Within its existing mining tenements Poseidon Bow River Diamond Mine Limited (Poseidon) proposes to extend its alluvial diamond mining operation into areas where ongoing exploration has defined economically viable alluvial reserves of diamonds. The mine and tenements are located at the southern end of Lake Argyle on Lissadell Station about 205 km from Kununurra by road.
The original mining proposal was not assessed under Part IV of the Environmental Protection Act 1986, but environmental conditions were set under several Works Approvals and Licences under the provisions of Part V of the Act. It was approved by the then Department of Mines in 1987 for Freeport Bow River Properties Ltd. (Freeport) which subsequently sold the project to Poseidon. Mining commenced in 1988. As the water level of Lake Argyle subsided, exploration in low lying areas along Limestone Creek identified extensions of the ore body. Poseidon developed a proposal to mine this area and submitted a Consultative Environmental Review in May 1990. Environmental approval for that operation was granted in October 1990.