Officials warn of Sheyenne concernsDevils Lake has more than tripled its watery footprint since the early 1990s and now is likely to reach a new record level this summer.
By: Patrick Springer, INFORUM
Devils Lake has more than tripled its watery footprint since the early 1990s and now is likely to reach a new record level this summer.
To alleviate flooding on the lake, the North Dakota State Water Commission wants to more than double the flows from the outlet into the Sheyenne River.
And that scenario is causing alarm downstream among Cass County water districts that are concerned increased flows will cause “millions of dollars in repairs and improvements” to the Sheyenne Diversion.
“We need to prepare the diversion for the additional water that’s going to come,” said Tom Fischer, chairman of the Cass County Joint Water Resource District, which oversees the Sheyenne Diversion.
Cass County water officials have written to warn about the adverse effects to the Sheyenne Diversion from the increased flows, and to argue that state law would require a special permit.
To protect the diversion, Cass County officials want the state to help rip-rap the bottom and sidewalls of four miles of the 7 1/2-mile diversion to protect against erosion during periods of sustained high flows.
“We’ll evaluate it and work something out,” said Todd Sando, assistant state engineer, adding that the Sheyenne Diversion already experiences erosion damage.
“They do have some valid concerns so we’re going to try to address them,” Sando said, adding that the outlet will operate within constraints, both to maintain water quality and flood control.
Fischer, who also is a state senator representing Fargo, is encouraged following the meeting with state officials about Cass County concerns.
“They understand what the need is,” he said. “We just needed to let them know.”
Built in 1992, the Sheyenne Diversion protects areas including West Fargo and Horace from flooding. The channel has a grass bottom, and experiences damage such as slumping and erosion during periods of high use.
Engineers have calculated that the diversion would have operated
54 percent of the days from 2000 to 2009 if the higher flows from the Devils Lake outlet are approved, instead of the 22 percent that occurred.
The Ramsey County and Towner County watershed districts are expected to decide in March whether to approve the State Water Commission’s request to increase flows in the Devils Lake outlet from 100 cubic feet per second to 250 feet per cubic second.
The National Weather Service has predicted that Devils Lake has a 50 percent chance of reaching a level of 1,452.1 feet – less than 8 feet below the level it drains naturally, and uncontrolled, into the Tolna Coulee, which flows into the Sheyenne River.
“We don’t want to see that occur because it would be devastating, both for water quality and flood control,” Sando said. “It’s a real risk, and it keeps increasing.”
The Sheyenne Diversion was designed in 1989, before Devils Lake began its rapid rise, and has handled a lot of water in the wet period that has soaked both the Red River Valley and Devils Lake Basin since 1993.
Readers can reach Forum reporter Patrick Springer at (701) 241-5522