2015 has been a great year for the restoration program at Friends of the Rappahannock. We have partnered with countless schools, businesses, non-profits, and local governments to install a wide range of projects throughout the watershed. In the coming months, FOR seeks to install a new and innovative stormwater best management practice (bmp) in the Rappahannock Canal. This pilot project will include the construction and installation of two practices called Floating Treatment Wetlands (FTW).
What is a Floating Treatment Wetland?
FTWs are constructed manmade ecosystems designed to mimic natural wetlands. FTWs are designed using floating rafts that support wetland obligate plant species. FTWs float on a wet pond water surface- or in this case canal, and can be used to improve water quality by filtering, consuming, or breaking down pollutants (e.g., nutrients, sediment, and metals) from the water.
What do they Do?
FTWs can provide a variety of ecosystem services including fish and wildlife habitat, beautification, and water quality improvements. In our pilot project, FTWs are designed to increase the ability of a previously installed stormwater bmp to remove target nutrients Nitrogen and Phosphorus by absorbing nutrients through complex root systems. These target nutrients are of concern in the Rappahannock River and throughout the Chesapeake Bay as a part of the Total Maximum Daily Load (TMDL) which targets pollutants negatively impacting the Chesapeake Bay and outlines strategies to mitigate these pollutants.
How do they Work?
FTWs float on the water’s surface while allowing the plants it supports to have submerged root systems. These plants directly remove nutrients through a process called Biological Uptake. Within the root systems of the wetland plants, microorganisms thrive and are able to break down and consume nutrients and organic matter through a process known as Microbial Decomposition. Finally, the large root systems also act as a filter for sediments and associated pollutants.
FOR Pilot Project
In winter of 2014 FOR approached the City of Fredericksburg to discuss the FTWs and the possibility of adding one to an existing stormwater pond in the City limits. We then reached out to the U.S. Army Corps of Engineers and successfully obtained a Nationwide 5 permit for the project. In the spring of 2015, FOR reached out to a unique classroom at the University of Mary Washington to find a student to lead the project. We were so fortunate to find Meredith Palumbo who called dibbs on the project that day! Meredith is a junior biology/environmental science major. She was able to research FTW, develop a design for a 100 square foot FTW, create and source materials for the project, and even find funding! In Fall 2015 she brought a group of students to the FOR headquarters and we built two 100 square foot FTW. Our designs chose to use native plugs including pickerelweed, juncus, carex stricta, and cardinal flower. We plan to monitor the success of these two practices this spring with the hopes of adding more to the canal and placing additional FTW in stormwater ponds throughout the City of Fredericksburg.
Generous funding for this project has been awarded by the CLIF Bar Family Foundation.