(a) Nothing in this chapter shall prevent a municipality or county from requiring a developer to construct reasonable project improvements in conjunction with a development project.

(b) Nothing in this chapter shall be construed to prevent or prohibit private agreements between property owners or developers and municipalities, counties, or other governmental entities in regard to the construction or installation of system improvements and providing for credits or reimbursements for system improvement costs incurred by a developer including interproject transfers of credits or providing for reimbursement for project improvement costs which are used or shared by more than one development project.

(c) Nothing in this chapter shall limit a municipality, county, or other governmental entity which provides water or sewer service from collecting a proportionate share of the capital cost of water or sewer facilities by way of hook-up or connection fees as a condition of water or sewer service to new or existing users, provided that the development impact fee ordinance of a municipality or county or other governmental entity that collects development impact fees pursuant to this chapter shall include a provision for credit for such hook-up or connection fees collected by the municipality or county to the extent that such hook-up or connection fee is collected to pay for system improvements. Imposition of such hook-up or connection fees by any governmental entity to pay for system improvements either existing or new shall be consistent with the capital improvement element of the comprehensive plan and shall be subject to the approval of each county, municipality, or combination thereof which appoints the governing body of such entity. The adoption, imposition, collection, and expenditure of such fees for system improvements by any governmental entity shall be subject to the same procedures applicable to the adoption, imposition, collection, and expenditure of development impact fees by a county.

(d) Nothing in this chapter shall apply to a water authority created by Act of the General Assembly, as long as such authority is not established as a political subdivision of the State of Georgia but instead acts subject to the approval of a county governing authority.