Nystrom, E.A. 2018 tabular digital data Reston, VA U.S. Geological Survey https://dx.doi.org/10.5066/F7J964HB https://doi.org/10.3133/sir20175064 Nystrom, E.A. 2018 Publication (Other) Scientific Investigations Report 2017-5064 Reston, VA U.S. Geological Survey https://doi.org/10.3133/sir20175064 From 2013 to 2015, bathymetric surveys of New York City’s six West of Hudson reservoirs (Ashokan, Cannonsville, Neversink, Pepacton, Rondout, and Schoharie) were performed to provide updated capacity tables and bathymetric maps. Depths were surveyed with a single-beam echo sounder and real-time kinematic global positioning system (RTK-GPS) along planned transects at predetermined intervals for each reservoir. A separate set of echo sounder data was collected along transects at oblique angles to the main transects for accuracy assessment. Field survey data was combined with water-surface elevations in a geographic information system to create three-dimensional surfaces representing reservoir-bed elevations in the form of triangulated irregular networks (TINs); the TINs were linearly enforced to better represent geomorphic features within the reservoirs. The linearly enforced TINs were used to create bathymetric maps of the reservoirs; contours were mapped at 2-foot intervals and capacity was calculated at 0.01-foot intervals. This dataset contains the elevation-area-capacity table. Data were obtained to map the bathymetry of the New York City West of Hudson drinking water reservoirs (Ashokan, Cannonsville, Neversink, Pepacton, Rondout, and Schoharie) to aid management of the reservoirs. 201409 ground condition Complete Not planned -74.455361218 -74.432155159 42.391823104 42.337659825 USGS Thesaurus bathymetry single-beam echo sounder GPS measurement USGS Metadata Identifier USGS:58069b69e4b0824b2d1d4285 Geographic Names Information System (GNIS) Schoharie Reservoir Schoharie County Greene County Delaware County none none Elizabeth Nystrom U.S. Geological Survey, New York Water Science Center Mailing and Physical

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Troy New York 12180 United States 518-285-5634 nystrom@usgs.gov In Cooperation with the New York City Department of Environmental Protection Environment as of Metadata Creation: Microsoft Windows 7 Version 6.1 (Build 7601) Service Pack 1; Esri Arcgeographic information system 10.3.1 (Build 4959) Service Pack N/A (Build N/A) Accuracy of data was assessed using a separate set of echo sounder points collected for the purpose of quality assurance. No formal logical accuracy tests were conducted Data set is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record carefully for additional details. No formal positional accuracy tests were conducted The vertical accuracy of reservoir-bed elevations was assessed using a separate set of echo sounder points collected for the purpose of quality assurance (QA). The QA dataset was collected and processed using the same methods as the main data set; QA points were compared to the nearest main point (within 3 feet [ft]). For Schoharie Reservoir, the median vertical difference between the points was 0.20 ft; the 95th percentile was 2.18 ft, and the NSSDA fundamental vertical accuracy calculated at the 95-percent confidence level was 3.04 ft (n = 1,298). Depth measurements were made using a 200kHz single beam echsounder during September 2013 to July 2015. Position data were collected using RTK-GPS. Echosounder and position data were processed in HYPACK, including integration of depth and position data, screening and removal of spikes and errors, correction of raw measured depth for speed of sound changes with depth due to thermal stratification, and calculation of reservoir-bed elevation from depth and water-surface elevation measurements. Data were then imported into a geographic information system for spatial processing. 20160922 Contours were generated at a 2-foot interval using the 3D Analyst tools in ARCMap. Linearly-enforced TINs were converted to 2-m cell-size rasters using natural neighbors, and then low-pass filtered to remove unrealistically sharp edges before creation of contours. 20160922 Attribute Table Table containing attribute information associated with the data set. Producer defined Elevation, ft NAVD88 Elevation, in feet above NAVD 88 Producer defined 995.08 1143.63 feet Elevation, ft DEP Datum Elevation, in feet above New York City Department of Environmental Protection Bureau of Water Supply Reservoir Datum Producer defined 996.18 1144.73 feet Depth below spillway, ft Depth below reservoir spillway crest elevation, in feet Producer defined -15 133.55 feet Area, ft2 2-dimensional surface area of reservoir at specified elevation, in square feet Producer defined 14130 59656000 feet Volume, gal Volume of reservoir at specified elevation, in gallons Producer defined 10540 25775000000 feet The entity and attribute information provided here describes the tabular data associated with the data set. Please review the detailed descriptions that are provided (the individual attribute descriptions) for information on the values that appear as fields/table entries of the data set. The entity and attribute information was generated by the individual and/or agency identified as the originator of the data set. Please review the rest of the metadata record for additional details and information. ScienceBase U.S. Geological Survey Mailing and Physical

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Denver CO 80225 United States 1-888-275-8747 sciencebase@usgs.gov Not for navigational use. Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty. Although these data have been processed successfully on a computer system at the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty. The USGS or the U.S. Government shall not be held liable for improper or incorrect use of the data described and/or contained herein. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. tabular digital data https://dx.doi.org/10.5066/F7J964HB None. No fees are applicable for obtaining the data set. 20200825 Elizabeth Nystrom U.S. Geological Survey, New York Water Science Center Hydrologist Mailing and Physical

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Troy New York 12180 United States 518-285-5634 nystrom@usgs.gov FGDC Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998