OMG I think these are beavers.
There was a whole group of them on the grass, but most were startled and went into the lake.
Scale is hard, but they are too big and the wrong shape for otters.
I've seen beavers once before, way out on a quiet stretch of river.
But these guys? In TOWN. There's a road behind me, a lady gardening, her little dog yapping at mine (which startled them)
I've tried to pass on my enthusiasm for nature and wildlife to my Grandson without forcing him to share my interest. I'm hoping he (and his friend) will remember tonight when, after a shaky start, we saw a family of Beaver (2 adults and this year's kit). If he doesn't I will 
just having a search and found a paper from 2014 that showed Beavers were present in Kielder in Northumberland possibly as late as the 1390s
https://www.researchgate.net/publication/285780963_New_evidence_of_late_survival_of_beaver_in_Britain
