The board by rule shall establish standards for recreational facilities to be developed and maintained by a district and for the allocation of a district’s funds for developing and maintaining recreational facilities in relation to a district’s financial requirements for other purposes. To prevent duplication of recreational facilities provided by other governmental entities, rules adopted by the board under this section must require a district, before developing recreational facilities, to make findings that the size and location of the facilities have been established in consideration of municipal or county recreational facilities, whether existing or proposed, that serve or will serve the area in which the district is located.