The remediation of the Union Canal breach at Muiravonside

Key project features: 

• Emergency response
• Canal remediation works
• Geotechnical and structural design
• Embankment resilience
• Stakeholder collaboration

The background

Following a once in 240-year flash flooding event last August, Mackenzie Construction was contracted to emergency works at the site of an embankment breach on the Union Canal, near Muiravonside. The scale of the breach resulted in a 30m wide gap and a loss of around 75,000m³ from the canal. Once the emergency dams were put in place and the water flow stopped, the priority was to establish a safe site for the embankment repair and a programme of resilience works to futureproof the 200-year-old Union Canal against future climate change events.

The challenge

The location of the breach presented several challenges. Past the locks of the Falkirk Wheel, the Union Canal stretches for 50km without any lock gates making it difficult to stem the initial flow. With the remote location of the breach, there were also access issues with no direct road access meaning a 600m long haul road had to be constructed.

Once the initial flow was stemmed and the repair works commenced, the project team then faced the key challenge of identifying the root cause for failure. With no embankment left and nothing to inspect, working with its contractors, Mackenzie Construction utilised drone footage to model the failure and identify the cause of the breach.

The canal network usually shuts down over winter for general upgrading works with a spring reopening date so there were time pressures on the project for the canal to be rewatered by early March 2021.