The environmental effects of rock drains : results from the Rock Drain Research Program

The efficient disposal of waste rock at coal mines is of significant economic importance and may mean the difference between a viable and uneconomic mine. When blast rock is disposed of in a valley bottom through which a watercourse passes, the base of the dump is referred to as a "rock drain". The use of formal rock drains to convey significant streamflows at mines in the mountainous regions of western Canada dates from 1980. Since then, rock drains have come into use at the majority of Rocky Mountain coal mines in Alberta and British Columbia. The Rock Drain Research Program was the first comprehensive study of the physical and flow-through characteristics of rock drains and their environmental effects. The program involved analysis and intensive field data collection (over a four year period) at Manalta Coal Limited's Line Creek Mine in south-eastern British Columbia. The project comprised investigations into the physical, flow-through, and environmental characteristics of rock drains. Potential environmental issues included rock drain effects on suspended solids and bedload, water temperature, water chemistry, aquatic invertebrates, and fish. This paper will present an overview of the "environmental effects" investigations of the program. These effects, though measurable in most cases, were found to be much less significant than initially anticipated. Apart from the physical reduction of aquatic habitat due to the presence of the drain, the impacts of the drains were found to be quite localized.Non UBCUnreviewedOthe