Union Canal breached in one-in-240year event
AFTER a night of heavy rain, a serious breach occurred on the Union Canal between Polmont and Muiravonside early on the morning of August 12.
Around 80mm of rain fell between midnight and 6am, with more than 40mm falling in one hour alone at 5am.
The significant volume of water flowing into the canal eventually overtopped and washed away part of the embankment, resulting in a breach which is now 30m wide.
It was first discovered by Barney Sowood as he cycled along the towpath with his washing, heading for the laundry facility at the Kelpies. Fortunately, as it is on a relatively straight stretch of the waterway, he was just able to stop in time.
Local residential moorers at nearby Causeway End saw levels in the basin rising steadily during the night, before dropping rapidly in the morning. The Scottish Environment Protection Agency (SEPA) have estimated this significant rainfall as a one-in-240-year event.
Scottish Canals staff acted swiftly, inserting stop planks at Manse Road in Linlithgow – a couple of miles east of the breach – and dropping sandbags into the channel to the west. Water, flowing out of the canal, found its way on to the main Glasgow-Edinburgh railway, totally closing the line.
By the end of the week, the flow of water from the breach had been stopped completely. The Scottish Canals workforce began to restore water levels on the east side of the breach, where the water feed is located, which will enable them to pump water to the west side: important for restoring boat movement between the Union Canal, the Falkirk Wheel down on to the Forth & Clyde Canal and the Kelpies.
A fish rescue has been managed, moving stranded fish from near the breach to an unaffected section of canal. Scottish Canals is working to identify a safe towpath diversion.
It is estimated that repair will take three to four months to complete. The impact of the breach on hire boat fleet, some of which is strung out along the Union Canal which has only just come out of lockdown, still has to be assessed.
The navigation authority has recently applied to Government for a £1 million capital grant towards dredging the waterway which, being a contour canal, fills up at 25mm a year from field run-off. Updates on the situation can be found at scottishcanals.co.uk and on social media.