Tyler V. King 20260226 tabular digital data USGS ScienceBase USGS ScienceBase https://doi.org/10.5066/P13N85SW There are multiple systems for mapping waterbodies within the conterminous United States. Prominent among them are the "High Resolution" and "Version 2" editions of the National Hydrography Dataset Plus. The National Hydrography Dataset Plus High Resolution (NHDPlusHR, Moore and others, 2025) uses "Permanent Identifiers" to identify waterbodies, while the National Hydrography Dataset Plus Version 2 (NHDPlusV2, McKay and others, 2012) uses "COMID" for the same purpose. While waterbodies may exist in both datasets, their spatial representation can vary, and there can be many-to-one relationships in both directions. One waterbody polygon in the NHDPlusHR may overlap with multiple waterbody polygons in the NHDPlusV2 and vice verse. The Hydrolakes dataset (Messager and others, 2016) is another system for mapping waterbodies. This system uses "Hylake Identifiers" to differentiate spatially explicit representations of waterbodies. This datarelease provides a simple method to look up waterbody identifiers across these three datasets. In each datafile overlapping waterbodies were identified and the respective waterbodies identifiers are listed. The datafiles also include the surface area for each data source and the surface area that is shared between data sources. Three of the files represent pairs of data sources. The fourth file represents the areas that are shared across all three datasets. There is also a data dictionary file that contains definitions for every column in the datafiles. Files: - NHDPlusHR_NHDPlusV2.csv: Data file of lookup table between Permanent Identifier and COMID - NHDPlusHR_Hydrolakes.csvL: Data file of lookup table between Permanent Identifier and HylakeID - NHDPlusV2_Hydrolakes.csv: Data file of lookup table between Permanent Identifier and HylakeID - NHDPlusHR_NHDPlusV2_Hydrolakes.csv: Data file of lookup table between Permanent Identifier and COMID and HylakeID - Data_Dictionary_Waterbody_Crosswalk.csv: Metadata file with definitions for columns in the data files. NHDPlusHR: Moore, R., McKay, L., Rea, A., Bondelid, T., Price, C., Dewald, T., & Hayes, L. (2025). User’s guide for the National Hydrography Dataset Plus High Resolution (NHDPlus HR) (Report Nos. 2025–5031; Scientific Investigations Report, p. 78). USGS Publications Warehouse. https://doi.org/10.3133/sir20255031 NHDPlusV2: McKay, L., Bondelid, T., Dewald, T., Johnston, J., Moore, R., and Rea, A., 2012 “NHDPlus Version 2: User Guide” Hydrolakes: Messager, M. L., Lehner, B., Grill, G., Nedeva, I., & Schmitt, O. (2016). Estimating the volume and age of water stored in global lakes using a geo-statistical approach. Nature Communications, 7(1), 13603. https://doi.org/10.1038/ncomms13603 Provide simple lookup tables between waterbody identifiers across common hydrographic indexing systems for waterbodies in the Conterminous United States. 2015 2024 observed Complete Annually -124.8047 -66.9500 49.3840 24.8466 ISO 19115 Topic Category inlandWaters environment climatologyMeteorologyAtmosphere USGS Thesaurus Rivers Hydrology Water Resources Waterbodies Hydrography USGS Metadata Identifier USGS:692f2402d4be026ff273aa53 None CONUS Conterminous United States None. Please see 'Distribution Info' for details. The USGS Water Mission Area - Hydrologic Remote Sensing Branch was responsible for production of these data. All products developed from these data should cite this data release (https://doi.org/10.5066/P13N85SW). U.S Geological Survey Tyler V King Supervisory Research Hydrologist mailing and physical

230 Collins Rd

Boise Idaho 83702 US 1-208-387-1352 tvking@usgs.gov Please acknowledge the USGS Hydrologic Remote Sensing Branch and cite the USGS data release as the source for all products developed from these data. operating system: Windows 11 software: R 4.5.2 dependencies: - terra = 1.8-80 - nhdplusTools = 1.4.0 - stringr = 1.6.0 - sbtools = 1.4.1 Luke A Winslow Scott Chamberlain Alison P Appling Jordan S Read 2016 publication https://cran.r-project.org/web/packages/sbtools CRAN https://journal.r-project.org/articles/RJ-2016-029/index.html No formal attribute accuracy tests were conducted. Spot checks were conducted to ensure that final identifiers mapped to the same features in the initial datasets. Values were checked to confirm that the computed overlapping areas were smaller than the areas of the initial datasets. This dataset includes waterbodies within the NHDPlusHR, NDHPlusV2, and Hydrolakes datasets that intersect each other. Identifiers from each data source that are not included in these files indicate that there is no spatial overlap for that waterbody. A formal accuracy assessment of the horizontal positional information in the data set has not been conducted. A formal accuracy assessment of the vertical positional information is not applicable as there is no vertical position information in this dataset. Richard B. Moore Lucinda D. McKay Alan H. Rea Timothy R. Bondelid Curtis V. Price Thomas G. Dewald Laura Hayes 2025 vector digital data https://pubs.usgs.gov/publication/sir20255031 U.S. Geological Survey https://doi.org/10.3133/sir20255031 Digital and/or Hardcopy 2025 publication date NHDPlusHR Provided NHDPlusHR waterbody polygons. Lucinda D. McKay Timothy R. Bondelid Thomas G. Dewald Craig Johnston Richard Moore Alan H. Rea 2012 vector digital data https://www.epa.gov/waterdata/get-nhdplus-national-hydrography-dataset-plus-data U.S Environmental Protection Agency https://www.epa.gov/waterdata/get-nhdplus-national-hydrography-dataset-plus-data Digital and/or Hardcopy 2012 publication date NHDPlusV2 Provided NHDPlusV2 polygons Mathis Loïc Messager Bernhard Lehner Günther Grill Irena Nedeva Oliver Schmitt 2016 vector digital data https://www.hydrosheds.org/products/hydrolakes HydroSHEDS https://doi.org/10.1038/ncomms13603 Digital and/or Hardcopy 2016 publication date Hydrolakes Provides Hydrolake polygons. U.S. Geological Survey 2025 vector digital data https://prd-tnm.s3.amazonaws.com/index.html?prefix=StagedProducts/Hydrography/WBD/National/ U.S. Geological Survey https://www.usgs.gov/national-hydrography/access-national-hydrography-products Digital and/or Hardcopy 2025 publication date WBD Provides HUC4 watershed boundaries Data download: Watershed boundaries were downloaded for the continuous United States from https://www.usgs.gov/national-hydrography/access-national-hydrography-products. The NHDPlusV2 snapshots were downloaded for the contiguous United States (units 01 through 18) from https://www.epa.gov/waterdata/get-nhdplus-national-hydrography-dataset-plus-data#Download. NHDPlusHR data were downloaded for each level 4 hydrologic unit code (HUC4) in the Continuous United States using the download_nhdplushr function in the sbtools package in R. All geospatial data was converted to a common coordinate reference system (EPSG:4326). NHDPlusHR NHDPlusV2 Hydrolakes WBD 20251201 Tyler V King USGS - WATER Supervisory Research Hydrologist mailing and physical

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Boise Idaho 83702 US 208-387-1352 tvking@usgs.gov Spatial Intersection NHDPlusHR and NHDPlusV2. For each HUC4: 1. the NHDPlusV2 dataset was subset to the watershed boundary, 2. the intersections between NHDPlusHR and NHDPlusV2 were identified using the intersect function in the Terra package in R, 3. the overlapping area between the NHDPlusHR and NHDPlusV2 polygons were computed using the expanse function in the Terra package in R, 4. the results of the NHDPlusHR to NHDPlusV2 intersection are stored in intermediate files, Intermediate files were appended together to produce NHDPlusHR_NHDPlusV2.csv 20251201 Spatial Intersection NHDPlusHR and Hydrolakes. For each HUC4: 1. the Hydrolakes dataset was subset to the watershed boundary, 2. the intersections between NHDPlusHR and Hydrolakes were identified using the intersect function in the Terra package in R, 3. the overlapping area between the NHDPlusHR and Hydrolakes polygons were computed using the expanse function in the Terra package in R, 4. the results of the NHDPlusHR to Hydrolakes intersection are stored in intermediate files, Intermediate files were appended together to produce NHDPlusHR_Hydrolakes.csv 20251201 Spatial Intersection NHDPlusV2 and Hydrolakes. For each HUC4: 1. the Hydrolakes and NHDPlusV2 dataset was subset to the watershed boundary, 2. the intersections between NHDPlusV2 and Hydrolakes were identified using the intersect function in the Terra package in R, 3. the overlapping area between the NHDPlusV2 and Hydrolakes polygons were computed using the expanse function in the Terra package in R, 4. the results of the NHDPlusV2 to Hydrolakes intersection are stored in intermediate files, Intermediate files were appended together to produce NHDPlusV2_Hydrolakes.csv 20251201 Spatial Intersection NHDPlusHR, NHDPlusV2, and Hydrolakes. For each HUC4: 1. the Hydrolakes and NHDPlusV2 dataset was subset to the watershed boundary, 2. the intersections between NHDPlusHR and NHDPlusV2 were identified using the intersect function in the Terra package in R, 3. the intersection between the intersection in step 2 and Hydrolakes were identified using the intersect function in the Terra package in R, 4. the overlapping area between the NHDPlusHR, NHDPlusV2 and Hydrolakes polygons were computed using the expanse function in the Terra package in R, 4. the results of the NHDPlusHR, NHDPlusV2 and Hydrolakes intersection are stored in intermediate files. Intermediate files were appended together to produce NHDPlusHR_NHDPlusV2_Hydrolakes.csv 20251201 Data_Dictionary_NHD_Waterbody_Crosswalk.csv Comma Separated Value (CSV) file containing data. Producer Defined File File in the data release Producer Defined NHDPlusHR_Hydrolakes.csv crosswalk between NHDPlusHR and Hydrolakes Producer defined NHDPlusHR_NHDPlusV2.csv crosswalk between NHDPlusHR and NHDPlusV2 Producer defined NHDPlusV2_Hydrolakes.csv crosswalk between NHDPlusV2 and Hydrolakes Producer defined NHDPlusHR_NHDPlusV2_Hydrolakes.csv crosswalk between NHDPlusHR, NHDPlusV2, and Hydrolakes Producer defined Column Column in file Producer Defined Name of the column in the datafile Definition Definition of the column in the datafile Producer Defined Definition of the column in the datafile code.zip Zipped file with R scripts used to produce cross-walk data files. Producer Defined Crosswalk of Lake Identifiers between versions of the National Hydrography Dataset and Hydrolakes for the Contiguous United States King, T.V., 2025, Crosswalk of Lake Identifiers between versions of the National Hydrography Dataset and Hydrolakes for the Contiguous United States : U.S. Geological Survey data release, https://doi.org/10.5066/P13N85SWS. U.S. Geological Survey GS ScienceBase mailing address

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Denver CO 80225 United States 1-888-275-8747 sciencebase@usgs.gov 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. Digital Data https://doi.org/10.5066/P13N85SW None 20260226 Tyler V. King USGS - WATER Supervisory Research Hydrologist mailing and physical

230 Collins Rd

Boise Idaho 83702 US 208-387-1352 tvking@usgs.gov FGDC Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998