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Flood Plain Information

Individuals interested in floodplain elevation, floodway, wetland, LPDA or past history of a property may contact;

Table 1: Contact information.
Contact Telephone

Julie Lomax Stormwater Administrator 

Kerry Behr   Stormwater Administrator 

630-493-8821

630-434-5489

Public Works 630-434-5460

What is a Flood Plain?

Floodplains are low lying land areas, usually bordering a water body, which floods during storm events. Federal Emergency Management Agency (FEMA) has delineated areas that have a 1% chance of flooding in any given year, commonly referred to as the "100-year flood plain" or the Special Flood Hazard Area (SFHA). Areas within the SFHA are regulated by FEMA.  Despite misperceptions that these areas should "only" flood once every 100 years, this is actually a statistical probability that translates to a 26% chance of flooding within the life of a 30-year mortgage and a 67% chance of flooding within a span of 100 years. Though the chance is low, it is possible to have more than one 100 year flood in a single year.

For more information on floodplains go to this link: https://pubs.usgs.gov/gip/106/pdf/100-year-flood-handout-042610.pdf

Why Protect Flood Plains?

Floodplains play a valuable role in providing natural and beneficial functions to Downers Grove. Undeveloped floodplains provide protection for buildings and properties, natural erosion & sediment control, and improved habitat for a variety of plants and animals.  Flood waters can spread over a large area providing benefits such as:

  • Slowing water down (higher speeds cause more damage)
  • Storing flood water that would otherwise be sent towards downstream properties
  • Allowing water to soak into the ground and recharge the groundwater aquifer
  • Moderating flood water temperatures, reducing the possibility of harmful effects on aquatic plants, fish, and animals

National Floodplain Insurance Program

Floods are fairly common events that cause the most destruction of all natural hazards, and more than three quarters of national emergency funding spent is due to flood events. Despite this, flooding is not included in a typical house insurance policy, and most insurance companies will not supply it. The primary supplier of flood insurance is provided through the National Flood Insurance Program (NFIP). As a condition of participation in the NFIP, floodplain management regulations must be enforced within the SFHA by local communities. These regulations restrict new construction within the SFHA, with the goal of significantly reducing the number of insurance claims over time. 

Is My Property Located in a Floodplain?

To determine whether your property is in or near a floodplain, visit the Village's Parcel Navigator map. Enter your address in the search box in the upper left hand corner. Go to the bottom of the page and click on the "layers" icon (it looks like a stack of papers) to open a box. Click on the "drainage" layer in that box to make the floodplain boundaries visible.

In June 2017 FEMA issued Updated Flood Plain Maps. These new maps have gone through an extended review period and are anticipated to be adopted in early 2019. Until they are officially adopted, the Village is required to use the higher flood elevation of two maps (existing or updated maps). You can check the updated floodplain locations on the Preliminary FEMA Changes June 2017 map.

Please note: the location of the floodplain on the maps is approximate and based on elevations. To determine the exact location of the floodplain on your property, a topographic survey is required. For more information contact the Village Stormwater Administrator at 630-434-5460.