In Southwest Colorado, where water rights are a marketable commodity, it’s important to know how much water is available.

Measuring the flow in the Animas River is one of the chores assigned to Jennifer Dansie, a hydrologic technician with the U.S. Geological Survey in Durango.

“We supply data that a lot of people, businesses and agencies depend on,” Dansie said recently while carrying out her duties at the USGS gauging station near the intersection of U.S. Highway 550 and 14th Street in Durango. “We collect nonbiased data. We don’t interpret it.”

Water districts, municipalities, farmers and ranchers, developers, construction engineers, researchers, rafting companies and the National Weather Service pay attention to the water flow in the Animas River, she said.

Dansie, a 10-year employee of the USGS, has a degree in environmental geology from Fort Lewis College. She worked for the agency for three years in Salt Lake City but jumped at the chance to return to Southwest Colorado.

The USGS maintains more than 7,000 gauging stations on rivers and lakes across the country. The Durango office manages 41 stations in La Plata, Archuleta, Montezuma, San Juan, Dolores, San Miguel, Ouray and Montrose counties.

The station near U.S. Highway 550 and 14th Street went into service in 1895, only six years after the first one ever was installed in New Mexico on the Rio Grande River to help determine whether there was sufficient water for irrigation.

The USGS computerized its gauging nationally in 1983 and first made real-time data available online in 1995.

The job this day for Dansie – the duty rotates quarterly among three hydrographers – is to calibrate equipment to ensure the most accurate readings possible.

On-site calibration is done every six to eight weeks. In the interim, solar-powered equipment at the station relays the river level via satellite to a database.

But direct observation plays a factor, too.

As an example, Dansie said, she and other hydrographers are alert to shifts of boulders or sandbars in a channel after high runoff because a change in their position can influence the water level at the gauging station.

Hydrographers also watch for readings that are out of the norm, Dansie said.

One reading Dansie took used a 20-pound, three-pontoon boat to ford the river. The Acoustic Doppler Current Profiler measured the width, depth and velocity of the water, which translates to cubic feet per second.

“If there’s a lot of sediment in the water, the signal in our ADCP doesn’t work,” Dansie said.

daler@durangoherald.com