U.S. Department of the Interior

U.S. Geological Survey

Fact Sheet 2011–3141

November 2011

U.S. Geological Survey (USGS) data resources are so vast that many scientists are unaware of data holdings that may be 

directly relevant to their research. Data are also difficult to access and large corporate databases, such as the National Water 

Information System (NWIS) that houses hydrologic data for the Nation, are challenging to use without considerable expertise 

and investment of time. The USGS Community for Data Integration (CDI) was established in 2009 to address data and information 

management issues affecting the proficiency of earth science research. 

A CDI workshop convened in 2009 identified common data integration needs of USGS scientists and targeted high value 

opportunities that might address these needs by leveraging existing projects in USGS science centers, in-kind contributions, and 

supplemental funding. To implement this strategy, CDI sponsored a software development project in 2010 to facilitate access and 

use of NWIS data with ArcGIS, a widely used Geographic Information System. The resulting software product, the NWIS Web 

Services Snapshot Tool for ArcGIS, is presented here.

U.S. Geological Survey (USGS) data resources are so vast that many scientists are unaware of data holdings that may be 

directly relevant to their research. Data are also difficult to access and large corporate databases, such as the National Water 

Information System (NWIS) that houses hydrologic data for the Nation, are challenging to use without considerable expertise 

and investment of time. The USGS Community for Data Integration (CDI) was established in 2009 to address data and information 

management issues affecting the proficiency of earth science research. 

A CDI workshop convened in 2009 identified common data integration needs of USGS scientists and targeted high value 

opportunities that might address these needs by leveraging existing projects in USGS science centers, in-kind contributions, and 

supplemental funding. To implement this strategy, CDI sponsored a software development project in 2010 to facilitate access and 

use of NWIS data with ArcGIS, a widely used Geographic Information System. The resulting software product, the NWIS Web 

Services Snapshot Tool for ArcGIS, is presented here.

In this example, the NWIS Web Services Snapshot Tool is used to retrieve surface water-quality data 

for sites in the Colorado Mineral Belt. Water-quality data are integrated with data from NHDPlus and 

the USGS National Geologic Map database to evaluate metal mobility in areas affected by historical 

mining, or that have mineralized or hydrothermally altered rocks (after Wanty and others, 2009). 

United States, many with a record of more 

than 100 years. NWIS data are considered 

the “gold standard,” authoritative source of 

hydrologic information and are accessed 

daily by USGS scientists and the public. 

Access to and management of NWIS 

data are fundamental to a variety of 

studies that examine the interrelations 

of the Earth’s hydrosphere, biosphere, 

lithosphere, and atmosphere.

ArcGIS is a software application 

developed by ESRI and is widely used 

by and available to all USGS scientists. 

The Snapshot Tool builds on software 

Product

The NWIS Web Services Snapshot 

Tool for ArcGIS enables rapid access to 

NWIS, a database containing hydrologic 

information for more than 1.5 million 

surface water, groundwater, and 

atmospheric monitoring sites throughout the 

Product

The NWIS Web Services Snapshot 

Tool for ArcGIS enables rapid access to 

NWIS, a database containing hydrologic 

information for more than 1.5 million 

surface water, groundwater, and

U.S. Geological Survey Community for Data Integration:

NWIS Web Services Snapshot Tool for ArcGIS
More than 1.5 million NWIS sites blanket the Nation, as shown here on the NWIS Mapper Web site (http://wdr.water.usgs.gov/nwisgmap).

development work of USGS scientists 

David McCulloch and Brian Reece over 

the last decade and addresses a critical 

need to quickly and efficiently access, 

manage, and use NWIS data within the 

ArcGIS environment. 

The primary scope of the current 

Snapshot Tool focuses on data retrieval 

and data management.

The Snapshot Tool allows scientists 

to query NWIS Web Services databases 

and download a “snapshot” (subset) of the 

NWIS data to a local ArcGIS geodatabase. 

The geodatabase created by Snapshot 

is structured to allow the scientist to 

immediately begin working with the data 

and eliminates the laborious process of 

reconstructing a workable geodatabase, 

which is currently the practice.

Data Retrieval

The Snapshot Tool uses the geospatial 

capabilities of ArcGIS to retrieve data directly 

from NWIS Web Services regarding site 

information, water-quality, instantaneous 

streamflow, and daily streamflow measurements. Based on user input, the Snapshot Tool 

sends requests to the NWIS Web Services and 

uses the returned data to create a geodatabase 

that reestablishes the relational data structure 

of NWIS, thus eliminating what once was a 

laborious and error-prone process. The user 

can immediately evaluate the spatial display of 

the data to determine the number, types, and 

distribution of sites within a study area. In a 

similar manner, water-quality and streamflow 

data can be retrieved and assessed to refine 

subsequent data searches. 

For more information, contact:

NWIS Web Services Snapshot Tool

Director, Texas Water Science Center

U.S. Geological Survey

1505 Ferguson Lane

Austin, TX 78754

512-927-3500

http://txpub.usgs.gov/snapshot

Community for Data Integration

Associate Director for Core Science Systems

U.S. Geological Survey

108 National Center, 12201 Sunrise Valley Drive

Reston, VA 20192

703-648-5748

http://www.usgs.gov/core_science_systems/

Authored by Sally Holl

Design and Layout by Jeanne S. DiLeo

Reference

Wanty, R.B., Verplanck, P.L., San Juan, C.A., Church, 

S.E., Schmidt, T.S., Fey, D.L., DeWitt, E.H., and 

Klein, T.L., 2009, Geochemistry of surface water 

in alpine catchments in central Colorado, USA—

Resolving host-rock effects at different spatial 

scales: Applied Geochemistry, v. 24, no. 4, April 

2009, p. 600–610.

Data Management

The Snapshot Tool creates a geodatabase with predefined relationships between 

sites and measurements taken at sites so 

that scientists can make queries, establish 

relationships with other spatial data, and edit 

the data without compromising the relational 

database structure and integrity. The Snapshot Tool translates numerous coded values 

and field names inherent to NWIS data into 

plain English so that scientists less familiar 

with NWIS terms can more readily understand the data. For example, the NWIS field 

name “parm_unt_tx” is displayed as “Result 

Unit of Measure” in the ArcGIS geodatabase.

With the NWIS geodatabase established, 

the scientist can use the functionality of 

ArcGIS to filter, visualize, and analyze NWIS 

data. In the ArcGIS environment, common 

workflow tasks, such as selecting subsets of 

data using Structured Query Language (SQL), 

importing data, such as field study results from 

a spreadsheet, building relationships to other 

data retrieved using the Snapshot Tool, and 

exporting data for use in analytical software 

packages are simplified and thus increase the 

overall efficiency of research.

Benefits to USGS Science

The Snapshot Tool allows scientists to 

explore hydrologic data while saving 

valuable time. It serves as an educational tool 

for new or infrequent NWIS users by 

translating the numerous codes associated 

with output files of NWIS data and enables 

efficient data retrieval and management for 

comprehensive integrated studies. Design 

Any use of trade, product, or firm names is for descriptive purposes 

only and does not imply endorsement by the U.S. Government.

and functionality of the Snapshot Tool are 

driven by the data integration and management needs of USGS scientists to answer 

questions about climate, the environment, 

wildlife, and other integrated science topics.

The NWIS Web Services Geodatabase 

Snapshot Tool and documentation are 

available at http://txpub.usgs.gov/snapshot. 

Pacific Ocean

Atlantic Ocean