Going Grey: Greywater Systems Catch on During Drought

03/23/2015 01:00 pm ET | Updated May 23, 2015

Winter storms brought rain to parts of California, but the storms brought little drought relief to the parched Golden State as a whole.

According to a recent L.A. Times editorial by NASA Jet Propulsion Lab water scientist Jay Famiglietti, California has “one year of water supply left in its reservoirs ” and “immediate mandatory water rationing should be authorized across all of the state.”

With more water regulations on the horizon, Californians have to learn to live with less water and start figuring out ways to conserve now.  

One of my personal resolutions for 2015 was to install a greywater system - using water from sinks, showers and washing machines - at our house to help irrigate our yard with water that would otherwise be flushed away. But with greywater systems come more rules and regulations, not to mention installation hassles, so I decided to reach out to greywater system expert Laura Allen for answers.

Allen is a co-founder of Greywater Action, a  California collaborative group dedicated to sustainable water culture and infrastructure, and author of a new DIY home water conservation guidebook, The Water-Wise Home.

In 1999, Allen built a greywater system in her backyard out of concern over household water use, which sparked an interest in exploring low-tech, sustainable water solutions. Today, Allen participates in writing state-level greywater and composting toilet codes, and leads sustainable water classes, workshops and training programs for professional greywater installers.

“The California drought is one of the most critical water issues facing the country today,” Allen said. “It highlights the need we as a country have to reexamine our use of water at all scales - agricultural, industrial, and residential.”

On the residential side, Allen notes, one overlooked solution is greywater.

“Greywater, gently used water coming from showers, sinks, and washing machines, is the most abundant supply of water most people don’t know exists,” she said. “A home can reduce their consumption while irrigation a beautiful landscape."

In her book, Allen outlines how residents can use a fraction of the water used in a conventional home without sacrificing modern comforts.

“Greywater systems save water,” Allen said, referring to a Greywater Action study researched in collaboration with the City of Santa Rosa, EBMUD and Ecology Action. “A recent study found overall water usage decreased after households installed greywater systems by an average of 17 gallons per capita per day (gpcd), which represents an average reduction of 26% (48 gpcd down from 65 gpcd).”

By comparison, Allen notes that if 10% of homes in Southern California installed a greywater system from their washing machine, it would save about as much water as the new Carlsbad Desalination Plant is projected to produce for San Diego.

The good news for Californians, Allen noted, is that greywater regulations have improved because of a lack a water resources. Some agencies even provide financial incentives for buildings that reuse water for irrigation purposes.

“Now, people can install a simple system in their homes legally, and some types of systems don't even require a permit so long as health and safety guidelines are followed,” she said. “Other systems do require permits. A few cities have improved their permitting process so it's doable for the average homeowner to get a permit. Other cities haven't, and people encounter frustrating and expensive hurdles, such as being double-permitted, requiring engineered drawings, or expensive soil testing. Other states, like Arizona and New Mexico, have very supportive regulations. Oregon and Washington have recently adopted a greywater code, though it is somewhat restrictive.

“The rest of the country either has an overly restrictive code in place, or no regulations. As states reexamine their codes the trend is towards better, more greywater friendly regulations.”

Allen’s website and book have more information on guidelines and the permitting process, as well as step-by-step instructions for building and installing simple laundry-to-landscape (L2L) and other sustainable water systems.

The San Francisco Public Utilities Commission has also created and handy San Francisco Graywater Design Manual for Outdoor Irrigation.

If you’re interested in more information on greywater systems, Greywater Action also holds workshops on creating your own water-wise home and landscape.

“It is exciting to see individuals all across the country rethink and redesign their home water systems,” Allen notes in her book. “It’s even more exciting to watch it scale up when a city or water agency invests in green infrastructure and promotes decentralized systems. From Portland, Ore., to San Francisco, Calif., from Tucson, Ariz., to Chicago, Ill., large-scale change is happening.”