| Title | Monitoring the Hydrologic System for Potential Effects of Geothermal and Ground-Water Development in the Long Valley Caldera, Mono County, California, U.S.A. |
|---|---|
| Authors | Farrar, Christopher D.; Lyster, Daniel L. |
| Year | 1990 |
| Conference | Geothermal Resources Council Transactions |
| Keywords | Environmental; Exploration; USA; California; Mono; Long Valley Caldera; Impact; Assessment; Injection; Underground; Hydrologic Survey |
| Abstract | In the early 1980s renewed interest in the geothermal potential of the Long Valley caldera, California, highlighted the need to balance the benefits of energy development with the established recreational activities of the area. The Long Valley Hydrologic Advisory Committee, formed in 1987, instituted a monitoring program to collect data during the early stages of resource utilization to evaluated potential effects on the hydrologic system. Early data show declines in stream flow, spring flow, and groundwater levels caused by 6 years of below average precipitation. Springs in the Hot Creek State Fish Hatchery area discharge water that is a mixture of nonthermal and hydrothermal components. Possible sources of nonthermal water have been identified by comparing deuterium concentrations in streams and springs. The equivalent amount of undiluted thermal water discharged from springs was calculated on the basis of boron and chloride concentrations. Quantifying the thermal and nonthermal fractions of the total flow may allow researchers to assess changes to flow volume or temperature of the springs caused by groundwater or geothermal development. |