DEVILS LAKE A major project to raise and extend the embankments to protect the City of Devils Lake from the rising water of the lake is nearing completion, weather permitting, says a U.S. Army Corps of Engineers official.
“The full project is expected to be completed this fall, weather permitting,” said Bonnie Greenleaf, project manager with the Corps’ St. Paul District.
“Everything is pretty much done,” she said, adding that turf establishment and some miscellaneous work will be finished next year.
Multiple embankment raises were done from 1996 to 2005, then with a dire forecast made in the fall of 2008, a permanent solution was needed to stay ahead of the lake, according to Corps officials.
The City of Devils Lake and the U.S. Army Corps of Engineers became partners on the Devils Lake Embankments’ project.
According to the Corps information, “To continue to meet the appropriate combination of levee and dam safety standards, it was necessary to raise the existing embankments protecting the City of Devils Lake, North Dakota, and extend the embankments to high ground. Previously, the embankments had been constructed to an elevation of 1,460 feet.
“The height required for the maximum pool elevator of 1,458 feet (where flows would begin out of the natural outlet at Tolna Coulee) is 1,466 to meet dam safety standards, with areas of higher wave run-up being slightly higher. When complete, the embankment length will increase from approximately 8 miles to more than 12 miles.”
The embankments to protect Devils Lake were raised in four phases:
Phase 1 (Highway 19 to Creel Bay), awarded in October 2009, is complete.
Phase 2a (west of East Ditch), awarded in November 2010, is complete.
Phase 2b, (East Ditch Pump Station) was awarded in May 2011. It will be completed shortly, weather permitting, but the pump station is operational, Greenleaf said. She said the East Ditch Pump Station is capable of pumping 312,000 gallons per minute.
Phase 3 (Highway 20 to airport), awarded in April 2011, has some embankment work left and will be completed weather permitting, Greenleaf said. The Highway 20 pump test was scheduled to be Oct. 30.
“There are a few pumps in the East Ditch pump station to be tested next spring and that will complete the pump testing for the project,” Greenleaf said.
Mike Grafsgaard, Devils Lake city engineer, said pump stations are required to pump interior drainage water that used to flow by gravity into the lake. The pump station became very massive in order to minimize the 100-year flood plain on the dry side of the flood protection.
The project has four new pump stations that were constructed by the Corps and one new pump station constructed by the North Dakota National Guard, according to the Corps. The pump stations will pump the stormwater on the interior side over the embankments, and range in capacity from 5,000 gallons per minute to 312,000 gallons per minute.
Multiple agencies are involved in the embankments project including the N.D. Department of Transportation, Federal Highway Administration, N.D. National Guard, N.D. State Water Commission, Federal Aviation Administration and Natural Resources Conservation Service.
The current estimated cost of the construction is $167.8 million, with the costs shared 75/25 between the federal government and the City of Devils Lake, according to the Corps.
When completed, the city will be projected from the maximum pool elevator that could occur and it is expected that no further embankment raises will be needed, the Corps said.
The ownership and maintenance of the project will be turned over to the city next year, Greenleaf said.