Bramley Associates have put together a Field Guide to Beaver Signs Recorded in South East England.

This guide shows positive signs of beaver activity but also signs that could be mistaken for beaver presence.

Unlike most guides that show many signs in 'perfect' condition we have displayed signs as they are found on survey works.

...
In 2018, Bramley Associates undertook a beaver survey of the Greater Stour valley, from Ashford to Sandwich Bay. The results showed that beavers are widespread.
 
Overall, it would seem that beavers in Kent are the second most widely distributed population in England.
 
It will be interesting to have beavers back in the UK...