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
Fond du Lac River (Saskatchewan) Fond du Lac River (Saskatchewan) The Fond du Lac River is one of the upper branches of the Mackenzie River system, draining into the Arctic Ocean, located in northern Saskatchewan, Canada. The river is long, has a watershed of , and its mean discharge is . The river begins at an elevation of at Cunning Bay on Wollaston Lake. It flows north to Hatchet Lake at an elevation of and continues to Waterfound Bay at an elevation of , where the tributary Waterfound River enters from the left. The river continues north to Kosdaw Lake at an elevation of ,