Tenn. Code Ann. § 69-5-1102

When a proposed improvement, drainage district, or drainage and levee district will require its location in more than one (1) county, the application by petition may in the alternative be made to the county court of any one (1) of the counties in which such district will be in part located, if established, such petition to be signed by persons residing in, and owning lands in, any one (1) or more of the counties. The court in which such petition is filed shall have full jurisdiction in the premises for the purpose of creating and establishing such drainage or drainage and levee district. It is not necessary to file such petition in the county court of any other county in which some of the lands lie that are to be included in the proposed district.