Hydrologic balance between surface waters and geothermal fluids in Dixie Valley, north-central Nevada, USA

Geothermal power production relies on elevated temperature, high-enthalpy and consistent transmissivity from the tapped geothermal system. The Dixie Valley power plant in north-central Nevada, has been in operation for the last 30 years with sustained fluid production and has experienced negligible temperature decrease. Indicating that the power plant has produced sustainably from the resource in that time. Chemical and isotope analysis does infer that the thermal fluids produced at the power plant are from meteoric sources yet the Dixie Valley hydrologic basin receives only an average total annual recharge of 28 million m³. The average annual fluid production at the power plant is more than 20 million m³, and would amount to a substantial portion of the total yearly aquifer recharge being produced by this facility. Mountain precipitation is suggested as the primary source for thermal fluid recharge. Mountain infiltration into regional aquifers ranges from 3-15% of precipitation and valley surface recharge is negligible due to roughly equivalent precipitation and evapotranspiration. It is unlikely that infiltration from mountain recharge is the primary fluid for this geothermal resource but rather a regional input from the broader subsurface saturated zone that supplies this system. (paper)