Misfit stream

The large Vale of Ewyas in south Wales, through which the small River Honddu flows. This means the River Honddu is a misfit stream.

A misfit stream is a river which is too big or small for its valley. If the river is too big for its valley, it is an overfit stream, and if the river is too small it is an underfit stream.

Misfit streams can have many causes, such as glaciation or human activity.