Scientists and engineers used a public seminar this week to explain how living shorelines work and how decades of local research are informing a proposed flood-protection project along Cambridge’s waterfront.
As part of the Make Cambridge Resilient initiative, the December 10 Virtual Living Shoreline Public Education Session summarized some of the thinking behind the ambitious flood-mitigation effort on the Choptank shore that would combine shoreline restoration with a raised embankment to protect low-lying parts of the city from storm surge and rising sea levels.
The session gave participants access to the science and engineering behind living shorelines and time to review data, models, and design concepts before final decisions are made. Much of the presentation drew on research conducted locally by the University of Maryland Center for Environmental Science in Cambridge (UMCES).
Research Shapes Living Shoreline Design
Presenters Cindy Palinkas, an associate professor at UMCES, and Laura Exar, a NOAA Coastal Management Fellow working with the state Department of Natural Resources, described how living shorelines, which typically use sand, marsh plantings, and sometimes stone structures, are designed to reduce erosion while supporting habitat.
Palinkas pointed to long-term baywide data showing that submerged aquatic vegetation naturally fluctuates over time. Using aerial imagery and field verification from a Virginia Institute of Marine Science database dating back to the mid-1980s, researchers examined seagrass trends before and after the installation of living shorelines. Offshore of the shoreline footprint, Palinkas said, seagrass levels generally track regional patterns rather than showing clear changes tied to construction.
She emphasized that the analysis did not examine the direct conversion of shallow-water habitat to marsh, an issue researchers continue to study.
Palinkas also described how living shorelines mature over time. Early installations often begin with clean sand and sparse vegetation, she said, but plants gradually trap finer sediments and produce organic material as they grow. Data from multiple sites showed that mud content increased for several years before stabilizing at levels similar to those in natural marshes. Researchers estimate that the process takes roughly eight to 10 years, though Palinkas noted gaps in available data.
Exar focused on habitat research and how scientists assess tradeoffs among shoreline designs. She described habitat suitability modeling, a method used in large restoration programs to evaluate how environmental conditions support various species across seasons and locations. Exar said combining that approach with concepts such as habitat connectivity and resilience can help planners compare design options and better understand ecological gains and losses.
From Habitat Science to Shoreline Engineering
Anna Johnson, a coastal engineer with the ecological restoration firm BayLand Consultants, explained how that science is applied in design. She said most living shoreline projects include sand placement, either as beach nourishment or as a planting base, and may also include protective features depending on site conditions such as wave energy and water depth.
Those features can include stone sills, temporary fiber logs that break down as vegetation becomes established, and manufactured structures designed to dissipate wave energy while also providing habitat. Johnson said segmented stone sills with gaps are now standard because they allow tides and wildlife to move between land and water.
Research presented during the seminar showed that while erosion can occur near those gaps, overall shoreline performance is similar to continuous structures. Johnson said that finding supports designs that preserve ecological connections without sacrificing erosion control.
Johnson said costs vary, but a typical living shoreline with marsh plantings and protective features can cost about $500 per linear foot, with more complex projects costing more.
Sam Eckert of the Maryland Department of Natural Resources addressed permitting and funding questions, including when hard shoreline structures may still be allowed. He said property owners can request waivers for structural approaches, usually in areas with high wave energy or deep water, but grant programs focused on habitat restoration generally do not fund projects that rely solely on hard structures.
Public Concerns and Project Funding
During public comment, questions turned to how the living shoreline would connect to a proposed embankment along parts of the Cambridge waterfront. Project representatives said the embankment is intended to reduce damage from severe storms and is being designed with sea-level rise and storm-surge projections.
Seminar participant James Linthicum, a waterfront resident, said he was concerned that the embankment could block the water views that drew him to his home in the first place and, in turn, diminish his property’s value.
“Taking my water view away will also take part of my property value away,” Linthicum said. “These are certainties to me. They’re not guesstimates. Once we lose our water view, it takes value away from our properties.”
Officials responded that the project’s primary funding from the Federal Emergency Management Agency (FEMA) is tied to disaster mitigation, not routine flooding. They pointed residents to tide gauge data from Cambridge and to state and university sea level rise projections.
A to-scale model of the proposed berm has been installed near Long Wharf Park to give residents a clearer sense of its height and appearance, and it will remain in place for several weeks.
The project’s first phase is funded through a $1.7 million Federal Emergency Management Agency Hazard Mitigation Grant Program award, and design is roughly 30 percent complete, including preliminary alignment and surveys with public review underway.
FEMA has also reserved about $16 million toward construction pending approval of the final design, but hopes that the agency’s Building Resilient Infrastructure and Communities program could help fund implementation were dashed when the program was canceled. Estimates for the overall implementation cost range from $30 million to $60 million, including construction, habitat features, and stormwater work.
Project leaders encouraged residents to review the information, submit comments through the project website, and attend additional outreach meetings planned for early 2026 as design work continues.
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