An oxbow lake is a crescent-shaped lake that is formed when a meandering river is cut off. Such cut-offs occur when when the downstream movement of one meander ‘catches up’ with the lagging movement of the bend immediately below it. Essentially, the outer banks of the meandering bends, over time, are expanded by the velocity of the river and its erosional process. When one meandering bend meets another, the river takes the shape a straight trunk portion, connected to a horseshoe shape. The water in the river is always looking for the straightest route, and thus the flow bypasses the horseshoe. Overtime this horseshoe shape is blocked from the flowing trunk of the river by depositional filling, and a horseshoe of standing water is left behind. This standing water is the oxbow, and in this picture you can see a part of the oxbow found in the south of Edmonton just off the Whitemud Drive.
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