Inspections and repairs of the Kelvin Aqueduct, Maryhill, Forth & Clyde Canal
Scottish Canals is conducting a major programme of investigation, design and repairs on the historic Kelvin Aqueduct in Maryhill, Glasgow, together with contractor Mackenzie Construction.
The Kelvin Aqueduct is an outstanding piece of canal engineering. At the time of its construction, more than 230 years ago, it was Britain’s largest aqueduct and a prototype for many later structures built on Scotland’s canal network.
To this day, it continues to carry the Forth & Clyde Canal across the deep valley of the River Kelvin, allowing boats to pass over the river on their way between the Firth of Forth and the Firth of Clyde.
Like all historic infrastructure, the aqueduct requires ongoing maintenance to manage the effects of natural weathering, water leakage, and the self-seeding of vegetation within its masonry. Read our blog about the historic finds on the aqueduct this year
The 236-year-old structure, which carries the Forth & Clyde Canal over the River Kelvin, began to leak towards the end of 2024. Since that time, we have dewatered the aqueduct’s trough, desilted the base of the trough, and conducted in-depth investigations of the structure, including building a digital twin.
The work has been challenging, with ingress of water into the trough on multiple occasions and much to learn about the structure which has been submerged underwater.
We have found out a lot about the approaches to design and construction used by the aqueduct’s 18th century builders, led by visionary engineer Robert Whitworth.
Part of the process of designing a permanent repair programme is to agree the approaches to works with Historic Environment Scotland (HES) and to obtain consents for the works.
The aqueduct is a listed structure, as well being a crucial operational asset on our network. It is also an important monument to Scotland’s outstanding history of civil engineering leadership with a lot to tell us about our heritage and past. This means that repairs and additions need to be sympathetic to the existing structure.
With this process now completed, we are embarking upon the repair phase of the programme.
Repair Programme
The repair programme will run to 1st March 2027, the date when we intend to have completed all repairs and rewatered the canal ready for resumption of navigation.
Works will comprise:
- Removal of the trees and vegetation from the underside and external walls of the structure (already begun) by rope-access technicians.
- Installation of anchorage points to simplify future maintenance and vegetation removal.
- Repointing the masonry to stop the leakage routes through the structure.
- Bentonite grout injection – this involves pumping a clay mix into the masonry. The clay swells in contact with water to block leaks, remaining soft enough that it is unlikely to dry out and crack at a later date.
- Re-instatement of the puddle clay liner.
- Conservation works to protect the historic timber structure discovered at the base of the aqueduct trough (which we believe was designed to protect the puddle clay from the deep hulls of the original sailing ships that passed through the aqueduct).
- We also hope to Install stop plank grooves for temporary damming of the structure in the future, which will be a less disruptive way of working on the aqueduct.
Public Exhibition - Canal Engineering in Maryhill
You can find out about the history of canal engineering in Maryhill, including the Kelvin Aqueduct, and our current projects at Maryhill Burgh Halls, where we have a joint exhibition running with the venue up to 11th October 2026.
Navigation
Navigation is suspended between Bowling Harbour and Lock 21 until the project is completed.
FAQs
Why is navigation on the canal suspended all the way from Bowling?
We have had to suspend boat movements from Bowling for the duration of the works as the dewatering of the stretch around the Kelvin Aqueduct means that we will not be able to guarantee sufficient water for boat movements along the length of the canal.
How long will pumping go on overnight?
Pumps have been installed on the canal to remove excess water from the dewatered section and the aqueduct trough. To reduce noise for local residents, we have installed sound barriers around the pump units.
I need to get through Kelvin Aqueduct to get to my home mooring. Is this going to be possible?
This will not be possible while works are ongoing. Please contact our Moorings Team to discuss arrangements for your vessel.
Will the Bowling Sea lock be operational?
Bowling Sea Lock remains operational but there may be some temporary restrictions to navigation. Please speak to the Lowland Canal Team before making plans.
How are water levels at Bowling going to be maintained?
We will continue to manage and monitor water levels along the canal, and we will update you if we anticipate any change in draft. If you experience any issues, please contact the Lowland Canal Team.
How will the weeds at Bowling to lock 37 be managed during the closure period?
Weed management will continue from Bowling to lock 37. Prior to re-opening navigation there will be a full length cut.
Can boats be lifted out/in by crane at Bowling?
There is a restriction on the size of vehicles that can cross the rail bridge at Bowling. If you need to enter or exit the canal, please contact the Lowland Canal Team to discuss your options.
Will I be compensated for the inconvenience of not being able to navigate?
For those who remain at Bowling and Temple Wharf during the closure, we will apply a pro-rata credit to navigation licences from May 2026 until navigation is re-opened.
How can I remove my boat if I decide to give up my mooring during the closure?
If you are considering leaving the canal network before navigation re-opens, please contact the Moorings Team to discuss your options.
Where can boats be lifted out/in at other locations on the Lowland canal network?
Boats can be lifted in/out at the following locations:
- Union Canal: Hub 8 at Calders Cresent, Edinburgh. Stewartfield Slipway Broxburn.
- The Falkirk Wheel: Plaza area.
- Forth & Clyde Canal: Auchinstarry, Firhill Basin, Drop Lock area.
Please contact boat movements or the lowlands customer team to discuss options.
Will I be permitted to sell my mooring with my boat?
Moorings cannot be sold along with a boat. If you are planning to sell your boat, please contact the Moorings Team.
Contacts
Please direct enquiries to the Kelvin Aqueduct Project Team at: enquiries@scottishcanals.co.uk, or call us on 0141 332 6936 (Monday to Thursday 8.30am-5pm, Friday 8.30am - 4.30pm).
If you have any questions related to a mooring, please contact moorings@scottishcanals.co.uk
For any other boating enquiries, please contact lowland.canals@scottishcanals.co.uk, 07810 794 467
Project updates
Update on progress of inspection and design work (Tuesday 23rd June)
Over recent months, we have worked with Mackenzie Construction to dewater the aqueduct and undertake extensive inspections of the condition of the trough and masonry.
With the inspections completed, we are now:
- Developing the long-term repair plan to stop the leakage from under the archways;
- Conducting non-destructive testing of the current mortar to understand its condition so that we can choose the best material for regrouting.
- Working with Historic Environment Scotland (HES) to agree the approaches we will take to repairs and obtain the necessary consents. Both the aqueduct and canal are Scheduled Monuments. This means that we need to obtain special consents for repairs (unless they fall under a pre-agreed list of works).
- Clearing vegetation and mortar from the aqueduct’s trough.
19th May
Announcement of a target re-opening date of September 2026 as detailed above.
26th March
While we dewater the canal and stabilise water levels, we are running pumps overnight. We are revising our temporary dam design and options for moving water downstream, and we are looking for opportunities to switch to a gravity feed later in the programme to reduce the need for pumps. Thank you for your patience with the works and the overnight pumping while we resolve this issue.
20th March
Historic Environment Scotland (HES) made an initial visit to record and catalogue the assets exposed during dewatering. Further visits are planned by HES and our own Engineers, Consultants and Contactors are all keeping records of progress, structures and conditions
26th February
The fish relocation, conducted by APEM, is now completed . Fish have been moved from here to other sections of the canal ahead of the full dewatering and engineering works.
Contact us
If you have any questions or concerns, please contact us at enquiries@scottishcanals.co.uk or on 0141 332 6936 (Monday to Thursday 8.30am-5pm, Friday 8.30am - 4.30pm).
Header photo credits: © Copyright Michael Dibb
