Amherst Island Wetland Reconstruction Project

Project by Ducks Unlimited Canada.

Location: County of Lennox & Addington, ON.

For more information on this project, please contact Lynette Mader, Manager of Provincial Operations, Barrie, ON.


The Amherst Island Marsh project is large coastal wetland located along the southwestern shore of Amherst Island.  This wetland was historically regulated by Lake Ontario water levels before the construction of the Moses Saunders dam near Cornwall in the late 1950’s. Stabilization of the Lake’s hydrological regime lead to an extreme overgrowth of aquatic emergent vegetation throughout the basin and greatly restricted the diversity of waterfowl and wildlife species that could utilize this and other coastal marshes.

In 1997, Ducks Unlimited completed a conservation initiative that aimed to enhance the biodiversity of this site and provide brood rearing and staging opportunities for an array of dabbling and diving waterfowl.  The project now consists of a managed area totaling 143.4 ha (354.3 ac) and a protected area equaling 172.8 ha (427.0 ac).   A range of wetland water levels are managed within an impoundment that is contained by a 2 km earthen dyke, coupled with a variable level water control structure and an electric pump. 

Repair work is required along sections of the earthen dyke where muskrat burrowing has resulted in some extensive slumping. This reconstruction initiative will restore the structural integrity to the dyke by creating a clay core and augmenting the dyke in the slumped sections to bring the dyke back up to original design standards. The original plate steel structure remains in good condition and will be maintained as is. The dyke rebuilding will permit water levels to be managed at desirable depths to maximize wetland habitat productivity. The last component of the required work is some minor maintenance on the existing pump to ensure it remains in good operational condition to assist with water level management. 

Long-term conservation impacts and benefits

This project will ensure that the Amherst Island wetland conservation project remains a productive wetland habitat for the next 25 years. The management of the wetland habitat will address the negative impacts associated with Lake Ontario water level stabilization. Waterfowl breeding, migratory, and staging habitat will be sustained. The local community will benefit from increased hunting, bird watching and recreational opportunities.

New tools, methodologies, landscape practices or protocols

The reconstruction of this project includes the rebuilding of eroded sections of the 2,000 meters of earthen dyke and the maintenance of the existing electrical pump system that is used to supply and manage water levels in the marsh. DUC biological and engineering staff will implement the refurbishment activities, including the completion of project design, securement of government permits, as well as oversight of the construction activities. Permitting and the securement of required approvals for this work is underway and will be completed before the initiation of the project. Long term conservation agreements (originally 50 years with 26 years remaining) are in place with the 13 landowners.