The Chesapeake Bay Hyper-Resolution Hydrography Database is intended to facilitate analysis of the landscape in the Chesapeake Bay watershed through identification of headwater and other low-order streams or drainage features (e.g. ditches) that, to date, may be absent from existing hydrography data products. A full description of the methodology and accuracy assessment is provided in the accompanying report titled: "Hydrography Mapping Supporting Modeling and Targeted Conservation: Project Overview and Lessons Learned". The data products were developed by the Chesapeake Conservancy and the University of Maryland Baltimore County (UMBC) as part of a 6-year Cooperative Agreement between the Chesapeake Conservancy and the U.S. Environmental Protection Agency (EPA) and a separate Interagency Agreement between the USGS and the EPA to provide geospatial support to the Chesapeake Bay Program Office. The data release is structured by eight-digit level hydrologic unit codes (HUC8) for the Chesapeake Bay watershed. Each HUC8 contains seven files (see below) and uses the following nomenclature: where HUC_ID and WATERSHED_NAME are placeholders for HUC8 ID(s), and local watershed name(s) (e.g., "Hydrographic Datasets for Hydrologic Unit 02050101 - Upper Susquehanna") Data Release Structure: Project Overview and Lessons Learned.pdf (Project overivew, methodology and accuracy assessment) huc_[HUC_ID]_streamLine.zip (Stream Lines) huc_[HUC_ID]_streamPoly.zip (Stream Polygons) huc_[HUC_ID]_agDitches.zip (Agricultural Ditches) huc_[HUC_ID]_rdDitches.zip (Road Ditches) huc_[HUC_ID]_geomorphon1m.tif (Geomorphon 1-meter) huc_[HUC_ID]_geomorphon10m.tif (Geomorphon 10-meter) metadata_[HUC_ID].xml (metadata xml)

This data release links habitat assessment sites to both the NHDPlus Version 2 and NHDPlus High Resolution Region 02 networks using the hydrolink methodology. Linked habitat sites are those compiled by the Interstate Commission on the Potomac River Basin (ICPRB) during creation of the Chesapeake Bay Basin-wide Index of Biotic Integrity (Chessie BIBI) for benthic macroinvertebrates (https://datahub.chesapeakebay.net/LivingResources). The data set contains a unique sample identifier created by ICPRB, survey program, coordinates of sample, linked V2 COMID and HR Permanent Identifier, and information regarding uncertainty in the attribution. We strongly caution the use of sampling points with attribution uncertainty to avoid spurious attribution of geospatial data to benthic macroinvertebrate samples.

This data release links habitat assessment sites to both the NHDPlus Version 2 and NHDPlus High Resolution Region 02 networks using the hydrolink methodology. Linked habitat sites are those compiled by the Interstate Commission on the Potomac River Basin (ICPRB) during creation of the Chesapeake Bay Basin-wide Index of Biotic Integrity (Chessie BIBI) for benthic macroinvertebrates (https://datahub.chesapeakebay.net/LivingResources). The data set contains a unique sample identifier created by ICPRB, survey program, coordinates of sample, linked V2 COMID and HR Permanent Identifier, and information regarding uncertainty in the attribution. We strongly caution the use of sampling points with attribution uncertainty to avoid spurious attribution of geospatial data to benthic macroinvertebrate samples.

This data release contains three 10-meter resolution GeoTIFFs representing 10-meter (35-foot), 30-meter (100-foot) and 90-meter (300-foot) riparian buffer zones along shorelines, rivers, streams, and other lotic (flowing) water features. The layers are binary, where the value of each cell represents the presence or absence of the buffer zone. In addition, the data release contains shapefile layers that document the extent of corrections that were made to the data to address errors in the stream network (see processing steps section for more details).. The methodology combines various fine-scale input layers, including a 1:24k stream network and Chesapeake Bay 1-meter resolution Land Use/Land Cover to approximate banks of stream channels and waterbodies to better define the riparian zone (CBP, 2023; Hopkins and others, 2020). For shorelines and large rivers, the width of the buffer zone (10, 30, 90 meters) begins at the banks, where land meets water. For finer scale (1:24k) stream features, the buffer zone includes both water and riparian land area, where the buffered width begins at the estimated top of bank. Each 10-meter resolution riparian buffer zone GeoTIFF dataset is contained in an individual .zip file (CBW_riparian_10m_24k_2024.zip, CBW_riparian_30m_24k_2024.zip, CBW_riparian_90m_24k_2024.zip). The shapefile layers that contain the data correction extents are available in the correction_layers.zip file.

This data release contains three 10-meter resolution GeoTIFFs representing 10-meter (35-foot), 30-meter (100-foot) and 90-meter (300-foot) riparian buffer zones along shorelines, rivers, streams, and other lotic (flowing) water features. The layers are binary, where the value of each cell represents the presence or absence of the buffer zone. In addition, the data release contains shapefile layers that document the extent of corrections that were made to the data to address errors in the stream network (see processing steps section for more details).. The methodology combines various fine-scale input layers, including a 1:24k stream network and Chesapeake Bay 1-meter resolution Land Use/Land Cover to approximate banks of stream channels and waterbodies to better define the riparian zone (CBP, 2023; Hopkins and others, 2020). For shorelines and large rivers, the width of the buffer zone (10, 30, 90 meters) begins at the banks, where land meets water. For finer scale (1:24k) stream features, the buffer zone includes both water and riparian land area, where the buffered width begins at the estimated top of bank. Each 10-meter resolution riparian buffer zone GeoTIFF dataset is contained in an individual .zip file (CBW_riparian_10m_24k_2024.zip, CBW_riparian_30m_24k_2024.zip, CBW_riparian_90m_24k_2024.zip). The shapefile layers that contain the data correction extents are available in the correction_layers.zip file.

The Chesapeake Bay Hyper-Resolution Hydrography Database is intended to facilitate analysis of the landscape in the Chesapeake Bay watershed through identification of headwater and other low-order streams or drainage features (e.g. ditches) that, to date, may be absent from existing hydrography data products. A full description of the methodology and accuracy assessment is provided in the accompanying report titled: "Hydrography Mapping Supporting Modeling and Targeted Conservation: Project Overview and Lessons Learned". The data products were developed by the Chesapeake Conservancy and the University of Maryland Baltimore County (UMBC) as part of a 6-year Cooperative Agreement between the Chesapeake Conservancy and the U.S. Environmental Protection Agency (EPA) and a separate Interagency Agreement between the USGS and the EPA to provide geospatial support to the Chesapeake Bay Program Office. The data release is structured by eight-digit level hydrologic unit codes (HUC8) for the Chesapeake Bay watershed. Each HUC8 contains seven files (see below) and uses the following nomenclature: where HUC_ID and WATERSHED_NAME are placeholders for HUC8 ID(s), and local watershed name(s) (e.g., "Hydrographic Datasets for Hydrologic Unit 02050101 - Upper Susquehanna") Data Release Structure: Project Overview and Lessons Learned.pdf (Project overivew, methodology and accuracy assessment) huc_[HUC_ID]_streamLine.zip (Stream Lines) huc_[HUC_ID]_streamPoly.zip (Stream Polygons) huc_[HUC_ID]_agDitches.zip (Agricultural Ditches) huc_[HUC_ID]_rdDitches.zip (Road Ditches) huc_[HUC_ID]_geomorphon1m.tif (Geomorphon 1-meter) huc_[HUC_ID]_geomorphon10m.tif (Geomorphon 10-meter) metadata_[HUC_ID].xml (metadata xml)

The Chesapeake Bay Hyper-Resolution Hydrography Database is intended to facilitate analysis of the landscape in the Chesapeake Bay watershed through identification of headwater and other low-order streams or drainage features (e.g. ditches) that, to date, may be absent from existing hydrography data products. A full description of the methodology and accuracy assessment is provided in the accompanying report titled: "Hydrography Mapping Supporting Modeling and Targeted Conservation: Project Overview and Lessons Learned". The data products were developed by the Chesapeake Conservancy and the University of Maryland Baltimore County (UMBC) as part of a 6-year Cooperative Agreement between the Chesapeake Conservancy and the U.S. Environmental Protection Agency (EPA) and a separate Interagency Agreement between the USGS and the EPA to provide geospatial support to the Chesapeake Bay Program Office. The data release is structured by eight-digit level hydrologic unit codes (HUC8) for the Chesapeake Bay watershed. Each HUC8 contains seven files (see below) and uses the following nomenclature: where HUC_ID and WATERSHED_NAME are placeholders for HUC8 ID(s), and local watershed name(s) (e.g., "Hydrographic Datasets for Hydrologic Unit 02050101 - Upper Susquehanna") Data Release Structure: Project Overview and Lessons Learned.pdf (Project overivew, methodology and accuracy assessment) huc_[HUC_ID]_streamLine.zip (Stream Lines) huc_[HUC_ID]_streamPoly.zip (Stream Polygons) huc_[HUC_ID]_agDitches.zip (Agricultural Ditches) huc_[HUC_ID]_rdDitches.zip (Road Ditches) huc_[HUC_ID]_geomorphon1m.tif (Geomorphon 1-meter) huc_[HUC_ID]_geomorphon10m.tif (Geomorphon 10-meter) metadata_[HUC_ID].xml (metadata xml)

The Chesapeake Bay Hyper-Resolution Hydrography Database is intended to facilitate analysis of the landscape in the Chesapeake Bay watershed through identification of headwater and other low-order streams or drainage features (e.g. ditches) that, to date, may be absent from existing hydrography data products. A full description of the methodology and accuracy assessment is provided in the accompanying report titled: "Hydrography Mapping Supporting Modeling and Targeted Conservation: Project Overview and Lessons Learned". The data products were developed by the Chesapeake Conservancy and the University of Maryland Baltimore County (UMBC) as part of a 6-year Cooperative Agreement between the Chesapeake Conservancy and the U.S. Environmental Protection Agency (EPA) and a separate Interagency Agreement between the USGS and the EPA to provide geospatial support to the Chesapeake Bay Program Office. The data release is structured by eight-digit level hydrologic unit codes (HUC8) for the Chesapeake Bay watershed. Each HUC8 contains seven files (see below) and uses the following nomenclature: where HUC_ID and WATERSHED_NAME are placeholders for HUC8 ID(s), and local watershed name(s) (e.g., "Hydrographic Datasets for Hydrologic Unit 02050101 - Upper Susquehanna") Data Release Structure: Project Overview and Lessons Learned.pdf (Project overivew, methodology and accuracy assessment) huc_[HUC_ID]_streamLine.zip (Stream Lines) huc_[HUC_ID]_streamPoly.zip (Stream Polygons) huc_[HUC_ID]_agDitches.zip (Agricultural Ditches) huc_[HUC_ID]_rdDitches.zip (Road Ditches) huc_[HUC_ID]_geomorphon1m.tif (Geomorphon 1-meter) huc_[HUC_ID]_geomorphon10m.tif (Geomorphon 10-meter) metadata_[HUC_ID].xml (metadata xml)

These tabular data are the summarization of land use/land cover related variables within the Chesapeake Bay watershed using the xstrm methodology bringing these data to the 1:24,000 scale. Variables being counted as land use/land cover related include all land use and land cover data. This also contains datasets that are split off or combined from source data (eg. agriculture or impervious only datasets combined from agriculture or impervious land use/land cover classes). Outputs consist of tabular comma-separated values files (CSVs), and parquet formatted files for both the local catchment and network summaries linked to the National Hydrography Dataset Plus High-Resolution (NHDPlus HR) framework by NHDPlus ID. Local catchments are defined as the single catchment the data is summarized within. Network accumulation summaries were completed for each of these catchments and their respective upstream catchments. The summarized data tables are structured as a single column representing the catchment id values (ie. nhdplusid) and the remaining columns consisting of the summarized variables. The downstream network summary type is not present within the dataset as no summaries were conducted using that summary type. Additionally, for a full description of the variables included within these summaries see xstrm_nhdhr_lulc_chesapeake_baywide_datadictionary.csv in the attached files. The xstrm local summary methodology takes either raster or point data as input then summarizes those data by "zones" (hereafter referred to as catchment(s)), in this case the NHDPlus HR catchments. The network summaries then take the results from the local summaries and calculates the desired network summary statistic for the local catchment and its respective upstream or downstream catchments. As a note concerning use of these data, any rasters summarized within this process only had their cells included within a catchment if the center of the raster cell fell within the catchment boundary. However, the resolution of the input raster data for these summaries was considered to provide completely adequate coverage of the summary catchments using this option and given computing power limitations. If a confirmed complete coverage of a catchment is desired (even if a raster cell only is minimally included within the catchment) then it is recommended to rerun the xstrm summary process with the "All Touched" option set to True. These data were updated in September 2024 and August 2025. Some changes during these revisions include the removal of several variables unnecessary to the use of the data summaries, correction of incorrectly calculated area variables and all dependent variables, and the addition of several new variables. For a full list of changes see, xstrm_nhdhr_lulc_chesapeake_baywide_versionhistory.txt. Further information on the Xstrm summary process can be found at the Xstrm software release pages: Xstrm: Wieferich, D.J., Williams, B., Falgout, J.T., Foks, N.L. 2021. xstrm. U.S. Geological Survey software release. https://doi.org/10.5066/P9P8P7Z0. Xstrm Local: Wieferich, D.J., Gressler B., Krause K., Wieczorek M., McDonald, S. 2022. xstrm_local Version-1.1.0. U.S. Geological Survey software release. https://doi.org/10.5066/P98BOGI9.

These tabular data are the summarization of land use/land cover related variables within the Chesapeake Bay watershed using the xstrm methodology bringing these data to the 1:24,000 scale. Variables being counted as land use/land cover related include all land use and land cover data. This also contains datasets that are split off or combined from source data (eg. agriculture or impervious only datasets combined from agriculture or impervious land use/land cover classes). Outputs consist of tabular comma-separated values files (CSVs), and parquet formatted files for both the local catchment and network summaries linked to the National Hydrography Dataset Plus High-Resolution (NHDPlus HR) framework by NHDPlus ID. Local catchments are defined as the single catchment the data is summarized within. Network accumulation summaries were completed for each of these catchments and their respective upstream catchments. The summarized data tables are structured as a single column representing the catchment id values (ie. nhdplusid) and the remaining columns consisting of the summarized variables. The downstream network summary type is not present within the dataset as no summaries were conducted using that summary type. Additionally, for a full description of the variables included within these summaries see xstrm_nhdhr_lulc_chesapeake_baywide_datadictionary.csv in the attached files. The xstrm local summary methodology takes either raster or point data as input then summarizes those data by "zones" (hereafter referred to as catchment(s)), in this case the NHDPlus HR catchments. The network summaries then take the results from the local summaries and calculates the desired network summary statistic for the local catchment and its respective upstream or downstream catchments. As a note concerning use of these data, any rasters summarized within this process only had their cells included within a catchment if the center of the raster cell fell within the catchment boundary. However, the resolution of the input raster data for these summaries was considered to provide completely adequate coverage of the summary catchments using this option and given computing power limitations. If a confirmed complete coverage of a catchment is desired (even if a raster cell only is minimally included within the catchment) then it is recommended to rerun the xstrm summary process with the "All Touched" option set to True. These data were updated in September 2024 and August 2025. Some changes during these revisions include the removal of several variables unnecessary to the use of the data summaries, correction of incorrectly calculated area variables and all dependent variables, and the addition of several new variables. For a full list of changes see, xstrm_nhdhr_lulc_chesapeake_baywide_versionhistory.txt. Further information on the Xstrm summary process can be found at the Xstrm software release pages: Xstrm: Wieferich, D.J., Williams, B., Falgout, J.T., Foks, N.L. 2021. xstrm. U.S. Geological Survey software release. https://doi.org/10.5066/P9P8P7Z0. Xstrm Local: Wieferich, D.J., Gressler B., Krause K., Wieczorek M., McDonald, S. 2022. xstrm_local Version-1.1.0. U.S. Geological Survey software release. https://doi.org/10.5066/P98BOGI9.