Concrete canal solutions for a changing climate

Recent catastrophic failures have focussed attention on the durability of the UK canal system, much of which was built 250 years ago. Modern concrete and cementitious solutions could significantly extend the performance life of existing canals and provide a long-lasting, durable solution for both old and new planned waterways reports Britpave, the infrastructure industry association.

On New Year’s Eve 2024, rising water on the Bridgewater Canal in North Cheshire hid the ongoing softening of the 250-year-old earth embankment. The embankment collapsed and water from almost two miles of the canal flooded the surrounding farmland. Fast forward a year later and on 22nd December 2025 the Llangollen Canal in Whitchurch, Shropshire, suffered from a failed embankment with resultant flooding and three narrowboats falling into a 50-metre crater in the canal bed.

The UK’s ageing canal system is subject to a modern problem: the impact extreme flooding and drought event resulting from climate change. Most canals are made with built-up earth embankments and linings of compacted clay. Small cracks in the clay lining allows water to seep through. The more water that seeps through the greater the potential for internal erosion of the embankment resulting in failure and collapse. External embankment erosion can occur when heavy rainfall causes water to flow over the top of the banks and so soak and weaken the bank from the other side. Extreme rain and storm events resulting from climate change increases this water pressure. Summer hot weather and drought events also have an adverse impact leading to embankments to dry out and crack. These cracks allow winter rainfall to seep into and saturate embankments increasing the potential for instability and failure.

The need for the canal system to have assured performance is underlined by the Canal and River Trust, set up to manage over 2,000 miles of waterways, reporting that the use of canals is busier than it has ever been, even at the height of the industrial revolution. Some 35,000 boats are registered to use English and Welsh canals; the UK canal system supports over 60,000 jobs and brings in an annual £1.5 billion from water-based tourism and jobs.

The use of soil stabilisation can provide such assured performance. Soil stabilisation is a well-established civil engineering technique use to improve and strengthen soils. It involves the use of hydraulic binding materials such as cement and lime that are mixed-in on site to provide a strengthens poor or unsuitable soils with compressibility, high water content, low shear strength issues. An important benefit of soil stabilisation is that it is carried out in-situ. For canal projects this means that saturated soils can be rendered and canals reconstructed without the impact of multiple lorry trips disposing or importing additional soils and aggregates.

The validity of using soil stabilisation for canal embankment and base construction has been confirmed by recent research(1) by Nottingham Trent University which underlined its long-term performance and addressed the misconceptions concerning potential leaching in water. The research included a range of extreme immersion tests that proved that the potential of leaching cementitious materials into water was extremely low, especially if good industry soil stabilisation practices are followed.

Cementitious solutions also include slipformed concrete canal linings. These offer a durable and long-lasting alternative to puddled clay. Concrete linings minimise water loss through seepage, negate erosion of canal banks, reduce the need for ongoing maintenance, and provide high levels that structural stability that reduces the risk of collapse.

Future major canal projects include the proposed Grand Union Canal Transfer scheme to bring drinking water from the Midlands to the Southeast and the construction of a new 26km canal linking the Grand Union Canal in Milton Keynes to the River Great Ouse in Bedford as part of the Oxford-Cambridge Growth Corridor.

For maintaining the existing network or constructing new canals, soil stabilisation and concrete linings offer durable, long-lasting solutions that are resilient to the impacts of climate change.

1.The Leachability of Stabilised Soils, Research Report, Britpave 2025