Planning for Floating Treatment Wetlands Project
The planning phase for the Floating Treatment Wetlands (FTWs) Project will be coming to a close in the next few months. The purpose of the project is to determine the usefulness of incorporating FTWs into existing basins within Harris County, which are meant to aid in stormwater treatment.
The experiment is currently aimed at being implemented at the Lawson basin, one of two areas planned to receive the FTWs. Following the plan’s completion in April 2022, construction bidding will follow, with construction beginning in June 2022. Following the implementation of the wetlands, the Flood Control District will monitor the wetlands for a period of two years while analyzing the benefits the project has brought to the basin and the surrounding areas.
As of February 2022, Phase 1 of the project is 90 percent complete, with the remaining percentage consisting of wrapping up the Island Material Type recommendations (e.g. this informs the Flood Control District which islands to purchase in Phase 2: Construction and Installation, Monitoring), completing preparatory data analysis, and preparing planning documents for the anchors and monitoring stations to be installed.
Phase 1 of the project has been focused on the incorporation of performance standards that should be considered when determining the best type of FTW for use in stormwater retention systems within Harris County, which include cost-effectiveness, water quality enhancement achievement, vegetation features, constructibility, and wildlife habitat services provided. Additional considerations during this period have included anchoring techniques, aesthetic value, maintenance requirements, physical stress, and longevity.
FTWs are an inventive technology that utilizes water quality enhancement processes known to occur within natural floating wetlands. They incorporate emergent wetland plants onto floating rafts. Such a design, in theory, provides numerous benefits for the treatment of stormwater, including being able to treat storm water under highly variable water depths caused by rapid changes in storm water runoff that would normally erode or flood shorelines and areas containing submerged and emergent plant communities. Employing FTWs in stormwater retention basins, allows for the opportunity to improve the quality of stormwater released back into waterways.