How Los Angeles leads the way in water conservation

These days, California's a watchword for severe drought. But the city with a famous (and immortalized in film) problem with water is leading the way in innovative solutions for the water shortage.

Image credit: 19951007 01 Los Angeles River by David Wilson/flickr/CC BY 2.0

Writing for The New York Times, Jacques Leslie outlines all the ways Los Angeles has managed to reduce its water usage to the point where it uses less than it did in 1970, despite a 1.1 million increase in population. It started with activists providing the local government with a proof of concept:

[T]wo environmental campaigners, Dorothy Green of Heal the Bay and Andy Lipkis of TreePeople, were telling anyone who would listen that the flood-control infrastructure should be reorganized to capture water, not cast it into the sea. If storm water is harvested and directed into aquifers, they argued, floods can be prevented. Then the stored water can be pumped when needed, treated and consumed.

To prove his point, in 1998 Mr. Lipkis's nonprofit retrofitted a house in South Central Los Angeles, then staged a mock flood. The house's roof was lined with gutters that fed rainwater into two 1,800-gallon cisterns, and the lawns in the front yards and backyards were lowered six inches to form a wetland. On the big day, local officials watched from beneath umbrellas as a 4,000-gallon water truck dumped around 15 tons of water on the roof, yet none of it left the premises.

The property functioned instead as a miniature watershed, storing water for outdoor use or absorbing it and redirecting it to an aquifer below. Flood-control officials were so impressed that they dropped a $42 million proposal they had been considering for a storm drain in a highly flood-prone section of the San Fernando Valley called Sun Valley and instead introduced a plan to test storm water capture there.
The resulting plan, completed in 2010, retrofitted a Sun Valley city block into a rain catcher, with rain water collected into barrels for later use. Any run-off waters a network of rain gardens and sidewalk plants. The plan also redone the flood-prone streets:

The street itself was excavated, filled with a six-foot-deep layer of gravel fed with rainwater through large perforated pipes and topped with pavement; in an average rain year, that expanse should collect enough water for 80 houses, not just the 24 retrofitted ones. As the water slowly drips into the aquifer below, it is cleansed of pollutants it collected on the street. By encouraging natural processes that perform ecological services, the project simultaneously mitigates flooding, pollution and water scarcity.
The results, notes Leslie, are impressive. The price tag of the Sun Valley project was $300 per acre, while the price of importing water hovers between $800 and $1,000 per acre. Fully implementing this system in the city could add as much as 309,000 acre-feet per year to the city's water supplies, when the current consumption is 587,000 acre-feet per year.

The result is a 20-year plan to completely retrofit the city, which Leslie points out will be difficult when over 100 different entities work in Los Angeles County's water business. And even though Los Angeles has been relatively quick to recognize and use a new solution, it can't be implemented soon enough to relieve the current drought. However, it's still an encouraging sign that a city the size of Los Angeles, in a state that is constantly trying to save money, can lead by example in the area of water conservation.

http://io9.com/how-los-angeles-is-le...tio-1669678481



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