899. If the interested parties agree they shall have a deed of agreement prepared, with as many duplicates as necessary. One duplicate shall be filed at the office of the secretary-treasurer of the municipality, or, if the properties are situated in more than one municipality, then at the office of the secretary-treasurer of each of the municipalities within the boundaries of which the properties affected are situated; and, from and after the date of such filing, the deed of agreement shall be binding upon the parties who have signed the same.
If the deed of agreement concerns a watercourse governed by a procès-verbal or a by-law, it is substituted, de jure, for such procès-verbal or by-law.