Kamloops Lake is located in the dry interior of British Columbia adjacent to the City of Kamloops.

The lake is bounded on all sides by steep embankments with level areas only near creek deltas and at the inlet and outlet. The surrounding land is mostly uninhabited and within the dry belt interior grasslands composed of bunchgrass and sagebrush with pockets of Douglas fir, Ponderosa pine and spruce.

The lake appears to be a widening and deepening of the Thompson River which enters at the east end and exits at the west end. The limnology of the lake is controlled by the Thompson River which has large fluctuations in annual flow with over 60% occurring in the early summer during freshet (May-Jul.). Bulk residence times are very short, ranging from 20 days to 340 days with a mean of 60 days. The Weyerhaeuser Pulp Mill discharges daily an average of 182,000 m3 of biologically treated effluent to the Thompson River just upstream of the lake. The City of Kamloops periodically (Oct. & Nov.) discharges up to 35,000 m3 day-1 of tertiary treated domestic effluent. Major water quality problems which became evident in the Thompson River downstream of the lake in the early 1970's were attributed to the discharges. Improvements in water quality have occurred through improved treatment of the effluents.