Abstract: Session D  11:50 am (Back to Session D)
Finding a Balance Between Stream Restoration Goals and Floodplain Regulations

Brett Long, PE
Baltimore, MD

Stream restoration projects typically require a floodplain regulatory review.  These regulations apply at the Federal (FEMA), State, and Local level and the purpose is to reduce hazards and costs to people and property.   These regulations can also drive stream restoration design requirements and approaches.   Most regulated floodplains require zero or minimal increase in floodplain elevations or extents for proposed design approval.  These regulatory drivers can significantly impact the restoration approach selection.  For instance, designers may need to choose between filling the existing channel to achieve floodplain reconnection or excavating the floodplain to reduce channel entrenchment due to potential floodplain impacts.  These restoration approaches can have significantly different costs and impacts on adjacent natural resources.  This existing versus proposed comparison of floodplains can be challenging to navigate since the existing reference condition is typically severely down-cut and hydraulically efficient channel as compared to a channel with a well-connected floodplain, which is typically a goal of stream restoration projects.  Also, project landowners typically understand the need to restore a channel but don’t understand potential floodplain impacts to their property and are reluctant to approve of any such changes.  Other regulatory drivers such as forest conservation laws can limit the implementation of certain restoration approaches such as floodplain excavation or reducing the bank slope due to associated tree impacts.  Some ordinances also require an easement on all floodplain areas to complete a restoration project, which requires a significant accommodation of the affected owner.  This presentation will describe various the floodplain regulations that impact stream restoration projects, how they influence restoration approach, and how an additional understanding of the impact of these regulations can lead to improved project success for all stakeholders.