We rarely see the creatures we undertake surveys for as part of hydro-schemes, road and rail or housing developments. Often we rely on seeing signs that protected species are active in the area. We deploy trail cameras with night infra red cameras and are often rewarded with surprising images and videos.
Here an otter leaves the watercourse to 'spraint' (mark with a tar like substance) its resting up place or couch. Its was not seen to use the dry overhang just make sure any other otter passing knows who owns this particular site. Otters will range over large areas and have a number of such sites providing shelter for them when needed.