Floodplain or Special Flood Hazard Area Management

Floodplain Management

Flooding happens when water bodies receive a greater volume of water than they can handle at one time. Floods are a natural part of the water cycle and can even be beneficial, however humans have affected the landscape drastically. By building on floodplains, draining wetlands, and controlling storm water, we have increased the likelihood of flooding and the extent of damage done by floodwaters such as erosion, loss of property, loss of frontage and loss of habitat.

What is a Floodplain or Special Flood Hazard Area (SFHA) and why is it important?

A river, stream, lake, or drain may on occasion overflow their banks and inundate adjacent land areas.  The land that is inundated by water is defined as a floodplain. In Michigan and nationally, the term floodplain has come to be commonly understood as the land area having a 1% chance of being inundated by the overflow of water in any given year. (This was previously referenced as a 100-year flood with many believing it would happen once every 100 years, but this is not true; it could happen more or less often.)

Floodplain areas are important natural features because they give time for sediment to settle out of floodwaters, thereby keeping it out of water bodies. Floodplains often support wildlife habitat and are frequently used by humans.

The Special Flood Hazard Area (SFHA) is that portion of land subject to inundation by a flood and/or flood-related erosion hazards.

Who creates the floodplain maps and designates their locations?

The Federal Emergency Management Agency (FEMA) is responsible for studying and updating floodplain maps throughout the country.  This information is found on the Federal Flood Insurance Rate Maps (FIRM). Within the maps, there are different designations based on the flood risk.

Where are the Floodplain or Special Flood Hazard Areas in the City of St. Joseph?

The floodplain or special flood hazard areas in the City of St. Joseph are found along and near Lake Michigan, the St. Joseph River, Paw Paw River, and in ravines.  FEMA has been working for a number of years to develop new FIRMs incorporating the threat of wave action along the Lake Michigan shoreline; we understand these maps may come to fruition between late 2023 and mid-2024.  In addition, a separate effort to re-map the St. Joseph River is underway.

What is the National Flood Insurance Program (NFIP)?

The National Flood Insurance Program (NFIP) is a Federal program enabling property owners in "participating communities" to purchase insurance protection against losses from flooding. The insurance is designed to provide an insurance alternative to disaster assistance to meet the escalating costs of repairing damage to building and their contents caused by flood.

The first Flood Insurance Study (FIS) was created in 1976 and the City’s first FIRM was published in 1978.  These documents were replaced by a new FIS and FIRMs in 2006.  The City of St. Joseph is a “participating community” in the National Flood Insurance Program.  

Why does flooding occur?

With increasing development in the floodplain, open spaces, and wetlands, our land has lost the ability to soak up rain. Areas that were once effective at storing excess flows are now being replaced by buildings and pavement that have made the land increasingly impervious. As a result, floods have become far larger and more frequent.

On occasion, flooding takes place along the St. Joseph River due to ice jams or ice dams occurring when chunks of ice clump together and block the flow of the river.  Ice jams are caused by melting snow and ice in the springtime.