Planning Assistance to States: Red River Basin Long Term Flood Study

U.S. Army Corps of Engineers, St. Paul District
Published March 22, 2019
Updated: March 29, 2022
Purpose

The purpose of this study is to investigate the effectiveness of various flood risk reduction measures basin-wide to reduce main stem peak flows by 20% for the larger rare events such as the 0.5% (200-year) and 0.2% (500-year) chance of exceedance floods.  

Location

The Red River of the North rises in Lake Traverse near Wheaton, Minnesota, and flows north towards Canada and ultimately to Lake Winnipeg. This is a basin-wide study in Minnesota and North Dakota.

Description

The Red River Basin Commission (RRBC) produced the Long Term Flood Study (LTFS) in 2011 after the 2009 flood. Minnesota and North Dakota expressed the need for a coordinated, comprehensive, proactive plan that responds to and mitigates flooding and flood damages throughout the Red River Watershed. The 2011 LTFS report provided 48 recommendations ranging from immediate needs and critical risks to long term studies. A 2015 status report showed that substantial progress had been made for about 20% of the recommendations, but that limited, or no progress had been made for about 50% of the recommendations. The focus of the study will be on the 0.5% (200-year) and 0.2% (500-year) chance of exceedance floods.

Study tasks include updating hydrology models with sensitivity to climate variability and other factors like storage, impacts of changed hydrology on levee certification, analysis of risk reduction goals, effectiveness of flood plain regulations, and storm water management.

Status

A partnership agreement was executed between the U.S. Army Corps of Engineers and the sponsor (Red River Basin Commission) in November 2018. The sponsor will meet all or a portion of their cost-share requirements through work-in-kind efforts.

Phases 1 and 2:

  • Hydrologic data for floods in the range of the 0.5 to 0.2% chance exceedance events are being developed.
  • Impacts of flood storage are being investigated. The study is scheduled to be completed in fall 2022.
Authority

Section 22 of the Water Resources Development Act of 1974 (Public Law 93‒251), as amended. The study is being conducted under the Corps’ Planning Assistance to States (PAS) program, following the 50/50 cost-share formula with the non-federal sponsor. The sponsor may contribute additional funds beyond this formula.

Funding

The following is a summary of the funds required for the Red River Basin LTFS PAS Project:

Total Study Cost Phases 1 and 2                     $650,000

Total Federal Funds Allocated to Date           $325,000