How to Get a Floodplain Permit for Stream Restoration Projects
By Matt Barnes, PE, CFM
Completing stream restoration projects can be challenging and can get increasingly daunting when you need a floodplain permit. Floodplains are regulated at multiple levels of government to protect both public safety and natural resources. Balancing restoration and regulation is no simple task, so understanding how floodplain permitting works is critical to your project’s success.
Flood damage has prompted government agencies–at nearly all levels–to look for ways to protect against flooding. Large amounts of time and money are spent mapping and preparing for the dreaded “100-year flood.” Floodplain maps are valuable tools to estimate the possible extent of a flood but are only as good as the survey of existing conditions and analysis. If site conditions from a previously mapped restoration project change, most likely the floodplain maps will no longer be accurate.
Stream Restoration in the SFHA
In most cases, a restoration project that lies in a mapped floodplain will require a floodplain permit. The mapped floodplain is known as the Special Flood Hazard Area (SFHA). Permits are needed to show that the project will not increase flooding risk within the SFHA. In Montana, floodplain permitting begins at the community level (at the city or county government) and is overseen by the Montana Department of Natural Resources and Conservation (DNRC), which itself is overseen by the Federal Emergency Management Agency (FEMA). Montana’s local officials have broad discretion over restoration projects in the SFHA and can define requirements to show that a project will not increase flooding risk. Some communities have more extensive requirements than others.
There are various SFHA designations with varying levels of regulations. Local officials who administer permits in the SFHA are reviewed by DNRC and FEMA, which can determine flood insurance rates within that county or city.
Navigating the Stream Restoration Permitting Process
Conservation entities focused on restoring natural watersheds may feel that floodplain permit requirements are overly strict, but should remember that flooding is an important part of riparian ecosystems. For example, in some cases, floodplain regulations require that projects demonstrate a less than a 0.01 foot rise in the base flood elevation while others also require that the project has the ability to withstand the forces of a 100-year flood. This can seem like a non-starter to some conservation organizations because the cost to navigate and secure floodplain permits can sometimes skew the cost-benefit balance of a project.
At the same time, consulting with those who have experience with floodplain regulations, hydrologic and hydraulic analysis, and project design can open avenues that fit into a restoration project’s objectives and budget. Most local officials are happy to permit and support restoration projects so long as their regulations and policies are met.
So, for your next project that lies within a mapped SFHA, take extra steps to sit down with your local officials and knowledgeable engineers for a clear understanding of your permitting options. The information and time spent with these entities is the best bet to a successful permit application process and ultimately a project that helps restore our Montana watersheds.
Matt Barnes is a professional engineer and certified floodplain manager who works in Morrison-Maierle’s Helena office. A native Montanan, he enjoys being in the outdoors with his wife and son when not working in the outdoors as a specialist in natural resources engineering.
Technical review of this project provided by Luke Carlson, PE, CFM