The planning commission shall have full power and authority to make such investigations, maps and reports of the resources, possibilities and needs of the city or town as it deems desirable, providing the total expenditures of said commission shall not exceed the appropriation for its expenses. Upon completion of any such reports the planning commission shall submit the same to the city council or town commissioners with its recommendations. It shall report annually to the city council or town commissioners on the activities of the planning commission during the preceding year.