High-resolution bathymetry and water quality dataset from an impounded lake in Northeast Florida, USA.

Guana Lake, in Northeast Florida, is an impounded estuarine lake suffering from excess organic matter accumulation due to nutrient inputs from the watershed and restricted tidal flushing. This article presents a high-resolution dataset of bathymetry and water-quality parameters collected in Guana Lake compiled to support hydrodynamic and water quality modeling efforts. Data were acquired over four survey days in April-May 2023 using a YSI HYCAT autonomous surface vehicle equipped with a multibeam Acoustic Doppler Current Profiler (ADCP) and a multi-parameter water quality sonde. The dataset comprises thousands of point measurements of water depth, bed elevation, and water quality metrics (temperature, salinity, dissolved oxygen, pH, turbidity, and chlorophyll-a) at high-frequency across the ∼10 km length of the Lake. This data has been polished and is provided along with derived spatial maps of bathymetry and water quality distributions. The data are valuable for calibrating and validating numerical models of the Guana Lake system and similar estuaries, and they offer insights into managing water control structures to mitigate eutrophication. This dataset can be reused to investigate nutrient dynamics under different flushing scenarios, to test the performance of autonomous survey platforms in shallow vegetated waters, and to inform best practices for estuarine water quality management.