Canal section near Marlborough to be dredged after lorry crash
Mr Coles said the truck knocked down a 4m section of the bridge wall, which itself was about half a metre wide.
All the debris went straight into the canal: "We've got a navigation that should be around 1.2m deep and is now around ankle deep in the middle."
The trust is also dealing with an environmental clean up after diesel and oil leaked into the waterway too - "so we've managed to boon that off and soak it out" Mr Coles added.
He said there had been a "huge impact" to those who need to use the canal, so the priority was to get the waterway and towpath open first.
The bridge restoration would take a "lot longer", he added.
Mr Coles has asked people to avoid the area when walking: "The public right of way is closed.
There's a lot of loose masonry there as well.
Please let us complete our work as quickly as possible."