It would take 20 years for this arrangement to become a prescribed right benefitting your neighbour.
Your should create a formal arrangement, contract not an easement, renewable annually allowing you to pass on any charges and to terminate at will if necessary.
Not sure where on the Web you would find a precedent. I would have to say that you should get a lawyer to draft one up for you. You could see if a local solicitor would set it up on a fixed fee. Just to make sure it is done correctly.