Detroit regularly faces the hazards of flooding.  Flooding can happen anytime from the spring through the falleven winter if warmer than usual temperatures lead to rain rather than snowfall.  Flooding tends to be caused by heavy rain: the faster the rainwater reaches the river channel, the more likely it is to flood. Heavy rainfall can also overburden the sewer system.  Check out the resources below for important information on the dangers of flooding:

What is a floodplain?

A floodplain is an area adjacent to a river that is subject to flooding. 

FACT: Floods are the nations most common and costly natural disaster and cause millions of dollars in damage every year.

What can you do to help prevent flooding? 

Water conservation! During heavy rainfall and snow melt, cutting consumption can make a difference when storm water threatens to overwhelm the system. Flush less, delay doing laundry, taking showers or running the dishwasher.

FACT: Homeowners and renters insurance does not typically cover flood damage. 

Is flood insurance necessary?

Floods can happen anywhere — just one inch of floodwater can cause up to $25,000 in damage. Most homeowners insurance does not cover flood damage. Flood insurance is a separate policy that can cover buildings, the contents in a building, or both, so it is important to protect your most important financial assets — your home, your business, your possessions. Due to the likelihood of damage in a flood zone, your lender will generally require you to purchase a flood insurance policy.

Flood Insurance Rate Maps (FIRMs)

To determine a community's risk to flood hazards, FEMA performs an engineering study called a Flood Insurance Study (FIS). A FIS is a compilation and presentation of flood hazard areas along rivers, streams, coasts, and lakes within a community. The results of the FIS are shown on FEMA’s flood maps called Flood Insurance Rate Maps (FIRMs), and in the accompanying description of the study called an FIS report.

The Letter of Final Determination (LFD) is sent to the community to establish the FIRM and FIS report effective date and initiate a formal sixth-month period during which the community must adopt the FIRM and FIS report to become or remain eligible for participation in the National Flood Insurance Program (NFIP). The City of Detroit received our Letter of Final Determination on April 21, 2021. The formal six month period will end on October 21, 2021 and the Preliminary FIRM will become effective.

Preliminary FIRM data is available through FEMA's Flood Map Changes Viewer.

Community Rating System (CRS)

The City of Detroit through its Buildings, Safety Engineering and Environmental Department participates in the Federal Emergency Management Agency (FEMA) National Flood Insurance Program's (NFIP) Community Rating System (CRS).  

The National Flood Insurance Program's (NFIP) Community Rating System (CRS) is a voluntary incentive program that recognizes and encourages community floodplain management activities that exceed the minimum NFIP requirements. As a result, flood insurance premium rates are discounted.

The discounts will be applied automatically upon renewal of the flood insurance, so when it is time for the resident to renew their flood insurance, there will be a line item in the invoice from the insurance provider showing a 10% reduction due to community participation in the CRS.  

Environmental Affairs also maintains copies of Flood Insurance Rate Maps and Flood Insurance Studies for review.  For more information you can contact: Rickelle Winton (313)-224-4357

Jefferson Chalmers Prevention Plan

HISTORY: Jefferson Chalmers has been hit with major flooding events since the 1950s.


Preventing future catastrophic flooding is the primary goal. Ultimately, the goal is to work towards removing Jefferson Chalmers from the FEMA designated 100-year floodplain.

The U.S. Army Corps of Engineers, at the request of the City of Detroit, performed an initial Floodplain Management Study to identify effective long-term flood mitigation measures in the Jefferson Chalmers neighborhood.


 The City, in partnership with the U.S. Army Corps of Engineers, will perform additional studies to determine next best steps which are feasible and cost effective. There will be extensive community engagement around any proposed changes.