rainwater collection system
Many Northern California counties now offer rebates for rain barrels purchased for residential use. (Water Cache)

Water didn’t just pour into city streets during last week’s storm, it was also stashed away by rain harvesting enthusiasts.

“It’s crazy we have all this wasted water that is flooding our cities and we could be capturing and using it,” says Claire Elliot, a home owner in Palo Alto. Elliot has six barrels in her back yard that she uses to water her plants.

Though they hold a total of 300 gallons of water, she says all six filled up within a couple of hours.

“I was excited to see them fill up but the question is whether I can use all the water before the next storm event.”

The water is not potable but can be used as “graywater,” for outdoor irrigation, laundry and dish washing.

Volunteers for Acterra, an environmental non-profit, install rain barrels at Arastradero nature preserve in Palo Alto. (Acterra)
Volunteers for Acterra, an environmental non-profit, install rain barrels at Arastradero nature preserve in Palo Alto. (Acterra)

It hasn’t been universally embraced. In parts of the West, rainwater harvesting has been outlawed, seen as an infringement on those who have downstream water rights on rivers where that rain might end up.

But Californians have legally been able to collect household runoff without a permit since 2012. In fact, several counties and the Bay Area Water Supply & Conservation Agency provide up to $100 in rebates for barrels or cisterns purchased for rainwater harvesting.

BAWSCA has issued 75 rebates since launching its program in October. “We were getting calls the first day after the program was announced,” says Water Resources Manager Michael Hurley.

San Francisco will start a similar program by spring of next year.

Most systems for corralling rainwater use a barrel, a mesh screen and a diverter. As rainfall collects in rooftop gutters, instead of gushing out of downspouts it takes a detour through the diverter and into storage.

Since the first rush of water often contains contaminants like leaves, insects and animal waste, many diverters will capture this debris and prevent it from flowing into the barrel, and the mesh discourages mosquitoes from using the collected water as a nursery.

In Australia, rainwater collection systems became standard accessories during the recent nine-year drought known as the Big Dry, but have been slower to catch on in California. During a previous four-year program, San Francisco issued fewer than 1,000 rebates for rain catchments within the city.

“This is a tangible activity that people can do on their own to try and help address drought conditions,” said Hurley. “It won’t be the entire solution but it provides some benefit to home owners and the region.”

Rain barrels are available at most large hardware supply stores and hold between 50 and 200 gallons of water. A 100-gallon barrel costs about $200.

Storms a Boon for Rainwater Harvesters 18 December,2014Lindsey Hoshaw

  • Alexis
    • Pat Hendriks

      does the Rain Barrel Diverter System include Rain Barrels? It is not clear from the description especially the part describing how to assemble the s ystem. And are there any Ca locations where these are sold? thanks

      • Lindsey Hoshaw

        Hi Pat,
        Thanks for the comment! You’ll usually need to buy all the parts separately. Some companies sell everything but the barrel: http://rainreserve.com/complete-diverter-kit

        You’d probably be able to buy supplies locally at Home Depot or Lowe’s but I would call ahead and check.


  • Vinita
  • We should abolish laws against collecting rainwater. Its like kicking the Karma baby in the face. Jesus would not do this.

  • Roger

    I believe collecting rainwater is a waste of time and money with the small volumes that most people can collect. 200 gallons of water will only last a couple of weeks in a small garden and then you are back to using potable water. During the rainy season you don’t need the stored water and after 2 weeks you need to use city water for 7 or 8 months. Therefore you may conserve maybe a 1000 gallons watering during the dry periods between storms and one last time as the dry season starts.

    • anysteph

      Even so, 1,000 gallons across millions of households absolutely makes a difference.

      • Roger

        Assuming a family of four uses the Bay Area average of 84 gallons per person per day, they will still use 122,640 gallons in a year, so saving 1000 gallons a year is saving only 0.82% of their total annual use. It would be far better to have plants that don’t need water during the winter, dry or wet, and that need little water in the summer. Spend your rain barrel money on drought resistant plants instead.

  • Charlee Myers

    Although at least the idea of collecting rainwater is finally taking hold in California, it does not take long to realize that not only are 55 gallon drums woefully inadequate but also do not provide much stored water over the long term. Rainwater catchment is common over much of the US, especially in the Southwest. Anyone interested can find out much more about rainwater harvesting by going to http://www.arcsa.org

  • Jeff Hutcher

    I would like to echo Charlee’s comment and add that rainwater is NOT considered Gray water. Graywater is recycled water that comes from showers, baths, lavatories, and laundries. As for reusing rainwater for other than irrigation, California requires that the water be treated to NSF 350 standards for non-potable use on the interior of the building. Rainwater is used for potable water systems outside of California with the proper design and treatment. The Current California Plumbing Code has the regulations in chapter 16 for Gray Water and Chapter 17 for Rainwater. Design standards are in ARCSA standard 63. Become a member and be part of solving the water crisis. A few storms will not end our drought and most water ends up as run off. Totally wasted. FInd out more at http://www.arcsa.org

  • Jeff Hutcher

    Wayne, The current regulations make for safe design. After Katrina rainwater catchment systems were outlawed because there were no mosquito controls and they breed like, well, like mosquitoes. Also, while rain barrels do not need permits, mosquito control is essential. Also, the article is a little misleading in saying no permits are required. They just don’t need to be permitted by the water quality control board. You are not exempt from permits from you local Jurisdiction. Again, barrels do not require permits.


Lindsey Hoshaw

Lindsey Hoshaw is an interactive producer for KQED Science. Before joining KQED, Lindsey was a science correspondent for The New York Times, The Boston Globe, Forbes and Scientific American. On Twitter @lindseyhoshaw

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