Boats along a stretch of the 140km Kennet and Avon Canal were left high and dry after a boater was "rushing and left the paddles up".
The Canal and River Trust said that the boater had left the lock gates ear the Barge Inn in Seend, Wiltshire open, as a result of which the water just drained away.
A section of the waterway was left with hardly any water on Tuesday.
The water levels have since been restored.
Boater accidentally drains Avon and Somerset Canal
— Canal Network (@Canal_Network) July 18, 2018
A boater accidentally drained a stretch of the Kennet and Avon Canal after leaving all the lock gates open Tuesday near the Barge Inn in Seend, Wiltshire.https://t.co/DOkZRsyGct