South Lake County sits on sand, and sand keeps no secrets about water: pour it on and it slips past the roots almost as fast as it lands. That makes irrigation the quiet backbone of every green yard in Groveland, above all through the dry stretch of April and May before the summer rains return. South Lake Irrigation works on the lawns and the watering that keeps them alive here: sprinkler zones, heads, the arcs of spray that decide whether a yard stays lush or browns at the corners. There is real pleasure in a system set right, water landing on the grass instead of the sidewalk, a thin patch by the mailbox finally filling in. Before sunrise, when a Groveland street hisses softly with sprinklers, that is this trade at work in the dark.