'Living shorelines' seen as better way to adapt to erosion, storm surge
Stonington — At the 2.6-acre preserve known as Dodge Paddock, the waters of Little Narragansett Bay are pretty much allowed to come and go as they please.
“If you’re going to live on the water, you’ve got to live with the water,” said Beth Sullivan, Stonington town chairperson and steward for the Avalonia Land Conservancy, which owns the parcel. “The shoreline here is living in that there’s a more dynamic interface. There’s not a hard edge here.”
One Wednesday, Sullivan and Juliana Barrett, extension educator for Connecticut Sea Grant, visited the preserve, a natural oasis for walkers amid the compactly built Stonington Borough, to check on plantings and other work done there over the last 18 months. The project was a response to poundings the site took during Hurricane Irene in 2011 and Superstorm Sandy in 2012, when storm surge flooded one section, flattened dunes in another and threw mounds of sand and rocks atop a meadow. It also tore a gouge in a sea wall at one end.
But instead of rebuilding the wall higher and longer, Sullivan and others at Avalonia opted for a softer approach, one that would accommodate rising sea levels and storm surges: They decided to leave the area as natural as possible. This has included planting shrubs and grasses adapted to salt water on the new dunes that were created by Sandy, digging a channel so tides can flow freely in and out of a low-lying marsh in the center, and allowing tide-tolerant grasses to spring up on their own along the rocky shore.
“The rocks will slow the wave action, and the marsh is coming up naturally,” said Barrett, who worked with Avalonia on the project. “The marsh will play the role of being a sponge, and will help with the wave energy coming in.”
The way Dodge Paddock looks now is one of the few examples Barrett and other coastal environment experts can point to thus far on the Connecticut coast as a “living shoreline,” a concept that is being promoted in areas prone to erosion.
Peter Francis, supervising environmental analyst at the state Department of Energy and Environmental Protection, said a law passed in 2012 favors “living shoreline” projects over those that aim to re-engineer the shoreline with sea walls and jetties. Recent storms, he said, have demonstrated that hardened structures in many cases worsen erosion problems for adjacent properties, as well as degrade habitat for wildlife. Today, he said, applications for new sea wall projects are rejected unless the applicant meets very specific and limited conditions.
“We’ve been working after Sandy and Irene to develop softer, more resilient projects that are able to stand day-to-day erosion,” he said. “Our staff is really trying to push this type of project.”
Thus far, he said, there are only a few “living shoreline” projects, including one led by Sacred Heart University at a site in Stratford that includes installation of offshore “reef balls” that provide structures for marinelife while slow wave action. The concrete balls, set several feet from shore, are like large boulders filled with holes that let the water pass through.
“It acts as a buffer, but doesn’t accelerate wave action like a sea wall does,” he said.
In other areas, a living shoreline might be a sandy slope planted with beach grasses and shrubs that hold the soil, or a combination of large and small stones placed along the shore with wetland plants behind it, Francis said. Other projects might include shellfish beds that serve as breakwaters.
While projects can take many different forms, the essential common characteristic is that they all “maintain the connection between the water and the land” rather that creating a distinct edge, he said. In essence, living shoreline projects mimic natural areas that mitigate erosion, like the dunes and marshes at Waterford Town Beach and Harkness Memorial State Park next door.
A couple of applications for projects are pending, including two at sites in East Lyme and Old Lyme, Francis said.
“We haven’t seen very many applications yet, but interest is rising,” he said.
One of the few projects completed thus far is on the Fourmile River in Old Lyme. John Lust Jr., a Branford-based environmental consultant, worked with the property owners, who declined to be named. The 160-foot waterfront at their home had experienced severe erosion after recent storms, he said. Neighboring homes have sea walls and bulkheads that magnified the effects of waves and high tides at the site.
“Their shoreline has been eroding away,” Lust said.
After about a year of back-and-forth negotiations with DEEP, he said, the agency gave permits for a project that involved creating a slope with plantings, with a buffer of rip-rap just offshore.
“We’re at the beginning of a learning curve about what constitutes a living shoreline,” he said. “This is a policy that will evolve. There will have to be some compromises.”
To spread the word about living shorelines, Connecticut Sea Grant, DEEP and other organizations have run three recent workshops to acquaint town planners, coastal engineers, land trusts and others. During the last of the workshops, at Harkness in September, participants brainstormed some model projects at specific sites along the park’s shoreline, then got feedback, Barrett said.
“We need more in-the-ground projects, so people can see them, and we can monitor them, and see what the possibilities are,” she said.
The Connecticut Institute for Resilience and Climate Adaptation, based at the University of Connecticut’s Avery Point campus in Groton, has also been creating tools for living shoreline projects, said Rebecca French, director of community engagement for the institute, which is a partnership of UConn and DEEP. The tool is an online wave modeling forecaster. It uses localized data to predict the level of wave action at a specific site, so planners can better determine whether a living shorelines would be suitable, and what type of design would work.
“A lot of Connecticut’s coastline is very, very vulnerable to erosion,” French said. “You can’t put a living shoreline in everywhere. They’re not appropriate for areas with really big waves.”
Urbanized areas with docks and piers typically aren’t suitable, she said, but parks, waterfront lawns and “softer” areas along the coast are.
“We really need more demonstrations of how these projects can work,” she said.