Development of an Integrated Surface Water-Groundwater Model for Wetland Restoration and Habitat Evaluation in a Southwest Florida Basin Using MIKE SHE Part III: Application of the Regional Scale Model

The Picayune Strand Restoration Project (PSRP), sponsored by the South Florida Water Management District and the US Army Corps of Engineers, aims to restore 95 square miles of drained wetland areas in Collier County, Florida, to its natural condition. The over-drainage of this area because of land development activity in the 1950s has had several detrimental ecological and hydrologic impacts, including reduction of groundwater levels, increased freshwater inflow to critical estuaries, increase of invasive exotic vegetation and upland species, increased fire frequency, and loss of wildlife habitat connectivity. The restoration of the Picayune Strand is an extremely important element of the Comprehensive Everglades Restoration Plan (CERP) project, because it is located at the center of critical preserved areas that serve as wildlife habitat and because it serves as the headwaters of the Ten Thousand Islands estuary. To evaluate a restoration scenario proposed in an earlier study, two integrated surface water and groundwater models were developed for the area using the MIKE SHE/ MIKE 11 applications. One of these, described in Part I of this series of papers, is a hydrologic design tool (HDT) which addresses surface water hydraulic conditions that govern facility placement, sizing and design. The other is a planning and evaluation tool created to enable evaluation of watershed habitat and surface water responses. Calibration of the second application is described in Part II of this series, while this paper (Part III) focuses on the application of that model to evaluate the system. This application was unusually complex, partly because of the intimate interrelationships between surface and groundwater conditions in this region, and partly because of the physical scope of the project. The proposed restoration project includes i) construction of three high capacity pump stations with a total capacity of 4,700 cfs, ii) construction of a spreader canal network intended to distribute water to historic flow ways, iii) partial backfilling of the existing drainage network, and iv) removal of roads within the strand. Consequently, the model suite had to consider long-term responses of the surface water and groundwater system associated with rather extensive changes in drainage features. Results of the model application indicate the proposed plan is sufficient to restore the extent of historic flow ways and hydro-periods, and together with results from the earlier HDT demonstrates that it will not increase flooding in neighboring urban areas or otherwise affect private lands, transportation corridors or other critical built infrastructure elements. The paper discusses and contrasts the ways that transportation, wildlife, urban development and other perspectives were addressed and resolved using this suite of tools.