E-Mail Water is an ephemeral thing. It can emerge from an isolated spring, as if by magic, to birth a babbling brook. It can also course through a mighty river, seeping into the soil until all that remains downstream is a shady arroyo, the nearby trees offering the only hint of where the water has gone. The interplay between surface water and groundwater is often overlooked by those who use this vital resource due to the difficulty of studying it. Assistant professors Scott Jasechko and Debra Perrone, of UC Santa Barbara, and their colleagues leveraged their enormous database of groundwater measurements to investigate the interaction between these related resources. Their results, published in