Work has begun to refill a stretch of the Worcester-Birmingham Canal which emptied after contractors damaged an underground drainage system.

An area from the Diglis Basin to the lock gates by the Commandery Museum half a mile away was drained after the culvert was damaged on 12 December.

Work was taking place to upgrade the canal when the culvert, which is about 200 years old, was struck by a post.

British Waterways said it would take about a week to put the water back into the canal, at a speed of 160 litres per second.

The damage was done with this post

Julia Hones, from the Diglis Basin Users Group, saw the canal emptying.

"We informed the lock-keeper and he went up to the next lock and he ran water in from there, and the next lock after that, but unfortunately the water just went down and down and completely disappeared."

Narrow boats were stranded when the canal emptied.

Neil Bedford, spokesman for British Waterways, said it was an unfortunate incident: "It's not what we would have wanted, but the thing is we're dealing with a structure that's over 200 years old."

"We're dealing with records that go back into the early 18th Century.

And, despite all the checks and different pieces you can do, unfortunately it can be one aspect of canal work."