Passive Rainwater Harvesting

Two types of rainwater harvesting trap and hold storm run-off: active harvesting and passive harvesting. The goals of passive water harvesting are to slow the runoff down, spread the water out, and soak the water in. This is achieved through land contouring that catches and directs runoff using berms and swales into catchment areas. At GardenCasaKayT, the backyard was largely cleared except for the major landscape trees, and 60 yards of 1/4 minus decomposed granite was introduced in order to create two catchment areas we nicknamed Lake Ebony and Lake Mesquite, along with the berms and grading that guide water to them. Then, five separate channels of drip irrigation were installed that provide water in the dry seasons. In the front of the house, diverters were installed on the roof dividing the runoff into gutters that feed catchment basins in the tortoise pen on the east side where grasses and other tortoise foods grow, and a rain garden for succulents including aloes and agaves shaded by two hybrid mesquites. On the north-west, a gutter drains and channels water to water two large Aleppo Pines and to flood one of the orchards. Virtually all the water falling on the roof area of the primary dwelling is passively harvested and directed to the various catchment areas. The Front Circle garden area is at the highest elevation on the property. Several catchment areas have been created to maximize water retention, and the driveway has been contoured so that any overflow is directed around the garage to the two orchard areas on either side.

More Information