Hawaii Coastline Report Links Resilience with Access

A landscape architect-led study from the University of Hawaii combines climate adaptation and waterfront access.

By Timothy A. Schuler

A vision for 20 miles of Honolulu’s waterfront is based on a network of amphibious green spaces that buffers the city from sea-level rise. Image courtesy of the University of Hawai’i Community Design Center.

United States-controlled islands such as Hawaii, Guam, Puerto Rico, and American Samoa are rarely mentioned in U.S. climate coverage, but the projected impacts of sea-level rise to island communities are severe and far-reaching. According to a report from the State of Hawaii’s Coastal Zone Management program, if seas rise as projected over the next century, Honolulu will face an acute loss of “valuable urban land, the geographic isolation of Waikiki, frequent disruption of…transportation systems, and inestimable property losses. Inundation may render much of the present urban district uninhabitable.”

That report was published in 1985. In the 35 years since, Hawaii has taken little discernible action to mitigate or adapt to this future. In 2012, a law was passed establishing statewide policy guidelines for climate change adaptation but mandated only that state agencies “explore adaptation strategies” to respond to sea-level rise. Now, a recent study from the University of Hawaii Community Design Center (UHCDC) will provide a foundation for more serious debate around Hawaii’s climate future and outline a vision for a more resilient, better connected, and people-centered waterfront. The study’s long title, South Shore Promenade and Coastal Open Space Network Study: Resilience and Connectivity by Design, highlights its twin—and intertwined—concerns: climate adaptation and increased access to the Honolulu shoreline. (The latter is particularly important in a state in which public access to coastal areas is guaranteed by law but where, in practical terms, obstacles remain.)

Funded by the State of Hawaii, the study was led by Judith Stilgenbauer, ASLA, the director of the landscape architecture program at the University of Hawaii at Mānoa, along with a team of landscape architecture faculty and students at the UHCDC. Over the course of 450 pages, the document maps the extent of climate-related threats to Honolulu’s primary urban center and proposes an approximately 20-mile shoreline promenade that would link a series of amphibious green spaces. It provides site-level concepts for three particularly high-risk areas, proposing radical transformations that would address flood risk for vulnerable communities in part through the reintroduction of Hawaiian agricultural systems.

The industrial corridor of Kalihi Kai benefits from the reintroduction of a version of a traditional Hawaiian fishpond. *Image courtesy of the University of Hawai’i Community Design Center.*

“You can’t look at a living shoreline system in Hawaii without acknowledging that there used to be this remarkable sequence of freshwater productive ecosystems,” Stilgenbauer says. “Lo‘i and then fishponds and then ocean-based fisheries. All of that could become part of layered, living-shoreline systems.”

Though not an implementable plan, the study is valuable for the way it visualizes living shorelines for an island context, says Justine Nihipali, a program manager for the state’s Coastal Zone Management program. In 2020, the state formalized its intent to pursue nature-based coastal infrastructure by banning seawalls and other shoreline hardening measures on private property. But Nihipali says that while there is “a strong push to work on nature-based solutions, we don’t actually know what that looks like here, because we have higher-energy coasts than a lot of places that are implementing living shorelines.”

Matthew Gonser, the chief resilience officer for Honolulu and a landscape architect by training, says the notion of a publicly accessible, more connected shoreline acknowledges the important cultural relationship between Hawaii’s lands and waters and aligns with the city’s recently adopted Climate Action Plan, which includes a push to cut carbon emissions from transportation, which accounts for 45 percent of the city’s overall greenhouse gas emissions. “A lot of the waterfront is not that well connected or accessible,” he says. “People-powered, micro-mobility enhancements can go a long way to [support] not just public health but climate action.”

Timothy A. Schuler, the editor of NOW, can be reached at timothyaschuler@gmail.com and on Twitter @Timothy_Schuler.