The Liard River originates in the southern portion of the Yukon Territory (Figure 1). The river flows southeast across the British Columbia border, past the town of Liard River. Then, the Liard flows north across the Northwest Territories border to the confluence with the South Nahanni River and continues northeast, where it joins the Mackenzie River. The Frances River comes from the north and meets the Liard 20 km upstream from Watson Lake. Other major tributaries which are further downstream include the Kechika, Fort Nelson, Petitot and South Nahanni Rivers. The Liard River is under ice from November to April.
There are three water quality monitoring stations on the Liard River (Upper Crossing in the Yukon, Lower Crossing in British Columbia, and Fort Liard in the Northwest Territories - see Figure 1). The Upper Crossing monitoring station is located at the Alaska Highway Bridge near the Yukon/British Columbia border and 11 km west of Watson Lake. The water quality of the other two stations is discussed in two separate reports (Jang & Pommen, 1996a & 1996b). Some mining activities are located within the Liard River headwaters. Forestry occurs around the Meister, Rancheria and Liard Rivers. Plans for a hydroelectric project near the town of Liard River, British Columbia exist, but are not expected to proceed within the next twenty years (MacDonald, 1993).
Data for this report are from sampling by Environment Canada, between 1983 and 1994, and are stored under ENVIRODAT station number YT10AA0001. The water quality indicators are plotted in Figures 3 to 45. Water Survey of Canada operated a flow gauge at the water quality monitoring station (site number YT10AA001). The drainage area at the flow station is 33 400 km2. Flow data are graphed in Figure 2.