UKWOT currently has 20 outdoor enclosures, a cub hospital, two cub isolation rooms and five indoor cub rooms at its current site, which it does not have to pay and rent for.
The charity, which can care for 40 cubs at once, takes them in from across the country, often after cubs’ mothers were killed in road crashes.
Staff said they needed to rebuild all of the existing facilities at the new site to be able to continue looking after the cubs.
Mr Webb said he was “shocked” when he was told the landowner needed the site back.
He said: “I’m not angry, I am disappointed. I’m extremely disappointed because we always thought this was going to be our home and centre for however long we needed it.”
Mr Webb said there would not be enough time to dismantle the centre and they urgently needed to rebuild it so the otters had somewhere to be cared for.
He said the only option was to have most of the site demolished and “cut our losses, which is probably in excess of £40,000”.
He added: “It’s sad for us, it’s sad for the volunteers, it’s sad for the charity.”