This dataset, termed "GAGES II", an acronym for Geospatial Attributes of Gages for Evaluating Streamflow, version II, provides geospatial data and classifications for 9,322 stream gages maintained by the U.S. Geological Survey (USGS). It is an update to the original GAGES, which was published as a Data Paper on the journal Ecology's website (Falcone and others, 2010b) in 2010. The GAGES II dataset consists of gages which have had either 20+ complete years (not necessarily continuous) of discharge record since 1950, or are currently active, as of water year 2009, and whose watersheds lie within the United States, including Alaska, Hawaii, and Puerto Rico. Reference gages were identified based on indicators that they were the least-disturbed watersheds within the framework of broad regions, based on 12 major ecoregions across the United States. Of the 9,322 total sites, 2,057 are classified as reference, and 7,265 as non-reference. Of the 2,057 reference sites, 1,633 have (through 2009) 20+ years of record since 1950. Some sites have very long flow records: a number of gages have been in continuous service since 1900 (at least), and have 110 years of complete record (1900-2009) to date. The geospatial data include several hundred watershed characteristics compiled from national data sources, including environmental features (e.g. climate – including historical precipitation, geology, soils, topography) and anthropogenic influences (e.g. land use, road density, presence of dams, canals, or power plants). The dataset also includes comments from local USGS Water Science Centers, based on Annual Data Reports, pertinent to hydrologic modifications and influences. The data posted also include watershed boundaries in GIS format. This overall dataset is different in nature to the USGS Hydro-Climatic Data Network (HCDN; Slack and Landwehr 1992), whose data evaluation ended with water year 1988. The HCDN identifies stream gages which at some point in their history had periods which represented natural flow, and the years in which those natural flows occurred were identified (i.e. not all HCDN sites were in reference condition even in 1988, for example, 02353500). The HCDN remains a valuable indication of historic natural streamflow data. However, the goal of this dataset was to identify watersheds which currently have near-natural flow conditions, and the 2,057 reference sites identified here were derived independently of the HCDN. A subset, however, noted in the BasinID worksheet as “HCDN-2009”, has been identified as an updated list of 743 sites for potential hydro-climatic study. The HCDN-2009 sites fulfill all of the following criteria: (a) have 20 years of complete and continuous flow record in the last 20 years (water years 1990-2009), and were thus also currently active as of 2009, (b) are identified as being in current reference condition according to the GAGES-II classification, (c) have less than 5 percent imperviousness as measured from the NLCD 2006, and (d) were not eliminated by a review from participating state Water Science Center evaluators. The data posted here consist of the following items:- This point shapefile, with summary data for the 9,322 gages.- A zip file containing basin characteristics, variable definitions, and a more detailed report.- A zip file containing shapefiles of basin boundaries, organized by classification and aggregated ecoregion.- A zip file containing mainstem stream lines (Arc line coverages) for each gage.
This resource provides datasets for stream discharge (flow rate) in cubic feet per second, and gage height (stream depth) from 924 active USGS gages in the Hurricane Harvey impact zone across Texas, Louisiana, Mississippi and Arkansas (see shapefile for all gages).
These data were obtained from the USGS National Water Information System (NWIS) [1] using R scripts provided here. When running these R scripts, 745 of the 924 gages had gage height values, and 577 of the 924 had discharge values. For help in using these R scripts here are some resources from USGS. I used R Studio on Windows for these retrievals.
Formats provided: - Shapefile and csv for gage locations, including link to USGS gage details [1] - Tabular (csv) datasets for timeseries of water discharge (flow rate) in cubic ft/sec, and timeseries of gage height in ft. - R scripts to download timeseries data from NWIS
References [1] USGS NWIS - interactive portal for stream gage site info [https://waterdata.usgs.gov/nwis] [2] USGS NWIS - Community home page for Geological survey R Archive Network (GRAN) [https://owi.usgs.gov/R/] [3] USGS NWIS dataRetrieval R library tutorial [https://owi.usgs.gov/R/dataRetrieval.html#1] [4] USGS NWIS site test tool [https://waterservices.usgs.gov/rest/Site-Test-Tool.html]
U.S. Government Workshttps://www.usa.gov/government-works
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The USGS National Hydrography Dataset (NHD) downloadable data collection from The National Map (TNM) is a comprehensive set of digital spatial data that encodes information about naturally occurring and constructed bodies of surface water (lakes, ponds, and reservoirs), paths through which water flows (canals, ditches, streams, and rivers), and related entities such as point features (springs, wells, stream gages, and dams). The information encoded about these features includes classification and other characteristics, delineation, geographic name, position and related measures, a "reach code" through which other information can be related to the NHD, and the direction of water flow. The network of reach codes delineating water and transported material flow allows users to trace movement in upstream and downstream directions. In addition to this geographic information, the dataset contains metadata that supports the exchange of future updates and improvements to the data. The NHD supports many applications, such as making maps, geocoding observations, flow modeling, data maintenance, and stewardship. For additional information on NHD, go to https://www.usgs.gov/core-science-systems/ngp/national-hydrography.
DWR was the steward for NHD and Watershed Boundary Dataset (WBD) in California. We worked with other organizations to edit and improve NHD and WBD, using the business rules for California. California's NHD improvements were sent to USGS for incorporation into the national database. The most up-to-date products are accessible from the USGS website. Please note that the California portion of the National Hydrography Dataset is appropriate for use at the 1:24,000 scale.
For additional derivative products and resources, including the major features in geopackage format, please go to this page: https://data.cnra.ca.gov/dataset/nhd-major-features Archives of previous statewide extracts of the NHD going back to 2018 may be found at https://data.cnra.ca.gov/dataset/nhd-archive.
In September 2022, USGS officially notified DWR that the NHD would become static as USGS resources will be devoted to the transition to the new 3D Hydrography Program (3DHP). 3DHP will consist of LiDAR-derived hydrography at a higher resolution than NHD. Upon completion, 3DHP data will be easier to maintain, based on a modern data model and architecture, and better meet the requirements of users that were documented in the Hydrography Requirements and Benefits Study (2016). The initial releases of 3DHP include NHD data cross-walked into the 3DHP data model. It will take several years for the 3DHP to be built out for California. Please refer to the resources on this page for more information.
The FINAL,STATIC version of the National Hydrography Dataset for California was published for download by USGS on December 27, 2023. This dataset can no longer be edited by the state stewards. The next generation of national hydrography data is the USGS 3D Hydrography Program (3DHP).
Questions about the California stewardship of these datasets may be directed to nhd_stewardship@water.ca.gov.
Includes daily USGS streamflow measurements for 454 gauges throughout the Mississippi River Basin for the period April 1, 2010 to May 1, 2016, a shapefile of the USGS gauges, and assuming a theoretical launch date of the Surface Water and Ocean Topography (SWOT) Mission being April 16, 2010, sampled SWOT-observed discharges with and without preliminary SWOT discharge uncertainties (based on Hagemann et al. 2017; DOI: 10.1002/2017WR021626) .
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Supporting datasets for Allen et al. (2018) - Global Estimates of River Flow Wave Travel Times and Implications for Low-Latency Satellite Data, Geophysical Research Letters, https://doi.org/10.1002/2018GL077914
The code used to produce these data is available as a Github repository, permanently hosted on Zenodo: https://doi.org/10.5281/zenodo.1219784
Abstract
Earth-orbiting satellites provide valuable observations of upstream river conditions worldwide. These observations can be used in real-time applications like early flood warning systems and reservoir operations, provided they are made available to users with sufficient lead time. Yet, the temporal requirements for access to satellite-based river data remain uncharacterized for time-sensitive applications. Here we present a global approximation of flow wave travel time to assess the utility of existing and future low-latency/near-real-time satellite products, with an emphasis on the forthcoming SWOT satellite. We apply a kinematic wave model to a global hydrography dataset and find that global flow waves traveling at their maximum speed take a median travel time of 6, 4 and 3 days to reach their basin terminus, the next downstream city and the next downstream dam respectively. Our findings suggest that a recently-proposed ≤2-day latency for a low-latency SWOT product is potentially useful for real-time river applications.
Description of repository datasets:
"ARCID" : unique identifier for each river segment line, defined as the river reach between river junctions/heads/mouths. The first 10 attributes are taken from Andreadis et al. (2013): https://doi.org/10.5281/zenodo.61758
"UP_CELLS" : number of upstream cells (pixels)
"AREA" : upstream drainage area (km2)
"DISCHARGE" : discharge (m3/s)
"WIDTH" : mean bankfull river width (m)
"WIDTH5" : 5th percentile confidence interval bankfull river width (m)
"WIDTH95" : 95th percentile confidence interval bankfull river width (m)
"DEPTH" : mean bankfull river depth (m)
"DEPTH5" : 5th percentile bankfull river depth (m)
"DEPTH95" : 95th percentile confidence bankfull river depth (m)
"LENGTH_KM" : segment length (km)
"ORIG_FID" : original ID of segment
"ELEV_M" : lowest elevation of segment (m). Derived from HydroSHEDS 15 sec hydrologically conditioned DEM: https://hydrosheds.cr.usgs.gov/datadownload.php?reqdata=15demg
"POINT_X" : longitude of lowest point of segment (WGS84, decimal degrees)
"POINT_Y" : latitude of lowest point of segment (WGS84, decimal degrees)
"SLOPE" : average slope of segment (m/m)
"CITY_JOINS" : an index associated with how likely a city/population center is located on the segment. Population center data from: http://web.ornl.gov/sci/landscan/ and http://www.naturalearthdata.com/downloads/10m-cultural-vectors/10m-populated-places/
"CITY_POP_M" : population of joined city (max N inhabitants)
"DAM_JOINSC" : an index associated with how likely a dam is located on the segment. Dam data from Global Reservoir and Dam (GRanD) Database: http://www.gwsp.org/products/grand-database.html
"DAM_AREA_S" : surface area of joined dam (m2)
"DAM_CAP_MC" : volumetric capacity of joined dam (m3)
"CELER_MPS" : modeled river flow wave celerity (m/s)
"PROPTIME_D" : travel time of flow wave along segment (days)
"hBASIN" : main basin UID for the hydroBASINS dataset: http://www.hydrosheds.org/page/hydrobasins
"GLCC" : Global Land Cover Characterization at segment centroid: https://lta.cr.usgs.gov/glcc/globdoc2_0
"FLOODHAZAR" : flood hazard composite index from the DFO (via NASA Sedac): http://sedac.ciesin.columbia.edu/data/set/ndh-flood-hazard-frequency-distribution
"SWOT_TRAC_" : SWOT track density (N overpasses per orbit cycle @ segment centroid). Created using SWOTtrack SWOTtracks_sciOrbit_sept15 polygon shapefile, uploaded here.
"UPSTR_DIST" : upstream distance to the basin outlet (km)
"UPSTR_TIME" : upstream flow wave travel time to the basin outlet (days)
"CITY_UPSTR" : upstream flow wave travel time to the next downstream city (days)
"DAM_UPSTR_" : upstream flow wave travel time to the next downstream dam (days)
"MC_WIDTH" : mean of Monte Carlo simulated bankfull widths (m)
"MC_DEPTH" : mean of Monte Carlo simulated bankfull depths (m)
"MC_LENCOR" : mean of Monte Carlo simulated river length correction (km)
"MC_LENGTH" : mean of Monte Carlo simulated river length (m)
"MC_SLOPE" : mean of Monte Carlo simulated river slope (-)
"MC_ZSLOPE" : mean of Monte Carlo simulated minimum slope threshold (m)
"MC_N" : mean of Monte Carlo simulated Manning’s n (s/m^(1/3))
"CONTINENT" : integer indicating the HydroSHEDS region of shapefile
Col1: segment unique identifier (UID) corresponding to the ARCID column of the riverPolylines shapefiles
Col2: Downstream UID
Col3: Number of upstream UIDs
Col4 – Col12: Upstream UIDs
FID : unique identifier of each polygon
CENTROID_X : polygon centroid longitude (WGS84 - decimal degrees)
CENTROID_Y : polygon centroid latitude (WGS84 - decimal degrees)
COUNT_count: SWOT sampling frequency (N observations per complete orbit cycle)
USGS_gauge_site_information.csv : table containing the list of USGS sites analyzed in the validation and obtained from http://nwis.waterdata.usgs.gov/nwis/dv Header descriptions contained within table.
validation_gaugeBasedCelerity.zip contains polyline ESRI shapefiles covering North and Central America, where USGS gauges provided gauge-based celerity estimates. These files have FIDs and attributes corresponding to riverPolylines shapefiles described above and also contrain the folllowing fields:
GAUGE_JOIN : an index associated with how likely a gauge is located on the segment. Gauge location information is contained in USGS_gauge_site_information.csv
GAUGE_SITE: USGS gauge site number of joined gauge
GAUGE_HUC8: which hydrological unit code the gauge is located in
OBS_CEL_R: gauge-based correlation score (R). Upstream and downstream gauges were compared via lagged cross correlation analysis. The calculated celerity between the paired gauges were assigned to each segment between the two gauges. If there were multiple pairs of upstream and downstream gauges, the the mean celerity value was assigned, weighted by the quality of the correlation, R. Same weighted mean was applied in assigning R.
OBS_CEL_MPS: gauge-based celerity estimate (m/s).
tab1_latencies.csv contains data shown in Table 1 of the manuscript.
figS3S4_monteCarloSim_global_runMeans.csv contains the mean of the Monte Carlo simulation inputs and outputs shown in Figure S3 and Figure S4. Column headers descriptions are given in riverPolylines (dataset #1 above). Some columns have rows with all the same value because these variables did not vary between ensemble runs.
figS5_travelTimeEnsembleHistograms.zip contains data shown in Figure S5. Each csv corresponds to a figure component:
tabdTT_b.csv : basin outlet travel times for all rivers
tabdTT_b_swot.csv : basin outlet travel times for SWOT
tabdTT_c.csv : next downstream city travel times for all rivers
tabdTT_c_swot.csv : next downstream city travel times for SWOT
tabdTT_d.csv : next downstream dam travel times for all rivers
tabdTT_d_swot.csv : next downstream dam travel times for SWOT
These data include base flow separation estimates for 64 USGS streamflow gages in the Lake Superior watershed from 1945 to 2020, shapefiles of the gaging stations and watersheds for each gaging station, and a zipped folder of graphics of the base flow separation results. The base flow separation estimates were calculated using the U.S. Geological Survey Groundwater Toolbox (Barlow and others, 2014) for any complete water years of record for these gages from 1945 to 2020. The shapefile of the gaging stations includes the starting and ending years of data for each station, the number of years of record. The watersheds shapefile includes the source for the watershed delineation, the watershed area, and the number of upstream and(or) downstream gaging stations on the same river system. If there are upstream gaging stations in the river system, the watershed delineated is only the incremental part of the watershed between gaging stations. The baseflow separation estimates for each gaging station include daily, monthly, and annual output from the Groundwater Toolbox for six estimation methods included in the software (full references are available in Barlow and others, 2014): the baseflow Index-Standard method, HySep Fixed Interval, HySep Local Minimum, HySep Sliding Interval, baseflow Index-Modified, PART, and BFLOW. A summary of the annual baseflow estimates for all the gaging stations using all the methods is provided also is included in this data release. This data release is one of three child items under the overall data release at https://doi.org/10.5066/P9084UKQ.
In 2008, the U.S. Geological Survey (USGS), Woods Hole Coastal and Marine Science Center (WHCMSC), in cooperation with the U.S. Army Corps of Engineers conducted a geophysical and sampling survey of the riverbed of the Upper St. Clair River between Port Huron, MI, and Sarnia, Ontario, Canada. The objectives were to define the Quaternary geologic framework of the St. Clair River to evaluate the relationship between morphologic change of the riverbed and underlying stratigraphy. This report presents the geophysical and sample data collected from the St. Clair River, May 29-June 6, 2008 as part of the International Upper Great Lakes Study, a 5-year project funded by the International Joint Commission of the United States and Canada to examine whether physical changes in the St. Clair River are affecting water levels within the upper Great Lakes, to assess regulation plans for outflows from Lake Superior, and to examine the potential effect of climate change on the Great Lakes water levels ( http://www.iugls.org). This document makes available the data that were used in a separate report, U.S. Geological Survey Open-File Report 2009-1137, which detailed the interpretations of the Quaternary geologic framework of the region. This report includes a description of the suite of high-resolution acoustic and sediment-sampling systems that were used to map the morphology, surficial sediment distribution, and underlying geology of the Upper St. Clair River during USGS field activity 2008-016-FA . Video and photographs of the riverbed were also collected and are included in this data release. Future analyses will be focused on substrate erosion and its effects on river-channel morphology and geometry. Ultimately, the International Upper Great Lakes Study will attempt to determine where physical changes in the St. Clair River affect water flow and, subsequently, water levels in the Upper Great Lakes.
I have updated this abstract to: this data displays the mean discharge rate of the Rio Grande River near Alamosa, Colorado. The data covers from February 1, 1994, to February 1, 1995. The drainage area for this site is 1,710 square miles. The gauge is maintained and operated by the USGS Colorado Water Science Center. This gauge is part of the Rio Grande River Basin which has been uploaded as a shapefile showing the boundary, along with a shapefile of the Rio Grande River as well. The final object added is a raster of the recorded precipitation in the Rio Grande River Basin.
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This resource contains data inputs and a Jupyter Notebook that is used to introduce Hydrologic Analysis using Terrain Analysis Using Digital Elevation Models (TauDEM) and Python. TauDEM is a free and open-source set of Digital Elevation Model (DEM) tools developed at Utah State University for the extraction and analysis of hydrologic information from topography. This resource is part of a HydroLearn Physical Hydrology learning module available at https://edx.hydrolearn.org/courses/course-v1:Utah_State_University+CEE6400+2019_Fall/about
In this activity, the student learns how to (1) derive hydrologically useful information from Digital Elevation Models (DEMs); (2) describe the sequence of steps involved in mapping stream networks, catchments, and watersheds; and (3) compute an approximate water balance for a watershed-based on publicly available data.
Please note that this exercise is designed for the Logan River watershed, which drains to USGS streamflow gauge 10109000 located just east of Logan, Utah. However, this Jupyter Notebook and the analysis can readily be applied to other locations of interest. If running the terrain analysis for other study sites, you need to prepare a DEM TIF file, an outlet shapefile for the area of interest, and the average annual streamflow and precipitation data. - There are several sources to obtain DEM data. In the U.S., the DEM data (with different spatial resolutions) can be obtained from the National Elevation Dataset available from the national map (http://viewer.nationalmap.gov/viewer/). Another DEM data source is the Shuttle Radar Topography Mission (https://www2.jpl.nasa.gov/srtm/), an international research effort that obtained digital elevation models on a near-global scale (search for Digital Elevation at https://www.usgs.gov/centers/eros/science/usgs-eros-archive-products-overview?qt-science_center_objects=0#qt-science_center_objects). - If not already available, you can generate the outlet shapefile by applying basic terrain analysis steps in geospatial information system models such as ArcGIS or QGIS. - You also need to obtain average annual streamflow and precipitation data for the watershed of interest to assess the annual water balance and calculate the runoff ratio in this exercise. In the U.S., the streamflow data can be obtained from the USGS NWIS website (https://waterdata.usgs.gov/nwis) and the precipitation from PRISM (https://prism.oregonstate.edu/normals/). Note that using other datasets may require preprocessing steps to make data ready to use for this exercise.
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This resource contains medium-resolution (1:100k) National Hydrography Dataset (NHDPlus) [1] map data for a region of 39 Hydrologic Unit Code (HUC) 6-digit (HUC6) basins around the Hurricane Harvey impact zone across Texas, Louisiana, Mississippi and Arkansas. This includes 5978 subwatersheds, 190,192 catchments, and 192,267 flowlines.
USGS active stream gages (924) were downloaded from the USGS National Water Information System (NWIS) [2] and augmented with each gage's HUC2, HUC4, HUC6, HUC8, HUC10 & HUC12 basin identifiers, and COMID of the NHD stream reach for the containing catchment. This allows the user to easily aggregate gages by various watershed boundaries.
NOAA Advanced Hydrologic Prediction System (AHPS) [3] has 362 river forecast points in the Harvey study area. Many of these are co-located with USGS NWIS gages to leverage authoritative observation data.
A shapefile of Texas dams (7290) was directly received from the Texas Commission for Environmental Quality (TCEQ) [4]. They suggest if you have any questions about data, to make an Open Records Request [5].
References [1] NHDPlus Version 2 [http://www.horizon-systems.com/NHDPlus/V2NationalData.php] [2] USGS NWIS [https://waterdata.usgs.gov/nwis] [3] NOAA AHPS [https://water.weather.gov/ahps/forecasts.php] [4] TCEQ Data and Records [https://www.tceq.texas.gov/agency/data] [5] TCEQ Open Records Request [https://www.tceq.texas.gov/agency/data/records-services/reqinfo.html]
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This resource contains GIS layers necessary to reproduce the analysis of the paper "Stakeholder-Driven Design of a Flood Risk Streamflow Monitoring Network for Louisiana, USA" submitted to the Journal of American Water Resources Association (JAWRA). The analysis of this paper is focused on designing a streamflow gauge monitoring network as part of the Louisiana Watershed Initiative (LWI) program to enhance the hydrologic modeling and monitoring capabilities of the state of Louisiana. The monitoring network is optimized to capitalize on the resources made available by the LWI program while serving the needs of the local, regional, and federal stakeholders in Louisiana as much as possible. The factors taken into the optimization algorithm included the collected feedback from the stakeholders, as well as a variety of geospatial and geomorphic characteristics of the Louisiana stream network. The analysis also used the current and past conditions of stream monitoring (e.g., existing and discontinued USGS locations). A final set of 123 stream gauges were selected to be deployed. The shapefile containing this set of gauges is also included in this resource.
Continuous resistivity profiling (CRP) surveys were conducted at Cape Cod National Seashore in 2004 and 2006 in order to test hypotheses about groundwater flow under and into estuaries and the Atlantic Ocean. Coastal resource managers here and elsewhere are concerned about nutrients that are entering coastal waters via submarine groundwater discharge, which are contributing to eutrophication and harmful algal blooms. CRP is used to measure electrical resistivity of sediments, a property that is sensitive to differences in salinity of submarine ground water. The 2004 and 2006 surveys used floating resistivity streamers of 100 m and 50 m respectively. The depth penetration of the streamers is approximately 20% of the streamer length which translates to approximately 20-25 m with the 100 m streamer and 12-14 m with the 50 m streamer. These data were processed using AGI's EarthImager 2D software.
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This dataset, termed "GAGES II", an acronym for Geospatial Attributes of Gages for Evaluating Streamflow, version II, provides geospatial data and classifications for 9,322 stream gages maintained by the U.S. Geological Survey (USGS). It is an update to the original GAGES, which was published as a Data Paper on the journal Ecology's website (Falcone and others, 2010b) in 2010. The GAGES II dataset consists of gages which have had either 20+ complete years (not necessarily continuous) of discharge record since 1950, or are currently active, as of water year 2009, and whose watersheds lie within the United States, including Alaska, Hawaii, and Puerto Rico. Reference gages were identified based on indicators that they were the least-disturbed watersheds within the framework of broad regions, based on 12 major ecoregions across the United States. Of the 9,322 total sites, 2,057 are classified as reference, and 7,265 as non-reference. Of the 2,057 reference sites, 1,633 have (through 2009) 20+ years of record since 1950. Some sites have very long flow records: a number of gages have been in continuous service since 1900 (at least), and have 110 years of complete record (1900-2009) to date. The geospatial data include several hundred watershed characteristics compiled from national data sources, including environmental features (e.g. climate – including historical precipitation, geology, soils, topography) and anthropogenic influences (e.g. land use, road density, presence of dams, canals, or power plants). The dataset also includes comments from local USGS Water Science Centers, based on Annual Data Reports, pertinent to hydrologic modifications and influences. The data posted also include watershed boundaries in GIS format. This overall dataset is different in nature to the USGS Hydro-Climatic Data Network (HCDN; Slack and Landwehr 1992), whose data evaluation ended with water year 1988. The HCDN identifies stream gages which at some point in their history had periods which represented natural flow, and the years in which those natural flows occurred were identified (i.e. not all HCDN sites were in reference condition even in 1988, for example, 02353500). The HCDN remains a valuable indication of historic natural streamflow data. However, the goal of this dataset was to identify watersheds which currently have near-natural flow conditions, and the 2,057 reference sites identified here were derived independently of the HCDN. A subset, however, noted in the BasinID worksheet as “HCDN-2009”, has been identified as an updated list of 743 sites for potential hydro-climatic study. The HCDN-2009 sites fulfill all of the following criteria: (a) have 20 years of complete and continuous flow record in the last 20 years (water years 1990-2009), and were thus also currently active as of 2009, (b) are identified as being in current reference condition according to the GAGES-II classification, (c) have less than 5 percent imperviousness as measured from the NLCD 2006, and (d) were not eliminated by a review from participating state Water Science Center evaluators. The data posted here consist of the following items:- This point shapefile, with summary data for the 9,322 gages.- A zip file containing basin characteristics, variable definitions, and a more detailed report.- A zip file containing shapefiles of basin boundaries, organized by classification and aggregated ecoregion.- A zip file containing mainstem stream lines (Arc line coverages) for each gage.