From May 2017 to November 2019, the U.S. Geological Survey conducted bathymetric surveys of New York City's East of Hudson Reservoirs. Bathymetry data were collected at New Croton Reservoir during June 2017, July 2017, and October 2017. Depth data were collected primarily with a multibeam echosounder. Quality assurance points were measured with a single-beam echosounder. Water surface elevations were established using real-time kinematic (RTK) and static global navigation satellite system (GNSS) surveys and submersible pressure transducers. Measured sound velocity profiles were used to correct echosounder depth measurements for thermal stratification. Digital elevation models were created by combining the measured bathymetry data with lidar elevation data surrounding the reservoirs; gaps in the combined data were estimated (for example the tops of submerged islands) or interpolated. Files included in this Data Release include: grids (tiff format) of reservoir bed elevation, data ...

From May 2017 to November 2019, the U.S. Geological Survey conducted bathymetric surveys of New York City's East of Hudson Reservoirs. Bathymetry data were collected at Croton Falls Reservoir during August 2017, May 2018, and October 2019. Depth data were collected primarily with a multibeam echosounder; additional bathymetry points were measured using an acoustic Doppler current profiler (ADCP). Quality assurance points were measured with a single-beam echosounder. Water surface elevations were established using real-time kinematic (RTK) and static global navigation satellite system (GNSS) surveys and submersible pressure transducers. Measured sound velocity profiles were used to correct echosounder depth measurements for thermal stratification. Digital elevation models were created by combining the measured bathymetry data with lidar elevation data surrounding the reservoirs; gaps in the combined data were estimated (for example the tops of submerged islands) or interpolated. Files included in this Data Release include: grids (tiff format) of reservoir bed elevation, data source, and cell data standard deviation; shapefiles of elevation contours at a 2-foot interval and of single-beam echosounder quality assurance points; and text files (comma-separated value format) of elevation-area-capacity table, measured GNSS points, water surface elevation time series (tides) used to process echosounder data, measured sound velocity profiles, and average sound velocity profiles used to process echosounder data. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.