The Thames Barrier will mark its 21st anniversary on Monday.
Experts predict the barrier will be used more frequently
Said to be the largest movable flood barrier in the world, it is London's primary protection against flooding.
Spokesman Andy Batchelor said the barrier had become a "significant landmark for the city, protecting 1.25m Londoners from flooding.
"The barrier is only at the start of its life, we expect to use it more and more frequently as climate change progresses," he added.
"It has proved to be an incredibly versatile tool in protecting 1.25m Londoners from flooding," said Mr Batchelor, Thames tidal manager.
Climate change experts have predicted the existing Thames barrier, built in the 1970s, may not be able to cope with rising tides.
"We are already looking at the continued protection of London over the next 100 years through our project, Thames Estuary 2100," added Mr Batchelor.
The project assess flood risk and river management over the next century.
Darren Johnson, Green Party member for the London Assembly, said the barrier was being used more frequently.
"The barrier has been extremely important in terms of protecting London but is being used more and more.
"In the previous five years the barrier has been used 55 times but in the five years before that it was used 12 times.
"There are questions as to how long it's going to be viable with the threat of climate change and the rising sea levels."