Draa Field Pond is an approximately 3.5-acre stormwater detention pond located in Titusville, Florida. While the pond was originally planted with littoral zone vegetation when first constructed, over time nuisance aquatic vegetation has proliferated within the pond and choked out most of the desirable vegetation. Additionally, excessive nuisance aquatic vegetation within the pond results in the internal loading of nutrients through the process of vegetation senescence and decomposition. This process of nutrient loading is particularly undesirable within the pond due to its connection with the Indian River Lagoon (IRL).
ECT was retained by the City of Titusville to manage the mechanical harvesting of vegetation from the pond and evaluate the nutrient reduction benefits of the harvesting activities (project). To accomplish this, ECT conducted biomass sampling within the pond and obtained high-resolution aerial imagery via drone. Using the ground-truthed biomass data, ECT mapped vegetation communities within the pond to characterize species coverage for nutrient removal calculations. This approach provided a significant cost savings as opposed to conducting a more labor-intensive biomass survey. ECT also performed a statistical evaluation of plant tissue nutrient data to determine whether average or median concentrations were representative of the plant community as a whole. The project determined that vegetation harvesting in the pond removed approximately 98.68 pounds of phosphorus and 785.56 pounds of nitrogen that would otherwise potentially reach the IRL.