(Beckwourth) - Starting at some point in late April or early May, the California Department of Water Resources will be conducting an airborne geophysical survey of the Sierra Valley.

This work, involving the collection of data from a large hoop towed beneath a helicopter flying roughly 200 feet above the ground, is designed to reveal underground geologic structures by measuring the electromagnetic properties of subsurface materials. Typically, fine-grained materials, such as silts and clays, are electrically conductive and represent areas resistant to the percolation of water. Coarse-grained materials, like sands and gravels are electrically resistive and more likely to allow recharging of an aquifer.

Funded by voter-approved Proposition 68, the data will assist the Sierra Valley Groundwater Management District with the implementation of measures designed to assist with efficient recharging of the Sierra Valley aquifer.