Project to protect Hillman Marsh will begin this summer

A project led by the Essex Region Conservation Authority will protect close to 2,000 acres of wetland in Southwestern Ontario and also keep agricultural lands and homes from flooding.

Article content

Kevin Money, director of conservation services, said there is an estimated price tag of $10 million attached to the effort.

Article content

“It’s the largest single project we’ve taken on,” Money said. “This is rather unique as far as what we’re trying to achieve.”

Hillman Marsh is located along Lake Erie just west of Wheatley at the point where the shoreline turns southward toward Point Pelee. Unfortunately, due to the construction of the pier and harbor at Wheatley and shoreline protection measures such as the installation of armor stone, migrating sand is no longer being deposited in sufficient quantities onto the narrow band of land – the barrier beach – that has historically sheltered the marsh from the power of the lake. During a winter storm event in 2017 when lake levels had peaked, the barrier was breached and expert opinion suggests the half-kilometer opening will only get larger, leading to the eventual loss to the marsh entirely.

Article content

“The landscape of that shoreline study area with the pier at Wheatley has dramatically affected sand movement,” Money said.

The marsh provides spawning, nesting and feeding habitat for a diverse number of species, including several species at risk. It is home to several turtle species, many bird species, amphibians and a wide array of plants. The marsh and the barrier beach also protect the Mersea Road 1 dyke which was not designed to withstand the direct power of the lake should the marsh be compromised.

A breach in the dyke would cause about 2,000 acres of farm and residential land that lies below the lake level to flood.

Money and other ERCA staff members, along with Zuzek Inc. and SJL Engineering which both specialize in coastline projects, and staff with Environment and Climate Change Canada, worked for about 18 months to put together a report that was released in February this year. There were extensive consultations with community stakeholders including the Caldwell First Nation which owns a section of the marsh. While more funding will be needed to complete the project, Money said enough has been raised to move forward.

Article content

Fundamental to the project will be the construction of an artificial barrier beach which will include a stone core topped with sand transported from the Wheatley dredging program. There is about half a million in provincial government dollars in place to begin initial physical work this summer, the construction of a 40-meter test section extending from the East Beach Road at the south end of the Marsh.

Meanwhile, modeling of natural conditions such as wave action, sediment transport, and hydrodynamics will be used to finetune the design of the project. Construction of the artificial barrier beach with a permanent outlet is scheduled to continue in 2026 and be completed by 2027. In 2027 and 2028, work will continue with the construction habitat islands in the marsh that will also serve to help direct the flow of water and other features. Impacts of the measures will be monitored and adjustments introduced as deemed necessary.

Three different design concepts were considered with the nod being given to the high-crested barrier beach design. However, given the complexity of the natural forces at play, future adjustments are possible.

Article content