Estero-Imperial-Cocohatchee Integrated Flood Management Model

The Estero-Imperial-Cocohatchee (EIC) watershed located along the southwest coast of Florida has in recent years experienced a number of severe floods. The watershed is characterized by small topographic gradients and the southwestern area of the watershed is a large swamp area. The agricultural and urban development in the area has changed the original flow paths and due to insufficient conveyance capacity and under sized hydraulic structures, water levels in the area rise during long continuous periods of rainfall and floods the cities. An integrated hydrological/hydraulic model is being developed for the watershed with the main objective of simulating flooding. The model is based on an integrated, distributed hydrological model (MIKE SHE) encompassing overland flow, unsaturated zone flow and groundwater flow dynamically coupled to a river hydraulics model (MIKE 11). Although primarily used for flooding purposes, on event basis, the modeling system is versatile and may be used for continuous simulation investigating water resources aspects and environmental impact assessment on wetlands, e.g. Corkscrew Swamp. Compared to traditional flood models the integrated approach provides a physical representation of the flow processes rather than lumped rainfall-runoff modeling. In the EIC watershed with slowly increasing water levels the response of the entire hydrological system will affect the critical flood levels. The integrated model offers better possibilities for analyzing the causes and effects with respect to flood management. Furthermore the model will form a basis for setting up a surface water quality model, which will assist local governments and the South Florida Water Management district (SFWMD) assessing the water quality impacts of various management scenarios.