This is a river that only flows occasionally and can be dry for several years at a time. These kind of rivers are found in regions with limited or highly variable rainfall, or can occur because of geologic conditions such as having a highly permeable river bed.

Some of these rivers flow during the summer months but not in the winter. Such rivers are typically fed from chalk aquifers which recharge from winter rainfall. In the UK these rivers are called Bournes and give their name to place such as Bournemouth and Eastbourne.