ADA developed a stormwater master plan for the City of Cape Coral. The work involved extensive updates and recalibration of an existing integrated groundwater/surface water model that was originally developed for the expansion of I-75 in northwest Lee County. Additional canals, new surveyed cross-sections, water control structures, irrigation, and pumping operations within the City were added to the model. As part of model development, extensive research on the City’s canal system was conducted, creating advanced working knowledge of the City of Cape Coral’s water control system.

The model was run for dry season and wet season conditions so that the impact of antecedent conditions can be evaluated for various design storms. Design storm simulations (2-, 5-, 10-, 25-, and 100-year events) were conducted to determine the level-of-service challenges associated with canal water control structure operations. Extent of road-flooding for each design storm was quantified using GIS tools. The miles of flooded roads within each Cape Coral drainage basin was used to prioritize the level of flooding within the basins. The project evaluated a range of flood control and water quality treatment alternatives, and ADA provided recommendations for gate operations, weirs, and culverts.

ADA developed an integrated surface water and groundwater model of the Lehigh Acres Municipal Services Improvement District (LA-MSID, formerly ECWCD) and surrounding areas of Lee County. As part of model calibration, gage data was evaluated for data inconsistencies and reported to LA-MSID. The model was used to evaluate various water resources improvement projects to reduce flooding risk, identify surface water storage opportunities in the basin that would attenuate freshwater runoff to estuaries, maximize groundwater recharge, and restore natural flow in wetlands areas. Two projects that utilized the upgraded model were the GS-10 Preliminary Engineering Analysis for Water Storage Area and Greenbriar Preserve Rehydration and the Hydrologic and Hydraulic Modeling for SR 82 Expansion.

GS-10 PRELIMINARY ENGINEERING ANALYSIS FOR WATER STORAGE AREA AND GREENBRIAR PRESERVE REHYDRATION.

ADA re-calibrated the MIKE SHE/MIKE 11 model of LA-MSID with focus on updating structure changes and the hydrogeological data with new information found in the Section 10 (GS-10) area. The goal was to develop the best possible operation for using GS-10 as a dry season water storage area and means of 1) increasing hydroperiods in Greenbriar Preserve and 2) reducing peak flows to the Caloosahatchee River. Several scenarios were developed and analyzed using the 2-year simulations to determine the best operation.

HYDROLOGIC AND HYDRAULIC MODELING FOR SR 82.

ADA assisted LA-MSID in evaluating whether their canals could accept FDOT (District 1) runoff without flood attenuation within the road right-of-way. This project utilized the existing LA-MSID Watershed Model; updating the model where possible and improving calibration. Design storms were run with the additional runoff from SR-82 as determined from external ICPR model runoff results. ADA provided extensive planning-level recommendations for managing the additional flows from SR-82. The recommendations help FDOT District 1 save money, which can then be provided to LA-MSID to fund their canal improvement projects

During the dry season, water levels in the Lower Hillsborough River have been dropping low enough to significantly increase salinity levels resulting in negative impacts on estuarine conditions, and ongoing public concern. In the past, Morris Bridge Sink has been used as an emergency water supply source and has now been identified as a key component of Southwest Florida’s plan for greater augmentation and recovery efforts. ADA has been tasked with establishing baseline conditions and continued monitoring of water levels, wetland vegetation and bathymetry, soil subsidence, and biological parameters in and around Morris Bridge Sink. Evaluating the potential impacts of pumping on wetlands near the sink is a key component of the consumptive use permit. Quarterly reports are submitted to the District and a report is presented to DEP annually.