The long summer of high releases from the Jamestown and Pipestem dams could be entering its last week, according to officials with the U.S. Army Corps of Engineers.
"We have no change to the river plan we've been working with," said Brian Twombly, hydraulic engineer for the corps. "We could start ramping down the releases in mid-October and reach the bottom of the flood control level in mid-November."
Combined releases from the two dams have been at 1,800 cubic feet per second since April and were increased to 2,400 cfs in August.
Reed Schwartzkopf, Jamestown city engineer, said the decreases in the releases are made in small increments of as little as 50 or 100 cfs every day or two. The slow drop in the river level allows the saturated river banks to dry out slowly and remain stable.
The Jamestown sanitary sewer system continues to cope with the 2,400 cfs combined releases, according to Schwartzkopf.
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"The system is maintaining," he said. "It is not functioning as well as we'd like but it is functioning."
Schwartzkopf said the system has been handling about 8 million gallons of sewage and water per day. He estimates that about 2 million to 2.25 million gallons is actual sewage. The rest is water infiltration into the system from the high ground water.
"It has remained steady through the months that the river flows have been higher," he said.
At the peak of the 2009 flood the system was pumping more than 10 million gallons per day along with other sewage pumped directly into the river. But even the current 8 million gallons the system is running is above its designed capacity.
"The system is highly stressed," Schwartzkopf said. "The more you put into it the harder it is to keep the sewage out of the neighbor's basement."
The odd- and even sewage-use system and a call to remove sump pumps from the system are still important, Schwartzkopf said. The odd and even system asked that homes with odd house numbers do heavy water use tasks like laundry on odd-numbered days. Even-numbered homes should perform those tasks on even-numbered days.
City ordinance prohibits draining sump pumps into the city sanitary sewer system although it is believed by officials the practice still continues.
"Most normal years the community could handle the inflows," he said. "But we haven't been normal in three years. Every amount put into the sewer puts stress on the system."
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Relief from the planned sanitary sewer upgrade is still two years away. The engineering request for proposal is currently being developed. The project is slated for two construction seasons with work starting during the summer of 2012 at the earliest.
Even with the reservoirs down to normal winter levels in November, releases will likely continue through the winter.
"Through the winter we will pass any inflows so the reservoirs won't come up at all," Twombly said. "Current inflows are about 200 cfs into each reservoir. That may go down a bit before winter. We are likely looking at combined releases of between 100 and 300 cfs through the winter."
That could pose a problem for a possible river cleanup this winter.
"Getting debris out of the river is a big challenge this winter," Schwartzkopf said. "If we cannot operate safely, and get decent tree removal, we'll have to let it go."
Schwartzkopf said they hoped to remove all the trees that had fallen into the river over the past years. However, if the continued releases from the dams keep the river ice free through the winter the project may become too dangerous and expensive.
"A lot of debris decreases the efficiency of the river," Twombly said. "But that is something left for the city to accomplish."
Both Schwartzkopf and Twombly said it was too early to forecast any 2012 flood scenario.
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"The outlook for next spring is better than it was," Schwartzkopf said. "The dry September helped the farmers and it also helped to dry out the surface so we don't go into freeze up like an ice cube."
Twombly is more pessimistic.
"It's too early to tell now," he said. "The groundwater is pretty high and that is what's now driving the current inflows. Lots of snow with high ground water could increase the reservoir levels next spring."
Sun reporter Keith Norman can be reached at (701) 952-8452 or by email at knorman@jamestownsun.com
