River Capture

River capture, also called stream capture or piracy, occurs when a stream with greater erosive power, usually because it drains to a lower base level or has a steeper gradient, erodes headward until it breaches the divide separating it from a neighbouring drainage and diverts that neighbour headwaters into its own channel. The captured stream below the point of diversion is left as an underfit misfit stream in an oversized valley, a mismatch that is often the clearest field evidence a capture occurred. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/