Releases will decrease from Jamestown Dam beginning today, according to Brian Twombly, hydraulic engineer for the U.S. Army Corps of Engineers in Omaha, Neb.
"We start by reducing the releases from the Jamestown Dam by 150 cubic feet per second Tuesday, Wednesday, Thursday and Friday," he said. "That brings the combined releases down to 1,800 cfs which is just below the flood stage for the James River in Jamestown."
Beginning Oct. 22 reductions of releases of 50 to 75 cfs will be made from either Jamestown or Pipestem dams. The reductions in releases continue until mid-November. At that time the reservoir levels should be at the bottom of the flood control pool. This is the level the reservoirs are held at through the winter in preparation for spring runoff.
The Jamestown Reservoir is currently at 1,436.8 feet above mean sea level which is 6 feet above the flood control level of 1,431 feet. The Pipestem Reservoir is currently at 1,462.7 feet which is 19.7 feet above the flood control level of 1,442.4 feet.
The corps hopes to reach the flood control levels before ice forms on the reservoirs. However, if there is additional precipitation or an early freeze up, it may not make this goal. This could impact the safety of winter sports involving the reservoirs.
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"It's not a decision we make," Twombly said. "But we have been talking with recreational officials about these possibilities although it is too early to know how it would impact recreational use."
If the reservoir levels are being reduced after the ice forms it can cause the ice surface to collapse which poses a safety concern.
"From a biological issue there would be no cause to close the reservoirs to ice fishing," said B.J. Kratz, fisheries biologist for the North Dakota Game and Fish Department in Jamestown. "Obviously drawing down the reservoirs causes safety concerns but we don't have any plans that are as drastic as closing the fisheries."
Ice safety concern is an issue the corps hopes to avoid. Twombly said the corps would make every effort to complete the reservoir draw downs before the lakes freeze over. That requires some continued good weather.
"Conditions have been almost ideal the last weeks," he said. "Even the rains were slow rains that have soaked into the ground and not produced much increase in inflows. The forecast for the week looks good as well."
Sun reporter Keith Norman can be reached at (701) 952-8452 or by email at knorman@jamestownsun.com
