New wetlands created in Southern Ontario

The Ontario Stone, Sand & Gravel Association (OSSGA) has released a study on the creation of wetland features at former aggregate pits and quarries within the Greenbelt, Oak Ridges Moraine and Niagara Escarpment Plan Areas of Canada.

The study reveals a total of 293 hectares of aquatic habitat features – or the equivalent of 1,849 NHL-sized hockey rinks – have been created through the rehabilitation of surrendered aggregate sites.

“The preservation and restoration of aquatic habitat and wetland ecosystems across Southern Ontario is critical,” says Norman Cheesman, executive director at OSSGA. “Almost 70 percent of Ontario’s original wetlands have been lost to growth and development. Creating new wetland features and habitats is an environmentally exciting component of the extraction and rehabilitation cycle.”

Aggregate rehabilitation in Ontario is mandatory. The Aggregate Resources Act requires that aggregate licenses undergo progressive and final rehabilitation prior to being surrendered. Through the rehabilitation of aggregate extraction sites, there is an opportunity to create and restore natural heritage features, including aquatic ecosystems that contribute to the natural heritage features and hydrologic features and functions of the Greenbelt.

“The public is often unaware that former aggregate sites can be rehabilitated into significant wetlands,” Cheesman says. “Many of our producers have partnered with Conservation Authorities and non-governmental organizations like Ducks Unlimited to create productive wetland projects that support biodiversity, offer flood protection and mitigate the effects of climate change.

“In the area covered through the study,” Cheesman says, “nine of the new wetlands were identified by the government as part of provincially significant wetland complexes. This means that these rehabilitated sites are meeting the Ministry of Natural Resources and Forestry’s strict criteria for designation of significant wetlands based on their biological, social or hydrological features.

“The aggregate industry is also thinking outside the box with their approach to rehabilitation efforts. One producer has even established a sustainable aquaculture fish farming operation that uses excess fish nutrients to support the growth of wetlands surrounding the rehabilitated quarry.”

Aquatic features become points of interest in recreational parks or golf courses, become part of provincially significant wetland complexes or are located adjacent to existing natural heritage features, and can contribute to biodiversity and ecological functions on a local and broader landscape level.

OSSGA is planning a second phase of the study to field verify the findings to understand the ecological and social value of these important aquatic features.

The study, conducted on behalf of OSSGA by Skelton Brumwell & Associates Inc., looked at the 123 surrendered licenses within the study area. The results found that:

• Nine wetlands were found to be part of Provincially Significant Wetland (PSW) complexes.
• 68 (or 55 percent) of sites contained one or more aquatic habitat features.
• A total of 173 aquatic features were identified and analyzed using aerial photography.
• 63 percent of the features were found to be ponds.
• 33 percent of the features were classified as wetlands.
• 4 percent were a mix of both ponds and wetlands.

Significantly more wetland has been created by the aggregate industry than reflected in this study, which, by design, excludes aquatic habitat features created through progressive rehabilitation on the approximately 3,700 active licenses within the study area.

Examples of rehabilitated wetlands in southern Ontario include:

• Milton Limestone Quarry/Kelso Quarry Park in Milton
• Burlington Quarry/Kerncliff Park in Burlington
• Snyders Flats in Bloomingdale
• McMillan Pond in Aberfoyle