Task 10 – Build Out Analysis

A future conditions scenario was developed based on future land use and population increase projections looking 20-years into the future. This scenario was simulated and compared to the existing conditions model output and represents conditions with and without flood mitigation projects. An analysis quantifying the amount of storage required to meet the flood mitigation goals for the entire study area was also conducted using the future conditions model developed. The objective of the evaluation was to determine how many acre-feet of water should be stored during the wet season to mitigate the additional flooding impacts resulting from increased imperviousness in each of the four areas. A model analysis of watershed discharge rates was performed followed with recommendations on basin allowable discharge rates. 

As with the increasing impervious surfaces, a scenario evaluating the 2040 conditions also included the effects of a rising sea level. Rising sea levels may impact the boundary conditions and tidal outfalls for several branches within Lee County. The NOAA tidal gauge at Naples Pier has been recording sea levels since 1965. Over the 54 year period of record, the data shows increasing sea levels with a linear sea level trend of 3.02 ± 0.45 mm/year based on monthly mean sea level according to NOAA (image below). This is equivalent to 0.99 feet over a 100 year period (NOAA, 2019).
NOAA Sea Level Trend for the Naples Pier (NOAA, 2019)