17 North Beach Street
Nantucket, MA 02554
(508) 228-1515
Nature's Filter
Rain gardens are an innovative approach to reducing stormwater runoff into Nantucket Harbor.
Written By Brian Bushard
Photography By Kit Noble
The Nantucket Land Bank’s pocket park on the corner of Easton Street and North Beach Street started flooding as soon as the rain came down. Just as it was intended to do. This is a rain garden—a property designed to absorb stormwater from the road before it inundates the streets downstream. In doing so, it takes in nutrients from the runoff before they flow into the harbor.
“Instead of going straight into a storm drain and being released at Children’s Beach, [the water] is going directly into the soil and being filtered by plants,” said Rachael Freeman, the interim executive director of the Land Bank. “That’s one level of purification.”
The Land Bank purchased the 0.2-acreproperty at 65 and 67 Easton Street for $900,000 in 2020. Then came a $784,250 construction project spearheaded by Speakman Excavating LLC. Water enters the park through a gap in the curb—also known as a stormwater inlet—during a storm, catching runoff as it flows down the edge of Easton Street. Two swales allow the water to pass through the center of the park. The westside of the property is a constructive wetland, with plants in place to absorb the water coming in, while the east side features an open lawn and walkway with picnic tables for sunny day lunches.
“Water going into the harbor from Children’s Beach is coming down from that area,” Freeman said. “By drawing that into a wetland, we’re restoring water quality in the long run. The first inch of runoff captures the most pollutants.”
The property is part of a growing network of rain gardens and restored wetlands intended to mitigate the effects of both stormwater runoff and saltwater flooding from Nantucket Harbor. The Land Bank is one of several players in the development of that network. One area the town is considering for another rain garden is on the corner of Francis Street and Washington Street. Town officials are also considering a long-term plan for the Saltmarsh Senior Center that includes relocating the facility to the current site of Our Island Home and replacing the asphalt on the Washington Street Extension site with permeable pavement to allow water to seep in.
There’s not a lot of green area that is town property, so how do we deal with stormwater?” Leah Hill, the town’s coastal resilience coordinator, said. The corner of Hulbert Avenue and Easton Street across from the U.S. Coast Guard Station Brant Point is one example, according to the town’s stormwater manager, Charles Johnson. That area “wants to be a wetland pretty badly,” he said.
But there are some areas of downtown where a rain garden only gets you so far. In 2021, the town released its coastal resilience plan, outlining not only the long-term impacts of runoff to water quality, but the risk of sea-level rise on coastal downtown areas that are already prone to flooding. That report, conducted by Arcadis, identified 2,373 structures at risk of flooding and erosion, with a total cumulative annual cost of $3.4 billion. In the downtown area, the report estimated public roadways leading to Steamboat Wharf will see “frequent loss of service at monthly high tide” in the coming years and that by 2050, the wharf itself will be “completely cut off from surrounding roadways at monthly high tide.”
“We already have flooding today, and the risk is only going to increase to the point where eventually there’s no access to the Steamship [Authority] in coastal storms and high tides,” Hill said.
Easy Street has become the epicenter of downtown flooding. During a winter storm, islanders can almost always expect water to rush in from the harbor, and flooding from high tides repeatedly inundates the road. Projections show several feet of water regularly coming up over the road in future storm and high-tide events. Unlike on Easton Street, there are hardly any green spaces along Easy Street, save the Land Bank’s park on the harbor and several small patches of grass and hedges along the sidewalk. For Easy Street, the town is in the design phase to raise the road itself, with the hope of securing state and federal funding for the project—which town officials admit would be a major undertaking.
“These are big, expensive projects,” town sustainability programs manager Vince Murphy said. “The idea is you go through the design and public vetting, and get feedback. We need state and federal funding—[sources] like the Inflation Reduction Act. We’re up against Boston, Fall River and all these other towns applying for large-scale grants. We’re punching above our weight class, but the idea is to leverage what we have and have the right people applying for these grants.”
Addressing coastal flooding and sea-level rise takes a variety of approaches. You can retreat from the shoreline, raise structures or adapt. And in some cases, you can work with nature.
“We should be looking at areas where there’s a need for flood storage, a need for runoff storage,” Freeman said. “We saw a need in the area [on Easton Street and North Beach Street]. We also wanted to have it be a little educational. The path loops around the two swales, and the goal is to get people to interact with these wetlands in a way where they can see how they’re functioning. We hope people find them beautiful at some level.”
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