By ANDREW CONNOR

In 1993 brigades of volunteers, working alongside the United States National Guard, hastily filled sandbags to create makeshift dikes as flood water overtook the riverside town of Warsaw, Illinois––among them, then 8-year-old Jessica Henson (ARCH ’08). Heavy rainfall and colder than normal temperatures led to above-average soil moisture, causing hundreds of miles of the Mississippi River to swell and the ensuing flood to result in billions of dollars in damage. Known as the Great Flood of 1993, it remains as one of the worst floods in U.S. history.

Though Henson vividly remembers the flood’s destruction, she also recalls, more fondly, the land around the area teeming with wildlife, and playing with her brother along the many streams that branched from the river.

“Life centered around the river where I grew up. We lived by the heartbeat of the Mississippi River, right at what is historically known as the Des Moines Rapids and Lock and Dam 19, and, gosh, we loved it,” says Henson. “But what the river was doing at any given moment was very present. My dad worked in a corn syrup refinery along the river, and when the river was low, it had implications for their cooling processes. When the river was high, it impacted getting to my grandma’s house because the bridges would close.”

Living so close to the Mississippi River instilled in Henson a love of nature and the outdoors that stays with her today, and as she grew up, she acquired a passion for architecture as well. To test whether architecture was really the path for her daughter, Henson’s mother signed her up for Experiment in Architecture at Illinois Institute of Technology, a summer program for high school students interested in the profession.

“I think my parents sent me to that two-week program to determine that it was wrong for me,” says Henson. “But it was so perfect; I had probably the best two weeks of my life. It was all the things that I had wanted to do, bringing together art and creativity with my interest in math and engineering.”

Initially, Henson wasn’t planning to attend Illinois Tech. The Experiment in Architecture program was great, but she says the lack of nature in Chicago intimidated her. Still, she applied, and when she received the Camras Scholarship that provided a full ride, she couldn’t pass up the opportunity. Henson initially gravitated toward structural engineering, going so far as to minor in it. But in her fourth year, to fill a requirement, she took a course on the history of the Prairie School and landscape architecture, which changed everything.

“If architecture felt perfect already because of the combination of things, landscape architecture was one step further; it brought in my love for the environment,” says Henson. “Those landscape architects working in the Midwest, like Jens Jensen and O. C. Simonds, had all these conversations about the prairie rivers and the limestone. They were thinking about that as designers and as stewards of a larger environmental and regional context. In that, I started to think a lot about the landscape that I had grown up in.”

After graduation Henson enrolled in the Master of Landscape Architecture Program at the University of Pennsylvania and began working for OLIN, the renowned landscape architecture firm founded by Laurie Olin, whom Henson likens to “a modern-day Frederick Law Olmsted.” Henson began researching and teaching courses about the Mississippi River and its surrounding context at the University of Illinois at Urbana-Champaign, ultimately leading to the creation of the book on which she serves as co-editor, Fresh Water: Design Research for Inland Water Territories, which analyzes the implications of design interventions in Midwestern waterways, including the Upper Mississippi River.

In 2014 Olin received a call from Frank Gehry––the star architect behind such buildings as the Guggenheim Museum in Bilbao, Spain, and the Walt Disney Concert Hall in Los Angeles––whom the nonprofit organization River LA tapped to explore how the 51-mile-long Los Angeles River could be improved through architecture. Gehry and Olin assembled an interdisciplinary team composed of OLIN landscape architects and planners, Gehry Partners architects, and engineers from Geosyntec. Henson became a part of that team, serving as an associate and one of the project’s managers, contributing to her recent rise to partner at the firm.

“Continuing to teach, Jessica moved to Los Angeles to organize, manage, and coordinate our office team with the architects, engineers, other consultants, Los Angeles County public agencies, citizen forums, and participation, which she has done brilliantly,” says Olin. “Her hands-on manner—in the field with workers, in group work sessions, and in public forums; her grasp of technical detail as well as the big picture of the environmental and social issues facing our nation and the world today; and her energy, initiative, and ability to work with a wide diversity of people and situations led to her rise within the firm.”

For the first two years the work was mostly pro bono with some grant funding, but in 2016 the County of Los Angeles voted to update the river’s master plan for the first time in 25 years. 

“We were so uniquely positioned to slot into there, and when we interviewed for the project with the county, they’re like, ‘Wow, you’re already two years into the data,’” says Henson. “The way we wrote the scope with the county for the LA River Master Plan is how you would approach an academic research project, multidisciplinary and based on the best data.”

Released as a public draft by LA County Public Works earlier this year, the plan is a sweeping but holistic vision for the future of the waterway, which spans Los Angeles County and 14 surrounding cities, and varies from human-made concrete channels, levees, and dams––the product of the U.S. Army Corps of Engineers’ effort that ramped up in 1938 to control the river’s flow and reduce flooding––to natural soft-bottomed reaches.

“As Los Angeles grew, transportation corridors and rail lines continued to hem in the river, leading to greater and greater risk during floods. As floodplain development expanded and as Los Angeles became more important to the national economy, huge investments were made to improve the conveyance of flood flows away from the city and into the Pacific,” says Mark Hanna, a Geosyntec engineer and one of the leaders of the master plan. “Today, because it is a calculation of risk and competition for dollars, flood infrastructure cannot be designed to protect against all flooding, while at the same time, there are other community needs such as access to park space, community connectivity, ecosystems, and water-supply increase. The equation just gets more complex with the real threat of climate change.”

The master plan attempts to reconcile the complex mishmash of engineering, environmental, and social factors that have caused pervasive flooding, pollution, limited access to public spaces, and disenfranchisement among surrounding communities. It aims to do so with social equity in mind and was informed by community engagement sessions. That is why the plan goes so far to include affordable housing––meant to mitigate the gentrification that often follows high-profile projects––along with proposals for flood mitigation and improved hydraulics. But environmental issues such as flooding and pollution tend to have a harsher impact on the most economically vulnerable, and they are becoming increasingly pervasive as a result of climate change, Henson says.

“The number of people near the southeast [part of the river] who live in a 500-year floodplain is remarkable––not in a good way. It also happens to be one of the most polluted, underserved, and economically depressed areas,” says Henson. “When you think about something like what happened in Houston a couple years ago, where they had two back-to-back 500-year storms, that makes a clear argument for the need to think about community resilience.”

The river’s length, diversity of its conditions, and array of issues at play make the LA River Master Plan immensely complex, with no one-size-fits-all solution. But there are recurring themes and strategies in the plan’s aims. Side channels that relieve pressure off the main channel could reduce the risk of flooding while creating much-needed ecological and educational opportunities. Expanded trails, bridges, and pedestrian plazas would create more recreation and social spaces for local residents. Off-channel sites could host community centers and affordable housing complexes. Native plantings would create green spaces for people and wildlife alike, while remediating polluted soil.

Implementation of the plan’s components will require the partnerships of Los Angeles County, the surrounding cities, and other entities. But crucially, Henson says that every definitive action within the plan is tied to a county department and potential fundraising streams, providing a clearer path to implementation than you would typically see in a master plan.

“We knew things would be expensive. It’s big, it’s long, and we did not want to leave anything as a ‘someone should.’ I think a lot of planning documents forgot to think about funding, leadership, governance, and implementation,” says Henson. “We didn’t want that, so we made a rule in our brain trust that there would be no ‘someone should’ in the plan, because that becomes ‘no one ever will.’”