Using empirical data and modeled scenarios of Everglades restoration to understand changes in coastal vulnerability to sea level rise

Coastal areas are increasingly vulnerable to the effects of sea level rise, and the coastal Everglades is no exception. The Comprehensive Everglades Restoration Plan (CERP) was launched in 2000 to restore the natural flow regime to the freshwater marshes of the Everglades. However, sea level rise has been affecting coastal habitats with increasing water levels and residence times of both salinity and marine nutrients. Here, we combined empirical data of water levels and sea levels with modeled CERP restoration scenarios. Water levels and fresh-to-marine head differences (FMHDs) were used as primary indicators of the vulnerability of the Everglades coastal areas to sea level rise and evaluate the relative benefits of restoration to these habitats. Four model scenarios were considered: a simulation of existing conditions baseline (ECB), full CERP implementation (CERP0), Central Everglades Planning Project with the Everglades Agricultural Area Reservoir (CEPPP), and a simulation of the natural/pre-drainage system scenario (NSM). Results demonstrated the differential vulnerability of coastal areas to sea level rise. The CEPPP restoration scenario achieved at least 60% and 30% of the full CERP freshwater and FMHD benefits in Shark River Slough, the largest freshwater flow-way in ENP, and Taylor Slough, the smaller flow-way in southeastern ENP, respectively. Hence, integration of FMHD metric in restoration efforts is essential to ensure restoration benefits extend beyond the freshwater marshes and improve coastal habitats.