Copper and gold mineralization was discovered in the Jordan River canyon in 1915. Mining activity continued intermittently under various operators until 1975, leaving a lasting industrial footprint in the watershed.

In December 1963, mining operations pushed a crown pillar to within 17 metres of the riverbed, causing a catastrophic collapse. The entire flow of the Jordan River entered the mine, triggering a blowout that released large volumes of debris downstream and permanently altered river channels and surrounding land.

An underground milling operation produced fine-grained mine tailings and flotation chemicals that were pumped through pipelines to tidewater. Disposal systems failed repeatedly, resulting in widespread contamination of terrestrial, river and marine environments.

An estimated 800,000 tons of mine tailings were deposited at Maple Beach (the bay south of The Jordan River Regional Park), contaminating coastal sediments and nearshore waters. These materials contained copper and other metals that continue to affect the local environment.

Despite objections from residents, fishers and government officials, permits were granted to discharge mine tailings into the Strait of Juan de Fuca via a submarine pipeline. The pipeline broke multiple times, allowing tailings to drift inshore and contaminate shellfish and beaches.

A provincial inspection report concluded that final reclamation at the Sunro Mine was satisfactory. This determination did not address long-term environmental contamination, and responsibility for the site was subsequently returned to the Crown.

Multiple studies and water sampling programs have documented elevated metal concentrations downstream of the mine site, including copper levels far exceeding provincial guidelines for freshwater aquatic life. Contamination from remaining waste materials continues to affect the watershed today.