As sea levels rise and the East Coast slowly sinks, flooding is getting worse in Boston—from sunny-day flooding during high tides to the icy water that surged down streets during the “bomb cyclone” in the city last year. But a new development on the edge of Boston Harbor, just completed on two abandoned wharves, is designed to withstand all those wet possibilities.
Next to the water, landscape architects created a “living shoreline,” with newly planted salt marshes and rocky beaches built on terraces behind a historic sea wall, providing new protection on land for the 400 apartments and condominiums in the mixed-use development. “Rather than building, say, a concrete seawall or deployable barrier around the pier portion of our wharf, we actually kind of peeled away some of the existing seawall to provide a terraced, living shoreline that contains various levels of salt marsh grasses and reclaims granite rocks that came from the sea wall,” says Shannon Lane, who worked on the project at the landscape architecture firm Halvorson Design. “That helps to dissipate wave and storm surge activity versus deflecting it.”
During extra high tides or storms, a retention area slightly uphill is designed to fill with the rising water. “[The design] does something that typically developers don’t do, which is invite water into the site,” says Nick Iselin, the general manager of development for Lendlease Americas, the developer behind the project, called Clippership Wharf. “We have this very dramatic look and feel over the course of the day as the site transforms.” Instead of a concrete path next to the water, the designers built a wooden boardwalk that people can still use as the water rises below them.
The buildings are set as high on the site as possible, with no apartments at ground level; the lowest residential floors are 14 feet above the current high tide. The architects worked to make the height appear inconspicuous. “The challenge really was one to design a solution that was seamless, so that it didn’t just seem like a big podium placed right up against surrounding roadways,” says Iselin. Everything at the ground level of the buildings—including retail stores, entryways, and parking for bikes and cars—can be protected with flood barriers that can quickly be slotted in place in advance of a major storm. “We can make decisions 24 hours ahead of time to deploy flood barriers, and pretty much any space that is protected by those can be buttoned up in an hour or so,” he says. The building also has a generator, along with solar panels on the roof that may later be connected to battery storage to provide power when the grid goes down.
The design decisions were necessary given flooding that’s already happening. It’s not clear exactly how much more sea levels will rise locally, but predictions are grim. “If you look out 10 years and trust some of the early projections, we might be faced with nine inches of sea-level rise over the next 10 years,” Iselin says. “And if you look out toward the latter half of the century, it could be 30 inches. It could be 60 inches. It’s a really staggering set of possibilities.” One 2016 study led by the University of Massachusetts suggests that sea levels could rise as much as 10 feet by the end of the century, and 37 feet by 2200, driven partly by disproportionate effects of melting Antarctic ice on the East Coast.
Natural solutions like the living shoreline are one key way to address the threat of rising water, says Lane, who says that the firm is moving away from traditional single-use infrastructure. “Whenever we’re faced with an issue, we like to try to counter it with a solution that has multiple purposes and functions,” she says. As the new shoreline dissipates waves, it can also filter stormwater before it flows into the harbor and reintroduce tidal ecosystems. “We’re providing a restored shoreline that hasn’t existed in probably 150 years.”