What is an oxbow lake and how is it produced?

Oxbow lakes are a feature of meandering stream systems. When a stream meanders, flow velocity is greatest along the outer edge of the meander loop, eroding into the surrounding . Through time and erosion the meander loops expand. Eventually the soil separating two successive meander loop becomes relatively thin. During a flood event, the stream channel may take the path of least resistance and cut through this thin barrier cutting off the meander loop. The cutoff meander forms the oxbow lake.