• Credit: Todd Trumbull/The Chronicle

While much of the nation is still waiting to thaw out from a long, cold winter, California, which is in the midst of a three-year drought, has recorded the warmest winter on record. According to Christian Science Monitor ("Warmest winter on record worsens California drought," 3/17/14),the dry spell in California is so bad that produce farmers are considering idling a half million acres of cropland, and several small communities are at risk of running out of drinking water. But the dry spell is not isolated to California alone (news that is particularly Surprising to those of us in colder climates who are now growing weary of frequent snow storms). Overall rainfall across the U.S. - an average of 5.7 inches in the past three months - has made for the ninth driest winter on record, according to the National Climatic Data Center. Already, 600 wildfires have burned in California since January, sparking predictions that this year's wildfire season will break the record, as well (CNBC "Western wildfire season 'likely to set a record,'" 2/20/14).

Ongoing drought has not only focused attention on the resiliency of housing (see "Can Your Home Survive a Firestorm?" 2/14/14), it has also intensified interest in saving water. According to a recent article in the San Francisco Chronicle, "investing in water efficiency may be among California's, and the West's, most effective and strategic path to water resilience ..." (see "Gray water's time in the sun," 2/24/14). The article makes the case for grey water recovery as a center piece for "saving California" ... or at least California landscaping. (The complete path to water resiliency will also have to include even simpler measures like low-flow fixtures).

Greywater is defined in the California  Health and Safety Code as “untreated wastewater that has not been contaminated by any toilet discharge, has not been affected by infectious, contaminated, or unhealthy bodily wastes, and does not present a threat from contamination by unhealthful processing, manufacturing, or operating wastes.” It includes the discharge from bathtubs, showers, bathroom washbasins, and clothes washers, but does not include waste water from kitchen sinks or dishwashers.

Under California regs, simple "laundry-to-landscape" irrigation systems - grey water recovery from washing machines that do not alter the existing plumbing - do not require a permit, making them the easiest to implement. More elaborate systems will have to be permitted, which will also require a plot plan, drawings and plans of the graywater system, and soil tests. The Greywater Guide offers a helpful discussion of codes in several states, plus detailed guidelines for designing and installing grey water irrigation, and even grey water treatment for indoor re-use. This latter option is sure to  face intense regulatory scrutiny. But if the drought continues, state health officials could relax controls much quicker than we might imagine.