JAMESTOWN, N.D. – Releases from Jamestown and Pipestem Reservoirs will remain at 1200 cubic feet per second longer than expected due to continued high runoff into the reservoirs. Earlier this year, releases from the reservoirs were expected to fall below 1200 cfs in early June. However, during the last 30 days above normal rainfall has occurred in much of the James River and Pipestem Creek basins upstream of the reservoirs.
Releases will not have to be increased as a result of the increased runoff, but it is expected that the 1200 cfs release will be continued until at least late June. As a result of increased rainfall and runoff, reservoir pool levels at both Jamestown and Pipestem Reservoirs have continued to increase. Jamestown Reservoir is currently at a level of 1439.9 feet with 2000 cfs inflow and 1000 cfs release. The reservoir is forecast to peak on June 6 at a level of approximately 1440.5 feet. Pipestem Reservoir is currently at a level of 1471.8 feet with inflows at 500 cfs and a release of 200 cfs. The reservoir is forecast to peak on June 5 at a level of approximately 1472.5 feet.
Combined releases will be maintained at the 1200 cfs level until at least late June, then gradually reduced as the remainder of the flood control storage is evacuated. With average precipitation, all the flood control storage in the reservoirs will be evacuated by early September. Evacuation of flood control storage could take longer if abnormally high rainfall continues. Reservoir flood control releases from Jamestown and Pipestem Reservoirs began April 27 and have been at the 1200 cfs level since May 23. The flood control releases initiated in late April have already reached as far downstream as Columbia, S.D. James River levels at Columbia and areas downstream will continue to gradually increase as the 1200 cfs release water migrates downstream.
The peak daily inflow into Jamestown Reservoir was 2,700 cfs on May 19 and the peak daily inflow into Pipestem Reservoir was 2,500 cfs on April 29. Without the dams in place, the peak discharge at Jamestown would have been about 3,900 cfs on May 19.
Jamestown and Pipestem Reservoirs are located along the James River and Pipestem Creek immediately north of Jamestown, N.D. Pipestem is a Corps project and Jamestown is a Bureau of Reclamation project that is regulated by the Corps when the reservoir is in the flood control zone.
The Corps, Bureau of Reclamation and National Weather Service will continue to monitor rainfall and runoff conditions, and will provide updated forecasts and release plans as conditions change.
With the continued high releases from the reservoirs, residents along the James River downstream from Jamestown should continue to monitor flood forecasts by the National Weather Service.
Flood forecasts on the James River in North Dakota and South Dakota are available on the Missouri Basin River Forecasting Center website at http://www.crh.noaa.gov/mbrfc/.
River stages on the James River in North Dakota and South Dakota are available on the U.S. Geological Survey Web site at http://nd.water.usgs.gov/floodinfo/james.html.