The Liard River originates in the southern portion of the Yukon Territory. 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 Fort Nelson River comes from the south and meets the Liard 50 km before the Northwest Territories border. The Petitot River from the east joins the Liard River at Fort Liard. Other major tributaries which are further upstream include the Frances River from the north and the Kechika River from the south. 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). The Fort Liard monitoring station is located at the Hudson's Bay Company Post, 1.2 km downstream from the confluence with the Petitot River. The water quality of the other two stations is discussed in two separate reports (Jang & Pommen, 1996a & 1996b).
Upstream from Fort Liard, oil and gas developments are located mainly on the Fort Nelson and Petitot Rivers and their tributaries. Mining activities on the Liard are concentrated upstream near the Dease and Kechika Rivers and downstream on the South Nahanni River. Forestry in the Liard River basin occurs in the Yukon and British Columbia. Some agricultural activities are present near Fort Nelson. Plans for a hydroelectric project downstream from the town of Liard River and near the Beaver River confluence 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 1984 and 1995, and are stored under ENVIRODAT station number NW10ED0001. The water quality indicators are plotted in Figures 3-45. Water Survey of Canada operates a flow gauge at the water quality monitoring station (site number NW10ED001). The drainage area at the flow station is 222 000 km2. Flow data are graphed in Figure 2.