Water availability for human and ecosystem needs is a function of both water quantity and water quality, as described in the U.S. Geological Survey (USGS) Water Science Strategy (Evenson and others, 2013). Recently, a quantitative approach to prioritize candidate watersheds for monitoring investment was developed to understand changes in water availability and advance the objectives of new USGS programs (Van Metre and others, 2020). In this study design, the contiguous United States (CONUS) was divided into 18 regions (referred to here as “hydrologic regions” or “HRs”) with relatively homogeneous hydrologic drivers and processes to represent the wide diversity in conditions that exist across the CONUS. The gap analysis focused on prioritizing new capabilities beyond the current USGS science in discharge and constituent concentration trends to develop integrated capabilities for assessing and modeling of the water-quality drivers of aquatic ecosystem health. Water availability can be limited by various water-quality parameters such as temperature, salinity, excess nutrients, suspended sediment, geogenic constituents, and other contaminants of emerging concern (CECs) depending on water sources and human or ecosystem needs (Stanton and others, 2017). This data release contains more than 100 geospatial variables summarized for each watershed at the Hydrologic Unit level 4 (HUC4) that were used to prioritize watersheds targeted for USGS research. Additionally, the data release includes the polygon layers of the modified HUC4 watersheds and the hydrologic regions used for the analyses.

Water availability for human and ecosystem needs is a function of both water quantity and water quality, as described in the U.S. Geological Survey (USGS) Water Science Strategy (Evenson and others, 2013). Recently, a quantitative approach to prioritize candidate watersheds for monitoring investment was developed to understand changes in water availability and advance the objectives of new USGS programs (Van Metre and others, 2020). In this study design, the contiguous United States (CONUS) was divided into 18 regions (referred to here as “hydrologic regions” or “HRs”) with relatively homogeneous hydrologic drivers and processes to represent the wide diversity in conditions that exist across the CONUS. The gap analysis focused on prioritizing new capabilities beyond the current USGS science in discharge and constituent concentration trends to develop integrated capabilities for assessing and modeling of the water-quality drivers of aquatic ecosystem health. Water availability can be limited by various water-quality parameters such as temperature, salinity, excess nutrients, suspended sediment, geogenic constituents, and other contaminants of emerging concern (CECs) depending on water sources and human or ecosystem needs (Stanton and others, 2017). This data release contains more than 100 geospatial variables summarized for each watershed at the Hydrologic Unit level 4 (HUC4) that were used to prioritize watersheds targeted for USGS research. Additionally, the data release includes the polygon layers of the modified HUC4 watersheds and the hydrologic regions used for the analyses.

This product consists of 29 datasets of tabular data and associated metadata for watershed characteristics of 1,530 study sites of the Surface Water Trends (SWT) project of the U.S. Geological Survey’s (USGS) National Water Quality Program (NWQP). The project is conducting national studies of trends in water quality of streams and rivers for periods ranging from 10 to 40 years, between 1972 and 2012. The data here include both static and time-series characteristics. Static data include primarily physical characteristics which have changed little over this period, such as geology, soils, and topography. Time-series data represent characteristics which may or may not have changed over time, such as land use, agricultural practices, precipitation, hydrologic modifications, atmospheric deposition, and population changes.

This product consists of 29 datasets of tabular data and associated metadata for watershed characteristics of 1,530 study sites of the Surface Water Trends (SWT) project of the U.S. Geological Survey’s (USGS) National Water Quality Program (NWQP). The project is conducting national studies of trends in water quality of streams and rivers for periods ranging from 10 to 40 years, between 1972 and 2012. The data here include both static and time-series characteristics. Static data include primarily physical characteristics which have changed little over this period, such as geology, soils, and topography. Time-series data represent characteristics which may or may not have changed over time, such as land use, agricultural practices, precipitation, hydrologic modifications, atmospheric deposition, and population changes.

The U.S. Geological Survey (USGS) developed a systematic, quantitative approach to prioritize candidate basins that can support the assessment and forecasting objectives of the major USGS water science programs. Candidate basins were the level-4 hydrologic units (HUC4) with some of the smaller HUC4s being combined (hereafter referred to as modified HUC4 basins). Candidate basins for the contiguous United States (CONUS) were grouped into 18 hydrologic regions. Thirty-three geospatial variables representing land use, climate change, water use, water-balance components, streamflow alteration, fire risk, and ecosystem sensitivity were initially considered to assist in ranking candidate basins for study. The two highest ranking candidate basins in each of the 18 regions were identified as semi-finalists for selection as “Integrated Water Science Basins.” The initial 33 geospatial variables are included within this data release. Also included in this data release are the polygon layers of the modified HUC4 basins and the hydrologic regions used for the analyses and a separate data dictionary to define the variables.

The U.S. Geological Survey (USGS) developed a systematic, quantitative approach to prioritize candidate basins that can support the assessment and forecasting objectives of the major USGS water science programs. Candidate basins were the level-4 hydrologic units (HUC4) with some of the smaller HUC4s being combined (hereafter referred to as modified HUC4 basins). Candidate basins for the contiguous United States (CONUS) were grouped into 18 hydrologic regions. Thirty-three geospatial variables representing land use, climate change, water use, water-balance components, streamflow alteration, fire risk, and ecosystem sensitivity were initially considered to assist in ranking candidate basins for study. The two highest ranking candidate basins in each of the 18 regions were identified as semi-finalists for selection as “Integrated Water Science Basins.” The initial 33 geospatial variables are included within this data release. Also included in this data release are the polygon layers of the modified HUC4 basins and the hydrologic regions used for the analyses and a separate data dictionary to define the variables.

In 2013, the Regional Stream Quality Assessment (RSQA) study was started as part of the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) project. One of the objectives of the RSQA is to characterize the relationships between water-quality stressors and stream ecology and subsequently determine the relative effects of these stressors on aquatic biota within the streams (Garrett and others, 2017; Journey and others, 2015; Coles and others, 2019; Sheibley and others, 2017; May and others, 2020). The study was implemented in five regions across the United States (U.S.); the Midwest (MSQA) in 2013, the southeast (SESQA) in 2014, the Pacific Northwest (PNSQA) in 2015, the northeast (NESQA) in 2016, and California (CSQA) in 2017. To meet this objective (correlations with and effects of stressors), a framework of fundamental geospatial data was required to develop physical and anthropogenic characteristics of each study region for the watersheds and riparian zones associated with each sampling location. This dataset includes 150 selected environmental characteristics for the 483 sites sampled across all regions of the study. The characteristics were derived over the five years (2013 to 2017) using geospatial summary techniques where spatial information is summarized based on spatial extents such as watersheds. The characteristics were developed using the geospatial data for the location of the water-quality sites, delineations of areas draining to the sites (watershed boundaries, including the boundaries of the lower 5 kilometers [km] of watershed [Lower Basin] for the NESQA and CSQA study regions), and riparian-zone boundaries defined from buffers along digitized riparian reaches (Qi and Nakagaki, 2020). This dataset consists of 3 tables: 1) the main data file containing the environmental characteristics of sites, watersheds (including the boundaries of the lower 5 km of watershed for the NESQA and CSQA study regions), and riparian zones, 2) the data dictionary that describes the variables in the data file, and 3) the full citations associated with the references cited in the data dictionary.

In 2013, the Regional Stream Quality Assessment (RSQA) study was started as part of the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) project. One of the objectives of the RSQA is to characterize the relationships between water-quality stressors and stream ecology and subsequently determine the relative effects of these stressors on aquatic biota within the streams (Garrett and others, 2017; Journey and others, 2015; Coles and others, 2019; Sheibley and others, 2017; May and others, 2020). The study was implemented in five regions across the United States (U.S.); the Midwest (MSQA) in 2013, the southeast (SESQA) in 2014, the Pacific Northwest (PNSQA) in 2015, the northeast (NESQA) in 2016, and California (CSQA) in 2017. To meet this objective (correlations with and effects of stressors), a framework of fundamental geospatial data was required to develop physical and anthropogenic characteristics of each study region for the watersheds and riparian zones associated with each sampling location. This dataset includes 150 selected environmental characteristics for the 483 sites sampled across all regions of the study. The characteristics were derived over the five years (2013 to 2017) using geospatial summary techniques where spatial information is summarized based on spatial extents such as watersheds. The characteristics were developed using the geospatial data for the location of the water-quality sites, delineations of areas draining to the sites (watershed boundaries, including the boundaries of the lower 5 kilometers [km] of watershed [Lower Basin] for the NESQA and CSQA study regions), and riparian-zone boundaries defined from buffers along digitized riparian reaches (Qi and Nakagaki, 2020). This dataset consists of 3 tables: 1) the main data file containing the environmental characteristics of sites, watersheds (including the boundaries of the lower 5 km of watershed for the NESQA and CSQA study regions), and riparian zones, 2) the data dictionary that describes the variables in the data file, and 3) the full citations associated with the references cited in the data dictionary.

In 2013, the Regional Stream Quality Assessment (RSQA) study was started as part of the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) project. One of the objectives of the RSQA is to characterize the relationships between water-quality stressors and stream ecology and subsequently determine the relative effects of these stressors on aquatic biota within the streams (Garrett and others, 2017; Journey and others, 2015; Coles and others, 2019; Sheibley and others, 2017; May and others, 2020). The study was implemented in five regions across the United States (U.S.); the Midwest (MSQA) in 2013, the southeast (SESQA) in 2014, the Pacific Northwest (PNSQA) in 2015, the northeast (NESQA) in 2016, and California (CSQA) in 2017. To meet this objective (correlations with and effects of stressors), a framework of fundamental geospatial data was required to develop physical and anthropogenic characteristics of each study region for the watersheds and riparian zones associated with each sampling location. This dataset includes 150 selected environmental characteristics for the 483 sites sampled across all regions of the study. The characteristics were derived over the five years (2013 to 2017) using geospatial summary techniques where spatial information is summarized based on spatial extents such as watersheds. The characteristics were developed using the geospatial data for the location of the water-quality sites, delineations of areas draining to the sites (watershed boundaries, including the boundaries of the lower 5 kilometers [km] of watershed [Lower Basin] for the NESQA and CSQA study regions), and riparian-zone boundaries defined from buffers along digitized riparian reaches (Qi and Nakagaki, 2020). This dataset consists of 3 tables: 1) the main data file containing the environmental characteristics of sites, watersheds (including the boundaries of the lower 5 km of watershed for the NESQA and CSQA study regions), and riparian zones, 2) the data dictionary that describes the variables in the data file, and 3) the full citations associated with the references cited in the data dictionary.

A digital representation of the watersheds of 43 sites on large river systems sampled by the National Stream Quality Accounting Network (NASQAN) of the U. S. Geological Survey (USGS) in 2000 was created primarily from 1:250,000 hydrologic units(HUCs) in the United States. Watershed information from Canada and Mexico was incorporated to complete the areas draining to the sampling sites from outside the United States. The sampled rivers are in one of four major river systems: the Mississippi, the Colorado, the Rio Grande, or the Columbia.