Flooding and Floodplain Management

Flooding can happen anywhere it rains, and the City of Arnold has experienced many floods. Just because you haven’t experienced flooding in the past doesn’t mean you won’t in the future. Flood risk is determined by multiple factors, including rainfall, river flow on both the Mississippi and Meramec Rivers, topography, flood-control measures, and changes due to development. Understanding your risk and taking steps to reduce it can help you recover more quickly after a flood.

Flooding Information

Localized Flooding

Localized flooding can occur quickly during intense rain events. Residents can help minimize this risk by:

  • Properly disposing of waste materials such as leaves, grass clippings, branches, trash, concrete, and fireworks—never placing them in storm drains.
  • Ensuring that French drains and downspouts direct water away from building foundations.
  • Grading yards to slope away from foundations, preventing water from pooling.
  • Landscaping with native plants, which have deep root systems that absorb more water and reduce runoff.

Flash Flooding

Flash flooding can result from heavy rainfall in a short time. To stay safe during flood conditions:

  • Never drive through floodwater—”Turn Around, Don’t Drown.”
  • Keep children and pets away from floodwater.
  • Report flooded streets to Public Works at 636-282-2386.

Flood Resources and Information

Flood Insurance Information

Most standard homeowners and commercial property insurance policies do not cover flood damage. However, the City of Arnold participates in the Federal Emergency Management Agency (FEMA) National Flood Insurance Program (NFIP), making flood insurance available to residents.

Buildings located in a Special Flood Hazard Area (SFHA)—also known as the 100-year floodplain—must carry flood insurance if they have a federally backed mortgage. Flood insurance rates are set by FEMA and can be obtained through an insurance agent.

For details on flood insurance rates, requirements, and claims, visit:

Properties in a Designated Floodplain

FEMA publishes Flood Insurance Rate Maps (FIRMs) to identify SFHAs in communities. The City’s current FIRMs are publicly available, and residents can easily access them through the FEMA Flood Map Service Center. The City has also prepared step-by-step instructions to help residents locate their property on the maps.

If you believe your property has been incorrectly included in the SFHA, you can request a Letter of Map Amendment (LOMA) from FEMA. This typically requires:

Floodplain Development Regulations

Any construction or development activity within the SFHA—including earthwork, fill, excavation, or tree clearing—requires a Floodplain Development Permit before work begins.

For more information on the permit process and floodplain regulations, visit the associated weblinks or contact the City of Arnold Floodplain Administrator at 636-282-2378.