpack in the mountains and plains.

In their monthly news release, the Corps said given that the mountain snowpack is near normal, but the plains snowpack is below normal, the current forecast for runoff in 2009 is 22.3 MAF. That figure is 90 percent of average. If the forecast verifies, the level of Lake Oahe south of Bismarck is forecasted to peak near 1596 feet this summer. Fort Peck is expected to crest at near 2217 feet.

"Runoff for 2008 totaled 26.4 million acre feet (MAF)," said Larry Cieslik, chief of the Water Management office in Omaha.

"This is the first year since 1999 with runoff above the normal 24.8 MAF. The higher inflows combined with low releases due to good downstream tributary inflow pushed storage in the reservoirs to 44.8 MAF. It is forecast to total 45 MAF on March 1, 2009."

Steady to rising reservoir levels during the spring fish spawn at the three large upper reservoirs are likely if there is normal or above normal runoff. However, continued drought conditions may not make that possible at all three, a Corps spokesperson said. If that is the case, the Corps will set releases at Garrison Dam to result in a steady to rising pool during April and May, to the extent reasonably possible. The ability to provide such conditions depends on the volume, timing and distribution of the runoff from melting snow on the plains and in the mountains of Montana and Wyoming.

The Weather Network