Evaluation of Hydrodynamic Effects of Waterway Restoration on Estuarine Ecosystems in Charlotte Harbor, Florida
Charlotte Harbor is the second largest open water estuary in Florida, located along the Gulf Coast of Florida and at the mouth of the Myakka and Peace Rivers. The region serves as habitat to great biodiversity and wildlife and is also a popular location for boaters. North of the harbor, the Manchester Waterway supports a growing 1,800 home residential community interested in improving navigational access to open water. Three channel alignments have been proposed by the Manchester community for restoring flow conditions that were altered during development for the purpose of reducing travel time to open water, providing additional recreational opportunities, and with the potential to improve ecosystem health. In order to predict the resulting ecosystem impacts, we are evaluating the effects of restoration on estuarine hydrodynamics.
Flow Study
Estuaries are hydrodynamically complex for they are influenced by tidal forces, freshwater flows, salinity variations, and often intricate coastal land morphology. The Manchester Waterway is tidally influenced via connections to Tippecanoe Bay, Alligator Bay, and through the mangrove wetlands of the Charlotte Harbor Aquatic Preserve. In order to investigate present water flow conditions within the waterway, data loggers were installed in the field to gather time series data for water levels, temperature, and salinity.
Model Development
We are working closely with the Manchester community in developing a hydrodynamic model of the Manchester Waterway and Charlotte Harbor to evaluate different restoration scenarios. The model features an unstructured grid using the Delft3D FM Suite, populated by data collected in the field and from online databases. The fully calibrated and validated model will be modified to simulate the resulting flow for each of the three proposed alignments under the following conditions:
1. Present weather conditions
2. Sea level rise projections
3. Extreme weather events
4. Combination of sea level rise + extreme weather
A comparison of model evaluation results will be used to advise the Manchester Community about the potential impacts of different access options to Charlotte Harbor.
