Metadata for this geodatabase describe datasets included in the bathymetric study completed for Lago Patillas in August 2019. The U.S. Geological Survey, in cooperation with the Puerto Rico Electric Power Authority, carried out a bathymetric survey to update stage-volume table for Lago Patillas and to generate a bathymetric map. Water-depth data were collected using a bathymetric data collection system coupling a digital depth sounder (single-beam fathometer) and a high-quality antenna. Raw water-depth data collected in August 2019 were referenced to the water-surface elevation at the time of the reservoir survey and were merged with light detection and ranging (lidar) cloud data collected in 2016–17. The dataset included in this geodatabase consists of the following: (1) data points (XYZ) collected in the 2019 bathymetric survey through a fathometer and graduated hand-held rod measurements; (2) 2016–17 lidar-cloud data; (3) boundary of Lago Patillas at an elevation of 67.55 meters above the Puerto Rico Vertical Datum of 2002; (4) a digital terrain model created from data stored in the geodatabase; and, (5) a stage-volume table calculated at 1.0-meter stage intervals from the terrain model.