Agency gathers data about salinity of water under Paradox Valley
MONTROSE — The U.S. Geological Survey began using a helicopter last week to study the features of the Paradox Valley in western Montrose County, collecting soil salinity data to learn how the area formed over the past 250 million years.
The flights are expected to continue through the end of the week, depending on weather conditions, according to USGS spokeswoman Marisa Lubeck.
A low-flying helicopter is flying multiple routes over the Paradox Valley from south of the Dolores River to the northwest end of the valley, including areas around the towns of Bedrock and Paradox, according to a press release from the USGS.
The helicopter is operated by Abitibi Helicopters Ltd. from Calgary, Canada, whose pilots will cover an area four miles wide by 14 miles long, suspending USGS radio equipment on a cable beneath the helicopter, measuring electrical properties found in the Earth.
The equipment can penetrate the Earth’s surface up to 1,500 feet and will provide scientists data to better understand the area’s basic geological framework and assist in understanding the hydrogeological system as it pertains to the area’s aquifer, according to Jared Abraham, a geophysicist with the USGS.
“This area is a complex geological environment that has impact on the salinity of the Colorado Basin,” Abraham said. “Water managers often put this data directly into groundwater models to do predictive analysis of management scenarios.”
The Paradox Valley was formed nearly 250 million years ago by the collapse of a massive salt dome.
According to the USGS, groundwater in the valley comes into contact with the top of the salt formation, where it becomes nearly saturated with sodium chloride. Saline concentrations have been measured in excess of 250,000 milligrams per liter, by far the most concentrated source of salt in the Colorado River Basin.
Groundwater then surfaces in the Dolores River. Reclamation studies show that the river picks up more than 205,000 tons of salt annually as it passes through Paradox Valley.
Data collected during this survey will be used to map the depth and flow of saltwater beneath the valley. The USGS also is preparing a report for the Bureau of Reclamation, describing the flow of saltwater to the Dolores River.
The USGS said residents in these areas should not be alarmed by the low-flying aircraft.