Home » Projects » Canal Towpath Void Filling and Water Sealing


The canal towpath void filling and water sealing project, aimed to address a critical infrastructure issue identified by the local council. The canal towpath in Cromford, a historic structure, was experiencing significant water leakage into the adjacent field. This leakage was not only a structural concern but also a potential environmental hazard, threatening the local wildlife habitat and the usability of the towpath itself.


The primary challenge presented was the leakage of water through the towpath into an adjacent field, creating a risk to the surrounding environment and the structural integrity of the towpath. The council sought an effective and quick solution to rectify this issue without causing extensive downtime or disruption to the towpath, which is used by the local community and canal visitors.

Discovery of Voids

Voids beneath the towpath were discovered using a Ground Penetrating Radar (GPR) survey. Substantial washout had occurred meaning the canal water was escaping through the towpath.  However, pinpointing the exact location and depth of these voids proved challenging, complicating the task of designing an effective solution.

Geobear Solution

Geobear proposed a targeted solution utilising geopolymer injection technology. By analysing the GPR survey data and visual inspections, Geobear designed a pattern grid injection strategy. This approach allowed for the precise injection of geopolymer at specific depths and intervals, effectively reducing the permeability of the towpath and creating a waterproof barrier.

Environmental Considerations

A key aspect of Geobear’s solution was its environmental sensitivity. The geopolymer used is environmentally inert, ensuring no negative impact on the canal or its surroundings. In the event of any material leakage into the canal, the geopolymer’s properties allow for easy detection and removal, as it solidifies quickly and floats on the water surface, posing no threat to the aquatic ecosystem.


While the case study primarily focuses on Geobear’s solution, alternative methods for addressing such issues might include traditional civil engineering approaches, such as excavation and physical barrier installation. However, these methods could be more disruptive, time-consuming, and potentially harmful to the environment.


The implementation of Geobear’s geopolymer injection solution presented several benefits:

  • Quick Installation: The entire project was completed in less than a day, significantly minimising disruption to the towpath and its users.
  • Environmental Safety: The solution had no negative impact on the canal or adjacent areas, preserving the local ecosystem.
  • Efficiency: Geobear’s approach allowed for precise targeting of the problem areas, ensuring the stability and longevity of the towpath.
  • Accessibility: The technology enabled access to difficult-to-reach areas without the need for heavy machinery or extensive physical infrastructure.


The Canal Towpath Void project exemplifies innovative engineering solutions to complex environmental and infrastructural challenges. Geobear’s approach, characterised by rapid deployment, minimal environmental impact, and effective resolution of the leakage issue, underscores the potential of geopolymer injection technology in modern civil engineering practices.

This case study not only demonstrates the successful mitigation of a specific problem but also highlights the importance of adaptability, precision, and environmental responsibility in infrastructure maintenance and repair.


Contact Us

Please use this contact form or navigate to the contact us page and send us a message. We will respond to you within 24hrs.

Alternatively please call us on 0800 084 3503 and speak to our customer services team. Calling from Ireland please go to the contact us page.

We deliver projects on any sort of building or structure – from conservatory extension problems to 80,000m2 warehouses and road infrastructure. In most cases we will have the best solution, so get in touch today.

  • This will help us as we can look at local site conditions.
  • This field is for validation purposes and should be left unchanged.