Search for groundwater gets high-tech boost
Groundwater is one of the hottest ticket items in California’s water world these days.
But much about it is a mystery. Where is it? How does it move? Which are the best spots to percolate water into the ground for storage?
At least two technologies hope to answer some of those questions: airborne electromagnetic surveys and interferometric synthetic aperture radar. That’s AEM and InSAR for short.
AEM uses large hoop frames dangled from helicopters that bombard the earth with radio waves and measure the responses to determine what materials are underground down to 1,000 feet deep. InSAR uses satellite radar waves to measure how much the earth’s surface has sunk or bulged upward to determine how water moves underground.
AEM technology has advanced to the point that the state Department of Water Resources will begin regular helicopter surveys over California groundwater basins starting this summer. The flights will begin in the Salinas Valley and may reach the San Joaquin Valley by fall, but flights haven’t been scheduled that far out yet.