Using Gray Water at Home: Simple Systems for Water Conservation

As California endures drought, many homeowners turn to gray water. While some options require detailed designs, practical techniques can be as simple as placing a bucket in the right place. Drought-conscious Californians can help meet the 25% water reduction mandate with these home-scale methods.

Buckets of Water

Imagine the fresh water flowing down the drain while the shower warms. The average American uses 17.2 gallons showering; many in older homes waste the first few gallons due to cold temperatures. Capture this with a 3-gallon bucket. Use it to water edibles or front-yard foliage.

Go further: reuse bath water for lawns and ornamentals. Stretch it by dumping in the toilet for water-wise flushing (average toilet uses 3.6 gallons/flush). Use collected gray water within 24 hours to avoid bacteria buildup.

In the kitchen, place a plastic basin in the sink. Collect water from rinsing vegetables or washing hands, and sprinkle on the front lawn. City dwellers without dishwashers can recycle dish-soaking water for ornamentals.

Laundry to Landscape

Since 2009, California allows diverting washing machines to gardens. Art Ludwig, author and ecological designer of Oasis Designs, led the effort and serves as a knowledge hub. 40 million Californians can save 14-40 gallons per load with Ludwig's laundry-to-landscape system.

The system uses the washer's pump to disperse water to the garden. Horizontal-axis machines yield 10-25 gallons/load; vertical-axis yield ~40 gallons. With biocompatible detergent, this gray water irrigates ornamentals and fruit trees, including citrus. Ludwig uses 1-inch polyethylene pipe to handle the rush without a surge tank or stressing the pump. Many California cities offer rebates.

Plumbing Alterations

Bathroom sinks can connect to adjacent toilets, funneling faucet water to fill the bowl. Kitchen sinks can hook to gray water gardens with underground piping to ornamentals. Systems must prevent backflow into potable water. These methods generally require permits; consult your city before constructing.