Springs dot landscape near Mead

Monday, June 8, 1998 | 10:14 a.m.

In the parched, rocky landscape surrounding Lake Mead, searching for water anywhere away from the lake or the Colorado River seems to qualify as an errand for a fool.

But Karl Pohlmann, an assistant research hydrologist for the Desert Research Institute's Water Resources Center in Las Vegas, is no fool.

He has discovered more than 80 springs in the 1.5 million-acre Lake Mead National Recreation Area that includes lakes Mead and Mojave. As a result, the area around the springs will be protected from urban sprawl and wild life preserved.

"We expected to find the origin of the regional aquifers," Pohlmann said, explaining that groundwater originates far outside the area.

"The most significant and unexpected finding of the study was the existence of so many springs that discharge groundwater from small flows," he said. These waters receive most, if not all, of their discharge from local rainfall.

The local springs, some of which are seasonal, make up more than a third of the area's total water sources, but they are not used to serve Southern Nevada's thirsty population. The springs are seasonal and can't be relied on by water utilities.

"The amount of water from these small springs may not be great," Pohlmann said, but the springs are often the only source of water for a number of small, diverse plant and animal habitats.

"They are critical to the area's natural character," Pohlmann said.

The National Park Service has been counting the springs since 1936 when the agency came to Southern Nevada, spokeswoman Karen Whitney said. Park Service rangers rescued rabbits and other small animals stranded on islands formed as the water rose behind Hoover Dam, she said.

Pohlmann was asked to hunt for the origin of the springs as the Las Vegas Valley population continues to boom, increasing the demands on the local groundwater. The Park Service wanted to find the source of the springs and protect them, Pohlmann said.

Assisted by DRI colleagues Jenny Chapman and Sam Earman with David Campagna of the College of William and Mary, Pohlmann applied advanced chemical and geological analysis to find the springs' origins and groundwater pathways.

Using stable elements and traces of radioactive tritium remaining from above-ground nuclear weapons explosions at the Nevada Test Site, Pohlmann tracked the springs.

The region's complex rock formations, which force ground water through various structures, chemistries and compositions, also added clues.

As more people visit the Lake Mead region, the National Park Service will use Pohlmann's study to help preserve the desert's natural diversity.

The Desert Research Institute is a non-profit, statewide division of the University and Community College System of Nevada. DRI has 400 scientists, technicians and support staff conducting some 140 research projects a year.