The City of Revelstoke and surrounding regions are located in the interior of eastern British Columbia, approximately 220 km north from the Canadian - American international boundary. The drainage area for the Columbia River at Revelstoke is approximately 26,700 km2 (Figures 1 and 2). The Mica and Revelstoke dams have a substantial effect on the water quantity and quality in this section of the river. The water uses for Columbia River water at Revelstoke are: irrigation, livestock watering, primary-contact recreation (i.e., swimming), drinking water, industry, wildlife, and aquatic life.
We concluded that:
· There was a declining trend in total phosphorus, probably due to the trapping effect of upstream dams and reservoirs.
· The river had a low sensitivity to acid inputs.
· Water hardness was lower than the optimum range for drinking water, but was still quite acceptable.
· Iron and manganese values that exceeded aquatic life and drinking water guidelines were probably in a particulate form and not biologically available, and would be removed by the drinking water treatment needed to remove turbidity.
· Turbidity values were lower than other natural rivers in the Kootenay area during freshet because of settling in the Kinbasket Lake and Lake Revelstoke reservoirs.
· Columbia River water at Revelstoke must be treated to remove turbidity and disinfected prior to drinking.
· One selenium value exceeded the maximum guideline for aquatic life in 1995. This value was collected in a sample with low suspended sediments (non-filterable residues or turbidity), indicating that the selenium was not in a particulate form, and may have been biologically available. The Bethlehem Resources Corporation's zinc mine in the Goldstream River Valley (now closed) may have been a source of the selenium.
· Water temperature met the guidelines for aquatic life and drinking water aesthetics, but was too cold for water-contact recreation (e.g., swimming).
· One zinc value exceeded the maximum guideline for aquatic life (algae) in 1991. This value was collected in a sample with low suspended sediments (non-filterable residues or turbidity), indicating that the zinc was not in a particulate form, and may have been biologically available.
We recommend that routine monitoring be discontinued on the Columbia River at Revelstoke with the exception of total phosphorus to track the trends in phosphorus input to the Arrow Lakes.
Figure 1 Columbia River Watershed
Figure 2 Columbia River at Revelstoke Watershed
Scale: 1 cm : 18 km