Low Cost Integrated Delivery Urban Green Infrastructure Case Study: University Park Neighborhood Rain Gardens Pilot Study
The University Park Neighborhood Rain Gardens pilot study included the design, implementation, and monitoring of thirty five (35) rain gardens in the Ballona Creek Watershed near the University of Southern California (USC) in Los Angeles. Funding for the pilot study came from the State Water Resources Control Board through Proposition 84 Santa Monica Bay Restoration Grant Program and from The City of Los Angeles - LA Sanitation (LASAN). LASAN identified the pilot study as an appropriate green infrastructure solution that could meet the goals of the Restoration Plan while replenishing groundwater aquifers through stormwater infiltration and providing community involvement through the beautification of a disadvantaged neighborhood. In addition, many cities and counties are scrambling to identify funding sources and mechanisms required for implementation of the Enhanced Watershed Management Plans (EWMPs) and Watershed Management Plans (WMPs). To address this issue, LASAN used this pilot study to evaluate the feasibility of developing a low cost green infrastructure solution capable of providing significant water quality and supply benefit and adhering to community priorities.
LASAN succeeded in their efforts and identified an integrated delivery team consisting of Geosyntec consultants and multiple subcontractors to design, implement, and monitor the rain gardens. LASAN and the consultant team identified 35 strategic locations for rain garden implementation in parkways within the study area bounded by Exposition Boulevard, Jefferson Boulevard, Vermont Avenue, and Western Avenue. Involving the construction subcontractor during the design stage allowed the team to iterate and adjust the design in order to meet cost and project requirements.
This presentation will discuss the advantages of an integrated delivery project, which include cost and time savings due to design streamlining with input from construction subcontractors upfront and removal of the bidding phase. In addition, it will focus on the simple and low cost design selected for the gardens, which includes drought resistant plants, topsoil and mulch, a choker layer, and a washed gravel storage area with a perforated PVC pipe for additional storage. During the design phase, LASAN and the consultant team developed a novel approach towards collecting trash and debris by including a boulder-lined sump at the inlet to each rain garden. These sumps are low cost (i.e., do not require curbing) and concentrate the trash and debris collected, which is expected to result in lower maintenance requirements in the future.
Finally, the presentation will discuss lessons learned during the pilot study, community engagement, and plans for future water quality monitoring. One of the lessons learned was the incorporation of pedestrian safety features to protect nearby vehicle passengers, bicyclists, and pedestrians when near the rain gardens. A proprietary curb inlet (Curb-o-let) was selected to provide a landing for adjacent vehicle passengers and an additional 18-inch mulch strip was provided with the same goal. Not only was a goal to keep the community safe, but community involvement was also a key component of this project. Involvement was encouraged by incorporating three plant palettes for the community to choose: “Simple green,”“Floral Bouquet,” or “Trojan Pride.” During an outreach event, residents were asked for their preferences, which informed the final landscape design. The community support was overwhelmingly positive and the neighbors became actively involved during construction.
The lessons learned and results of this pilot study will be shared to provide an example of a low cost green infrastructure alternative that can be implemented in the future throughout California.
Ken Susilo is a Senior Principal and Vice President with Geosyntec Consultants, managing the firm's Los Angeles operations. He has been a practicing water resources engineer and PE in California for 25 years, and is focused on multi-benefit water resources project planning, funding, development, and delivery. He is a D.WRE, and CPSWQ, and graduate of UC Berkeley.
Wing Tam is the Assistant Division Manager for LA Sanitation-City of Los Angeles. In this role, he is responsible for stormwater management and watershed protection programs, facilities, advance planning, and water quality compliance. Wing directs the Green Stormwater Infrastructure Program that includes Rainwater Harvesting, Green Streets, and Clean Water Bond. He has been a leader in the development of green infrastructure, urban runoff and stormwater management for over 25 years that led to the first integrated, multi-purpose green solutions designed to improve water quality, water supply, flooding, habitat, and open space creating healthier and sustainable communities. His work has been recognized by USEPA, NACWA, WEF, CEWA, APWA, and other organizations for demonstrated leadership in use of Green Infrastructures and sustainability. A Registered Professional Engineer, Wing holds Bachelor and Master of Science degrees in Civil Engineering with emphasis in Water Resources and Environmental Engineering.
Daniel Lee has over 12 years of experience working on a variety of public and private development projects in all phases of the project life cycle including planning, design, permitting, and construction management. His experience focuses on stormwater facilities and other various infrastructure projects. For the University Park Neighborhood Rain Gardens Project, he was the construction manager and managed subcontractor construction.
Majid Sadeghi is an Environmental Engineering Associate with LASAN. He has over 30 years of civil and environmental engineering and consulting experience, including hazardous waste management, pollution prevention assessments, design of industrial wastewater pretreatment facilities & gas collection/treatment systems. Majid has worked in water quality, wastewater, and hazardous waste regulations & has represented industries in regulatory negotiations, preparation of various civil/environmental engineering designs, compliance reports, as well as local, state, and federal permits.