ONE of Scotland’s major canals will remain closed for more than a year because of the scale of repairs required to fix a significant leak in a historic aqueduct.
A ten-mile stretch of the Forth & Clyde Canal between Glasgow and Bowling, where it joins the River Clyde, will now stay closed to boats until March – six months later than originally expected.
Scottish Canals said this is due to it not being able to guarantee water depths along the route until work is complete.
The closure, in place since February from the Maryhill locks just east of the Kelvin Aqueduct, was initially expected to end next month. However, repairs to the 236-year-old structure, once Britain's largest aqueduct, have proved more extensive than anticipated.
The leak, which had increased from a shower-like flow to what officials described as “emptying a bath” into the River Kelvin below, was initially thought to be linked to water lilies. Scottish Canals has now confirmed that tree roots were the main cause.
Denise Richmond, senior project manager for Scottish Canals, said: “The extent of repairs meant we made the decision to keep the canal closed to navigation until the start of the new season in March.
“There were fairly substantial rowan, birch and sycamore trees established on the outside of the aqueduct.
“Their root systems are strong enough to penetrate the joints in the masonry and clay liner to reach the water in the trough.
“Surprisingly, the ivy on the exterior and the lilies in the trough did not cause significant damage. The lilies already have a direct source of water so don't need to search.
“We knew the trees contributed but it was only once we dewatered and removed silt that we could see the extent.”
The work has cost more than £1 million so far. Scottish Canals said the absence of original 18th-century construction plans meant specialists had relied on methods including 3D laser scanning to understand the internal structure.
The final repairs will include grouting the walls, repointing, masonry repairs and adding more puddle clay to the aqueduct lining. Several weeks of rewatering and monitoring will then be needed early next year, followed by dredging and vegetation clearance before navigation can resume.
Scottish Canals said the closure had reduced boating income but was essential to public safety and the canal’s long-term future.
However, canal users said they were “deeply disappointed” by the extended shutdown.
Neil Kitchener, of the Inland Waterways Association, said: “We are deeply disappointed it will remain shut until spring at the earliest.
“The original plan was it would be closed for a few months to investigate the problem before re-opening.
“While there is a commercial case for this, there are a number of boats that can’t get through the aqueduct, and they are stuck where they are. Even a brief opening could have prevented this.”
