Omaha   (USACE  11-12-19)   The U.S. Army Corps of Engineers, reports, on Tuesday,  updated forecasts have indicated the river downstream of Jamestown and Pipestem Dams should not see significant ice formation for at least another week. To release as much flood storage as possible, combined releases will be held at 1,400 cubic feet per second until three days before the new forecasted date for ice formation.

To mitigate the risk of freeze-up ice jams or other ice-related flooding, the target combined release rate before ice sets in is 800 cfs. Three days before expected ice formation releases will be reduced 200 cfs per day to a combined release of 800 cfs.

Updated reservoir forecasts indicate combined winter releases are not expected to exceed 850 cfs; however, additional precipitation, earlier than expected ice formation on the river, or higher than expected baseflow could necessitate higher release levels. Ice conditions in the entire James River basin will be continually evaluated throughout the winter. The Corps of Engineers will operate to minimize the risk of ice-related flooding, and adjustments to the releases will be made as needed.

Jamestown Dam on Tuesday was at a pool elevation of 1442.0 feet, about 31% into the flood pool, and rising. Inflows into the reservoir peaked Oct. 30 and are dropping, currently near 800 cfs. Reservoir releases are 700 cfs.

Pipestem Dam on Tuesday was at a pool elevation of 1469.9 ft, about 34% into the flood pool, and dropping. The pool elevation peaked Oct. 29 at 1475.0 feet, which was 43% into the flood pool. Inflows are near 325 cfs, and releases are 700 cfs.

The Corps of Engineers is coordinating with relevant agencies in North and South Dakota.

James River level through Jamestown.

Jamestown Dam

Previously…

Omaha  (USACE)   The U.S. Army Corps of Engineers reports, new weather forecasts point to  the James River downstream of Jamestown and Pipestem Dams could see ice formation by the end of next week.

To mitigate the risk of freeze-up ice jams or other ice-related flooding, the target combined release rate before ice sets in is 800 cubic feet per second.

The U.S. Army Corps of Engineers – Omaha District will be stepping down releases 200 cfs per day with the target combined release rate of 800 cfs achieved Nov. 14th.

The table below details the current release schedule:

Jamestown Dam Releases (cfs) Pipestem Dam Releases (cfs) Total Combined Release (cfs)
Thursday Nov. 7 1,100 1,100 2,200
Friday Nov. 8 1,000 1,000 2,000
Saturday Nov. 9 900 900 1,800
Sunday Nov. 10 800 800 1,600
Monday Nov. 11 700 700 1,400
Tuesday Nov. 12 600 600 1,200
Wednesday Nov. 13 500 500 1,000
Thursday Nov. 14 400 400 800

River ice forecasts will be continuously updated during this time.  If conditions change and the forecast ice-in date shifts, combined releases will be held at 1,400 cfs until three days before the new ice-in date.

Updated reservoir forecasts indicate combined winter releases are not expected to exceed 850 cfs; however, additional precipitation, earlier than expected ice formation on the river, or higher than expected baseflow, could necessitate higher release levels.  Ice conditions in the entire James River basin will be continually evaluated throughout the winter.

The District will operate to minimize the risk of ice-related flooding, and adjustments to the releases will be made as needed.