Project Statement

Pasadena is known for balancing urban life and natural beauty. But this balance has prioritized economics, aesthetics, and recreation over ecological and public health. The Arroyo Seco is at the epicenter of this imbalance. A once meandering river was channelized and dammed for flood control, erasing its native ecology and vital contributions to groundwater. The project no longer views the river as a control, but as an opportunity to learn from. In our vision, the river should inform the human programs as it once guided the rhythms of the indigenous Gabrielino-Tongva people. The project fosters natural processes, connection, stewardship, and respect. It honors Pasadena’s legacy while envisioning a more resilient, ecologically rooted future.

Project Narrative

The Arroyo Seco Restoration Project seeks to reconnect Pasadena’s human-centered values with natural processes and ecological systems, prioritizing the health of the river as the foundation for public health, community stewardship, park programming and connectivity. We began by identifying four primary goals: to analyze existing and future hydrologic conditions, develop strategies to enhance habitat diversity, explore opportunities for programming informed by river restoration and community feedback, and improve equitable access and connectivity. Our first step was to understand how the river currently functions and what it needs to recover. Through HEC-RAS modeling, we analyzed 100-year storm scenarios to determine where and how flooding could occur. This allowed us to explore potential interventions that support ecological restoration while protecting communities. We reviewed relavant precedents and past studies, attended public meetings, and interviewed City staff to understand existing priorities and constraints. We also engaged in critical conversation with the Arroyo Seco Foundation and One Arroyo Foundation whose insight into community attitudes, policy limitations, and ecological concerns helped guide our thinking. 

In parallel, we collected social data by creating park user surveys and conducting informal interviews on-site. Our visits to the Arroyo—on foot and by bike—gave us firsthand knowledge of how people interact with the space. From this, we learned that most Central Arroyo users engage with the site recreationally, often unaware that the Arroyo Seco is a river. In contrast, visitors to the Upper Arroyo and Hahamongna Watershed Park demonstrated deeper awareness and concern for ecological health. This revealed a powerful design opportunity: to integrate the river into public life not only through landscape restoration, but through education. By connecting the Arroyo to nearby schools, interpretive centers, and programming, we hope to increase environmental literacy and long-term stewardship. 

Rather than imposing a design onto the river, we asked what would happen if the river informed and shaped the design—much like it did for the Gabrieliño people who once lived along its banks. Several design options were considered, from complete channel removal to more adaptive, incremental approaches. The strategy we developed balances hydrologic resilience with ecological restoration: introducing wider, more diverse channel systems and floodplains downstream, while preserving the dam and enhancing diversion infrastructure to simulate a more historic flow regime. Implementation would unfold in phases. By restoring one section at a time and monitoring how the river responds, we can adapt as we learn. This slow, seasonal recovery process allows for deep community involvement—schools and local organizations can take part in ongoing maintenance, education, and stewardship, strengthening their relationship with the river and each other. 

Our spatial and community strategies bring restoration to life. Our designs include an education hub with a nursery that fosters stewardship; A rerouted flow near Devil’s Gate Dam restores sediment and invites learning; A rewilded golf course merges ecology with recreation, and urban upgrades improve access and pedestrian safety. We aim to demonstrate a successful model of urban river revitalization through culture building, community reconnecting, and care to both the human and natural systems.