In a UK first, the Environment Agency, BAM Nuttall, Arup and Tarmac have successfully trialled the use of two low carbon concrete mixes for works at the Hexham Flood Alleviation Scheme.

The low-carbon concrete has been used across 3 panels, totalling 27 metres of the £6.5 million Hexham flood defences as part of a plan to reduce their carbon footprint, the Environment Agency (EA) has said.

Hexham is a popular tourist destination in Northumberland with visitors able to observe salmon leaping at the masonry arch bridge, dating back to 1793.  The Hexham flood alleviation scheme will help to protect up to 90 properties in one of the town’s most important commercial areas, providing increased job security by protecting the places people work, keeping businesses open and supporting the wider local economy.

The flood alleviation scheme is almost complete on the south bank at Tyne Mills Industrial Estate and features a new structure installed across the Skinnersburn which would also stop the River Tyne backing up when levels are high. The improvement works to the north bank at Bridge End Industrial estate consist of flood walls and embankment as well as featuring the sections of low carbon concrete at the former Reiver Sports site.

The EA say that more than half of its carbon footprint comes from the construction of flood defences. Using low carbon concrete, such as a new Portland limestone mix, developed by Tarmac, will improve Hexham’s resilience to the changing climate while also playing an important part of the organisation’s steps towards Net Zero targets.

So far, the trial has presented positive carbon savings compared to a standard concrete mix offering up to 70% reductions of CO2 emissions per cubic metre of concrete delivered to site.

It is hoped that the trials to find new ultra-low-carbon concrete alternatives, will enable future Environment Agency flood defences across the North East to be built more sustainably, with lower embodied carbon. They will also support the delivery of new sustainable concrete products, to the wider construction industry and help to achieve targets outlined in the Net Zero North East England partnership. This collaboration between local government, business, education, the public sector and civil society aims to drive a comprehensive regional approach to tackling the climate emergency.