Home / Southeast Michigan Flood Risk Management Feasibility Study
Several cars lined the road submerged in water. Southeast Michigan floods after record rainstorm
Two people taking photo of submerged car. Southeast Michigan floods after record rainstorm
Three people in a boat in a flooded neighborhood. Southeast Michigan floods after record rainstorm
Two people walking right to left in a flooded neighborhood. Southeast Michigan floods after record rainstorm
Flooded area with a 15 miles per hour speed limit sign. Flooded neighborhood in Southeast Michigan
Neutral shot of people listening to soldier standing at podium in a conference room. USACE Detroit District leadership addresses stakeholders
Group having a discussion around a table. Flood study planning charrette
Man pointing at map with others gathered around, listening. Flood study planning charrette
Woman addresses crowd at a podium Congresswoman Dingell shares constituents' experience after storm
Woman speaking to an audience. Congresswoman Tlaib recounts flood in Southeast Michigan
Several members pose for a photo standing behind a table with a banner that reads, "GLWA, Great Lakes Water Authority." USACE and GLWA signs cost sharing agreement for study

Study Overview

Congress Authorizes Flood Risk Management Study for Southeast Michigan

This study is authorized in the 2022 Water Resources Development Act (WRDA) which allows the U.S. Army Corps of Engineers (USACE) to work on flood risk management in Southeast Michigan.

In WRDA 2022, Congress expanded USACE’s authority to study comprehensive flood risk management. This authority may help communities better manage flood risk in urban areas.

Non-Federal Sponsor

Following legislation passed in 1986, congress required USACE to partner with a non-Federal sponsor to develop feasibility studies. This legislation identified cost-sharing provisions as well as key roles and responsibilities for sponsors to play in project planning and design. The sponsor must contribute 50% of the study costs that exceed $100,000, and the sponsor plays a key role in defining the water resources problems, objectives, and study scope.

The non-Federal sponsor for this study is the Great Lakes Water Authority (GLWA). GLWA is the regional wastewater utility for southeast Michigan, providing wastewater services for nearly 30% of Michigan. GLWA has requested USACE to study comprehensive flood risk in southeast Michigan, to address flooding issues including:

  • Flooding caused by heavy rainfall
  • Fluctuating water levels in the Great Lakes and connecting waterways
  • Impacts from climate change

About the Study

Southeast Michigan has experienced repeated, widespread flooding for decades and has received five federal disaster declarations due to flooding since 2000. Flooding in the region has resulted from more intense and frequent rainfall, storms, and fluctuating Great Lakes and connecting corridor water levels. This flooding causes damage to structures and infrastructure, impacts the local, regional, and national economy, and creates social hardship for Michiganders. The transportation system includes numerous below-grade highways, which require pumps to clear streets during rain events. During large storms, these highways can be closed for days at a time. Basement backups are increasingly common in portions of the region during large storms, where local or downstream surcharging leads to recurring household flooding.

According to the Federal Emergency Management Agency (FEMA), there have been more than 260,000 flooding-related Individual Assistance claims in the study area since 2004. 97% of the claims in Detroit occur outside FEMA’s Special Flood Hazard Area, highlighting a significant urban flooding issue in the region. FEMA has also reported more than 40,000 high-risk flood properties in the study area since 1978.

These high-risk flood properties have experienced either:

  1. Individual Assistance (IA) Repetitive Loss, where a structure has had at least two IA FEMA inspections showing some level of flood water in the structure, including basements/crawlspaces, or
  2. IA Severe Repetitive Loss, where a structure has had at least four IA FEMA inspections showing some level of flood water in the structure, including basements/crawlspaces, or
  3. National Flood Insurance Program (NFIP) Repetitive Loss, where a FEMA NFIP-insured structure has had at least two paid flood losses of more than $1,000 each in any 10-year period since 1978, or
  4. NFIP Severe Repetitive Loss, where
    1. Four or more $5,000+ claim payments were made, or
    2. Two or more claim payments were made cumulatively exceeding the structure’s value (before flood damage).

Explore FEMA’s Historical Flood Risk and Costs tool to better understand historical flood impact in your county.

In August 2014, the region experienced record-breaking rainfall—more than six inches in four hours—resulting in a federal disaster declaration. Another federal disaster declaration was issued after more than six inches of rain fell within 24 hours on June 26, 2021. After the June 2021 floods, the Great Lakes Water Authority worked with congressional representatives to authorize the study under the WRDA 2022 legislation. In 2024, USACE received an initial $500,000 to begin the study.

Our Shared Vision

Stakeholders at the Southeast Michigan Flood Risk Management Study charretteTo foster a shared vision for the Southeast Michigan Flood Risk Management Study, the USACE Detroit District and the Great Lakes Water Authority (GLWA) launched the study with a planning charrette that included local, regional, state, and federal government stakeholders in Detroit from Sept. 16-18, 2024. The group developed a preliminary shared vision, which will continue to evolve as more stakeholders are engaged. 

Widespread flooding in Southeast Michigan has led to significant economic burdens and social hardships. Urban, riverine, and coastal flooding in the region has increased risks to public safety and health, caused property damage, disrupted critical infrastructure, and led to economic losses for residents, businesses, industries, and local and state governments. The Southeast Michigan Flood Risk Management Study will investigate options to reduce risks to human life and lessen economic, industrial, and commercial flood damage in the study area over the period of analysis. Opportunities exist to improve community and infrastructure resilience, water quality and associated public health outcomes, public awareness of flood risk management and preparedness, and the overall quality of life in Southeast Michigan.

Study Area

Map of study area depicted by a green outlineThe study area includes the Clinton River, Lake St. Clair, Rouge River, and Detroit River watersheds, as well as the Great Lakes Water Authority’s separated and combined sewer service area.

Use the interactive map below to engage with data in the study area

Scope, Schedule, and Budget

The key components of the study scope are investigating the pluvial (rainfall-driven) and fluvial (riverine/coastal-driven) flooding analysis, a full array of alternatives and comprehensive benefit considerations, NEPA compliance, and community outreach.

The study team is requesting an exception to the schedule and funding requirements established by Section 1001 of the Water Resources Development Act of 2014. The exception would allow for exceeding the three-year timeline and $3 million federal cost limit, given the scale and complexity of the project. Once a schedule and budget are approved by the Assistant Secretary for the Army of Civil Works, it will be posted. The bulk of the study time and funding will be allocated to the alternative evaluation and analysis phase. This phase will include developing 2D hydraulic and hydrologic modeling, creating various economic models, preliminary engineering and design of potential alternatives, and analyzing environmental, historical, and cultural resources as well as community considerations.

Interactive Map

Plan Formulation

The Six-Step Planning Process

The USACE planning process is a structured approach to problem-solving. A six-step planning process is used iteratively, allowing steps to be repeated as needed for better problem understanding. Planning is performed by an interdisciplinary group of engineers, scientists, economists, and others. Stakeholder and public engagement play a major role, and public input in the decision-making process is valued.

Step 1: Identify Problems and Opportunities

Study's Draft Problems:

Problem 1: Recurring urban and riverine flooding has caused significant economic damage and social hardship throughout the study area as described by the following:

  1. Damage to residential and commercial structures. According to the Federal Emergency Management Agency (FEMA), there have been more than 260,000 flooding-related Individual Assistance claims in the study area since 2004, and there are over 40,000 structures in the study area that are considered high risk flood properties (HRFP). These HRFP structures have suffered repeated flood loss. (see HRFP definitions under the Study Overview section in the About the Study tab above)

  2. Impacts to commerce and industry. Road closures associated with flood inundation and associated property and structural damage has impacted the automotive industry including suppliers and assembly plants around the Midwest region. Flooding has also impacted other important sectors of the economy through direct (e.g. inundation) and indirect (e.g. decreased access, lost revenue) damages.

  3. Damage to infrastructure. Flooding in the study area has caused significant damage to infrastructure throughout the study area, including wastewater and water utilities, power, and pumping stations.

  4. Traffic user delays. Economic impacts of flooding and associated damage extend to user delays and associated costs from interstate and road closures.

Problem 2: Urban flood and riverine flood inundation of structures and infrastructure increases life safety risk throughout the study area as described by the following:​

  1. Loss of life due to inundated occupied vehicles. Flooding-related injuries and fatalities in the study area have occurred due to the inundation of occupied vehicles.

  2. Elevated life safety risk to occupied structures. Elevated life safety risk is associated with direct inundation of structures within the study area and may put the population living in or utilizing said structures at risk of losing their life.

  3. Inundation of critical infrastructure and structures. Inundation of critical infrastructure within the study area, including infrastructure associated with emergency services, first responders, critical utilities (e.g. power, roads, combined sewer systems), can also result in increased life safety risk.

  4. Isolation of communities. Inundation and damage to roadways reduces access to population centers, reduces access to critical facilities and services, and leads to isolated individuals and communities during and following flood events. This leads to increased life safety risk, especially the potential for indirect life loss.

Study's Draft Objectives and Opportunities

Objectives​

  • Life Safety. Reduce risks to human life associated with inundation of structures, critical infrastructure, and critical facilities (e.g., roads) in the study area over the 50-year period of analysis.

  • Industry and Commerce. Reduce economic damage to industries (e.g. automotive) and commerce resulting from urban and riverine flooding throughout the study area over the 50-year period of analysis.

  • Economic Damages. Reduce flood damage to property (residential, non-residential, critical facilities) and infrastructure (e.g. roads, water and wastewater utilities, power and pumping stations) in the study area over the 50-year period of analysis.

Opportunities

  • Resiliency. Increase community and infrastructure resiliency, the sustained ability to adapt and recover from significant flooding events, in the study area over the 50-year period of analysis.

  • Transportation. Reduce flooding-related impacts to transportation infrastructure in the study area over the 50-year period of analysis.

  • Quality of Life. Improve quality of life for individuals living within the study area impacted by flood inundation and associated damages.

  • Water Quality. Improve water quality and associated public health outcomes in the study area.

  • Public Education. Increase public awareness of flood risk management and preparedness for flood events through community education.

Step 2: Inventorying and Forecasting Conditions

An inventory of key resources within the study area and a forecast of how these resources could change in the future is being developed. The study team is currently in the data gathering and scoping phase. If you have past studies, models, or other information you think may be useful, get in touch with us.

Step 3: Formulating Alternative Plans

The study team, in collaboration with local government, tribal nations, and the public, will identify an array of alternatives, or potential solutions, for managing flood risk in the region. When initial alternatives are identified, they will be added to the online map.  

Step 4: Evaluating Alternative Plans

The performance of and effects of alternative plans will be evaluated, both quantitively and qualitatively, by comparing without project and with project conditions. The study team will evaluate the comprehensive benefits of each alternative – economic, environmental, and social impacts will be considered.

Step 5: Comparing Alternative Plans

Comparing alternative plans will reveal the plan expected to produce the greatest net benefits (benefits – costs) from among the alternatives considered.

Step 6: Selecting a Plan

A recommended plan will be identified based on the results of steps 4 and 5. That plan will be described in the draft feasibility report that goes out for public and agency review. Eventually, the study will result in a feasibility report signed by the Chief of Engineers and sent to congress for additional project authorization and appropriation to implement the recommended plan.

Non-Federal Sponsor

Great Lakes Water Authority Logo.png

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