Tenn. Code § 7-84-419
All money paid to the municipality in payment of the central business improvement district assessments and interest on the assessments shall be deemed to be a part of and constitute a separate fund for the payment of the cost and expenses of making the improvements in the district, for the payment of interim warrants and special improvement bonds with interest on the bonds issued against the central business improvement district created to make the improvements, and for no other purposes. The fund so created shall be held in the custody of the treasurer or other official of the municipality, kept intact and separate from all other funds and moneys of the municipality and shall be paid out only for the purposes specified in this chapter and as provided in the ordinance creating the central business improvement district. Such fund may be invested by the municipality in the same manner and under the same laws as provided for the investment of other public funds.
T.C.A. § 7-84-419