Mackenzie River from the Peace-Athabasca system are significantly slowed by the delta area at the western end of Lake Athabasca causing the lake to rise, and the excess water can only flow out after the rivers have receded. The same phenomenon occurs at Great Slave Lake, which naturally regulates the flow from the Slave River into the Mackenzie. There are river gages at several upstream points along the Mackenzie River. The average flow rate at the outlet of Great Slave Lake is . At Fort Simpson, below the Liard River, it is . At Norman Wells it is , and at the
Black Lake (Fond du Lac River, Saskatchewan) Black Lake (Fond du Lac River, Saskatchewan) Black Lake is a lake in the Mackenzie River drainage basin in northern Saskatchewan, Canada. It is about long, wide, has an area of , and lies at an elevation of . The primary inflows are the Chipman River, Cree River, Fond du Lac River, and Souter River; the primary outflow is Fond du Lac River, which flows via the Mackenzie River into the Arctic Ocean. The community of Black Lake is located on the northwest shore of the lake, near where the Fond du Lac River exits. The fish species in the