Expectations for Lake Sakakawea

2018 levels similar to last year

The level of Lake Sakakawea this summer is looking like it will be very similar to last year. That’s the take-away from the latest runoff projections issued by the U. S. Army Corps of Engineers for the Missouri River Basin.

The Missouri River, along with the Yellowstone, flows into the upper end of Lake Sakakawea. Spurred by Rocky Mountain snowmelt, the Missouri flows into Fort Peck Reservoir in Montana. Releases from that reservoir are generally responsible for the bulk of Missouri River flows that enter North Dakota. The free-flowing Yellowstone bypasses Fort Peck and joins the Missouri prior to entering Lake Sakakawea.

According to the Corps, the February runoff estimate for the Missouri River Basin is projected to 25.4 million acre feet of water. The January estimate was 26.6 maf. The long-term average is 25.3 maf.

Last year, the water elevation of Lake Sakakawea peaked near 1,846 feet. This year, based on projections with nearly 40 percent of the mountain snowfall season remaining, the reservoir is projected to top out about 1,845 feet. Lake Sakakawea stood at 1,839 feet Monday and is expected to drop approximately another foot by the end of February.

The Corps says mountain snowpack water content for the Missouri River Basin above Fort Beck was 114 percent of average on Feb. 1. At the same time the snowpack water content in the Fort Peck to Garrison reach, generally considered the Yellowstone River, was tracking at 124 percent of average. Missouri River Basin mountain snowpack historically peaks about April 15.