Staying ahead of the curve has always been important to the Los Angeles Stormwater Program, and that means adopting new stormwater management practices and in some cases completely rethinking how we look at stormwater pollution itself. One such approach is Low Impact Development (LID), which is a design principle modeled after nature, managing rainwater where it falls.

Native vegetation separates the sidewalk and the street, capturing regular urban runoff before it reaches the storm drain system.

The premise behind LID is pretty simple – mimic a site’s predevelopment hydrology by using techniques that filter, store, evaporate and contain runoff. The overarching philosophy for LID is to design solutions so that urban runoff is handled where the rain hits the ground, not at the end of the pipe. Such designs have numerous benefits over conventional stormwater management practices that include economic sustainability, the protection of public health, the improvement of community livability and the enhancement of our local environment. It’s not just about going green for the sake of going green; it’s about being smart when doing so.

Recently the City of Los Angeles City Council adopted a Green Streets Initiative that will incorporate numerous LID elements to manage runoff throughout the city. The Green Streets Initiative will implement projects in various open space areas such as streets, parkways, alleys, and parking areas.

By infiltrating urban runoff at different points throughout the city’s various watersheds, water does not enter the storm drain system where it flows to the ocean untreated.

“Our Green Streets Initiative will serve as a blueprint on how to effectively manage stormwater pollution and increase the water supply,” says Wing Tam, Bureau of Sanitation Green Streets Initiative project manager. “Addressing the issue before it becomes a problem is the best, most cost-efficient approach to dealing with urban runoff in Los Angeles. LID has the potential to have many positive benefits to our local communities.”

According to Community Conservancy International, nearly 40 percent of the needs for cleaning polluted runoff could be met by implementing LID projects on existing public grounds county-wide. Additionally, according to an August 2008 National Resources Defense Council report, LID projects implemented county-wide could save 41,000 to 83,000 acre/foot of imported water per year through groundwater recharge and water capture and reuse.

LID is just one facet of the City’s efforts to deal with stormwater pollution at the source. The application of LID to new developments is easier to apply than to rebuild the city’s existing infrastructure. As a result, areas that have already been developed require different ideas to ensure that they are striving to replicate nature’s model of treating rainwater where it falls.

In these instances the City is implementing initiatives such as the Standard Urban Stormwater Mitigation Plan (SUSMP) that addresses post-development stormwater pollution and peak flows from new and re-development projects. Other initiatives include the Downspout Disconnection Program that partners with local homeowners to capture rainwater with rain barrels, and green street projects that implement innovative local solutions from rain-catching cisterns to porous pavement on sidewalks to rain gardens that store stormwater in makeshift ponds to wetlands systems at parks. It is these types of neighborhood solutions that will solve our stormwater pollution problems and address our water supply needs.

It is the City’s belief that the tenants of SUSMP and the green street projects, along with the objectives of low impact development, will together help guide our city toward a sustainable stormwater future, where rainwater once again becomes the invaluable resource that Mother Nature intended.

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