Rockhill uses ECO-TERR's StabiliGrid ground-reinforcement system to mitigate stormwater runoff from his projects. “It's easy to install, cost-competitive with concrete or any other hard surface material, and looks great,” he says. Manufactured from recycled polyethylene, the water-permeable grids protect roots from damage and can be used for driveways and hillside-erosion control. ECO-TERR, 425.657.7958; www.stabiligrid.com.