Chemistry and Source of Water to Cave Springs, Great Basin National Park

Great Basin National Park encompasses about 120 square miles of the highest peaks of the southern Snake Range in eastern White Pine County, Nevada near the border with Utah. Adjacent Spring Valley and Snake Valley are places where the Southern Nevada Water Authority has applied for rights to pump ground water. The National Park Service is concerned that pumping of ground water could affect water resources of the park and are concerned about the effects of pumping on their water rights at Cave Springs. Cave Springs is in the Lehman Creek drainage about 1 mile upstream of Lehman Caves and the park headquarters. Additionally, Cave Springs are near two popular camping areas and the park managers also are concerned about potential sources of contamination to the springs. A recently completed study indicated that the Lehman Creek drainage near and downstream of Cave Springs could be susceptible to ground-water withdrawals from Snake Valley. Effects of pumping on water resources in the susceptible area is dependent on the location and quantity of water pumped from the ground. The source of water from these springs is unknown. Cave Springs could be more susceptible if the springs discharge from carbonate rocks because the rocks are juxtaposed against basin fill east of the springs.

Objectives

Determine the source of water to Cave Springs using geochemistry.

Strategy and Approach

The approach planned for determining the source of water to Cave Springs is to use geochemistry in relation to geology to determine if the discharge is derived from water flowing through the glacial deposits or if the water is from bedrock beneath and next to the glacial deposits. The study will include collecting water samples from Cave Springs, Lehman Creek, a permanent pool in Lehman Caves (Middle Cambrian Pole Canyon Limestone), and from a spring at the contact between Proterozoic Prospect Mountain Quartzite with Mesozoic granite near site B2 in the Baker Creek drainage. The samples will be analyzed for major and trace elements, stable isotopes of oxygen and deuterium, strontium isotopes, and carbon isotopes. Rock samples of Middle Cambrian Pole Canyon Limestone where Lehman Caves are located will be collected and fresh samples will be collected from an outcrop at the Gray Cliffs in the adjacent Baker Creek drainage. Rock samples will be crushed to 4 mm or less and equal portions of crushed rock and water from Lehman Creek mixed in sealed containers. The samples will be agitated 4 times a day. Water will be decanted from two sealed containers after 2, 7, and 14 days and analyzed for the same dissolved constituents as those from the natural samples. The chemical and isotopic analyses will be incorporated into geochemical mixing models using NETPATH (Plummer and others, 1994) and the geochemistry of water from Lehman Creek, Prospect Mountain Quartzite and Pole Canyon Limestone.

Relevance and Benefits

The proposed study is relevant to issues 2, 3, 4, and 5 of the Nevada Water Science Center Science Plan. Issues 2-4 pertain to human and ecological health and the quality of life. Issue 5 pertains to Federal-Local water conflicts. The study also is consistent with a goal of the USGS Strategic Plan, which is to provide water-resource managers with accurate, reliable, and impartial scientific information. The work will benefit the National Park Service by providing information necessary for sound resource management and protection decisions with respect to its water supply at Great Basin National Park.

Publications

Publications which were recently released are listed below. A complete list of USGS Nevada WSC publications about Eastern Nevada also is available: Eastern Nevada Bibliography

Prudic, D.E., 2007, Hydrology of the Great Basin National Park: Nevada Water Resources Association Regional Tour of the Carbonate System Guidebook, p. 49

Elliott, P.E., Beck, D.A., and Prudic, D.E., 2006, Characterization of surface-water resources in the Great Basin National Park area and their susceptibility to ground-water withdrawals in adjacent valleys, White Pine County, Nevada: U.S. Geological Survey Scientific Investigations Report 2006-5099, 157 p.