Fish living in the canal were rescued before it was drained
Major works are under way to help maintain a Wiltshire canal which celebrates its 200th anniversary this year.
Sixteen new lock gates will be installed on the Caen Hill flight of locks on the Kennet & Avon Canal over the next 12 weeks.
The works are part of British Waterways' £500,000 winter maintenance programme.
A spokesman said the new locks would mean less water was wasted.
Workmen have removed fish from the canal ahead of its draining to allow the removal of the old gates.
The British Waterways spokesman said: "While the canal looks like a tranquil place, in the background we are working around the clock to ensure that the waterway keeps running smoothly and has the right amount of water in it at the right time.
"The new locks at Caen Hill will help us to do this, and will mean that less water is wasted."
The flight is a scheduled ancient monument and thousands of visitors come to view the boats every year.
It will be reopened to the public once works are complete.