Tenn. Code Ann. § 11-21-112

To effect § 11-21-107 and this chapter, county conservation boards desiring to cooperate with the conservation board of another county or with the parks and recreation board of a municipality, created pursuant to § 11-24-104(a), or with a municipality operating a parks and recreation system created under § 11-24-103, shall enter into an agreement pursuant to title 12, chapter 9, the Interlocal Cooperation Act, with the cooperating party.