Canal restoration ahead of schedule, says Devon County Council

Work on the restoration of the Grand Western Canal is ahead of schedule, Devon County Council has announced.

The scheme, which started in July, is reconstructing a section of the canal at Halberton which breached during flooding in November last year. The County Council says that repairs are progressing well thanks to the relatively dry recent weather.

Work so far has focussed on rebuilding the embankment and building up the bed of the canal towards its final profile, which is now a recognisable shape near the Swing bridge and the location of the breach itself. The area west of the Swing bridge has been re-profiled due to minor overtopping and erosion that occurred at some point in the past century.

The embankment is being rebuilt within its existing footprint, but raised slightly in order to provide additional protection against future overtopping.

The next phase of the project will be to continue to trim the profile to the final shape ahead of the installation of an impervious liner throughout the length of the embankment. A heavy duty polyethylene liner, like that on the section from Greenway to Sellake bridges, will be used. This material will be covered and hidden and the repairs will eventually blend in with the existing canal.

While the upper part of the embankment has been constructed with locally sourced crushed limestone, the lower level has been rebuilt using the original embankment material that was deposited into the ‘lagoon’ area during the breach. This material was quite variable in composition and so to improve its suitability a process known as ‘lime stabilisation’ has been used. The process consists of ploughing powdered lime into the sandy/clay fill which has dramatically reduced the volume of material that had to be brought into the site. As well as using strengthened fill material, horizontal layers of geotextile mesh have been laid in the embankment to further enhance the embankment’s stability.

Councillor Roger Croad, Devon County Council Cabinet Member for Environment and Communities, said: “This dry spell has helped the scheme get a good head-start and it’s encouraging to hear that work is progressing so well. The canal is really starting to take shape and the local community can rest assured that this important attraction will be better than ever when the repaired section is re-opened early next year.”

Councillor Des Hannon, Chairman of the Canal’s Joint Advisory Committee and County Councillor for Tiverton East, said: “The dry weather’s been a huge help with rebuilding the embankment. It’s also provided a timely reminder that the aim of the project is to fix the canal and get proper control of water levels as well. We need a Goldilocks canal. Not too much water, but not too little either.”

Councillor Ray Radford, Devon County Councillor for Willand and Uffculme and Mid Devon Councillor for Halberton, said: “It is really pleasing to see the progress during this wonderful summer. As I live in Halberton I have gone regularly to see the progress being made. It will be finished well before the 200 year anniversary festival in May next year. The stretch from Greenway Bridge to Rock Bridge is being profiled and will enhance this half a mile of canal. Everyone must pay a visit.”

The downside of the dry weather has meant that water had started to evaporate on the Tiverton side of the breach. In order to maintain water levels for canal users and the horsedrawn barge, water was pumped into this side of the canal throughout last week.

Since the breach, half a mile of canal channel has been closed between Greenway Bridge and Rock Bridge, with a half-mile long towpath diversion in place between Swing Bridge and Watton Bridge. As part of the repair scheme, the towpath between Greenway Bridge and Rock Bridge is being widened to allow more room for bicycles and pedestrians in future.

The final elements of the embankment repair scheme, including the reinstatement of the towpath and refilling of the canal, are expected to be completed by early 2014.  However, works will continue at points along the canal over subsequent years to ensure that the canal is able to withstand future flood events and similar breaches are much less likely to happen again. These works will focus on ensuring embankments are secure, and on increasing the capacity of the Canal to shed water quickly once water levels rise to a certain point. A new automatic water level monitoring and alarm system has already been installed and tested and the Canal’s system of stopboards for damming the Canal under bridges will shortly be upgraded.

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