We are on the Huddersfield Narrow Canal in between Mosley and Staley Bridge. A storm event occurred at the late Christmas period into the early new year, and that caused two large scale slips between the canal embankment and the River Tame.
Our response to this emergency situation was that we had to close the canal here between Scout Tunnel to the north and all the way down to Lock 9 west in the south section of this canal. We've had to remove 1,200 tons of material all before we could start to reinstate the embankment of the canal.
As part of that reinstatement, we've now installed 900 rock bags into this location and we have then covered the rock bags in topsoil and coir matting. Our biggest challenge on this project has been access – this section of the canal is rather remote. We've had to create two access points working with third party landowners. We've also had to create an access point across the canal at one location and we've had to cross the River Tame at another location.
With the drought conditions that we've currently been experiencing, that has really helped us to get this work done and completed as quickly as possible as part of our design development and engineering solution. It's been a massive team effort. We've worked very closely with Chris Capel in design and development, with Bentley’s, and with our colleagues in heritage, environment, and ecology.
This work in total is probably going to be about £1.4 million. The solution that we've come up with was to use the rock bags, which have probably saved the Trust at least a couple hundred thousand pounds in both time and material.
The work here is almost complete. We are just finishing off, but we have got some additional works to complete in the near future. We'll be doing some grouting to the lock and we will be looking to increase the size of a weir upstream of this location, just to add a little bit of resilience with regards to water coming downstream. The towpath is open, and if it wasn't for the drought conditions that we're currently experiencing, the navigation would be back open.
A big thank you from myself and the rest of the project team to the people who have supported us through this year. We've had massive help from operations, from asset management, and across the wider project delivery team. It's been a huge team effort and everyone's worked collaboratively to get this canal back open as quickly as possible.
Our team offers design engineering support for the high-priority works teams and for the priority projects, including arising emergency jobs. We believe these slips were caused by a couple of factors during these storms in the winter between Christmas and New Year's. There was a lot of water in the canal, a lot of water in the river, and a combination of the river scouring away the toe of the embankment, along with overtopping from the canal and potentially some leaks from the wash wall. All these things combined to give a very saturated slope, which then slipped.
I got involved pretty early on – I came a few days after the slips and provided the design for the repair. I researched potential solutions for this sort of project. Initially I looked at things like gabions and concrete walls, but these are both quite labour intensive in and around the fragile structure that’s left. Then I came across these rock bags. They're fairly innovative, providing a lot of stability. They act like a gabion basket, but are more flexible. Over time they interlock once they're placed, acting as one solid mass and providing strength to the slope.
In total, we used about 900 rock bags. Other things we’ve done to add resilience include raising the towpath at the south slip, which was clearly a low point, and looking at increasing the size of the weir to the north of the lock to prevent overtopping in future.
We are seeing a lot of these arising emergency issues. Much of this is down to the nature of the infrastructure – it’s 250 years old. It's very old and would normally be at end of life, but we’re working hard to extend that life all the time. That’s where a lot of our work goes.
I remember the night of the weather. There was a lot of activity in the group chat because some of my team had been called out. I was actually off work the next day, but I decided to come in because I knew the team would need instruction and guidance, and that the escalation process needed to be kicked off.
When I visited the site, I was dumbstruck with what I saw. I know the Trust has experienced worse infrastructure damage over the years, but in my 16 years here I’ve never seen anything like that. I remember thinking, “Right, where do we start trying to fix this?” After that initial shock, I took a few steps back and thought, “Let’s just make it safe.” We needed to get an on-site assessment underway and make the area inaccessible so people weren’t putting themselves at risk. Instinctively, people are nosy – if something’s wrong, they will have a look, and in doing so could put themselves in harm’s way.
We fenced the site off at either end, fenced the lock, and then I started the escalation process. I spoke to my manager, he spoke to his, and it went all the way up to the top. I remember communication between myself, Steve Ballard and Julie Sharan, and that was maintained throughout the day. The next step was reaching out to all the departments that needed to be involved – asset management and others. Within hours, everyone felt confident that we were doing the best possible thing we could.
Meanwhile, my team supported contractors with water control – maintaining water levels, installing dams, fencing, and carrying out minor operational repairs. When the site demobilises, we’ll need to take the fencing away, test the lock, and make sure everything is still operational and fit for purpose before reopening.
Coincidentally, whilst all this has been going on, the canal’s been closed because of this defect, but we would have had to close anyway due to water shortages. This has been an issue on my patch and across the region – for example, on the Rochdale Canal, where we’ve struggled to maintain water levels. Fortunately, as this project comes to completion, water levels are resolving themselves. So it looks like we’ll be able to open at the same time as the defect is repaired.
