Severn Sound: Area of Concern (Delisted)

Severn Sound was designated an Area of Concern (AOC) in 1987 under the Canada-U.S. Great Lakes Water Quality Agreement. Pollution from wastewater, agricultural land uses and shoreline development led to degraded water quality and environmental health. Five out of 14 beneficial use impairments (BUIs) were identified, which measure the environmental, human health or economic impact of poor water quality. One additional beneficial use was deemed as “requiring further assessment”, meaning more information was required to determine whether they were impaired.


In 2003, Severn Sound became the second Canadian AOC to be delisted. We delist an AOC when monitoring shows that targets for all BUIs have been met and environmental quality has been restored.

Monitoring confirmed that environmental quality was restored through:

  • upgrades to reduce phosphorus from nine municipal sewage treatment plants, 600 private septic systems and use of best management practices at farms
  • the restoration and protection of 411 hectares of wetlands and connected watersheds,   planting of 132 vegetation buffers to protect against stream erosion, the creation of habitat corridors and the adoption of Natural Heritage Strategies by townships and municipalities
  • progress in establishing a healthy Trumpeter Swan population at Wye Marsh through a federal ban on toxic lead shot and the use of a sediment management technology to ensure existing lead shot pellets are out of reach of the swans

Restoration of beneficial uses

All beneficial uses are no longer considered “impaired”:

  • restrictions on fish and wildlife consumption (2002)
  • degradation of fish and wildlife populations (2002)
  • restrictions on dredging activities (2002)
  • eutrophication or undesirable algae (2002)
  • loss of fish and wildlife habitat (2002)
  • degradation of aesthetics (2002)

Our partners

We partner with other levels of government, non-government groups, Indigenous communities and members of the public. This restoration work required a large amount of scientific and technical expertise, local knowledge, hard work and the help of:

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