GOAL: Provide reliable flood control and risk reduction.

GOAL: D+

floodProvide reliable flood protection and risk reduction through well managed and maintained infrastructure, including appropriate floodplain connections for water conveyance and ecosystem benefits, and management of surface and storm water runoff to better protect life, property and economies.

arial view

Photo: David Y Lee

Dam

Photo: Ark. Parks & Tourism

arial view 2

Photo: US Army Corps of Engineers

flood

Photo: Jay Harrod/TNC

Flood road

Photo: David Y. Lee

flood control

Photo: David Y Lee

The threats from floods can increase significantly when watersheds lose their natural capacity to store water, when communities and other permanent structures are developed in flood-prone areas, when there are changes in the landscape that cause increased surface water runoff, and when infrastructure—such as levees and dams originally built to manage flood risk—begin to age or are not adequately maintained. The extent of flooding can often be reduced by a variety of strategies, including: reservoirs to reduce peak river flows; levees and flood walls to contain flood waters; and preserving wetlands to provide natural flood storage and to redirect flood waters. The chance of flooding can never be reduced to zero. The challenge for flood control and risk reduction in the future will be to maintain existing measures that have proven effective against damaging flooding—both structural and nonstructural—while at the same time finding new strategies that respond to a changing climate, rising sea level, coastal subsidence and erosion.

Related Links

The Technical Report

Grades Explained

Entire Mississippi Watershed

The watershed received a grade of D+ for Flood Control & Risk Reduction. The results in the Report Card were poor, especially because development within floodplains is increasing. Risks from severe river floods were highest in the eastern portion of the watershed and along the Lower Mississippi River, although intensive investment in flood control infrastructure avoided huge losses from the record flood in 2011.

Upper Mississippi Basin

The Upper Mississippi Basin received a grade of D+ for Flood Control & Risk Reduction. The Floodplain Population Change indicator in the Upper Mississippi received a failing grade and the Levee Condition indicator received a C grade. The Building Elevation indicator received a B- grade, among the highest in the watershed.

Ohio & Tennessee River Basin

The Ohio River Basin received a grade of C- for Flood Control & Risk Reduction. The Floodplain Population Change indicator in the Ohio Basin received a C- grade. The Levee Condition indicator received a C grade and the Building Elevation indicator received a C- grade.

Lower Mississippi Basin

The Lower Mississippi Basin received a grade of D for Flood Control & Risk Reduction. The Floodplain Population Change indicator in the Lower Mississippi received a D grade. The Levee Condition indicator received a D grade and the Building Elevation indicator received a D- grade.

Arkansas River & Red River Basin

The Arkansas River & Red River Basin received a grade of C- for Flood Control & Risk Reduction. The Floodplain Population Change indicator in the Arkansas & Red River basin received a C grade and was the highest in the watershed. The Levee Condition indicator received a D grade and the Building Elevation indicator received a C- grade.

Missouri River Basin

The Missouri River Basin received a C grade for Flood Control & Risk Reduction. The Floodplain Population Change indicator in the Missouri River Basin received a C grade. The Levee Condition indicator received a C grade and the Building Elevation indicator received a B grade, one of two basins with this highest grade.

What was measured and how it was evaluated

The Report Card measured trends in the number of people at risk, the condition of flood protection infrastructure and community preparedness.

  • Floodplain Population Change compared the change in number of people most at risk to flooding with the change in number of people living in a basin overall. The trend in number of people at risk was evaluated with U.S. Census data and the population within the 500-year floodplain.
  • Levee Condition reported the results of levee evaluations following inspections by the U.S. Army Corps of Engineers.
  • Building Elevation assessed the degree to which communities have adopted requirements to elevate structures above mapped flood levels. This is evaluated by the number of people living in communities that have adopted new, more protective elevation requirements for new structures. Evaluation of the number of people at risk and community preparedness was based on the proposed new federal flood protection standards.

Additional discussion

The results for Flood Control & Risk Reduction are an example of the difficulty the Report Card had in fully capturing data on certain issues in the watershed. Watershed experts and stakeholders recommended that the Report Card only measure flood risks throughout the entire watershed—but not flood damage prevented—because comprehensive and complete data could not be collected. This explains the poor grade for the Watershed only four years after the record 2011 Mississippi River flood, which resulted in minimal property damage and no loss of life.

A significant challenge for the future will be to maintain existing strategies that reduce flood damage—both structural and nonstructural—while at the same time responding to a changing climate and increased intensity rainfalls, rising sea level and coastal subsidence and erosion.

The AWI Report Card was developed over two years with significant amount of information and feedback from hundreds of experts and stakeholders throughout the watershed and nation. View a comprehensive Report Card technical paper that includes data sources, calculations and analysis.