Honor Award

Re-transforming Landscape at the Arroyo Seco Confluence

Yingjun Hu, Assoc. ASLA, Graduate, University of Southern California
Advisors: Robert S. Harris, Hon. ASLA; Charles S. Dwyer; Ying-Yu Hung, ASLA

The Arroyo Seco Confluence is a complicated site in which freeways, rail infrastructure and the rivers are tightly intertwined. What's more, the Confluence is a very important site with immense potential. The objectives of this study are to re-transform the Arroyo Seco from a channelized and single-functional channel to a multi-functional corridor of significant natural and cultural value, to provide safe access and create activities and recreation for people within the maze of preexisting infrastructure, to regenerate for developing to bring new life and investment to nearby urban areas.

In today's world, a lot of rivers are seriously polluted and channelized. This leads to a series of issues, such as ecological degradation of urban rivers, lack of accessibility, lack of open space around urban riverfront, disordered development of urban riverfront area, and the crisis of historical continuity and heritage protection.

The confluence of Arroyo Seco and the Los ANgeles River, located within the original flood plains of the Los Angeles River and Arroyo Seco water bodies, which are located within the lower Los Angeles River Watershed. The site is a complicated site in which freeways, rail infrastructure and the rivers are tightly intertwined. What is more, the Arroyo Seco has been channelized by concrete, freeways and rail infrastructure predominate much of the area. The Metro Gold Line cuts across the northern portion of the Project Area and provided frequent access to downtown Los Angeles, the many communities located in the northeastern sections of Los Angeles, and the cities of South Pasadena and Pasadena. The railroad tracks serving Metro's Metrolink regional passenger rail service and freight service parallel the western and eastern banks of the Los Angeles River, which are adjacent to a series of electrical transmission lines. The railroads, freeways and electrical transmission line are visual and physical obstacles to the future revitalization of the Arroyo Seco Confluence.

The Pasadena Freeway/State Route 110 (SR110) parallels the path of the Arroyo Seco. Entrances and exits to the from SR 110 are located on the northern perimeter of the Plan Area. The Golden State Freeway/Interstate Highway 5 (I-5) cuts north-south through the Project Area. I-5 runs in a trench from Lacy Street to Spring Street at the southeast portion of the Project Area. Entrances and exits to I-5 and SR 110 provide excellent regional access for the Project Area. Bt freeways, railways, and industrial physical structures create obstacles to pedestrian and bicycle modes of travel.

However, the Arroyo Seco Confluence is a very important site with immense potential: unparalleled opportunity for habitat and stream restoration; key spot for flood management and water quality improvements; easy access to touch the river; gateway to the river through Downtown; historical, cultural, environmental and hydrologic importance.

Basing on the above, the most important objective of this study is to transform the Arroyo Seco from a channelized and single-functional channel to a multi-functional corridor of significant natural and cultural value. Secondly, it is to provide safe access and create activities for recreation within the maze of pre-existing infrastructure. Thirdly, it is to create a synergy that elevates an urban riverfront landscape to a thriving and harmonious balance of complex systems where modern infrastructure meets natural ecology.

Concept framework:
1. Recovering the river corridor for providing an outline and structure for the infrastructure of green space.
2. Integrating natural system and building green streets for linking with the mountain and the river, and reconnecting the city and people to the river. Give the people access to a new green natural water's edge.
3. Regenerating for developing to bring new life and investment to nearby settlements.

Design Strategies:
1. Widen the deepen the channel for expanding floodplain and increasing flood capacity.
2. Introduce new landscape elements for water quality, such as terraced remediation wetland and wetland treatment system.
3. Plant native vegetarian communities for habitat and biodiversity.
4. Created pedestrian and bikeway system for providing access to people, and provide different open spaces along the river.
5. Redesign sidewalks along streets and use vegetated bioswale for capturing, storing and cleaning stormwater before it flows into urban sewer pipes and rivers.
6. Redevelop urban riverfront area and Improve public transit and bikeway system for connecting the historic site from Downtown Los Angeles to Pasadena.
7. Provide interesting and continuous tour route for residents and visitors.

Finally, the Arroyo Seco Confluence is commitment to multi-purpose, multi-use space, in which residents and visitors can interact with and experience their new surroundings in a multitude of ways. Such a dynamic environment will be a better places to live, work and play.

American Society of Landscape Architects