The Self Closing Flood Barrier is a carefully designed self-rising floodgate that has been in use globally since 1998. Its design uses the approaching floodwaters to automatically raise the barrier. The automatic operation, along with its minimal footprint with no need for steps or ramps makes this type of defence ideal for unmanned sites, for where aesthetic considerations mean that a permanent barrier is not acceptable, or where there would be insufficient warning and manpower to use manually installed barriers.

Single barriers are available up to 10m (32 ft)  in length and 2.5m (8 ft) in height. Multiple units can be linked together to create long runs where required, with permanent or removable intermediate posts.


Operation Overview

The barrier usually resides below ground in a vertical position within a steel or concrete trough. The barrier consists of a rigid foam core and a GRP outerlayer. When floodwater rises to a pre-determined level, the water spills into service pit and then through a pipe into the trough and causes the barrier to float and raise fully. When the trough is filled, an angled support block locks the barrier into place, sealing it and making it watertight. The barrier is now fully effective and watertight to its full height.

As the floodwater recedes, the barrier lowers to its resting position again. The trough can be ‘pumped out’ also to lower the barrier before the adjacent groundwater levels recede fully.



The Self Closing Flood Barrier configuration is in straight lengths from 1m (3 ft) with the overall flood barrier wall designed into suitable section lengths of up to 10m (32 ft) each as standard. Sections can be linked together using angled guide-posts for changes in direction.


  • Uses the floodwater itself to operate the barrier - no manual intervention required.

  • No storage required - the barriers recesses fully into the ground when not in use.

  • Fast action - with a fast flood the barrier will close within a minute.

  • Easy to test - the pit can be filled with water which automatically lifts the barrier ready for inspection.

  • Unlimited lengths - from 1m to 1km or more.


The Self Closing Flood Barrier can be used to protect areas such as:

  • Underground garages

  • Riverside defences

  • Coastal defences

  • Railway defences

  • Unmanned sites, such as utility stations

  • Building openings such as roller shutter doors.