- E.1: Determining if your project is in the floodplain
- E.2: Documenting alternatives to locating a project in the floodplain
- E.3: Determining if your project alters a waterway
- E.4: How to Address Adverse Effects
- E.5: How to provide helpful and relevant support documentation
E.3: Determining if your project alters a waterway
In general, alteration to a waterway, water flow, or drainage way includes any action that would straighten, shorten, change, divert, or interfere with a drainage feature, including removal or addition of any material, or changing the course of a drainage feature. Some examples of waterway modification include: upgrading culverts, building swales, lining channels with rock or concrete, installing storm water drainage inlets, pumping water away from an area, or creation of a detention pond. Any project that involves improving drainage away from an area has the potential to affect a nearby waterway by increasing storm water runoff volume to that waterway. If your project involves any modification to existing drainage patterns, whether in or out of the floodplain, it has the potential to cause negative impacts to the floodplain downstream and possible cause greater damage than the proposed project will fix. The documentation needed for FEMA to make this determination is discussed in Section E.-4.
If you determine your project will alter a waterway, answer “yes” to Section E, Question 2 in the PDM Environmental/Historic Preservation Questions. It is also necessary to coordinate with relevant regulatory agencies to identify permitting requirements. These agencies include the United State Army Corps of Engineers (USACE), state water resource agency or the local water management district that has jurisdiction over the floodplain in your area. Some of this coordination may have already occurred as part of your efforts in completing PDM Section C of the Environmental and Historic
You should initiate contact with each of these agencies, requesting that they identify any permitting requirements for this project. Your communication, should:
- Indicate you are applying for federal aid, and you are requesting information about permitting requirements for your project.
- Include the name of the nearest city and the names of the county and state where the project will occur.
- Include a detailed description of the proposed project and how the project will alter the waterway.
- Include a 1:24,000 USGS topographic map marked with the project location.
- Include a copy of a current H&H study.
These agencies typically take at least 30 days to respond, so it is important to initiate your correspondence early. If you have not received an agency response as you are finalizing your application, it is a good idea to follow up with them to find out when you can expect it or see if you can get relevant permitting requirements over the telephone. Indicate the status of this correspondence in the project application, and scan and attach any letters you receive in response to your contact.
Once you receive a response from the regulatory agency, read it carefully to determine if any permitting will be required, or if the agency needs additional information. Responses from regulatory agencies can contain valuable information pertinent to your project, such as: conditions for permitting required environmental mitigation measures, or even suggestions for changes to the scope of work. Incorporate comments from your local floodplain manager directly into the PDM application. If floodplain mitigation is required, include that in your scope of work and as a line item in your cost estimate. Be sure to include in your scope of work and cost estimate any post-construction treatments needed to restore the site such as seeding, mulching, or planting. Additional project costs that are necessary for permitting conditions, mitigation, and site restoration are eligible expenses under PDM if they are identified in the scope of work and in the cost estimate.