Elmer Avenue Green Street Project Explored

July 8, 2010 § 20 Comments

AFTER: Elmer Avenue Green Street with bioswales, underground infiltration galleries, solar lighting and more - photo by LASGRWC

A few weeks ago, L.A. Creek Freak had the pleasure of attending the grand opening of the Elmer Avenue green street project in Sun Valley. My earlier post mainly described the opening festivities, with little project information. Today’s article fills in more of the details.  

BEFORE: Elmer Avenue with no sidewalks, no stormdrains, no street lighting - photo by LASGRWC


First credit where credit due: This great collaborative multi-benefit project has many parents. They include:  the Los Angeles and San Gabriel Rivers Watershed Council (their project website is www.lasgrwc.org/elmer ) the city of Los Angeles (multiple Department of Public Works’ Bureaus: Sanitation, Street Lighting, and Street Services,  and the Department of Water and Power), TreePeople, U.S. Department of the Interior Bureau of Reclamation, California Department of Water Resources, California Water Resources Control Board, L.A. County Department of Public Works, Upper Los Angeles River Area Watermaster, Water Replenishment Distict of Southern California, Metropolitan Water District, city of Long Beach Stormwater Management Division, city of Santa Monica Environmental Programs Division, Pomona College, University of California Riverside, and Urban Semillas.

Big kudos also to Los Angeles City Councilmember Tony Cardenas and Public Works Commissioner Paula Daniels for their high-level actions in making the project happen.  

The Elmer Avenue Neighborhood Retrofit Project is located in Sun Valley, in the northeast San Fernando Valley. For a map showing the project location, see Creek Freak’s earlier post. It’s one block, about 600-feet long – 1/10th of a mile – with 24 detached homes. It’s a mainly Latino, working-class neighborhood, not poor, but not well-off.  

Look ma! No conduit! Solar streetlight on Elmer Avenue

One of the things that I found impressive about Elmer is that its public infrastructure is “off the grid” in a couple of ways. Creek Freak will mostly focus on the water aspects of that (below), but the street also has solar streetlights that are not attached to the electrical grid. These are actually the first such lights in the city of Los Angeles.

Of course, they’re long-lasting energy-efficient LED lights.  

The solar panels at the top of the lamppost are clear to see. Also, about a third of the way down the pole is a box, which contains the battery. There are no wires that connect this pole to the rest of the city’s electrical grid.  

The water on the street is also off of the city’s “water grid” – ie: the system of storm drains connecting to creeks, washes, rivers and the ocean. Historically this street suffered from problems with the water grid: drainage problems – the street used to flood during the rainy season.  

Now, all the rainwater that falls on this street (and on some adjacent streets) is captured. Nearly all of that water is infiltrated – soaked into the ground to recharge groundwater aquifers. The rest of the water is re-used.  

The main device that captures stormwater is a large underground infiltration gallery – buried below the street. I like to think of it as an underground box that’s missing the floor. In this case, here’s what the infiltration device looked like before it was buried:  

What the Elmer Avenue infiltration galleries look like before they were buried under the street - photo by LASGRWC

These are now buried – note the street level manhole cover. Runoff water flows into grated stormdrain openings at the north end of the street. The upstream openings are actually on Stagg Street – just around the corner from Elmer.  Excess water flows in, settles out some trash and other solids, then makes its way down those two black pipes. The pipes are perforated, so the water leaks out into the ground.

The soils in the northern San Fernando Valley are relatively good for infiltration (they’re basically the relatively unstable San Gabriel Mountains being washed into the alluvial plains), so, with the capacity of the two long perforated pipes and the area they leak into (plus the other street features), there’s enough volume to contain nearly any storm that could come along.

Bureau of Sanitation Engineer Wing Tam explained it all to me

All this capacity is a good thing, because there’s not really any outlets at the end of the pipes. Most projects like this might connect to a stormdrain for overflow volumes, but there’s no stormdrain in this area, so the infiltration is just off the grid.

In a deluge of biblical proportions, the underground and surface features could feasibly fill, and then stormwater would flow on the streets as it had before the project. Los Angeles City Bureau of Sanitation, Watershed Protection Division engineer Wing Tam assured me that the soil percolation is so good at the site, and the system volume so great, that this overflow should never take place.

Soaking the surface water into the ground mimics what a healthy natural watershed does. Instead of quickly sending polluted waters flooding into our rivers and creeks, projects like this send some of that water into our underground acquifers. That increases local water supply; we can pump that water up later, instead of importing so much water from faraway places – at great cost, including energy costs which contribute to global warming. It also helps us to make it easier to restore our creeks to health, because downstream from these sorts of projects, the creeks are a little less polluted and a little less flood prone.  

Longtime Creek Freak readers know that I am much less into the underground gizmos, than I am into the surface manifestations that reveal rainwater processes to the casual observer. The underground devices are more expensive to install and maintain than surface interventions. For healthy Los Angeles watersheds, we’re going to need some buried devices, which do great things for water quality and definitely do offer multiple benefits.

The drawback is that  these underground fixes can also put our water (and problems it too often carries) out of sight and out of mind. Water on the surface – like y’know creeks – is also more likely to provide broader spectrum of multiple benefits – improved water quality, increased water supply, decreased flood risk – plus urban greening, habitat, and an increased human awareness of and connection with natural processes going on around us. These above ground projects also increase in effectiveness over time, as plants grow and ecosystems become more complex. The gizmos tend to work perfectly on day one, then gradually get worse, and require maintenance efforts. 

(A parenthetical note regarding comparative volumes: The volume of the underground infiltration galleries is about 750,000 gallons – 2.3 acre-feet. The volume of surface infiltration in the project [described below] is about 115,ooo gallons… so the underground stuff is the workhorse in this project – contributing 87% of the capacity. Hiding a lot of volume underground allows for greater concentration and centralization.)  

The good news is that this project has the best of both worlds – plenty of great underground multi-benefit capacity, and also lots to see and follow on the surface, too.  

The features are both in the public realm – sidewalks, parkways – and in the private realm – front yards, driveways, walkways, even rain barrel cisterns. First, let’s take a look at the public area improvements.   

Sidewalk left, curb right, depressed swale mini-creekbed center, complete with drought-resistant native landscaping including yarrow

Prior to this project, the street had no sidewalks or curbs. Now it has both. Not ordinary ones, though. Between the curving sidewalk and curb (in the parkway), there’s a depressed area – technically called a bioswale – but basically a man-made mini-creekbed.  

At the upstream end of each swale is an inlet for rainwater to flow in from the gutter.  

Inlet for rain garden bio-swale

At the downstream end is a similar-looking outlet where excess rainwater can overflow back out into the street.  

Water from the street drains into the swale, where it soaks into the ground, and naturally waters the plants there. Here’s what the dry swale looks like:  

Dry curbside bioswale on Elmer Avenue - photo by LASGRWC

and here’s a shot of the same swale full of rainwater, from a rainstrom earlier this year:  

Elmer Avenue curbside bio-swale filled by half-inch rainstorm - photo by LASGRWC. Truth in blogging: this photo was actually taken before the one above it, which was taken a day later, showing how the water soaked in.

Elmer Avenue residents were engaged in the various aspects of the project; indeed, one reason the street was chosen was due to interest they showed during the selection process. The residents could choose various improvements to made on their property. Most participated; a few didn’t. Depending on what was needed and desired, different residents adopted different individualized features.  

Young oak tree among new flowering native landscape on Elmer Avenue

Improvements on private front yard property included installation of new waterwise native plant gardens.  

Rocky retrofitted front yard on Elmer Avenue

 Here’s a before shot of one home:  

Before: Elmer Avenue home, nice, but fairly typical suburban landscape with plenty of grass - photo by LASGRWC

  And here’s what it looks like after the retrofit was done with it:  

After - much less thirsty native groundcover, plenty of mulch, rocky swale... actually somewhat closer to what southern California landscape used to look like - photo by TreePeople

Spot the rain barrels

Here’s a Where’s Waldo type game: in the after images above, you can spot rain barrels?  They’re terracotta brick -colored like the photo on the left.  

The barrels are filled by rain running from the roof into the downspout. Once the rain barrel fills up, overflow water runs into the depressed rock-lined swale. Rain water saved in the barrels, can later be used to water the yard, conserving water and money. Rainwater is also very high-quality, with less salts than our local tap water (which isn’t too bad.) Plants love it.  

Some of the walkways and driveways were also converted to paver systems, which also allow for water to soak into the ground. In the photo above,  the curved brick pathway (along the driveway) is made of permeable pavers. Water percolates into the cracks between the bricks and sinks down into a gravel bed below them.  

Here’s a closer shot of a permeable driveway, being doused during the opening reception last month:  

Permeable driveway on Elmer Avenue

The Elmer Avenue Neighborhood Retrofit Demonstration project is an excellent project. It truly showcases many ways that we can make neighborhoods more sustainable, more healthy, more aware and how to look great while doing all that. I expect that this green street will just get better and better over time, too.  

If you’re in the area, I suggest that you drop by and check it out. Especially when rain is forecasted!


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§ 20 Responses to Elmer Avenue Green Street Project Explored

  • […] Valley. One of the L.A. River kayakers was Joe Linton, a.k.a. L.A. Creek Freak, who reports on the Elmer Avenue Green Street Project in Sun Valley. This green street is off the grid, with solar-powered street lights that aren’t connected to […]

  • Herbie Huff says:

    Joe! This all looks great, and I like spotting the rain barrels. I have three questions. The first (which I hope you won’t interpret as a criticism, cause it’s really just a question) is, how much did this cost?

    The second relates to building codes. Is it legal for anybody to put a rain barrel out to catch rainwater? I remember talking to you earlier about how building codes make it difficult to do catchment.

    The third question is random – do you know how Pomona College is involved in this project? I notice them in your upfront list of credits and my ears perked up because I worked closely with the Claremont Colleges’ water policies a couple years ago.

    Thanks for the detailed write-up and photos! I learn a lot when I read your posts.

    • Herbie and All, Joe and JT did a great job responding to the 2nd Question.

      Regarding the 1st question: the Cost for the project was approximately $2.7 Million, of that approx. $1.7 Million is the construction. We are working on a better breakdown of the costs of the underground versus above ground and will post it to our website when it is complete.

      For the 3rd Question: Professor Bo Cutter from Pomona College has worked with the project and the TAC provided support regarding economic analysis of the project and these types of projects.

  • Wally Knox says:

    I had not heard of you folks before I saw this posting. Who are you guys?

    This posting is absolutely gorgeous. You deserve much more attention.

  • Georgia says:

    The inclusion of the during and after rain event photo really supported your observations.

  • Mike Letteriello says:

    Excellent presentation. I already have a sustainable front yard, but a redo is now more in the works after seeing some of these photos. Good motivators.

  • chimatli says:

    What an amazing project! It cheered up day to read about it. Let’s make all of the streets in Los Angeles like this!

  • JT says:

    Great photos and info…Little puzzled at Herbie Huffs comment “I remember talking to you earlier about how building codes make it difficult to do catchment”.

    We have 18 rain barrels on our property. Also the City of Los Angeles gave away rain barrels last year in a pilot program in Mar Vista.
    There are currently plans underway to give homeowners rebates for rain barrels.
    (Santa Monica already does this) The news is updated on this site: http://www.lastormwater.org/index1.htm

    Not sure why there is confusion about having rain barrels.

    Good Luck.


    • Joe Linton says:

      @JT & Herbie (and I emailed to try to get answers for your other questions, Herbie) this probably deserves its own article… some day!

      Regarding harvesting rain and its legality in the city of Los Angeles: My understanding (which I mentioned briefly parenthetically here: https://lacreekfreak.wordpress.com/2009/07/22/l-a-city-rainwater-program-looking-for-westside-owners/ ) is that there are at least two institutional barriers to rainwater harvesting in the city of Los Angeles. It’s unclear that either of these are ever actually enforced… and they’re certainly waived for city projects like Elmer Avenue and the rain barrel installation pilot program.

      1. Building and Safety Codes
      I need to look up the actual language, but there are codes that say that when you build a site, you need to drain rainwater off your site into the stormdrain system.

      2. Water Rights
      The city of L.A. (mainly the DWP) has very stong legal rights to the above-ground and underground waters of the Los Angeles River, so if you’re harvesting rainwater upstream of the river (ie: anywhere in the river’s watershed) and preventing it from getting to the river… then the city can legally stop you from preventing the water from getting to them. It’s very unlikely that the city would come after a single rain barrel user on this… but it’s something where if I build a gazillion gallon cistern, and start selling water to my neighbors, I could get in trouble.

      To its credit, the city-DWP (and MWD and others) are interested in and involved in pilot projects (including Elmer Avenue) that will change this status quo. They know that some conservation is needed in times of drought/scarcity.. but they haven’t the official regulations just yet.

  • nancysteele says:

    Regarding costs – Edward answered the question correctly, but I want to point out that this is a “full course, soup to nuts” retrofit that is designed to demonstrate multiple strategies and techniques for an urban retrofit. Built into the costs are lots of hands on education and outreach plus water quality monitoring before and after. As Edward said, we are working on breaking down the costs for each strategy.

    Also, one correction to Joe’s excellent blog – the street has two catch basins, one on Stagg and one on Keswick, each connected to perforated pipes to collect the flow.

    • Joe Linton says:

      Thanks for the praise and for the correction! Keswick is at the south/downstream end of the block. Thanks, Nancy and Edward, Watershed Council folks for doing this project and for filling in details on the comments.

  • The legal questions are really valid concerns… but I have to wonder with infiltration projects, it would be odd for anyone to say you were taking water away from downstream users if they used the water primarily from groundwater and that is where you are PUTTING your runoff. Is giving someone MORE water against the rules?

    • Joe Linton says:

      Infiltration is a whole ‘nother can of worms.

      It’s of course great for a dozen reasons… but engineers worry about if it’s done at inappropriate locations (say chromium or radioactive toxic sites) it can turn a soil contamination issue into groundwater contamination. For the most part, I think that this is not an issue in residential neighborhoods in L.A. and soils actually help break down pollutants like small amounts of hydrocarbons… but it’s important to infiltrate in the right places… and there’re plenty of “experts” who don’t want people to infiltrate without things permitting and testing and fees and more.

      The want water, but it’s gotta be clean!

  • […] July 23, 2010 · Leave a Comment That’s what some people are calling the new green street retrofit – I guess because the swales look like little canals. Or maybe it’s because the street is just so pretty right now, after the plants have been in the ground for a couple of months. Emily Green, LA Times, calls it “The Dry Garden,” and Sunset Magazine’s Fresh Dirt blog says it is “a model, we hope, for the future.” I like the Mother Nature Network blog’s headline, “Elmer Ave. in Sun Valley, Calif., is ready for stormy weather.” You can read the most complete coverage on LA Creek Freak in the piece that has generated the most comments of any posting I’ve seen so far, “Elmer Avenue Green Street Project Explored.“ […]

  • Permapave had a storm grate retrofitted and installed at the Elmer Ave site on 10/29/10. 100% of gross pollutants will now stay above ground and only allow pure water to enter the storm drain system. This will also significantly reduce municipal maintenance spending – you no longer have to physically remove refuse from the system and floatables stay out of waterways. http://twitpic.com/31wv5n

  • […]  One project exemplifying this change is the Elmer Avenue Neighborhood Retrofit in Los Angeles California. The street was located where a confluence of multiple impervious […]

  • […] The infiltration trenches manage 87% of the storm water which is about 750,000 gallons. […]

  • […] That’s what some people are calling the new green street retrofit – I guess because the swales look like little canals. Or maybe it’s because the street is just so pretty right now, after the plants have been in the ground for a couple of months. Emily Green, LA Times, calls it “The Dry Garden,” and Sunset Magazine’s Fresh Dirt blog says it is “a model, we hope, for the future.” I like the Mother Nature Network blog’s headline, “Elmer Ave. in Sun Valley, Calif., is ready for stormy weather.” You can read the most complete coverage on LA Creek Freak in the piece that has generated the most comments of any posting I’ve seen so far, “Elmer Avenue Green Street Project Explored.” […]

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