Water data flows to the Web

It may be water under the bridge, but it doesn't have to be forgotten. The U.S. Geological Survey possesses historical information about water — stream flows, well levels, pH amounts and more — dating back more than 100 years. But the information was stored in 48 National Water Information System databases and access was limited.

A new Web site, however, provides a single point of access to all of that data as well as real-time information about water in all 50 states, the District of Columbia and Puerto Rico. The site, called NWISWeb (water.usgs.gov/ nwis), gives water managers, scientists, engineers, emergency managers, recreational water users and others a place to find surface and ground.water information collected in the past or still being collected.

"We have created a nation.ally seamless view of these 48 databases," said David Briar, a Montana-based USGS hydrologist who helped develop NWISWeb. "This is the first real attempt to put a Web interface on our water database."

USGS, charged with collecting Earth science information and supplying it to the public, began offering water data on the Web in 1995. However, that site was limited to stream-flow information — historical information and, later, current data transmitted by satellite from some 21,000 monitoring sites along streams. Other state-specific sites sprang up as well.

In 1998, USGS developers began designing a system that would display water information from all 48 databases, plus data such as precipitation and temperature. They also wanted to include information about more varieties of water bodies, such as lakes, wells and springs. NWISWeb is the result.

"I think it helps the American public see the vastness of the amount of data we have," said Susan Trapanese, chief of national Internet data systems for USGS. "People can see data much quicker than they could in the past and better find out what they really want."

About 1.5 million collection sites are represented on the Web site (see box), which contains the historical data and the current information from field workers and monitoring sites. Each of the 48 NWIS databases sends data to USGS headquarters in Reston, Va., where a central NWISWeb database server and Web server are housed.

Visitors to the Web site can use the information to evaluate water supplies and quality, forecast floods or droughts, help operate hydropower plants, navigate waterways or simply plan safe fishing, canoeing or rafting expeditions, according to USGS officials. Real-time water-level information helped some users respond when tropical storm Allison hit Texas in June, officials said.

The data quality was a major issue in developing the system, Briar said. Copies of the same data have been placed, and sometimes altered, throughout the 48 databases, resulting in incomplete or inaccurate datasets. The new system includes software to help local offices identify questionable data and prevent it from being included.

"We're trying to purge the data that we feel is highly questionable," Briar said. "Part of the process is to leave control of the data as close to where the data was collected as possible."

Although the site was intended to help the public access water data, USGS water officials have found it useful too, Briar said. Previously, accessing an NWIS database from another state required getting authorization or a copy of the information, he said. Now USGS researchers can use NWISWeb.

"It's really freed up the way we do business internally," Briar said. "We're using the Web more and more to do our own internal work."

There are plans to develop a mapping utility for NWISWeb, Trapanese said. Currently, a user needs longitude and latitude coordinates or must know the county or the name of a specific body of water. A map interface would be easier to navigate, she said.

Briar also said tools will be added to help users better understand what they're viewing.

"We've just gotten the data out, and I see significant enhancements coming down the pike to better place this data in context and explain what it means," Briar said. "That's what we're really focusing on."