A FloodFree Retractable Flood Barrier was exported to New Zealand and installed at Dickeys Road, Belfast, to complete the secondary flood protection system for Christchurch.

The Flood Barrier was needed to contain a large (6500 cubic metres per second) design flood in the Waimakariri River. In the event of the design flood event occurring, flood waters would have flowed over Dickeys Road into the wider Belfast area. Containment of floodwaters by raising Dickeys Road was not possible without compromising traffic safety.

The solution was the installation of a 12m Retractable Flood Barrier which is permanently installed within the aesthetics of the connecting levees and Dickeys Road. The track system is a permanent fixture within the road and meets Australian and New Zealand Specifications for heavy traffic loads and road safety.

This Retractable Flood Barrier may be operated manually or via an electric push button actuation system. The DC powered system with battery backup allows for electric operation, even during power failures. The barrier has been purpose built to meet specific site and operational requirements, and ensure 24/7 flood protection to a flood height of 1.1m, which allows for the design flood event plus freeboard.

It has been manufactured from structural marine grade aluminium, ensuring it is lightweight yet strong and durable. The track system is manufactured from grade 304 stainless steel components, to ensure it is fully trafficable with an extended asset life. To ensure longevity and reduced whole of life costs, the seals are mechanically fastened and designed to be easily replaced if required.

When in the closed position, this flood barrier isolates a two lane road. Both sides of the barrier have signage and warning delineation including reflective safety strips to alert road users of the closure.

AWMA worked closely with Environment Canterbury Regional Council and their consulting engineer, Good Earth Matters, to ensure the flood isolation supplied will meet the required flood protection objectives and the associated operational and maintenance requirements.

Good Earth Matters noted; “We appreciate the work that you and your team have put into this project and the support provided, including allowing us to witness the factory commissioning and verification testing before the barrier was shipped to New Zealand. From our perspective the visit was invaluable because it changed our thinking around the construction sequence, and focused us on the criticality of the track installation.”