Despite reduced releases Lake Sakakawea levels to change little in April

Much higher releases scheduled

Given present conditions throughout the Upper Missouri River System drainage, the water level of Lake Sakakawea is expected to remain relatively constant for the remainder of April.

Flooding in the lower portion of the Missouri Basin has resulted in less water being released through Garrison Dam. Outflow there has been 13,000 cubic feet per second for several days and is scheduled to remain at that rate until the end of April. Inflow and outflow are expected to be nearly equal at mid-month before inflow will nearly double outflow in the latter days of April.

Through April Lake Sakakawea is expected to rise only slightly. Sakakawea’s elevation Monday was 1,844.56 feet. It is projected to reach 1,844.9 feet by April 26. The major portion of runoff water from mountain snowmelt is yet to come.

Currently the U.S. Army Corps of Engineers forecast is for Lake Sakakawea to reach a peak elevation of 1,848.7 feet at the end of June. Spillway level is 1,854 feet. Last year Sakakawea peaked just below 1,853 feet.

In conjunction with spring snowmelt entering the reservoir, the amount of water being released through Garrison Dam will be increased accordingly. Latest projections call for Garrison releases to reach 36,000 cfs in July and August.

Runoff into the Upper Missouri, according to April 1 projections which do not account for excessive spring rains, is forecast to be 38.2 million acre feet of water. That compares to the long term average of 25.3 maf. Runoff a year ago exceeded 41 maf.

Sakakawea hit a historic high water mark in 2011 at 1,854.6 feet. From 2004-2008 the reservoir remained below 1,820 feet. From 2014 to today high water marks for the reservoir have been more than 1,840 feet.

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