New dens for Tophill Low's flood-hit otters
New dens have been built and cameras installed at a nature reserve to help protect and encourage the otter population on the River Hull.
The work at Tophill Low Nature Reserve near Driffield, East Yorkshire, was started after otters were forced out of their homes during the 2012 floods.
Yorkshire Water, which owns the reserve at its treatment works, said it was part of an £8m upgrade scheme.
Warden Richard Hampshire said he hoped the project would help otters to breed.
"In the floods of 2012 a lot of the natural holts [or dens] alongside the riverbank margins just went underwater and we saw a footage of a young cub being washed out of its home," he said.
"So we wanted to create a new holt that was above the flood line so they've got somewhere safe to breed in."
The water company said other work at its treatment plant included removing nitrates from the raw river water, which enters the site, and creating new breeding islands for avocets and terns.