Green Infrastructure in the City of Los Angeles - A question and answer session


Q. What is a “Green Infrastructure” project?

A: New designs for sidewalks and other landscape areas which will capture runoff and infiltrate it through landscaped and paved areas, utilizing permeable materials and drought tolerant plants. The purpose is to capture, clean, and store stormwater.


Q: What are the ideas behind Green Streets designs?

A: The streets and sidewalks of Southern California were designed and built in the 20th Century with the single purpose of moving water along quickly and directly to the ocean. What we have learned in the 21st Century is that we can design our streets and sidewalks to soak up the runoff through a more natural process, weaving the textures of nature into the streets and sidewalks. Studies have shown that if runoff is directed over vegetated areas, or areas with other kinds of porous material, the process of soaking through the soil cleans up the runoff and converts the pollution naturally.


Q: How exactly does that process work to make a difference?

A: The soil scrubs it. It is a circle of life process. In nature, there is no such thing as waste. What is waste in one setting is actually food in another. The worms, bugs and microscopic life in the soil feed on the types of things that would be pollution in water, but are food to them, when in soil.


Q: Why do we need Green Streets projects in Los Angeles?

A: Urban runoff is the number one source of pollution in southern California. We have to do everything we can to address this. Studies have shown that if we convert a lot of our paved areas from gray to green, we can address of much of the pollution in runoff.


Q. Are there Green Streets projects in other cities?

A: Yes. There are cities around the country that have started programs like this, including Chicago, Illinois; Seattle, Washington; Portland, Oregon; and Ventura, California.


Q: How many other Green Streets projects are there in Los Angeles?

A: There are at least two that have been completed and two that are in construction. The completed projects include a commercial street in downtown Los Angeles at Hope Street near 11th Street, and Oros Street, a residential neighborhood in Elysian Park.


Q: What are you learning from those Green Streets projects?

A: The projects are working well, and we are learning from the results. So far the maintenance has been minimal.


Q: What are the benefits to the City with these projects?

A: There are multiple benefits—cleaning the water is a very important one. But, these types of street and sidewalk designs can also recharge the groundwater and help with our water supply. In addition, the increased vegetation helps cool the environment when the weather is hot. And, the new designs help beautify a neighborhood.


Q: What does a project like this cost?

A: It varies, depending on the neighborhood and the site conditions. Some estimates are around $15,000 for one infiltration basin.


Q: Where does the funding come from for these projects?

A: We are seeking grant funding for the capitol costs of building these designs.


Q: What about maintenance--Who is responsible?

A: We would like to create partnerships with Green Street property owners. They have direct contact with the design and would be the first to know what looks right, what works, and how best to manage it.


Q: What if someone wanted to do a Green Street project on their own, how would they go about it?

A: We are creating design guidelines to be made available to the general public. This will allow residents to spearhead their own projects. The process should be in place within a year.


Q: How can I learn more about Green Streets LA?

View a powerpoint presentation presented to the Los Angeles City Council on December 9, 2008.

For an even more extensive look at Green Infrastructure in Los Angeles, view the paper "Green Infrastructure for Los Angeles: Addressing Urban Runoff and Water Supply Through Low Impact Development".


If you would like to find out more information please contact:

Wing Tam:  213.485.3985,
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