Groundwater conditions at Mammoth Lakes, Mono County, California

Abstract

A study is presented which describes and evaluates the groundwater resources of Mammoth Lakes, with an emphasis on the aquifer characteristics of the primary hydrogeologic unit. The boundaries of the study area are roughly coincident with the limits of the Town of Mammoth Lakes, Mono County, California. Groundwater-level measurements, aquifer test results and pumpage records are analyzed in relation to the local geologic framework. Drawdowns due to pumpage are examined, and used to estimate the long-term aquifer characteristics. The comparison of aquifer parameters calculated from long term and short-term pumping periods provides the basis for determining the sustainable pumpage of wells. Due to the nature of groundwater occurrence, and the presence of hydrologic boundaries, the amount of groundwater in storage is limited. Therefore, groundwater development must be based on groundwater inflow and other sources of recharge, as opposed to withdrawing groundwater from storage over the long term.