Data from Selected U.S. Geological Survey National Stream Water-Quality Monitoring Networks (WQN)
USGS Digital Data Series DDS-37

By Richard B. Alexander, James R. Slack, Amy S. Ludtke, Kathleen K. Fitzgerald, and Terry L. Schertz

Water-Quality and Streamflow Data

The water-quality and streamflow data sets are available for 679 locations in the United States including 63 HBN stations from 1962 to 1995 and 618 NASQAN stations from 1973 to 1995 (two stations belonged to both networks during the period of operations; also the number of network stations operated in any year periodically changed).

Note that the number of water-quality analyses conducted in NASQAN and HBN has changed over time because of changes in sampling frequency and the number of stations and water constituents (see the accompanying Open-File Report 96-337 for details).

Supporting information identifies and describes the water-quality and streamflow stations and watersheds, water-quality constituents, and the methods, remarks, laboratories, sample-collection agencies, and the laboratory measurement accuracy associated with the water-quality data.

WQN water-quality and streamflow data can be obtained for stations in a specific water-resources region by first selecting the corresponding region number from the list below. The organization of the data files and file formats are described in a subsequent section.

The Water Resources Council developed a hierarchial classification of hydrologic drainage basins in the United States of which the first level of classification consists of 21 water-resources regions as shown below.

Hydrologic Units of the United States Region 01 Region 02 Region 03 Region 04 Region 05 Region 06 Region 07 Region 08 Region 09 Region 10 Region 11 Region 12 Region 13 Region 14 Region 15 Region 16 Region 16 Region 17 Region 18 Region 19 Region 20 Region 21

The gray lines are state lines, the blue lines are major rivers, and the white lines are water-resources region boundary lines.

Region 01 New England
Region 02 Mid-Atlantic
Region 03 South Atlantic-Gulf
Region 04 Great Lakes
Region 05 Ohio
Region 06 Tennessee
Region 07 Upper Mississippi
Region 08 Lower Mississippi
Region 09 Souris-Red-Rainy
Region 10 Missouri
Region 11 Arkansas-White-Red
Region 12 Texas-Gulf
Region 13 Rio Grande
Region 14 Upper Colorado
Region 15 Lower Colorado
Region 16 Great Basin
Region 17 Pacific Northwest
Region 18 California
Region 19 Alaska
Region 20 Hawaii
Region 21 Caribbean

Organization of the Data Files

Within each of the 21 water-resources regions, the water-quality and streamflow data are organized in separate station and parameter files. The name of each file is ssssssss.ttt where ssssssss is the 8-digit USGS station number, and ttt is:

File Formats

Within each file there is one record for each date and time sampled except for the daily mean streamflow values where there is one record for each day of the month (31 records to a calendar year). The records are sorted by date, time, and ending date (which may be present for some biological data). The instantaneous streamflow recorded at the time of water-quality sampling is stored in each of the water-quality data files, and is available for use in cases where water-quality and streamflow pairs are required (e.g., correlations between water-quality and flow).

Supporting Water-Quality and Streamflow Information

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Last modified: Thu Mar 8 17:28:40 EST 2001