The Peculiar Hydrology of West-Central Florida’s Sandhill Wetlands, Ponds, and Lakes – Part 1: Physical & Chemical Evidence of Connectivity to a Regional Water-Supply Aquifer
Abstract The sandhill wetlands, ponds, and lakes of west-central Florida, USA, are an understudied, poorly understood variant of geographically isolated features. Their karst origin and xeric setting impart a characteristic ecohydrology, which is a function of their connectivity to a regional water-supply aquifer. This study describes their general hydrologic character and provides physical and chemical evidence of this connectivity. These findings advance fundamental understanding of sandhill wetland/water ecohydrology and endeavor to ensure their proper management and protection amidst increasing groundwater demands, ever-expanding development, and a changing climate.Water level elevations and/or geochemistry were compared for 12 wetlands, five ponds, two lakes, and 12 monitor wells (10 constructed in limestone, two in surficial sand) in west-central Florida. Hydrograph and regression analyses indicate widely ranging water levels for most features and wells that are similar in elevation and very highly correlated with each other (0.84<R2<0.99). Water geochemistry varies from rainwater to water in contact with limestone as a function of feature depth relative to the depth of the rainwater-limestone water mixing zone. Results suggest sandhill wetland/water features are surface water expressions of the underlying regional aquifer hydrology, distinguishing them from isolated features elsewhere and establishing them as a groundwater endmember along the hydrologic continuum.