An integrated environment model for a constructed wetland – Hydrodynamics and transport processes

• A comprehensive 3D model has been developed for constructed wetlands.
• The model can simulate hydrodynamics and transport processes in the wetland.
• Complete SAV and EAV formulations are included in the model.
• The model is calibrated and verified with measured data.
• The model is applied to support STA operation and management.

Constructed wetlands (CW) have become a popular technology for treating urban and agricultural stormwater runoff. In South Florida, Stormwater Treatment Areas (STAs) have been built to reduce phosphorus (P) concentrations in runoff from agriculture and other sources, including Lake Okeechobee discharges, prior to delivery to the Everglades Protection Area. The scale of this constructed wetland project is unprecedented in terms of size, cost, and scientific challenges. Models/tools are needed to provide detailed spatial and temporal information to optimize the P removal efficiency and to predict the dynamic response of STAs under a variety of management conditions. The Lake Okeechobee Environment Model (LOEM) developed for Lake Okeechobee has been enhanced to simulate hydrodynamics and transport processes in the wetland environment. The flow resistance caused by Submerged Aquatic Vegetation (SAV) and Emergent Aquatic Vegetation (EAV) is included in the LOEM-CW. The LOEM-CW is calibrated and validated with 6 years of measured data (2008–2013) at different locations in STA-3/4 Cells 3A and 3B. Through graphic and statistical comparisons, it is shown that the model simulated stage, flow velocity, water temperature, and total suspended solid (TSS) in the study area reasonably well. The LOEM-CW is poised to serve as a powerful tool in wetland management and STA operation.