On June 12, 1999 the William Alexander Dempsey Ecological Park was officially opened to the public. An area of wildlife, self-sustaining habitat, natural vegetation and water management, these ecological areas provide both environmental and passive recreational opportunities for local residents.

The Eco Park is named in honour of Bill Dempsey, a local resident and founding member of the Centennial Community and Recreation Association. He has spent many years working to preserve Centennial Creek. Mr. Dempsey's philosophy is to get in there and do what you can until you feel there's nothing more you can add.

Located within the Centennial Creek subwatershed, the ecological park is made up of three interconnected areas:

Willowlea wetland

Ellesmere wetland

Meadowvale wetland

Each of the sites in the Eco Park was constructed to renaturalize the watercourse and provide improvements to water quality. The sites offer opportunities for community enjoyment and education.

Additionally, habitat provided by the three sites owned by the city provides food and cover for wildlife, encouraging a return of biodiversity.

The movement of wildlife (e.g. birds) may occur along nearby yards, as they travel to the Rouge and Highland Creek watersheds, and to the lower reaches of the Centennial Creek: a promise of restored ecological functions in this stream valley.

Quiet greenspace provides an opportunity for walks and just being outside in nature - an excellent stress reducer. Children can benefit by observing and learning about natural processes, particularly when sharing this with new understanding with another.

Willowlea wetland
The purpose of this constructed wetland, located just south of Highway 401, is to allow for sediments to be trapped and its plants to filter out pollutants and naturally clean the water before it continues downstream. The use of two separate ponds with a filtering berm and overflow system makes this more efficient.

During rainstorms, the majority of water entering Centennial Creek, immediately south of Highway 401, is highway runoff. This runoff is polluted with gasoline and oil, salt, antifreeze and other road surface contaminants. It is important to treat this water before it travels through the creek, protecting the natural wetland south of this site.

Ellesmere wetland
This site located on the north side of Ellesmere Road and west of Meadowvale was home to excess soil which caused poor drainage for some rear yards in the area. That soil was removed to restore the valley to its original plain, (a natural rain storage area); a necessary part of the water cycle.

At the upstream of this facility, a large amount of the initial flow from a storm will be directed into a wet meadow, allowing for settling of unwanted particles. By holding back storm volumes, the local drainage area and downstream facility benefit.

Meadowvale wetland
Located at Meadowvale Road and Kingston Road is an offline stormwater management quantity and quality pond. Originally a dry pond, which is an area that will fill during a storm, this site was redesigned to expand the storage capacity and create a permanent pond/wetland for increased water quantity and quality control.

The newly designed stream channel carries the base flow (fed by groundwater), while two cells separate from the channel wait for storm volumes. These permanent pools will catch and hold silts (often polluted particles) found in the first 'flush' of a storm. During heavy storms, the whole area becomes flooded, so keeping a distance for a day or two is wise.