Port Bay Cobble Bell

Port Bay, New York, United States

Emulating natural condition through long-term adaptive management. The Port Bay cobble bell is located on Lake Ontario in a geologic context that has created a series of embayments protected by sandbars traditionally formed and fed by eroded drumlins (glacially deposited till left in linear hills). Reduction of erosion has minimized the inputs of the sediments that fed these protective sandbars and, in this case, has led to their breach, exposing the bay communities to ice and waves that can be highly destructive to property. Compounding the issue is the maintenance of community access from the bay to the lake, which requires the continual dredging of a channel though the bar. The removed material is typically placed on the channel’s east side, either upland or on the nearby beach. Funding to move the material farther is limited, as it is derived solely from fees paid by the community. The cobble bell is a sediment management project drawing inspiration from international Engineering With Nature concepts like the Dutch Sand Engine (but on a smaller scale). As such, it is intended to be a recurring, adaptively managed landform, reconstructed regularly to mimic the local conditions of bluff erosion and sediment input that characterizes the region. The cobble bell was designed by Healthy Port Futures with funding from the Great Lakes Protection Fund. Partners at the Wayne County Soil and Water District and the New York State Department of Environmental Conservation (NYSDEC) were fundamental to the success of the project, aiding considerably in its design and implementation.

Article Cover and above: The material transported from the cobble bell helps bolster the barrier sandbar that protects the homes around Port Bay from the waves and ice of Lake Ontario.

(Photo by Healthy Port Futures)

Producing Efficiencies

The cobble bell works by harnessing the energy of the waves and winds of Lake Ontario to transport sediment dredged annually from the boat channel downsystem to weak and failing areas of the sandbar, all without incurring costs beyond what was traditionally spent to place the material at an adjacent upland area where it is removed from the coastal system. This was achieved through long-term site observations, case studies, and physical models to assess just how the system worked and how it could function in a way that maximized operational efficiencies without increasing costs.

Using Natural Processes

The cobble bell is a form of adaptive coastal management, where information gathered from previous years can inform future decisions on an annual basis. And while the natural processes of wind and wave energy were studied and modeled to inform the initial design, the efficiency and adaptability of this process come from the ability to respond yearly based on what was observed and monitored in previous years. In this way, the cobble bell can continue to calibrate its relationship with the natural processes that drive it, allowing it to harness them for maximum benefit.

At Port Bay, the cobble bell form is created by removing sediment from the adjacent navigation channel and grading it out into the nearshore to be shaped by natural processes.

(Photo by Healthy Port Futures)

Broadening Benefits

The sandbar protecting Port Bay from volatile Lake Ontario is an essential piece of natural infrastructure for the community. Without it, ice and waves batter homes and docks, exacerbating erosive property loss around the bay. The sandbar has also been a habitat for the state-listed spiny softshell turtle (Apalone spinifera). The community’s economy relies heavily on water-based tourism, and access to Lake Ontario through the sandbar from the bay is essential. The project serves as a receiving area for dredged sediment that contributes to the local coastal ecosystem by keeping the sediment in the longshore system.

In a typical year, the cobble bell is eroded and transported within one or two weeks.

(Photo by Healthy Port Futures)

Promoting Collaboration

The cobble bell is the result of a highly productive collaboration between the design team, the local county soil and water conservation district, and the larger NYSDEC. With the help of the county representatives, the team was able to explain the project to the local community, who understood the value of both the long-term maintenance of the channel and the bolstering of the protective sandbar and saw the potential of the project to serve both of those roles simultaneously.

Typically completed with an excavator and bulldozer over one or two days, the cobble bell is intended to limit the time and funds needed to renourish the protective shoreline and its habitat.

(Photo by Healthy Port Futures)

Located just beyond the wave shadow of the jetty, the cobble bell works with the complex system of waves and currents at the mouth of the Port Bay navigation channel.

(Photo by Healthy Port Futures)