Posted on February 19, 2024
The most robust option for restoration of Hillman Marsh earned approval from the Essex Region Conservation Authority last week, but it’s likely to be at least four years before the major part of the project comes to fruition.
The plan calls for a high-crested barrier of stone and sand that allows for more vegetation, which acts as a line of defence from the pounding waves of Lake Erie. It also includes habitat islands, ponds for fish and a permanent outlet that allows for the passage of fish.
Hillman Marsh, located on Leamington’s east side and north of Point Pelee National Park, faces “a great deal of stress from coastal erosion processes as well as climate change … and as a result our wetland and the associated biodiversity within it is suffering,” Kevin Money, director of infrastructure told the board before the vote to approve the plan.
A barrier of sand that had previously separated Lake Erie from Hillman Marsh has been eroded since 2020. Depending on wind conditions, water is either drawn out of the marsh, killing large amounts of aquatic wildlife, or lake water enters, flooding the marsh. At some point in the future, a berm that protects lower-lying farmland and hundreds of houses could be ruptured.
“The actual mouth of the Hillman Marsh where the breach occurred continues to deepen and go farther and farther into the marsh,” Money told the board. “So the lake continues to go farther into the wetland every year.
“It is a significant breach in terms of how far it’s extended.”
When the wind blows from Hillman Marsh out to Lake Erie, water is drained from the marsh, resulting in dangerous conditions for aquatic life. The breach between the marsh and the lake is visible in the distance in this Jan. 31, 2024, photo.
The marsh is “highly susceptible to coastal erosion and wetland loss due to such factors as negative sediment supply, variability in ice cover, extreme water level fluctuations, and increased frequency and intensity of storm events,” a report prepared for the board says. “These factors have resulted in the loss of the barrier beach, the loss of aquatic vegetation, and increased vulnerability of sensitive marsh habitat.”
“Ice-free winters and higher lake levels due to climate change are expected to exacerbate these challenges to the overall resilience of the marsh and barrier beach.”
A striking illustration in the report prepared for the board shows a simulated berm breach that leaves large swaths of farmland and almost all of Point Pelee National Park underwater.
The plan approved Thursday proposes construction of a new barrier farther inland that can withstand the encroachment of Lake Erie.
The Town of Leamington is responsible for maintenance of the berm infrastructure and municipal authorities have been working closely with ERCA on the plan, said Money.
Once the restoration plan is complete, water quality would be improved and an increase in biodiversity can be expected, the report says.
Existing conditions of Hillman Marsh on the Point Pelee Foreland, looking southwest, with lake levels.
“Economic damages will be avoided with a barrier to act as a buffer between the lake and the marsh, protecting hundreds of homes and businesses that currently reside below lake level.”
The lands sit on territory or the Caldwell First Nation, which has yet to approve the plan. But members of the First Nation sat on the stakeholder committee and its leadership will be consulted, said Money.
The proposed restoration plan will cost about $10 million, including up to two years of engineering preparation before construction begins.
Hillman Marsh contains habitat for many species at risk, including the common hop tree and scarlet ammannia. Other rare, threatened or endangered species in the marsh or along the shoreline include the American lotus, king rail, large yellow pond-lily, least bittern, prothonotary warbler, swamp rosemallow and several turtle species, including northern map, snapping, spiny softshell, midland painted, and Blanding’s turtle.
Simulated scenario of a Road 1 dyke breach for the 100-year lake level of 176 M.
The marsh has been a “staple in Essex County for many decades,” the report says, hosting summer camps, nature tours, bird watching, educational field trips, and hunting.
