Issue date: 17th July 2013
An official turf cutting was held at the Grand Western Canal on 8th July to mark the start of restoration work from the breach of its northern bank near the Swing Bridge at Halberton on 21st November last year, after water spilled over the top of the embankment during torrential downpours and flooding.
The canal's owners Devon County Council has estimated that more than 16 million litres of water (the equivalent of more than 100,000 bathtubs or 6.5 Olympic swimming pools) flowed through the 23-metre wide breach onto neighbouring farmland. Emergency services spent days pumping water away from the area to make the area safe. Since then, the Council and its partners have been developing plans to reinstate the failed section of the canal and to introduce measures to reduce the likelihood of a similar occurrence. As well as repairing the breach, further works will be implemented to ensure the long term future of the whole canal. This includes inspections of all infrastructure along the canal, the installation of a water level monitoring alarm system, as well as additional and improved stop boards. The Council says that over the next few years, water management and associated infrastructure will also be improved along the whole canal.
The progress of the work will be dependent on site conditions and weather but the current programme is to initially establish a works compound and construct a temporary access track before the main repairs to the breached section of the canal embankment start in August. The embankment will be rebuilt within its existing footprint, but it will be slightly higher in order to provide protection against future overtopping.
This will be followed by the installation of the new canal lining during November and December. The canal will be lined over the length of the embankment with an impervious material. This material will be covered and hidden and the repairs will eventually blend in with the existing canal. Much of the material that was washed out during the breach will be strengthened and re-used in order to limit the amount of material that needs to be brought to site by road. The speed of water flowing through the canal and discharging at the breach also caused significant erosion of the canal bed either side of the fault. This erosion will also need to be repaired. 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.
The reinstatement of the towpath and refilling of the canal is then scheduled to be completed in early 2014. The work, which is to be carried out by contractor South West Highways Ltd, is likely to last for around six months so that the canal can re-open in early 2014, which will be in time for the canal’s 200th anniversary and IWA's National Trail Boat Festival at the end of May 2014.
Photo: Councillors Hannon (Devon County Council), Browse (Halberton Parish Council), Wilson (Mid-Devon District Council), Radford (Devon County Council and Mid Devon District Council) courtesy of Devon County Council.