For much of the 20th century, cities engineered rivers to solve an urgent problem: keeping people and property safe from floods. In Southern California, that meant transforming the Los Angeles River from a dynamic natural system into a concrete channel designed to move stormwater quickly and efficiently. That infrastructure provided critical flood protection, but at a high cost: Natural floodplains and habitats disappeared, ecosystems became fragmented and many communities lost their connections to the river.
Today, cities have an opportunity to think differently. Rather than focusing on designs that exclusively reduce flood risk, new approaches can work with natural systems to provide flood protection while restoring habitat, reconnecting groundwater and floodplains, and creating healthier, more accessible public spaces.
A new USC-led study at Taylor Yard, a former rail yard along the L.A. River in northeast Los Angeles, explores what those approaches could look like and how they might be applied, offering lessons that could extend far beyond Southern California.
"For decades, L.A. has been working to revitalize its namesake river," Associate Professor Alexander Robinson of the USC School of Architecture said. "But it hasn't been easy. One of the biggest challenges is finding ways to bring together the many different disciplines and stakeholders needed to reimagine the river and its infrastructure."
Designing with the river, not just around it
Taylor Yard - located between Cypress Park, Glassell Park and Elysian Valley - sits in a part of Los Angeles where neighborhoods, infrastructure and the river come together in complex ways. Since 2024, the team behind the Taylor Yard River Connection Study has been exploring new ways to reconnect the river with the rail yard area and the neighboring Bowtie parcel, while creating opportunities for the surrounding communities to access and experience the river.
Led by the USC Dornsife College of Letters, Arts and Sciences Public Exchange and the USC River Team, the project brings together experts from across the USC Viterbi School of Engineering, the USC School of Architecture and the USC School of Cinematic Arts, in collaboration with external project partners like the Mountains Recreation and Conservation Authority and the 100 Acre Partnership at Taylor Yard. The research was conducted in collaboration with the city of Los Angeles Bureau of Engineering, which provides the Hydraulic Research Laboratory facility, staff expertise in integrated hydraulic modeling and facilities operations training under a Memorandum of Understanding with USC School of Architecture.
"Taylor Yard offers a rare opportunity to restore some of the natural connections that once existed between the river and its surrounding landscape," Associate Professor Mitul Luhar of USC Viterbi said. "But it also illustrates why urban river restoration is so challenging. Decades of development have seen the construction of essential infrastructure like power lines and service roads, while remnants of its industrial past, such as historic railway turntables, remain as artifacts of the site's history." The site also contains significant lead contamination stemming from its use as a rail yard.
Rather than being deterred by those constraints, the USC team asked a new question: Given today's conditions, what can we do to help the river function more like a natural system?
The team developed three conceptual approaches, each exploring a different way to reconnect the river with habitat, groundwater and its historic floodplain while maintaining - or potentially improving - flood protection:
- One concept would create a side channel and vegetated island on the northern end of the site, allowing water and habitat to extend beyond the river's main channel and relieving flood pressure on the opposite bank.
- Another would create a groundwater-fed ecosystem at the southern end of the site.
- A third would reshape portions of the riverbank into terraces, potentially giving floodwaters more room while creating habitat and new opportunities for people to experience the river.
"We're not trying to prescribe a single solution for Taylor Yard," said Carling Monder, USC Public Exchange senior project manager. "These concepts show the different ways we can work with natural processes and make them part of how the site functions."
Testing what's possible
Reimagining a river is one thing. Demonstrating that new ideas can work safely is another.
Engineers combined advanced computer simulations with a 60-foot physical model of the river to see how different designs would affect water movement. The team tested conditions ranging from more common, smaller storms to increasingly severe ones likely to occur in the coming years.
Those findings informed the designs as they evolved. Landscape architects and an ecologist considered how engineering decisions could support habitat, native vegetation, groundwater connections and public access. Visualization experts from USC's engineering and cinema schools helped turn complex technical concepts into simple visual representations, making it easier for stakeholders to see how different approaches might change the river.
"Instead of considering public priorities, design, ecology and engineering one after another, they informed one another from the beginning," Luhar said. "This approach can help teams identify possibilities - or setbacks that would ultimately make a project unfeasible - on the front end, instead of later in the process."
A blueprint beyond Los Angeles
Like many cities around the globe, L.A. grapples with the reality of needing to make infrastructure updates - with limited resources - that can adapt to a changing climate. "The challenge and opportunity with this infrastructure is immense," Robinson said. "If we improve these landscapes by making them more natural, they could be transformative to the city - yet with the uncertainty of climate change, we also need them to simultaneously perform better as infrastructure."
The Taylor Yard River Connection study offers a model for how L.A. leaders can approach that challenge: Start with the natural systems that once made a place function, understand how the urban landscape has changed, and bring engineering, ecology, design and community needs together to determine what can be restored. The study also gives decision-makers a technical foundation for determining what comes next at Taylor Yard and an opportunity to demonstrate what that future can look like.
"The value of this work goes beyond Taylor Yard," Monder said. "It shows how we can look for opportunities to restore natural processes within the realities of our urban environments, and offers an approach that other cities that are facing similar challenges can use."
