Exclusive:Scotland's oldest canal shuts from Kelpies to Falkirk Wheel until 2026 for major work

Lock gates over a four-mile section of the Forth & Clyde between the Falkirk Wheel boat lift and the Kelpies equine statues will be replaced or refurbished.

The work is needed because they are nearing the end of their 25-year life after being installed when the .waterway was restored between 1999 and 2002.

Campaigners are unhappy at the prolonged closure, since major work is normally confined to the winter. But Scottish Canals said the 16-month shutdown would cut costs.

The so-called “Falkirk flight” of 14 locks was the first part of the Grangemouth-Bowling canal to be built in 1768 - Scotland’s first major artificial waterway.

The £4 million project will also involve bypasses being built round some locks to divert water so it will no longer cascade over the gates, increasing wear. It follows last winter’s biggest upgrade of the Falkirk Wheel since it opened.

At least six gates will be replaced between locks three to 16 at a cost of £250,000 each. The oak gates will be replaced with ekki, an African hardwood, or greenheart, from South America, to give them a likely 35-year lifespan.

Divers checking the state of the timber have found its thickness in places has reduced from 50mm to 15mm.

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Further west, more of the canal’s 32 locks will need work, which could mean further summer shutdowns.

Scottish Canals chief operating officer Richard Millar told The Scotsman: “We will be trying to work in the winter so we have got the summer season for boating, but there may be times when we need an extended [closure] period to make these works as efficient as possible.”

The Inland Waterways Association said it was “deeply concerned” about the length of the Falkirk closure, which it claimed was because Scottish Government-owned Scottish Canals did not yet have full funding for the work.

The association said: “Timbers forming the lock floors are, in places, in poor condition, with significant holes visible. These are relatively easy to replace, but it is the condition of the timber hidden under the masonry forming the lock chambers that poses a large unknown.

“It is this considerable uncertainly that dictates such an extended closure, as diving investigations can only determine the extent of lock-related works and the state of the visible sections of the timber flooring.”

However, Mr Millar said multiple winter closures for the lock work would have cost more, and the body expected its annual grant in next week’s Scottish Budget to remain similar to those of previous years.

He said: “It makes sense to cluster them for efficiency. With the amount we are going to do, we want to get best value for public money, so we are taking the really hard decision to extend the stoppage.”

Mr Millar said the challenge was the volume of work required at the same time, a quarter of a century after the landmark project to re-open the canal - and the Union Canal between the Falkirk Wheel and Edinburgh, which does not have any locks.

He said: “The Millennium Link was a really important project to re-open the lowland canals, involving 1,000 people and cost £83.5 million.

“It involved removing 36 major obstructions and we had to lift motorways, remove utility infrastructure and build new locks. Wester Hailes [in Edinburgh] had been built on the [Union] canal, so we had to dig right through it.

“The Forth & Clyde Canal was the first major hand-built, sea-to-sea navigation. It is an incredible piece of engineering, but, being the first, it’s kind of basic.

“We want to be able to manage the water, so at a number of locations we will be putting in a bypass which allows it to flow round the lock rather than over the gates.

“It will allow the gates to last longer in not having water constantly cascading over them, and for us to much better manage the water to utilise the canal for climate resilience.”

Mr Millar said it would copy the first ‘smart canal’ - a section of the waterway in Glasgow.

He said; “It’s a great example of us developing this heritage infrastructure for the future, allowing us to drop the canal by 4in (10cm) to enable us to take surface water from 3,000 new homes in Glasgow

“Creating bypasses throughout the canal system will allow us to extend that benefit to other areas and prepare for the climate change that we are already beginning to see.”

Mr Millar said the project would help maintain skills, which could involve experts drafted in from the Netherlands or Ireland.

He said: “One of our challenges is an ageing workforce - a lot of our skills were here 25 years ago, putting these gates in.

“What I want to do through these works is to pass those skills on to a new generation. So we’ll be working with young people, bringing in apprentices to make sure the skills of those who did all those works in the past are passed on, so we can keep doing this for the next 250 years.”

However, Mr Millar said the original canal builders would have marvelled the canals had lasted even this long.

He said: “I don’t think anyone that built the canals ever expected them to still be here 250 years later.”

A spokesperson for the Scottish Government’s Transport Scotland agency said: “Scottish Canals’ asset management strategy sets out its plan for flexibly managing and investment in assets between 2018 and 2030, directing resources to assets that pose the biggest safety risk to the public and projects that offer the greatest public value.”

It said Scottish Canals received £24m state funding in 2024/25 - half for capital projects such as upgrades - and generated another £10m from commercial activities.