Sun Valley Watershed

TreePeople is working in partnership with the Los Angeles County Department of Public Works, the City of Los Angeles and other local stakeholders to create a large-scale sustainable watershed management demonstration project in a 2,700-acre San Fernando Valley watershed.

The challenge

The underserved Sun Valley community located in L.A.'s San Fernando Valley has long suffered serious flooding problems. This is due, in part, to the hard pavement that covers much of the community. Instead of soaking into the ground or being captured for reuse, rainwater becomes polluted runoff with nowhere to go.

A plan for sustainability

In the late 1990s, at TreePeople's urging, the L.A. County Department of Public Works diverted funds from a proposed $42-million storm drain and allocated the money instead to retrofitting the watershed in accordance with the principles of sustainable watershed management.

The Sun Valley Watershed Stakeholders Group formed late in 1998 to examine the chronic flooding and devise sustainable solutions. Its mission is "to solve the local flooding problem while retaining all stormwater runoff from the watershed, increasing water conservation, recreational opportunities, and wildlife habitat, and reducing stormwater pollution."

The stakeholders group gives government agencies, civic groups, nonprofit organizations, private enterprises and residents the opportunity to work together to solve related problems previously tackled independently.

In collaboration with TreePeople, the group developed a Sun Valley Watershed Management Plan and Program Environmental Impact Report (PEIR). The Los Angeles County Board of Supervisors adopted the plan and certified the report in 2004. 

Sun Valley Park Multiuse Project

Tuxford Green Multiuse Project

Elmer Avenue "Green Street"


Sun Valley Park Multiuse Project

The Sun Valley Park Multiuse Project was completed in 2006 as part of the Sun Valley Watershed Management Plan. 

New sustainable features enable the park to treat stormwater and redirect it to two large infiltration basins, where the water is naturally filtered, before ultimately recharging the aquifer. Covered with playing fields, the two basins do their work silently, out of sight, while soccer and softball players are busy on the fields above. Recreational enhancements and educational signage were other important features of the multiuse project.


Tuxford Green Multiuse Project

The Tuxford Green Multiuse Project was completed in 2007 as the second phase of the overall Sun Valley Watershed Management Project.

The intersection of San Fernando Road and Tuxford Street was a serious problem spot during heavy rains in the Sun Valley Watershed. Chronic flooding in this heavily traveled part of Sun Valley often rendered roads impassible during the rainy season.

The project redesigned the intersection with a flood control system that conveys most stormwater under, instead of into, the busy intersection. Some of the water is stored in a 45,000-gallon cistern to be used for irrigating the landscaping at the new pocket park, which is planted with native and drought-tolerant species.


Elmer Avenue Green Street a Model of Environmental Healing

For decades, rain storms in Los Angeles turned Elmer Avenue, a residential street in Sun Valley, into a flood zone. In a region of the city built without storm drains, the rainy season often forced Elmer Avenue residents to wade through water simply to cross their street.

In a project led by the Council for Watershed Health, TreePeople participated with residents and other partners in transforming Elmer Avenue from a flood hazard zone to a street that’s a model of sustainability. View our five minute video "Miracle on Elmer Avenue" here:

TreePeople on a mission to save the planet

A typical approach to solving urban flooding has been to install storm drains to channel rainwater to the ocean. But as rain runs off streets and sidewalks it collects pollution and trash, which storm drains sweep out to rivers and the ocean, along with valuable water that could replenish our groundwater supplies.

Elmer Avenue demonstrates an alternative approach to dealing with flooding, related pollution, and the L.A. region’s chronic water shortages.

The street has been retrofitted with a variety of rainwater harvesting techniques that filter water back into the ground. It conserves water with the use of climate appropriate landscaping and native trees. This one city block now catches, cleans, and reuses rain and stormwater from a 40-acre area upstream. Infiltration galleries beneath the street are designed to provide 16 acre-feet of groundwater recharge annually (about the same amount of water used by 30 households in a year). The project increases wildlife habitat and community access to greenspace, and new sidewalks and solar powered street lights make the neighborhood safer and more walkable.

The result helps to reestablish the health of the Los Angeles River Watershed in a way that no neighborhood project ever has.

“The residents of Elmer Avenue are now watershed managers,” says Rebecca Drayse, former Director of TreePeople’s Natural Urban Systems Group. “Their properties and the street are literally interconnected - mimicking the natural hydrology of the Los Angeles River Watershed that’s been so greatly impacted by development for the past century.”

Neighbors have also experienced an increased sense of community and place as they’ve gathered to plant trees and care for their new landscape.

The new Elmer Avenue has become the embodiment of a Functioning Community Forest, TreePeople’s vision for a sustainable L.A. It’s a neighborhood that brings value to its environment and community by capturing the water, cleaning the air, healing the soil, and reducing its impact on surrounding land and the ocean. It’s a neighborhood that can better adapt to climate change, be resilient to droughts and flooding, and offer a healthier and more beautiful place to live.

TreePeople’s Role

TreePeople coordinated public outreach and assisted in surveying to identify a suitable street to undergo this transformation. Elmer Avenue was selected for the following reasons: pride and ownership in the neighborhood, need for infrastructure, notoriety for flooding, support from the local City Council member, and its location in the heart of Sun Valley, where TreePeople has focused for years on the Sun Valley Watershed Management Plan. During construction, TreePeople assisted the Council for Watershed Health with the project management, and led neighborhood outreach, tree planting and resident training.

Role of Partners

In addition to TreePeople, Elmer Avenue partners include:

  1. The Council for Watershed Health, which managed the transformation of Elmer Avenue and encouraged an innovative partnership between non-governmental organizations and public agencies.
  2. The City of Los Angeles, which constructed the major components of the street and parkway.

Funding was provided by:

  1. U.S. Bureau of Reclamation
  2. California Department of Water Resources
  3. County of Los Angeles Department of Public Works
  4. Metropolitan Water District of California
  5. Water Replenishment District of Southern California
  6. LA Department of Water and Power
  7. City of Santa Monic

Visit for more information about the Sun Valley Watershed Project. However, please note that the website has not been updated for some time. There is no information about current activities or upcoming projects.