Mike Osment, who works for the Trust, spotted the tiny reptile heading towards one of the canal locks, and was quick enough to snap a picture.
He said: "I spotted the little fella heading towards Standards Lock. I know they can swim really well but given how tiny he was I thought he might have a bit of trouble getting out, so I moved him along the bank a bit."
Laura Mullholland, ecologist at the Trust, said: "Grass snakes really do love the waterways and are great swimmers, but it's really rare to get to see one up close, especially one so tiny. They're a protected species, so while they're quite widespread, it can be difficult for them to find the kind of habitat they need to survive. A canal is ideal for them – we make sure the water's decent quality, and they act as ‘corridors' for the snakes to travel up and down. Visitors don't have to worry, though, they're completely harmless."
