San Francisco Dives into Rainwater Harvesting
It may be the middle of a drought in California, but two Fridays ago, students and public officials celebrated the power of rain at Caesar Chavez Elementary School in San Francisco’s Mission District. Mayor Gavin Newsom looked on as students used rain collected in large buckets to water a vegetable garden.
The scene came as part of a new citywide initiative to encourage collection and reuse of rainwater for non-drinking purposes. "Rainwater harvesting," city commissioners call it, though it’s just a fancy way of saying “irrigation." This ancient agricultural technique served as the cornerstone of early human civilization--and in modern urban centers, San Francisco officials say, it may help alleviate growing demand for drinking water supplies.
More than anything else, the San Francisco initiative aims to raise awareness of water consumption, and pave the way for innovative conservation methods to enter the public dialogue—not only in San Francisco, but also nationwide. “We’ve been hearing a lot about our carbon footprint, it’s time to start thinking about our water footprint,” said Ed Harrington, general manager of the San Francisco Public Utilities Commission.
So you wan to save your rain? You have a lot of options, but the San Francisco utility commission recommends connecting a 60 gallon bucket to your home's gutter system. When it rains, water will flow from your roof to the gutters, and then into the bucket. If the bucket fills up, you can flip a switch to have the gutter water discharge as if the bucket wasn’t there at all.
For a limited time, the city has teamed up with a local hardware store to offer discounts on easy-to-install buckets. If $70 seems a like a hefty investment for negligible savings on your annual water bill, there are always DIY options that you can make on the cheap. San Francisco resident Tara Hui, the rainwater harvesting enthusiast largely responsible for winning city officials' support, built her 25-barrel system at almost no cost using recycled barrels and found parts.
To be sure, a 60-gallon drum in your backyard won’t suddenly have reservoirs bursting at the seams. If half of Francisco’s roughly 750,000 residents managed to conserve one big bucket full of water annually, it would amount to 22.5 million gallons--enough to supply only about 175 of more than 105 million households in the United States (an average household uses 127,400 gallons of water annually, according to American Water Works Association).
There are also technological variables and regulatory hurdles to consider. People living in large apartment buildings or densely populated urban centers need large underground cisterns or other technology to harvest rainwater. While the legal groundwork now exists for single house bucket systems in San Francisco, considerable trailblazing would have to occur for larger and more complicated systems to become common.
Of course, water conservation efforts have to begin somewhere. If environmentalists want gray water and black water conservation systems to gain mass acceptance, a little blue bucket may be just the ticket to get started.