Work could begin as early as next summer on a newly approved, $2-billion plan to build a system that would divert floods on the Red River around Fargo, N.D., and Moorhead, Minn., if Congress authorizes funds for the U.S. Army Corps of Engineers' proposal.
The plan involves building a set of control structures and a 36-mile-long bypass channel to reroute floodwaters around the cities. The works should provide protection against a 100-year flood event and also bolster emergency measures that would be used to help the communities fight floods of even greater magnitude. The area has endured major flooding repeatedly, with notable flood fights in 1997, 2009, 2010 and 2011.
"We are on track to have some plan sets ready for construction, if we would get authorized funds in April 2013," says Brett Coleman, project manager in the Corps' St. Paul District. "If things go well, we would hope to have requests for proposals out next summer and, hopefully, start construction next year." The Obama administration endorsed the project in late March. Jo-Ellen Darcy, Army assistant secretary for civil works, on April 3 signed a record of decision on the final feasibility report and environmental impact statement.
The design selected would include construction of a diversion channel capable of conveying water at a rate of up to 20,000 cu ft per second. The channel would direct floodwater of the north-flowing Red River and tributaries around the Fargo-Moorhead metropolitan area, which has a combined population of about 209,000 people.
The project also would include establishing two staging areas upstream to temporarily store up to 200,000 acre-ft of floodwater. The staging areas would be used to buffer the flow when the diversion is activated to minimize downstream impact when the water rejoins the Red River on the other side of the cities. Development of the staging areas would affect an estimated 33,390 acres of land, 387 dwellings and 421 other structures on rural farmsteads and in two small communities. It would require 10 miles of tie-back levees and placement of control structures on two rivers and a creek. The diversion channel itself would require construction of channeling levees, a weir, two spillways and four "drop structures" to lower the elevation of the watercourse sharply in a short span.
Two planned aqueducts would carry streams over the diversion channel alignment on engineered structures, like cars on an overpass crossing a freeway. The streams now flow across the alignment at grade. "We are one critical step closer to making the locally preferred flood-control project for Fargo-Moorhead a reality," says U.S. Sen. Kent Conrad (D), chairman of the Senate Budget Committee. "Now, we will continue the difficult work of convincing our colleagues in Congress that the project should be authorized and funded. Though much work remains, I am confident that, at the end of the day, we will deliver the permanent protection this community needs."
Experts fear the Fargo-Moorhead area faces more catastrophic flooding in the future. According to the Corps, the Red River has exceeded flood stage in 48 of the past 109 years and in every year from 1993 through 2011. "We estimate that a 500-year event would flood nearly the entire city of Fargo and a large portion of the city of Moorhead as well as a major portion of West Fargo and several surrounding communities in the area," says Aaron Snyder, chief of the project management branch in the Corps' St. Paul District.
Without the diversion, the Corps estimates damages for a 100-year event would be about $6 billion. Estimated damages from a 500-year flood would exceed $10 billion, Snyder says.
Col. Michael Price, St. Paul District commander, says Darcy's signing the record of decision "is a huge milestone" for the metro area and for the teams working on this for more than three years. The district office and the cities of Fargo and Moorhead began the feasibility study in September 2008. The Corps published a final feasibility report and environmental impact statement last July. Conrad says the Fargo-Moorhead flood-control plan has the backing of the local community, Cass County, the state of North Dakota and, now, the White House. There is some opposition because of upstream impacts.
For the plan to come to fruition, Snyder says, Oxbow, N.D., for example, must be condemned and purchased. If Congress authorizes the project, the Corps is "hoping for construction funding of a little less than $100 million per year over the next eight and a half years," Snyder says. "The federal cost share is just over $800 million." The Corps already has done much of the design work in-house but plans to award additional design and engineering work to outside firms "where it makes sense," Coleman says. Construction would start at the downstream end.
The Corps has built other diversion channels in recent years, says Coleman. He cites one precedent: the Otter Tail River diversion, located in Breckenridge, Minn., which redirects the Otter Tail River north of the Red River and provides benefits to both Breckenridge and Wahpeton, N.D. "That diversion functioned for the first time in spring 2005," Coleman says.
"The levee portions of the project will be completed in 2012." However, Coleman points out that the Otter Tail River project is much smaller than the Fargo-Moorhead diversion and affects a smaller population. He says it is also important to note that the Otter Tail River diversion, which was authorized by Congress in 2001, was reauthorized at a higher cost ($39.36 million, up from $21 million) in the FY 2010 Energy and Water Development and Related Agencies Appropriation Act. Key Fargo-Moorhead authorizations and reports are posted on the International Water Institute website at www.internationalwaterinstitute.org/feasibility.