Tennessee Code Title 5. Counties § 5-19-112

(a) No county shall adopt the resolution provided for in § 5-19-103 until there shall have been presented to the regional planning commission serving such county a plan of services for a specified area or areas for study and a written report to be rendered within ninety (90) days after such submission unless, by resolution of the county legislative body or other governing body, a longer period is allowed.

(b) Such plan of services shall set forth, at a minimum, the identification and proposed timing of the services to be rendered.

(c) No county shall construct or acquire facilities under this chapter unless plans, including necessary engineering and financing plans, shall have been similarly presented to the planning commission for study and report.

(d) In the event there is no such regional planning commission, then the referral shall be to the local planning commission of the largest municipality within the county having such a commission, and, if no municipality within the county has such a planning commission, to the state planning office.