French to English Law/Patents Law: Contract(s)

In a concession agreement concerning a power generator installed near a waterfall, I have an article which relates to neighbours' rights to use the water and a "restitution en nature" carried out by the concession holder. I then have the following sentence: "Les contrats de restitution deja conclus a la date de delivrance de la presente concession sont enregistr�s au titre de l'article xx. En accord avec le concessionnaire, le riverain evince de ses droits d'eau peut preferer a la restitution en nature la cession onereuse de ses droits au concessionaire." Apologies for the lack of accents but they appear as symbols when I preview the question.