Back to Top

FEH Phase 3

CEES is excited to announce the third phase of the Indiana Silver Jackets, Fluvial Erosion Hazard (FEH) Mitigation Program is underway.

The Indiana Fluvial Erosion Hazard (FEH) Mitigation Program was developed by the Indiana Silver Jackets to address the flood hazard caused by erosion of stream banks during a flood. From 2006 to 2008 Indiana experienced a series of floods throughout the state, loss of property and damage to infrastructure was high, and the repeated losses raised questions about how flood impacts could be reduced.

Despite significant efforts, flood losses have continued to increase in Indiana, and around the nation. One area of flood loss that has not been historically addressed is the fluvial erosion hazard, despite recognition in the early 1990s that fluvial erosion could account for as much as 60% of the loss and damage from some floods. Despite that recognition, most flood hazard mitigation programs are still focused on the inundation portion of the flood hazard. 

The Indiana Silver Jackets (ISJ), after investigating ongoing FEH mitigation programs in Vermont and New Hampshire, and considering recommendations from the Federal Emergency Management Agency (FEMA), decided to develop an Indiana Fluvial Hazard Mitigation Program.  The ISJ believes that the FEH program fills a critical gap in hazard planning and mitigation for Indiana.

An ISJ partner agency, The Indiana Office of Community and Rural Affairs (OCRA), was able to provide funding to initiate the FEH Program using Community Development Block Grant (CDBG) Supplemental Disaster Recovery Funds. Those funds were available for the 82 Indiana counties with federally declared disasters in 2008. The ISJ identified an initial FEH team consisting of the Center for Earth and Environmental Science (CEES), The Polis Center, and the U.S. Geological Survey (USGS), to start developing the Program.  

Phase I of the FEH program included development of science-based tools for identifying and assessing FEH for stream reaches, a series of presentations and workshops to introduce the program, and some example FEH mitigation protocols. Broad-based interest in the program quickly led to requests for a second phase of the program focusing on the application of the science and tools developed in the first phase to problem areas in specific Indiana counties and watersheds

Phase 2 is ongoing and continues to focus on the development of Regional FEH Hazard mapping that identifies the FEH zones along selected stream reaches in the 82 eligible counties. Phase 2 also expanded outreach and education activities, as well as risk assessment activities. Throughout the first two phases of the FEH Program, the team has continued to deliver a message of hazard avoidance, and that message has been successful. However, avoidance is not always an option.

There are numerous areas around the state where historic buildings, infrastructure, and legacy problems require that the FEH team explore and develop options for protecting structures and infrastructure while minimizing impacts to the stream system.

From the beginning of the FEH program, the team has been thinking about how to deal with areas where avoidance is not an option, so CEES is excited to announce that that Phase 3 of FEH Program is now underway. Phase 3 may prove to be the most challenging part of the program to date.

The map below shows a portion of Franklin County, Ind., with the FEH corridor illustrated to identify areas with an increased potential for damage from fluvial erosion. The simple message is “avoid these areas and you reduce your potential for experiencing property loss or damage as a result of fluvial erosion”. 

In areas that are developed, the question changes from how to avoid the fluvial erosion hazard, to, “What do I do if I have built in an area with the potential for fluvial erosion?" The following image shows this situation.

The stream in the above image is hard to even see, but the red circle is around a point bar, an area of sediment deposition in the stream channel, and the primary process of floodplain development. Point bars are normal, but the presence of so many large, unvegetated point bars suggests a high erosion rate. Recent studies suggest that streams meander more in response to high sediment loads, but this stream has no room to meander before it encounters roads and houses.

Clearly, avoiding the hazard by not developing near a mobile stream is the easiest way to minimize the property risk loss, but there are lots of areas around the state that were developed before we understood the dynamic nature of streams. In those areas, we need methods that help protect property and infrastructure – without simply moving the problem upstream or downstream.

In Phase 3 of the FEH Program the team is focusing on how to best mitigate the fluvial erosion hazard in areas where avoidance is not an option, and evaluate best methods for protecting structures and infrastructure, while striving to minimize impacts on the stream system.  The evaluation of erosion mitigation measures frequently will require engineering design and oversight, so the FEH team for Phase 3 will include representatives from Christopher B. Burke Engineering LLC (CBBEL).  

CBBEL staff have been closely involved with the Indiana Silver Jackets because of their leadership role in the Association of State Floodplain Managers (ASFPM), and the Indiana Association for Floodplain and Stormwater Management (INAFSM), and are a natural partner for the FEH team.  We are collectively very excited by this opportunity. Support and funding for the Indiana Fluvial Erosion Hazard Mitigation Program continues to be provided by the Indiana Office of Community and Rural Affairs.

Phase 3 may prove to be the most challenging, yet exciting, part of the FEH program to date!  Visit the FEH Program website (http://feh.iupui.edu/) for more information.

- RCB


Terminology:

  • Fluvial erosion: erosion caused by the interaction of flowing water through the natural channels of rivers and streams
  • Mitigation program: a plan to reduce the severity or seriousness of a problem 
  • Inundation: when a rising body of water overflows onto normally dry land

 

 

rcbarr's picture
ABOUT THE AUTHOR