The water district board shall adopt and make available to the public rules and regulations relating to, among other things, the use of water, the rates of charge for its consumption and related services and the connection, expansion, improvement, construction and additions to water mains and the distribution system. Upon application for water main extensions and full compliance with the rules and regulations by the applicant, the board shall cause to be constructed such extensions which shall become the property of the water district. Upon completion of construction, the actual cost thereof shall be determined by the board and any excess in an advanced payment shall be returned to the applicant or any shortage therein collected by the board.

Where the board has specified and constructed a main extension of larger diameter than would otherwise be required for the immediate area to be served in order to serve additional areas anticipated to be developed, the board shall not impose the increased costs attributable to such increase in diameter upon the applicant.