| Summary: | 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.
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