Catherine Buley, Rain Garden Nursery, LandscapeMakeover.biz, HTT&T. Another example of roof tiles laid in vertically to edge a garden, and separate sections. At another project Scott Buley did this at Om El Arab in Santa Ynez California to separate sunken Rain Garden Beds with Palm Trees and grass-like plantings from the higher surrounding lawns. In an arid environment this is a wonderful way to conserve water and put it to extra use adjacent to lawns. Running turf drain tiles to this lowered bed puts the water to use twice, and further filters any possible nitrate runoff, etc..