Trail closures on the way as dredging of marsh resumes in Mississauga

The first-ever dredging of a northwest Mississauga marsh resumes in early July and the work will shut down part of a popular walking trail for the next several months, the city says.

A section of the Lisgar Meadowbrook Trail will be closed to the public for the duration of the Osprey Marsh dredging while other parts of the trail will be closed temporarily when work is taking place nearby (see image below), City of Mississauga Ward 10 Coun. Sue McFadden said in her latest newsletter to the community.

The councillor further noted dredging of the man-made stormwater pond will “carry on until late 2026” in an effort to allow it to better perform its important function.

“The marsh will be dredged by barge and the pond is not expected to be fully drained except for the very northeast cell where sediment will be deposited, dried and then trucked away,” McFadden explained. “This work follows the initial phase of dredging that took place last fall … please take caution and obey the trail closure signage in the area.”

(Image: Ward 10 Coun. Sue McFadden newsletter/City of Mississauga)

Osprey Marsh, located to the immediate northeast of Britannia Road West and Ninth Line, was built in the mid-1990s and is undergoing its first dredging.

Preparation work began last September and the dredging started in October. Various sections of trails were also closed at that time to allow the work to proceed.

McFadden said earlier Osprey Marsh is a man-made stormwater pond (or series of smaller ponds) that regulates the flow of rainwater and snow melt from storm sewers and the Sixteen Mile Creek upstream.

“Over time, sediment can accumulate at the base of the pond, reducing its capacity,” the councillor explained at the outset of the work last fall, adding this marks the first time Osprey Marsh has been dredged since it was built three decades ago.

“In order to comply with environmental regulations, the project will extend over multiple phases, starting with the drying of the northeast part of the pond in late October through December (2025). Water will remain in the rest of the marsh and dredging of those sections will occur by barge, with sediment being stored temporarily on the dry section established in the first phase.”

Aerial image shows location of Osprey Marsh and surrounding neighbourhoods.

Osprey Marsh, much like nearby Lake Wabukayne to the east, has also become home to numerous types of birds and other wildlife over the years.

One particular form of wildlife was causing some water flow problems at the marsh last fall.

At that time, city officials removed a number of beaver dams and beavers from in and around Sixteen Mile Creek and Osprey Marsh in the heart of the Lisgar community.

The critters, who were safely relocated, had built dams that were causing drainage problems near the creek and marsh. That subsequently led to the water flow issues, the city said.