News Releases

Higher inflows mean increased releases from Garrison Dam

Published June 18, 2018
On June 15, 2018 the mountain Snow Water Equivalent (SWE) in the “Total above Fort Peck” reach was 1.3” 43% of average. The mountain SWE in the “Total Fort Peck to Garrison” reach was 2.0”, 62% of average. The “Total above Fort Peck” reach peaked on April 19 at 23.0”, 141% of the normal April 15 peak. The “Total Fort Peck to Garrison” reach peaked on April 15 at 20.1”, 137% of thenormal April 15 peak.

On June 15, 2018 the mountain Snow Water Equivalent (SWE) in the “Total above Fort Peck” reach was 1.3” 43% of average. The mountain SWE in the “Total Fort Peck to Garrison” reach was 2.0”, 62% of average. The “Total above Fort Peck” reach peaked on April 19 at 23.0”, 141% of the normal April 15 peak. The “Total Fort Peck to Garrison” reach peaked on April 15 at 20.1”, 137% of thenormal April 15 peak.

OMAHA, NE - Releases from Garrison Dam are being stepped up from 44,000 cubic feet per second to 52,000 cfs.

Releases will be increased over 3 days, reaching the 52,000 cfs rate on June 20. Releases are being increased due to a continuation of high inflows from the melting mountain snowpack and rainfall runoff.  

The reservoir elevation at Lake Sakakawea, the Garrison reservoir, is currently 1851.1 feet, 1.1 feet into the Exclusive Flood Control Zone, which extends from elevation 1850 to 1854 feet. The reservoir is expected to peak near elevation 1852.5 feet in the next two weeks as runoff from the remaining mountain snowpack tapers off. 

The maximum power plant release is 41,000 cfs. Therefore, releases of 11,000 cfs will being made through the regulating tunnels. The 52,000 cfs release rate is expected to continue into early July. 

The 52,000 cfs release will result in a 1.5-foot river stage increase near Bismarck, from 10.5 feet to about 12.0 feet.

The Corps will continue to monitor basin and river conditions, including rainfall and mountain snowmelt, and will adjust the releases based on the most up-to-date information.

Due to the 11,000 cfs releases being made through the regulating tunnels, there will be no public access to the wing walls. The west tailrace access will remain fully open to the public. 

The mountain snowpack peaked April 19 in the Fort Peck reach and on April 15 in the Fort Peck to Garrison reach. Both reaches have less than 2.0 inches of snow water equivalent remaining. 

 View the mountain snowpack graphic here: http://www.nwd-mr.usace.army.mil/rcc/reports/snow.pdf.

Weekly updates on basin conditions, reservoir levels and other topics of interest can be viewed here: http://www.nwd-mr.usace.army.mil/rcc/reports/pdfs/weeklyupdate.pdf.

To view the detailed three-week release forecast for the mainstem dams, go to http://www.nwd-mr.usace.army.mil/rcc/reports/twregfcast.pdf.


Contact
Eileen Williamson
402-996-3802
eileen.l.williamson@usace.army.mil

Release no. 18-037