WATER MANAGEMENT OF THE STEEP ROCK IRON MINES AT ATIKOKAN, ONTARIO DURING CONSTRUCTION, OPERATIONS, AND AFTER MINE ABANDONMENT

Abstract

The Steep Rock Iron Mines at Atikokan, Ontario operated from 1944 to 1979. The iron ore was located at the bottom of Steep Rock Lake and water management was a key factor in developing the mines. Open pit mining required a massive water diversion scheme, including the diversion of the Seine River, draining of Steep Rock Lake, and construction of various dams and other diversion structures. In order to abandon the mine, the Province of Ontario required a suitable abandonment and long-term water management plan, and assessment of the condition of the various water control and diversion structures. Reclamation of the Seine River to its original course was not possible and, consequently, the water control structures, primarily dams and tunnels, will be operating in perpetuity. The water management during the development of the mines and during operations is described, as well as some insight into future water management options after abandonment.