USA: Red River Flood Risk Management Feasibility Study Underway

The Red River of the North Rural Nonstructural Flood Risk Management Feasibility Study is investigating nonstructural flood risk management measures for rural homes and farmsteads along the main stem of the Red River of the North and the Bois de Sioux River.

This study is another step to identify and implement flood risk management measures throughout the Red River Basin.

Implementation of this project would require authorization and funding from Congress. Participation in the project would be voluntary and a detailed site assessment would be completed for each interested landowner.

Structural measures such as dams, levees, and floodwalls alter the characteristics of the flood and reduce the probability of flooding in the location of interest. Nonstructural measures alter the impact or consequences of flooding and have little to no impact of the characteristics of a flood.

Traditional nonstructural measures include: elevation, wet and dry flood proofing, relocations and buyouts, and berms.

The Red River of the North Rural Nonstructural Flood Risk Management Feasibility Study is an interim product of the Red River of the North Basin-wide Watershed Study. The non-federal sponsors are Minnesota Red River Watershed Management Board and the North Dakota Red River Joint Water Resources District.

The study is an expansion of the work completed as part of the Fargo-Moorhead Metro Study that was completed in July 2011, as well as work completed for the Long Term Flood Solutions Report (LTFS) which was completed in September 2011. The Fargo-Moorhead Metro Study analyzed nonstructural measures as an additional incremental feature to be included in any of the diversion plans. While nonstructural measures were not included as part of the Federally Recommended Plan, it was determined that nonstructural flood risk management measures could be federally justified for approximately 29-percent of the structures investigated.

The LTFS Report outlined the need for action to identify and fund flood risk management measures throughout the basin. Specific recommendations related to nonstructural flood risk management include:

· Nonstructural floodplain management strategies should be an integral component of reducing flood damage risks in the basin.

· The USACE nonstructural assessment of identified structures has been completed for the F-M diversion project along the main stem in six counties deemed economically feasible for nonstructural mitigation.

· The USACE should expand its assessment along the entire main stem.

· A local sponsor should be identified to provide non-federal cost share of 35-percent and implement the mitigation in the next three to five years.

· Congress should authorize such a project and appropriate approximately $12 million in funding for the 65 percent federal cost share to mitigate.

The study area has been broken into three study reaches. Each reach has undergone a different level of analysis. The study reaches and level of analysis are as follows:

Reach 1: Outlet of Lake Traverse to the southern extent of the Fargo-Moorhead metro. This reach has a low level of detail, a structure count was completed but no nonstructural assessment will be completed during feasibility.

Reach 2: Georgetown, MN to Thompson, ND, this reach was completed as part of the Fargo-Moorhead Metro Study. All structures located in the 500-year floodplain + 1 mile buffer were evaluated for nonstructural measures. The full assessment can be found in Appendix P Part 2 of the Fargo-Moorhead Metro Study.

Reach 3: Thompson, ND to U.S.-Canadian border. For this reach a sample of structures located within the 1997 flood outline + 1 mile buffer were evaluated for nonstructural measures.

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Press Release, January 15, 2013; Image: usace