1. I regret to say that you won't be able to now state that these neighbours have now to get their own water supply. This is because the doctrine of estoppel prevents you from resiling from the representation that your neighbour could use the water supply. As your neighbour has relied to his detriment upon your representation made as long ago as 1973 (and one at a later date) the law does not allow you to resile from the making of this representation that they can use this water supply. In essence the law creates a form of legal restraint from allowing you to now require them to get their own water supply.
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