Solutions Series: Greywater Systems

Water is not only essential − it is extremely limited with our exponentially growing population. In California, it is especially important that we conserve water because our land is prone to drought, and we need to prepare for a future with a even bigger scarcity of water. Preparation for a more resilient water future begins in your own home.

Greywater systems are great ways to reuse water within your own home. “Greywater” refers to used water that comes from sources inside the home like the bathroom sink, clothes washer, and showers and baths; kitchen sink and toilet water is not reused (called “black water” or sewage). Greywater is not safe to drink, but, after filtration and microbial digestion, it can be used for washing, flushing toilets, and irrigation.

 A classic simple greywater system diverts water from a clothes washing machine through a pipe into your garden. It’s a powerful way to conserve water, especially during dry summers when rainwater catchment is not productive in most of California. The efficacy of these systems are in the numbers: there are 8 million greywater systems in the U.S. with 22 million users! Check out this personal greywater system!

Recent changes in California law make it easier to legally install greywater system on your property, and they are becoming very popular in the Bay Area. Make sure to check out your city’s regulations on greywater. Generally they will require you to prevent human contact with the greywater (i.e. by installing drip irrigation just below the ground), and prevent unintentional flooding of neighboring properties. Be sure to use environmentally safe soaps and detergents, especially if you are using greywater system to water your garden.  With that in mind, let’s start re-using perfectly good water to nourish a vibrant home garden!


  •  Conserves freshwater
  •  Saves money on water bills
  •  Irrigates plants; soil naturally purifies the water
  •  Reduce the energy and chemical dependence of tap water by recycling water on-site
  •  Reclaims otherwise wasted nutrients

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