Evaluating Effectiveness of Floodplain Reconnection Sites along the Lamoille Valley Rail Trail: A Blueprint for Future Rail/ River Projects

Lowering of abandoned rail beds to restore floodplain function is a river restoration practice with great potential, but which must also consider the multiple uses and functions of river and rail corridors, along with the potential impacts and benefits to adjacent infrastructure, life safety and health, and the environment. Using a two-dimensional hydraulic model and digital elevation model derived from an Unmanned Aerial Survey, the team will evaluate several alternatives for enhanced floodplain reconnection at a landowner-approved demonstration site on the Black Creek in Fairfield that would seek to restore 22 acres of floodplain by modifying 1,300 feet of embankment. The research team will quantify the effectiveness of each alternative for flood-water attenuation and sediment / nutrient storage over a range of design flows and evaluate potential impacts and benefits to adjacent infrastructure with potential changes in flood stage due to a reconnected floodplain. The completed research will also provide Vermont agencies with a protocol for identifying and prioritizing potential floodplain reconnection sites along river and rail corridors state-wide. Ten reconnection sites on the Lamoille Valley Rail Trail completed in 2006-2008 will be evaluated for their effectiveness.