For decades, the cities of Fargo, North Dakota, and Moorhead, Minnesota, have been plagued by flooding from the Red River of the North. Between 2009 and 2012, Barr worked with the U.S. Army Corps of Engineers (USACE) as part of a consulting team to complete a fast-track feasibility study that developed and compared alternative solutions. The selected solution, called the Fargo-Moorhead Area Diversion, centers on controlled staging and diversion of flood waters from the Red River and five major tributaries into a 30-mile diversion channel.
As part of the three-year study, Barr developed feasibility designs and developed construction cost estimates for eight major hydraulic structures, including two large, gated control structures, one main inlet structure into the diversion channel, two aqueducts conveying flows over the diversion channel, two drop structures, and one outlet structure to return the waters to the Red River. We led all geotechnical engineering aspects of the design, managing soft clays that are particularly challenging for slope stability and construction with reinforced concrete. We also authored a chapter of the federal Environmental Impact Statement about the project’s potential geomorphologic, erosion, and sedimentation impacts.
Starting in 2012, Barr assisted with value-based design workshops that resulted in over $100 million of cost savings and were recognized by two national awards. We then helped with transitioning the project from feasibility to the initial stages of detailed design for this $3 billion project. During this period, Barr served as the main technical advisor supporting comprehensive physical and numerical modeling of the Maple Aqueduct, working with USACE and a hydraulics research group at the University of Minnesota. We also led a sophisticated probabilistic analysis supporting the design of a meandering low-flow channel within the diversion to offset habitat loss. Our analysis demonstrated that, contrary to initial assumptions, the channel did not need to be lined or filled with riprap to protect lateral embankments, which saved design and construction costs.
The Fargo-Moorhead Area Diversion is currently under construction. When complete, this flood diversion project will reduce the risk of flood damage for over 250,000 people.
