U.S. Department of the Interior

U.S. Geological Survey

Fact Sheet 2004–3122

November 2004

Availability of Ground-Water Data for Washington, 2004

Printed on recycled paper

The U.S. Geological Survey 

has been investigating groundwater resources in the State of 

Washington since the early part 

of the 20th century. During this 

time, the use of ground water 

evolved from meager domestic 

and stock needs to complex 

requirements for public-water 

supplies, large irrigation 

projects, industrial plants, and 

numerous other uses. Groundwater data are of considerable 

importance in making resourcemanagement decisions 

including determining water 

availability, allocating water 

permits, and locating sources of 

pollution. 

National Water Information 

System

Ground-water data collected by the 

U.S. Geological Survey (USGS) are 

entered into the USGS National Water 

Information System (NWIS) (U.S. 

Geological Survey, 1998). The National 

Water Information System Web System 

(NWISWeb) web site, http://waterdata.

usgs.gov/nwis/, provides public access 

to several million items of historical and 

real-time data (U.S. Geological Survey, 

2002).

Ground-water data are published 

by the USGS in various data and 

investigative reports. A list of these 

reports is available at the USGS 

Washington Water Science Center’s 

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

data/gw/ and http://wa.water.usgs.

gov/pubs/.

Site Information

As of June 1, 2004, the Ground-Water 

Database for Washington contained 

descriptive-site-information for 85,922 

ground-water sites in the State. Of these 

sites, 84,940 are wells or test holes; 842 

are springs or seeps; and 140 are drains, 

excavations, or other types of groundwater sites.

Descriptive-site-information can be accessed 

at the USGS Washington Water Science 

Center’s web site, http://waterdata.usgs.gov/

wa/nwis/gwsi.

Ground-Water Levels and Real-Time Data

The Ground-Water Database for 

Washington (as of June 1, 2004) 

contained 222,035 discrete water-level 

measurements for 72,417 ground-water 

sites in the State. The database also 

contained data for one real-time groundwater site in Washington. 

Discrete depth-to-water data can be accessed 

at the USGS Washington Water Science Center’s 

web site, http://nwis.waterdata.usgs.gov/wa/

nwis/gwlevels, and hydrographs of the data can 

be accessed at http://wa.water.usgs.gov/data/gw/

lterm.htm.

Real-time data can be accessed at the USGS 

Washington Water Science Center’s web site, 

http://wa.water.usgs.gov/data/gw/rtime.htm, and 

hydrographs of the data can be accessed at http://

waterdata.usgs.gov/wa/nwis/current.

Ground-Water Database for 

Washington

The Ground-Water Database for 

Washington provides online access to the 

following ground-water data:

• Site information

• Ground-water levels

• Real-time data

• Water-quality data

The database is a combination of data 

collected by the USGS and by many 

other Federal, State, and local agencies; 

tribal nations; and numerous private and 

public organizations. The database does 

not include all the ground-water data for 

Washington.

Water-Quality Data

The Water-Quality Database 

for Washington contained data and 

information on the chemical, physical, 

and biological properties of ground water 

from 9,336 ground-water sites in the 

State (as of June 1, 2004).

Water-quality data can be accessed at the 

USGS Washington Water Science Center’s web 

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

Structure and Types of Data in the 

Ground-Water Database for Washington

Site Information

Ground-Water Levels Real-Time Data Water-Quality Data

Descriptive site information including latitude, 

longitude, well depth, and site use.

Depth to water or watersurface elevation in wells.

Data transmitted from 

selected ground-water sites.

Chemical, physical, and 

biological properties of 

ground water.
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Site Identification

Each site in the Ground-Water 

Database for Washington is assigned 

a unique site number and a unique site 

name. The site number 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. For example, 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.

Figure 1. Ground-water site naming system used in Washington.

References Cited

U.S. Geological Survey, 1998, National 

water information system (NWIS): 

U.S. Geological Survey Fact Sheet 

027-98, 2 p.

U.S. Geological Survey, 2002, 

NWISWeb: New site for the nation’s 

water data: U.S. Geological Survey 

Fact Sheet 128-02, 2 p. 

For more information contact

Ron Lane at rclane@usgs.gov, 

(253) 428-3600 ext. 2604, 

or 

Luis Fuste’ at lafuste@usgs.gov,

(253) 428-3600 ext 2653.

Washington Water Science Center

U.S. Geological Survey

1201 Pacific Avenue, Suite 600

Tacoma, Washington 98402

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

The site name for a ground-water 

site in Washington is based on the site’s 

location in terms of the Public Land 

Survey rectangular grid system (fig. 1). 

For example, in site name 25N/45E11K01, 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. 

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.