7-13-4521. Implementation of program. The board of directors may implement a local water quality program in parts of a local water quality district before the program is implemented in the district as a whole. If a program is initially implemented in only a portion of a district, the fees may be levied only against that part of the district where the program is being implemented. As the program is expanded throughout the district, each additional part of the district that is covered by the program shall pay the fee.