Hat tip to ‘just some guy’ for sending this in, from the latimes.com:
Dina and Irl Cramer were looking at the little-used pool behind their Manhattan Beach house when they realized: “It would be really nice to have a garden,” Dina said. But rather than simply jackhammer out the pool or bulldoze it full of dirt, the Cramers turned the pit into a case study for how Southern Californians can capture winter rains for use watering the garden. The edges of the pool were ground down, and the rest of the concrete form was retrofitted with a rainwater-storage system.
Now, in place of a concrete basin filled with chlorinated water, the Cramers have a stream, a small waterfall and about 100 lush plants — all fed with rain harvested from the roof and stored in recycled-plastic tanks underground. (At right, photos of the old pool and construction after it was filled.)
The water savings come not only from using less tap water to irrigate the garden but from not having the pool.
About 24,000 gallons of water can evaporate from a big pool every year, according to Mike Garcia, a self-described pond geek and founder of EnviroscapeLA, the Redondo Beach firm that designed the catchment system.
“The rainwater-harvesting system is the landscape world meets the pond world,” said Garcia, who likened the design to “a big, pondless waterfall on steroids.”
Garcia used a Clean Rain system, manufactured by Atlantic Water Gardens, that flushes the first minutes of a rainfall — often laden with dirt and roof debris — to the sewer. Then gravity feeds the subsequent “clean” rain into Eco Rain tanks installed where the pool used to be. The tanks can store 6,000 gallons, compared with the 50 to 70 gallons that a typical rain barrel can hold. Electric pumps send water from the Cramers’ storage tanks to a recycled-plastic Rain Bird drip irrigation system that feeds the plants as well as the waterfall and stream.
The Cramers said they spent five figures on the pool conversion, which broke ground in October. The system has been operational since late January, so the Cramers don’t yet know exactly how much energy is being used to pump and irrigate, or how much tap water they’re saving. But Garcia estimated that the waterfall costs less than 10 cents an hour to operate, the lighting 16 cents. The system is expected to irrigate the garden with rainwater 10 months out of the year. If the rainwater runs out, the system switches to tap water.