Last winter, after years of increasing erosion exacerbated by sea level rise, Long Island Sound breached a protective sand dune offshore of Fenwick leaving a recently restored marsh behind it vulnerable.
“There is concern that there is going to be more flooding, especially during large storm events,” said Juliana Barrett, an extension educator for the Connecticut Sea Grant project at the University of Connecticut who has been working in Fenwick for more than a decade. “The other thing is the sociological aspect of it. There is an informal walking path around the beaches of Fenwick. This is where you would exit and go up through the land trust parcel and go up on to the road and continue your walk, this could be gone.”
The sand dune and tidal marsh are on property owned by Lynde Point Land Trust, formerly part of the Hepburn estate.
“It’s bad for the marsh and houses behind,” said Andrew Fisk, the executive director of the Connecticut River Conservancy, a non-profit organization dedicated to protecting and advocating for the Connecticut River watershed. “Typically, in this situation, what people do is harden the coastline which is the wrong solution. We are instead proposing a living shoreline project using a dune system in order to dampen the wave energy.”
Living shorelines are an alternative to the traditional seawalls and bulkheads which lead to an increase in erosion on neighboring properties according to the Connecticut Department of Energy and Environmental Protection (DEEP). A living shoreline maintains or creates “natural coastal or riparian habitat,” according to DEEP.
With a $150,000 grant from the John T. and Jane A. Wiederhold Foundation and the support of the Lynde Point Land Trust, Connecticut Sea Grant, the National Fish & Wildlife Foundation’s Long Island Sound Futures Fund, the Robert F. Schumann Foundation and the borough of Fenwick, the approximately $250,000 project is scheduled to be completed by early 2020 pending approval by DEEP and the Army Corps of Engineers. The project would repair the dune and install rocks below the surface in a pattern set to diffuse the wave energy in order to decrease erosion of the sand.
“This allows for emergent marsh habitat to be established between those rocks and the dune itself,” Fisk said. “It has multiple benefits: protecting the resources you want to protect, protecting this marsh without introducing a foreign wall, reducing property loss, getting more dune and habitat, protecting the beach.”
Although DEEP has supported living shoreline projects since 2012, when hardening of the Connecticut coastline was limited by legislation, with more than 85 percent of the coastline of Connecticut privately owned, better stewardship of the coastline is dependent on landowners and private consultants. This will be only the second project constructed in Connecticut. The first was in Stratford four years ago.
“This is the type of project that we need to see more of in New England, we could be doing better shoreline and climate adaptation work across the Sound. There is urgency, the marsh is being affected and it needs protecting. This is an innovative and effective way to deal with a changed climate,” Fisk said. “The DEEP has been supportive of living shorelines as a policy priority for a while, that is true. I think the constraint has been finding landowners and funding to put projects together.”
At the Connecticut Institute for Resilience & Climate Adaptation (CIRCA) based at UConn Avery Point, James O’Donnell has been working on making it easier for private landowners and engineers to do just that.
“My interest is assessing how effective these structures are at reducing erosion and reducing the effect of waves during storms,” said O’Donnell, who has a background in coastal engineering. “We have shown that they do have a substantial impact on the waves, but we still need to provide better design criteria for engineers to follow. Engineering companies need to follow standard practices. These are well established for sea walls, but living shoreline approaches are more uncertain so engineering companies don’t want to do them until they know they can design them effectively.”
CIRCA took an active role in sponsoring the Fenwick project, to provide more opportunities for research and the development of these standard engineering practices.
A neighboring private effort
In neighboring Fenwood, another living shoreline project has been proposed by a private resident. The project includes placing boulders along an eroding waterfront in order to prevent more erosion.
“In an effort to have the stabilization project — which is often frowned upon by the DEEP — considered as living shoreline — something that the DEEP supports — a limited amount of fill will be placed behind the boulders with a type of wetlands plant planted on top,” said Torrance Downes, deputy director and principal planner at the Lower Connecticut River Council of Governments. “That, to the engineer, is establishing habitat/tidal resources worthy of the designation of living shoreline, and a quick uncomplicated approval.”
But with no clear definition of a living shoreline, there is no defined amount of reestablished wetland grasses and vegetation that a living shoreline needs to have.
“In this case, the proposed black grass in a small area along the boulders does not in [DEEP’s] opinion meet the definition of a ‘living shoreline.’ It’s nowhere near substantial enough,” Downes said. “So, there’s a difference in opinion. The engineer claims it is, the DEEP claims it isn’t.”
For most property owners, the purpose of a project is to protect a particular property, not to provide resiliency for the shoreline as a whole.
“The juxtaposition of these two proposals should give you a little insight into two ways that ‘living shorelines’ are looked at,” Downes said. “One can be used as a ‘tool’ for a property owner to get something DEEP doesn’t support, while the other is considered to truly be a conservation-based environmental enhancement.”
[embeddoc url=”https://ctexaminer.com/wp-content/uploads/2019/11/Hepburn-Living-Shoreline-proposed-design-Sept-2019.pdf” download=”all”]