As El Nino was producing some powerful storms this winter, officials from a water district serving farms just outside of Sacramento got an idea.

They opened the gates of a swelling Cache Creek and let the flood waters flow into the Yolo County Flood Control and Water Conservation District’s system of irrigation canals. The canals’ dirt lining is porous enough to allow the water to seep into the aquifers, recharging a groundwater supply that’s becoming more and more important to growers.