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
North River (Belmont Lake) which flows via the Trent River to Lake Ontario. North River (Belmont Lake) The North River is a river in the municipality of Havelock-Belmont-Methuen, Peterborough County in Central Ontario, Canada. It is part of the Great Lakes Basin, and is a right tributary of the Crowe River. The river begins at Imp Lake in geographic Methuen Township and flows south, past the Blue Mountain Mine at Devil's Lake, to Kasshabog Lake. It continues south to Long Lake, then turns east, then resumes a southward direction, and enters geographic Belmont Township. The river passes through Round Lake, turns east, and reaches