U.S. Department of the Interior

U.S. Geological Survey

Fact Sheet 2009–3082

August 2009 Printed on recycled paper

USGS Water Data for Washington

USGS Water Data for Washington

The U.S. Geological Survey (USGS) has been 

investigating the water resources of Washington State since the 

latter part of the 19th century. During this time, demand for 

water has evolved from primarily domestic and stock needs to 

the current complex requirements for public-water supplies, 

irrigation, power generation, navigation, ecological needs, 

and numerous other uses. Water-resource data collected by the 

USGS in Washington have been, or soon will be, published 

by the USGS Washington Water Science Center (WAWSC) in 

numerous data and interpretive reports. Most of these reports 

are available online at the WAWSC web page 

http://wa.water.usgs.gov/pubs/.

Water Resource Data

Water-resource data collected by the USGS are stored for 

internal use in the USGS National Water Information System 

(NWIS). To disseminate these data to the public, the USGS 

maintains a publicly accessible version of NWIS known as 

NWISWeb that can be accessed at 

http://waterdata.usgs.gov/wa/nwis/.

NWISWeb provides public access to several million items

of historical and real-time water-resource data, which can be 

viewed and downloaded in various formats. As shown in figure 1,

NWISWeb allows access to five categories of water resource data:

Real-Time Data

Real-time data are time-series data recorded at fixed 

intervals by automated equipment, are transmitted by satellite 

telemetry, and represent the most current hydrologic conditions. 

Real-time data for Washington are available at

http://waterdata.usgs.gov/wa/nwis/rt, 

and the web pages listed in the Surface water, Groundwater,

and Water quality sections. The real-time web-page contains 

streamflow, reservoir, water-quality, meteorological, and 

groundwater data from about 300 sites, including about 240 

sites that have satellite telemetry for real-time data and another 

20 sites that use other communications methods to transmit near 

real-time data.

Figure 1. Screen capture of NWISWeb home page for Washington.

In addition to water-resource data 

collected by the USGS, NWIS 

and NWISWeb include data 

collected by many other agencies, 

tribal nations, and organizations. 

However, neither database 

includes all the water-resource 

data collected in Washington State.

• Real-time data 

• Site information

• Surface water

• Groundwater 

• Water quality
Site Information

Descriptive site information for Washington is available at

http://waterdata.usgs.gov/wa/nwis/si. 

The site-information web page contains descriptive-information

for more than 91,000 data sites in Washington. About 86,000 

of these sites are wells or other groundwater sites, 850 are 

springs or seeps, 4,600 are surface-water sites, and 530 are 

miscellaneous sites such as subsurface drains and soil test sites. 

Descriptive information for each site includes: 

• Site identification number 

• Site name

• Latitude, longitude, and horizontal datum

• County and State where site is located

• Hydrologic Unit Code (HUC)

• Land surface altitude and vertical datum

• National and local aquifer in which well is completed 

(groundwater sites only)

• Drainage area (surface-water sites only)

Surface Water 

Surface-water data for Washington are available at

http://waterdata.usgs.gov/wa/nwis/sw.

The surface-water web page contains data for about 1,800 sites

in Washington, including:

• Real-time data for 253 automated sites

• Daily data for more than 1,057 sites 

• Daily, monthly, and annual statistics for 1,035 sites

• Peak-flow data for 975 sites

• Field measurements of streamflow discharge and 

gage height at 1,798 sites

Groundwater

Groundwater data for Washington are available at

http://waterdata.usgs.gov/wa/nwis/gw.

The groundwater web page contains data for about 73,000

groundwater sites in Washington including:

• Real-time water-level data for one site 

• Daily water-level for two sites 

• Daily, monthly, and annual statistics for two sites

• Field water level measurements for more than 73,000 sites
Water Use

Since 1950, the USGS has, at 5-year intervals, 

compiled and published data on the amount of water used 

in homes, businesses, industries, and on farms throughout 

the United States. The water-use data for Washington 

State can be accessed at the WAWSC web page at

http://wa.water.usgs.gov/data/wuse/.

Water Quality

Water-quality data for Washington are available at 

http://waterdata.usgs.gov/wa/nwis/qw. 

The water-quality web page contains data for nearly 15,000

sites in Washington, including 12,000 groundwater sites, 

2,700 surface-water sites, and 500 miscellaneous sites such as 

subsurface drains and soil-test holes. These data include:

• Real-time water-quality data from 28 automated sites

• Daily water-quality data for 55 sites

• Daily, monthly, and annual statistics of water-quality 

data for 39 sites

• Field and laboratory analyses of chemical, physical, 

biological, and other environmental properties for

about 15,000 sites
4 0N

1N

1 0

2 0

3 0

4 0N

1N

1 0

2 0

3 0

4 0 4 7E 1 0 2 0 3 0 1 0 1W 1E

1 0 2 0 3 0 4 0 4 5E 1 6W 1 0 1E 1W

Willamette Meridian 

Willamette Base Line 

SECTION 12 

6 MILES 1 MILE 

25N/45E-11K01 

D C B A

E F G H

M L K J

N P Q R

R. 45 E. 

T. 

25 

 N. 

6 5 4 3 2 1

7 8 9 10 11 12 

18 17 16 15 14 13 

19 20 21 22 23 

NW NW NE NW NW NE NE NE 

SW NW SE NW SW NE SE NE 

NW SW NE SW NW SE NE SE 

SW SW SE SW SW SE SE SE 

SECTION 12 

1 MILE 

NW NE 

SW SE 

24 

30 29 28 27 26 25 

31 32 33 34 35 36 

W A S H I N G T O N 

474033117044001 

For surface-water and other sites where water is 

exposed on the land surface, the site ID is typically 

an 8 to 10 digit downstream order number, which 

locates the site in terms of the site’s distance from 

the source (upstream end) of the surface-water body. 

For surface-water sites the station name consists of 

five parts: (1) the feature name (stream, canal, or 

reservoir); (2) the generic name (“River,” “Lake,” 

“tunnel” and so on); (3) the term to indicate location 

(“at,” “above,” “below,” “near,” and so on); (4) the 

place name (city, town, or major feature); and (5) 

the State or States where the reference place name is 

located. For example: SPOKANE RIVER BELOW 

UPRIVER DAM AT SPOKANE, WA. 

Water Data for Other States

Publicly viewable water-resource data for other 

states are available at 

 http://waterdata.usgs.gov/wa/nwis/nwis

by using the navigation buttons in the lower left

corner of the banner to select the data category and 

geographic area of interest. 

 

Public Inquires and Data Requests

Inquires and requests for data and reports may be 

made on-line at the WAWSC web-page,

http://wa.water.usgs.gov/pubinfo/

Or by contacting the Public Information Officer,

 253-552-1635

Washington Water Science Center at:

U.S. Geological Survey

Washington Water Science Center

934 Broadway, Suite 300

Tacoma, Washington 98402

http://wa.water.usgs.gov/

Although many agencies 

and organizations in 

Washington use similar 

numbering and naming systems, 

consistency of assigned site 

numbers and names between 

agencies should not 

be assumed. 

Site Identification

Every site in NWIS and NWISWeb is assigned a unique 

site identification number (site ID) and a unique site or station 

name. For groundwater, springs, and most non-surface-water 

sites the site ID is a 15-digit number formed from the initial 

latitude and longitude of the site in degrees, minutes, and 

seconds, and a 2-digit sequence number. The first 6 digits of the 

site number are the latitude, the 7th through 13th digits are the 

longitude, and the 14th and 15th digits are sequence numbers 

used to distinguish between sites at the same location. Leading 

zeros are used as needed so the site number will not contain 

blank spaces. Although the site number is based on the initial 

latitude and longitude of the site, once assigned, the number 

is used only as an identification number; it has no location 

significance and cannot be changed.

The site name for a ground-water site in Washington is 

based on the site location in terms of the Public Land Survey 

rectangular grid system (fig. 2). For example, in site name 

25N/45E-11K01, 25N indicates the township north of the 

Willamette base line; 45E indicates the range east of the 

Willamette meridian; 11 indicates the section; and K indicates 

the 40-acre tract (quarter-quarter) within the section. The 

number following the section (01) is a sequence number that 

indicates the order in which wells in the same quarter-quarter 

were identified for entry into the database. A suffix after the 

sequence number indicates that a well has been deepened (D1) 

or reconditioned (R1) after its initial construction. The suffix S 

identifies a site as a spring rather than a well.

Figure 2. Well numbering system in Washington.