Tenn. Code Ann. § 7-33-201

For the purpose of raising funds with which to pay that portion of the cost of improvements chargeable against the municipalities authorized in this chapter, the municipality shall have the power and authority to issue its bonds pursuant to the Local Government Public Obligations Act of 1986, compiled in title 9, chapter 21 in an amount not exceeding one third (1/3) of the cost of any such improvement or improvements.