Sun Valley Watershed

Los Angeles County Department of Public Works Earns Platinum

The Sun Valley Watershed Multi-Benefit Project in Los Angeles County, Calif., has earned the Envision® Platinum award—the highest level attainable in the Envision system. The L. A. County Board of Supervisors accepted the award from ISI President and CEO, William Bertera, during the Board Meeting on August 26, 2014.

The County of Los Angeles Department of Public Works, as the managing agency, provided leadership and coordination in the development of the Sun Valley Watershed Multi-Benefit Project, which is a first-of-its-kind venture geared to managing storm water for the Sun Valley Watershed. The project provides flood protection, improved watershed health, increased open space and recreational opportunities, and increased wildlife habitat. The project also received 67% of the Department’s applicable Envision credits; the most any project has received to date from the Envision infrastructure rating system.

The project consists of several completed components including Tuxford Green, Sun Valley Park Drain and Infiltration System, Elmer Avenue Neighborhood Retrofit, and the Elmer Avenue Paseo. Other components include the Rory M. Shaw Wetlands Park and the Sun Valley Watershed Upper Storm Drain System and Recycled Water Line, which are in the final design stage. The Valley Steam Plant and the Whitnall Powerline Easement components are in the conceptual design stage.

“The Sun Valley project received the ISI Envision Platinum award because of its high levels of restorative qualities applied in a previously underdeveloped area,” said ISI President and CEO, William Bertera. “Sun Valley’s high rating also reflects remarkable innovation — not only does the project mitigate flooding in an area that has historically had issues with severe floods, but it also retains storm water in a manner that fulfills local water needs and reduces storm water pollution all at the same time,” Bertera said.

Public Works Director Gail Farber said she was proud of the project and the achievement of its platinum award status.

“The Sun Valley Watershed Management Plan represents the County’s most comprehensive effort to date to include watershed management and sustainability principles into Public Works’ horizontal infrastructure projects,” Farber said. “The evaluation of this project by the industry’s leading sustainability rating system has allowed Public Works to benchmark the plan and showcase the County’s ongoing commitment to sustainable practices.”

The Envision system measures sustainability in infrastructure projects through the measurement of five categories: Quality of Life (QL), Leadership (LD), Natural World (NW), Resource Allocation (RA), and Climate and Risk (CR) that contribute to overall credits for the positive social, economic, and environmental impacts in a community in the planning, design and construction of infrastructure projects. The highest-rated project categories that Sun Valley scored using the Envision rating system included:

Quality of Life (QL): The proposed project rated highly in the Quality of Life category. In relation to the stormwater and flood protection, the project included the transformation of an inert landfill to a flood control detention basin, wetland, and park that greatly benefits the local community at many levels. The project eliminates local street flooding during moderate storm events, which enhances public safety and health. The project also includes storm water quality improvement measures such as wetlands and trash exclusion devices, and will provide the community with access to much needed public space for social interaction and recreation.

Leadership (LD): Los Angeles County provided leadership and coordination in developing the Sun Valley Watershed Management Plan. The implementation of the management plan is dependent on strong partnerships and collaborations between various agencies, environmental groups, political offices, and the community. The project components were developed and designed based on key stakeholder involvement. In some instances, the community had direct input in the project design such as choosing the recreational amenities in the public park. Los Angeles County performed extensive outreach, purchasing a landfill site, incorporating sustainable design, and improving community living. A long-term monitoring and maintenance plan was also implemented effectively to maintain the viability and function of the project.

Natural World (NW): The project scored highly in the Natural World category primarily due to the main scope of the work: restoration of floodplain functions and the management of stormwater. The construction of detention basins and wetlands will store and treat stormwater respectively from the affected watershed prior to ground infiltration for recharge of local aquifers. The project also restores native habitat to the project site with native landscaping, and incorporates wetlands, infiltration trenches and basins, bioswales, and treatment trains to reduce pollutant load concentrations prior to ground infiltration. Best management practices are stipulated and implemented during construction to prevent surface runoff from the site. A detailed hazardous material removal plan was developed to contain, handle, and remove contaminated material safely from the project site.

Also rated by the ISI Envision system were the Resource Allocation and Climate and Risk categories of the Sun Valley Watershed Multi-Benefit project, along with the three previous categories. Highlights from these categories helped the project win with the Envision Platinum award and include:

Resource Allocation (RA): The project promotes water conservation by capturing, treating, and infiltrating stormwater to local aquifers to protect fresh water availability for the region. Native plants are used throughout the project to minimize irrigation usage. A recycled water line is proposed to help irrigate the Rory M. Shaw Wetlands Park component of the project.

Climate and Risk (CR): A statewide climate impact assessment study, the California Adaptation Planning Guide by the California Natural Resource Agency, states adaptation considerations for the “South Coast Region” that include: “sea level rise, increased wildfire risk, public health, socioeconomic and equality impact, and water supply.” The Sun Valley Watershed Multi- Benefit project prepares for long term adaptability for climate variations such as drought and floods by adjusting the operational levels of the detention and infiltration basins. The transformation of a landfill to the functional wetlands and park will substantially improve community livability. Dust and pollutants that are created from the unloading of waste material will cease to exist. Haul traffic of diesel trucks which is used to service the landfill site will be eliminated, and the air quality will improve as a result.