When rainy weather arrives, it's harvest season
By: John Upton
Examiner Staff Writer
October 9, 2008
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| Sarah Minick and Tara Hui of the SFPUC test the rainwater harvesting system as final touches are put on it in preparation for the Big Blue Bucket eco-fair. (Juan Carlos Pometta Betancourt/Special to The Examiner) |
SAN FRANCISCO — Rainwater-harvesting systems have long graced rooftops in far-flung, water-poor lands, but for some San Franciscans — such as Tara Hui of Visitacion Valley — the exotic practice is a modern-day reality.
Hui is a trailblazer of rainwater harvesting in San Francisco, having started a small operation when it was still outlawed by The City.
Now, the 38-year-old urban farmer has 25 barrels connected to the 1,000-square-foot roof of her home — and Hui is acting as an adviser and pinup girl for a city-run campaign to convince others to emulate her once-renegade ways.
Hui picked up the empty ingredient drums for free from food manufacturers and paid about $200 for plumbing equipment, she said.
“I felt really terrible irrigating with freshwater from the tap,” Hui said. “So I just started tinkering and I looked online for some resources.”
Fortunately for Hui and residents who hope to cut utility bills and prevent sewage-tainted floods in The City, water officials are lending a helping hand to the growing conservation trend.
A plumbing rule was changed in 2005 to allow San Franciscans to rearrange their gutters to funnel rainwater into tanks and drums.
The change allows residents to conserve water as well as reduce the amount of rainwater that flows into The City’s sewer system.
The sewage and stormwater that gushes beneath the streets can overload the sewer system during storms.
“There’s no reason why we should send all of this rainwater to our treatment plant when we could capture it and use it,” said Public Utilities Commission official Sarah Minnick. Minnick is spearheading a campaign of giveaways, workshops and potential subsidies to promote urban rainwater harvesting as part of a $100,000 water-outreach program.
If every drop of rain falling on a 1,000-foot roof in the Mission district is harvested, a household could save 12,500 gallons of water and $196.41 on their water bills in a year of average rainfall, according to analysis of Public Utilities Commission figures and historical weather data from The Examiner.
Minnick suggests using harvested rainwater for cleaning and irrigation rather than for drinking. City permits and plumbing skills are needed to use rainwater in toilets.
Rainwater has long quenched households in the dry continents of Australia and Africa, and droughts and growing demand for water in the United States are beginning to help a growing industry sell more equipment here, industry members told The Examiner.
California’s rainwater-harvesting industry is in its infant stages, but it’s growing quickly as the statewide water crisis becomes more severe, said Tim Pope, president of the 500-member American Rainwater Catchment Systems Association.
“As water’s getting more scarce, people are getting a bit more hip to it,” said Tim Antonoplos, a salesman for a tank-supply company based in Southern California, where rainwater harvesting is more common than in Northern California.
The 20 or so inches of rain that fall each year in San Francisco — which is less than half that of Portland, Ore., and about 50 percent more than that of Los Angeles and Stockton — is very clean because it falls from storms that have arrived from the Pacific Ocean, National Weather Service meteorologist Dwane Dykema said.
Despite the abundance of clean rainfall, just a handful of San Francisco residents have started capturing water that runs off their rooftops since 2005.
“People don’t quite know what to do with the water,” Minnick said. “People call us, and we try to hook them up with various resources.”
To demonstrate rainwater harvesting’s simplicity, Minnick’s team recently installed an array of eight rain-catching barrels at the water treatment plant in the Bayview district. They bought the barrels, which were originally used to import olives into the U.S., from a hardware store.
The Public Utilities Commission will begin raffling off 100 barrels during workshops at its Big Blue Bucket Eco-Fair at Jerrold Avenue and Phelps Street in the Bayview from 10 a.m. to 2 p.m. Saturday, and it’s considering offering subsidies to cut the costs of harvesting systems, Minnick said.
Water from above fuels plans for new City Hall
A lavish network of ponds and fountains planned in front of City Hall will be nourished using rainwater, but it will also be topped up with tap water or groundwater during drier months.
The decorative system, which might provide water for irrigation and to flush toilets, will trap stormwater to help prevent it from flooding The City’s sewers after storms, according to Public Utilities Commission water official Rosey Jencks.
The network is part of Mayor Gavin Newsom’s recently announced plan to turn the Civic Center into a “sustainability district.”
One of the district’s goals would be an 80 percent water-use reduction at City Hall.
Newsom spokesman Joe Arellano said nonstorm-water sources of water will sometimes be used for the feature, saying drinkable water will be used only “where required.”
Funding for the $2.6 million system has not been secured.
“We hope to receive future Federal Energy and Water Appropriations, SFPUC budget line items and grants,” Arellano said in
an e-mail.
Do-it-yourself rainwater harvesting
Tips
Redirect your downspout into containers connected by tubes
Use emptied food-grade barrels instead of new plastic containers
Food manufacturers sometimes give away empty barrels
Avoid harvesting water off tar-covered rooftops
Clean your rooftop before installing a system
Clear debris out of gutters frequently
Costs
$10 to $35: Empty 55-gallon wine or food barrel
$660: Plastic 400 gallon urban water tank (29” x 60” x 71”)
$28 and up: Gutter connection with leaf and mosquito screen
$58 and up: Optional diverter to avoid initial runoff from dirty rooftop
$28: Optional water filter
$525: Optional 115-volt hose pump
Sources: Public Utilities Commission; craigslist.org; Loomis Tank Centers; Tara Hui
