Whenever all the owners of rights to water within any service area, by agreement in writing, shall have organized themselves into an association for the purpose of financing the distribution of the water to which they are entitled and shall have agreed therein as to the apportionment of the expense and the payment thereof and shall have filed with the department a copy of the agreement duly certified and authenticated by the president and secretary of the association, the department shall thereafter submit the statement provided for in this chapter to the association.