County of San Diego Department of Public Works
Multi-Benefit Stormwater Management Planning Study for Casa de Oro and Spring Valley Communities
Paradigm led a team to support the County of San Diego Department of Public Works, through a collaborative effort with San Diego Coastkeeper and California Environmental Rights Foundation (CERF), to develop an innovative multi-benefit stormwater planning approach for the Casa de Oro and Spring Valley communities within the Spring Valley Creek watershed. The goal of this project was to improve on previous stormwater planning efforts, focusing primarily on water quality improvement, through consideration of multiple additional benefits of projects to simultaneously address flood control, climate change resiliency, and infrastructure investments within disadvantaged communities.
Paradigm developed a comprehensive approach to screen project opportunities representing a diverse range of typologies, including incorporating green infrastructure within curbs and crosswalks, linear green streets, and regional facilities. Paradigm identified numerous multi-benefit scoring metrics, addressing categories such as environmental benefits (e.g., water quality, water harvesting), design considerations, climate resiliency, community benefits (e.g., pedestrian access, park amenities), benefits to disadvantaged communities, and more. A total of 23 metrics were considered, which were used to evaluate up to 100 projects. For eight of the highest ranked projects, Paradigm led the development of conceptual designs, including preliminary engineering site plans, cost estimates, stream restoration, and quantification of stormwater volumes managed.
Paradigm also developed a modeling decision framework to support cost-benefit analysis and the identification of the most cost-optimal project implementation strategy to address planning goals. The system included simulation of hydrology and water quality to assess water quality goals, linked to a separate stormwater project modeling and cost-optimization system for simulation of the thousands of combinations of projects to support cost-benefit analysis and selection of the most cost-effective strategy. The selected implementation plan was then simulated in the model under future climate change conditions to quantify additional benefits for resiliency.
Community-Focused Stormwater Project Services
Paradigm continued their support to the County in a project to engage and build partnerships with the community to identify and implement green infrastructure projects that seek to maximize multiple benefits and contribute to the attainment of water quality improvement, flood control, water conservation, community enhancement, and climate change resiliency goals established by the Multi-Benefit Stormwater Management Planning Study. The communities addressed by the Planning Study includes nearly 80,000 residents with many areas categorized as underserved and in need of infrastructure investments. Additionally, the watershed has a need for focused revitalization and improvements to the stormwater conveyance system to provide adequate flood control and improve deteriorated water quality conditions. This fact was painfully felt in January 2024, as the watershed was one of the hardest hit by extreme winter storms, causing intense flooding and damage to many homes in the area.
Within the first year of the project, the County established a partnership with a local community-focused non-profit to conceptualize and design a project on a site that is used for community gatherings, education, recreation, and many other services, and incorporating stormwater control features such as green infrastructure and onsite stormwater harvesting and reuse. The project will serve as an important public demonstration of the benefits of stormwater projects and help build support for similar projects that can be implemented in additional public and private lands throughout the study area. The Paradigm team coordinated with the County and project partner to prepare conceptual designs of green infrastructure and stormwater harvesting features that can be incorporated within the site, and prepared design options and associated graphics and communication tools that were utilized for discussions with the project partner and community to obtain feedback and input on considerations for project design.
