Male beautiful demoiselle
Back at The Narrowboat pub today to take another look at those canal banks. The sections with steel shuttering/palings up against the soil are useless for water voles because you can't make burrows in metal. But I'm pleased to say there are stretches of the canal where, although the banks have been reinforced, it's with a waterproof fabric and wood, around which the voles can work. The photos show how they've swum underneath the wooden railing and made themselves little shelters between the wood and grass.
Another way of helping water voles to at least travel along sections of shuttered or concrete canal in safety is to install coir rolls along the bank sides, as the wildlife trust have done here: http://www.wandletrust.org/?p=838