Winterbourne (stream)

A winterbourne is a kind of intermittent stream fed by an aquifer, primarily chalk aquifers, but occasionally limestone aquifers. The winterbourne flows in the winter, typically from December until approximately April, before declining until the following winter. When it rains, the porous chalk holds water in its aquifer and releases the water at a steady rate. During the dry season, the water table can fall below the level of the stream bed, causing it to dry up. The length of the dry phase depends on the longitudinal position of the stream.

The word derives from the Old English , meaning "winter stream". It is common as an element in English place names.