The Brookside Park Stormwater Capture Project will significantly improve water quality in the Arroyo Seco and Los Angeles River and increase water supply for the City of Pasadena’s Raymond Basin. The project aims to improve water quality by capturing and treating stormwater and dry weather runoff from the northwest portion of the City while bringing community-focused improvements through above ground features.
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Community Outreach
and Public Meetings
Brookside Park Stormwater Capture Project
Join us to learn about recent project updates and design refinements!
Community Project Update and Information Session Actualización Comunitaria y Sesión Informativa del Proyecto de Captación de Aguas Pluviales de Brookside Park
WEDNESDAY, SEPTEMBER 23RD | MIÉRCOLES 23 DE SEPTIEMBRE | 5PM-7PM La Casita Del Arroyo, 177 S Arroyo Blvd.
WHAT YOU'LL LEARN
90% design refinements
Summary of outreach efforts
Updates on project funding
Project timeline and next steps
LO QUE APRENDERÁ
Avances del diseño al 90%
Resumen de los esfuerzos de divulgación comunitaria
Actualizaciones sobre la financiación del proyecto
Cronograma del proyecto y próximos pasos
Presentation and Q&A Begin at 5:15 pm
Presentación y preguntas a las 5:15 pm
PASADENA CALIFORNIA • CITYOFPASADENA.NET
Stay tuned for details about our next event – we hope to see you there!
stay tuned...
Drainage Area
Brookside Park Stormwater Capture Co-Benefits
The Brookside Park Stormwater Capture Project integrates both underground stormwater infrastructure and above-ground improvements to enhance environmental and social value for the community. The Project has two distinct components:
- Underground Stormwater and Water Quality Elements: The project will divert storm and urban flows conveyed by the Seco Street Drain for pretreatment, subsurface storage and infiltration, and may include additional treatment by filtration to return cleaner water to the Arroyo Seco channel. This treatment process will remove trash, sediments and priority pollutants from conveyed flows, improving the water quality within the Arroyo Seco, which flows downstream to the Los Angeles River and, ultimately, the Pacific Ocean.
- Aboveground Improvements: The project site offers the opportunity to improve and enhance the existing surface parking lot post-construction. Various above-ground community-focused improvements will be considered and refined through input from the community, key stakeholders, park users, and the City during the collaborative design process.
Schematic Design
The refined design builds off the preliminary concept framework to include technical details and specifications. Final design will be shaped by detailed analysis and feedback from outreach and engagement efforts.
Project Schedule
Project Background
The Brookside Park Stormwater Capture Project, identified in the City’s Storm Drain Master Plan to address regulations pursuant to the Los Angeles County Municipal Separate Storm Sewer System (MS4) Permit, focuses on implementing green infrastructure, nature-based solutions and best management practices (BMPs) to achieve its water quality objectives. By diverting and treating runoff from 1,166 acres, the project aims to improve water quality, recharge critical groundwater supplies, and enhance existing amenities in the Parking Lot I. Community engagement efforts throughout and solicited feedback will inform each stage of design to develop a final approved design concept.
The project will divert dry weather, and stormwater flows from the historic Seco Street Drain to a subsurface infiltration unit below the existing parking lot. This unit will capture, treat, and recharge local groundwater supplies in the Raymond Basin aquifer, which has experienced groundwater level drops due to years of pumping and water scarcity. Secondary treatment BMPs will include bioretention cells, enhanced tree canopy, and vegetated bioswales to address surface runoff pollution and enhance the aesthetics of the current site.
Brookside Park, owned and operated by the City of Pasadena, is located just south of the Rose Bowl on North Arroyo Boulevard immediately adjacent to the Arroyo Seco Channel, within the Upper Los Angeles River watershed management area. Nestled at the south end of the Rose Bowl, existing park features include the Jackie Robinson Baseball Stadium, two lighted softball diamonds, a multi-purpose field for various sports, picnic areas with barbecue pits, play areas, restrooms, and drinking fountains, in addition to Kidspace Children’s Museum and the Rose Bowl Aquatic’s Center.
Department Lead and Funding
The Department of Public Works is leading this project, working collaboratively with the community, key stakeholders, and interagency partners. Funding for the project’s design comes from the Los Angeles County Safe, Clean Water Program Regional Funding with the Feasibility Study funded by the City’s Measure W Local Returns.
The Safe, Clean Water Program provides local, dedicated funding to increase local water supply, improve water quality, and protect public health. For more information regarding Los Angeles County’s Safe, Clean Water Program please go to https://safecleanwaterla.org/
Over 12 community members participated in the Public Information Meeting conducted from 6pm to 8pm at La Casita Del Arroyo on November 13, 2025. Staff and consultants provided information on the project, including the purpose, co-benefits, stormwater components, a summary of outreach and engagements, and the California Environmental Quality Act (CEQA) process.
You can view the presentation in the Brookside Public Information Meeting Presentation
Public Information Meeting Event Images
Event Gallery
Community Outreach Event #5
Over 30 participants explored the refined project design and learned about the LID components on April 22, 2026 from 3pm to 6:30pm at the Brookside Golf Club. Participants learned from engineering experts on the proposed underground stormwater system and discovered the proposed bioswale habitat and its role in stormwater management.
You can learn more about the community’s feedback in the Brookside Outreach Meeting 5 Key Takeaways
Community Outreach Event #4
Over 14 community members joined Pasadena City Councilmember Tyron Hampton, City staff, and consultants, on a guided walk on April 17, 2026 from 10am to 12pm at Parking Lot I of the Brookside Park. Staff and consultants provided information on the proposed stormwater improvements and engaged in conversations about how the proposed stormwater capture system can benefit the community and region.
Community Outreach Event #3
Over 25 participants shared their preferences for desired above-ground improvements at the Arroyo Seco Trash Clean-Up pop-up on May 7, 2025 from 9:00am to 11:00am.
You can learn more about the community’s feedback in the Brookside Park Event #3 Outreach Summary
Geotechnical Evaluation
A Geotechnical Evaluation provides site-specific information about soil and groundwater conditions, including how water moves through the ground (infiltration). This technical analysis helps understand site constraints and opportunities, and informs how stormwater features can be safely and effectively designed.
Brookside Park Geotech Report
Preliminary Design Report (PDR)
The Preliminary Design Report brings together information from multiple technical studies—including geotechnical, environmental, and engineering analyses—to evaluate and compare design options. It identifies a recommended approach based on overall project goals, such as water quality improvement, stormwater capture, environmental considerations, long-term maintenance, cost, and alignment with funding program requirements that the City uses to evaluate the best design approach.
Brookside Park PDR
These documents work together as part of the project development process. The Geotechnical Evaluation provides important technical input, while the Preliminary Design Report integrates that information with broader considerations to guide project design. For this reason, they are most meaningful when reviewed together.
Final Design Plans
Early-stage design plans (such as 30% plans) are iterative working documents that evolve as technical analysis, agency coordination, and community input are incorporated. These materials are part of the ongoing design process and are refined over time as the project advances. Final Design Plans will be posted once completed and once all final approvals are obtained.