Benson Lake is a small but very deep coastal mountain lake situated in the coastal western hemlock zone on the northern end of Vancouver Island. From August 1962 through January 1973, the Benson Lake Coast Copper Mine, operated by Cominco Ltd. disposed of its mine tailings by depositing them, under permit, into the deep basin of the lake. As a result, the lake was occasionally subjected to extended periods of increased lake turbidity levels. Furthermore, the tailings smothered the lake’s sediments and this destroyed all traces of invertebrate life.
These increased turbidities were also found in the Lower Benson River. This also resulted in elevated levels of zinc in the water and in the flesh of fish taken from the lake.
In 1973, Cominco Ltd. ceased operations and all dumping of tailings in the lake ceased. Testing of the lake, conducted 10 months later, found that tailings material in the lake’s waters had settled down and that Benson Lake’s clarity had returned to normal conditions. Also, the increased levels of zinc in the lake’s water had subsided. However, it was noted that the bottom of the lake still was devoid of any invertebrate life.
In September 1990, more than 17 years after the mine closed, it was found that Benson Lake now showed little evidence of the fact that it was the recipient of mine waste.
The fishing in the lake is now good to great and the fish show no signs of increased levels of pollution in their flesh, but there is still an increase in levels of zinc in their livers. Personally, l would only catch and release the fish in this lake. The camping on the lake is great and there is plenty of wildlife here to keep your camera clicking.