By Tony Kirby and Vanessa Thompson

With a population of over 80,000 people, the City of Pacoima is one of the oldest neighborhoods in the San Fernando valley of Los Angeles, California. The closing of factories around Pacoima in the early 1990s started an economic decline, and Pacoima has become one of the most underserved communities in the Los Angeles area.

Pacoima’s park-poor status and its highly permeable soils, together with the rise of the grassroots environmental justice organization, Pacoima Beautiful, has recently led the City to become a focal point for innovative groundwater recharge and community pilot projects. A recent street vacation project at Bradley Ave created a small community space (Bradley Ave Plaza). However, the success of this project was impacted by the alley that bisects this space, which was run down and not well utilized due to safety concerns, especially at night. As a standalone project, the space was under-utilized and offered limited value to the community.

Reimagining Pacoima

The Bradley Plaza Green Alley pilot project is both an innovative stormwater and community project that reimagines how alleys function in the Los Angeles area. The project team, which is comprised of The City of Los Angeles, The Trust for Public Land and Pacoima Beautiful as the client team, and Arup as the lead Designer and Engineer of Record, were driven to design and construct a project that not only managed stormwater effectively, but created a community space with which people  could interact safely. From the start, the community was involved in the design process. Initially, a community design charrette was held at the project site so that the community could have a say on three concepts that the team had developed. In addition to stormwater management, which was part of the project’s grant funding requirements, the community wanted better lighting and more shade, landscaping, and interactive play and exercise elements along the alley. The community also voted to incorporate the Bradley Ave Plaza into the alley project so the alley and plaza could be designed as a single project, increasing the opportunity for community amenities and making the plaza, which is at the midpoint of the alley and closed to traffic, the focal point of the project.

Breaking Down Barriers

The project moved into formal design with the preferred elements of all three concepts being incorporated from the community design charrette. The design team of Arup and Landscape Architect RIOS had a larger palette to express the design after the plaza was incorporated into the project by the client team. The design team strategized to combine the planting, shade and stormwater elements into the project corridor and challenged the conventional design of Los Angeles’ alleys. The existing sidewalk was removed, the central v-gutter (a City standard) was also challenged, and the alley sloped in one direction to a series of stormwater planters on the south side to provide initial filtrations. A subsurface infiltration trench and dry well system was designed to drain the planters and infiltrate the runoff along the alley to replenish the aquifer. The project treats stormwater from a 4.5-acre watershed far exceeding any City requirements.

Agreements were made between the City (Department of Sanitation) and a low-income housing authority which abuts the south side of the alley to locate stormwater best management practices (BMPs). This included many of the stormwater planters, within their right-of-way but with a commitment from the Sanitation Department to maintain them. Shared street signage and traffic controls were incorporated along the alley to avoid the need for large speed tables and promote the European shared surface concept, a first for the City of Los Angeles.

The plaza was totally transformed with the project team taking the opportunity to utilize this area for community gatherings, performances, and a nature classroom to promote outdoor learning. A large shade structure and “social stacks” for community seating are the centerpiece of this space and provide what the community demanded: a safe and shaded area for gathering, performance and meeting. A wall along the alley has also been given over to local artists for a large mural, which is part of Pacoima’s recent heritage and community with a passion for art and expression.

Looking Forward but Remembering the Past

The project is groundbreaking in several ways and provides a new template for transforming Los Angeles’ 900+ miles of alleys. However, the heritage of Pacoima was not forgotten, and as a gesture to the indigenous Tataviam Band of Mission Indians that put Pacoima on the map, Tataviam symbols were designed and incorporated into the custom salvaged timber amenity elements throughout the project.  The alley’s bonded asphalt surfacing and pattern provide a further link back to the City’s heritage through its depiction of running water as large streams of water used to flow through the area from the surrounding mountain canyons. These refer to this project as a stormwater mitigation project at heart but also so much more in its finished form. The project has transformed a standard and downtrodden service alley into a Place for People and, over time, will help reconnect the community to this space and the heritage of the City.

As structural engineers, we have a unique opportunity to contribute to the improvement of resiliency in our cities. Without being restricted by the minimum building code requirements, having clear communication on project specific seismic performance objectives with our clients at the onset of a project would allow us to deliver resilient buildings that would remain functional even after rare earthquake events. This, in conjunction with making digital investments in the industry, will help us achieve resiliency in our communities.

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