Construction of $2.75B flood diversion moves ahead south of Fargo while legal fight drags on
FARGO — The headlines have been filled with legal clashes, but work on the Fargo-Moorhead flood diversion has been going on quietly with ground preparation underway for the inlet that will divert water from a flooding Red River into the diversion channel.
The work a mile south of Horace started with pumping water that had filled an area that was excavated in 2017 before construction on the $2.75 billion flood control project was halted by a lawsuit filed by upstream opponents.
In a ruling earlier this year, a federal judge is allowing construction work in North Dakota on the diversion even as the lawsuit and administrative challenges of a key permit for the project by Minnesota regulators play out.
Pumping water at the inlet site ended in mid-September, allowing construction crews to excavate, removing part of two huge mounds of dirt formed to help settle the ground where concrete structures for the inlet will be built beginning late next year, said Virginia Regorrah, Fargo resident engineer for the U.S. Army Corps of Engineers.
Wet weather has slowed efforts, but the contractor has flexibility in finishing the preparations, she said.
"They have a lot of leeway," she said. Pile-driving tests will begin soon, but visible work likely won't take place until late 2020. Also, before construction begins, crews will perform deep soil mixing, preparation to enable the soils to support the large, heavy concrete inlet structure.
"They want to make sure the site is stable," she said. "There's a lot of innovative, cutting-edge engineering that's going into it. When you really start seeing a lot of work is 2021."
The inlet-in-progress is located near the intersection of Cass County 17 and 16 south of Fargo.
"It's still on schedule, even though it doesn't look like a lot of work is being done," said Joel Paulsen, executive director of the Metro Diversion Authority.
Next spring, work will start on the Wild Rice control structure, which will control flows of the Wild Rice River, a tributary that joins the Red River south of Fargo. The Wild Rice structure, which will be about a mile east of the inlet structure, is designed to significantly reduce flooding along the Wild Rice between the control structure and the Red River.
Work on the Wild Rice control structure, which requires less pre-loading of the soils, will progress more rapidly than the inlet, Paulsen said.
Meanwhile, the U.S. Army Corps of Engineers is designing the Red River control structure, which will regulate flows on the river during times of extreme flooding, triggering the temporary storage of water upstream to prevent downstream impacts.
"That's going to be kind of the crown jewel of the project," Paulsen said. "It will be the biggest structure," with a cost estimated by the Diversion Authority of around $238 million.
A contract to raise Interstate 29 from Horace to Oxbow, a 2.5-mile stretch, is scheduled to be awarded in January 2021. The highway must be elevated because of the impoundment of water during extreme floods.
Work also is progressing on in-town features in Fargo-Moorhead to safely handle Red River levels of 37 feet when the diversion is operating.
Even as work is underway and planning continues, the project faces administrative appeals by the Buffalo-Red River Watershed District, based in Barnesville, Minn. The watershed district also is withholding its local permit for the project.
A hearing on the administrative appeal challenging a permit issued by the Minnesota Department of Natural Resources is set to begin in June 2020 and likely will last several months.
Assuming the DNR permit is upheld, the Diversion Authority will proceed with bids for construction of the 36-mile diversion channel, which will be built under a public-private partnership. Technical bids and financial proposals for the diversion channel will be evaluated next fall, with selection of the low bidder expected in November 2020, Paulsen said.
Then, with firm cost figures in hand, "We'll be able to make the final financial request we need from the North Dakota Legislature," he said.
So far, North Dakota has committed $540 million and the federal government $750 million, leaving an estimated shortfall of $120 million for the project. Voters in Fargo and Cass County approved special sales taxes to pay the local portion of the project's cost.