Ox bow lakes start when a meander loop becomes very large and only a narrow strip of land separates the river channel (called the meander neck). Lateral erosion continues, shortening this meander neck. When the land fully shortens, the river floods over it so main flow of the water doesn't go across the neck. This shortcut now breaks down the banks and carves a new channel. This new channel becomes established over time by continued vertical and lateral erosion. New deposition from this new channel fully cuts of the neck, detaching the two and forming an ox bow lake
