Tenn. Code Ann. § 4-6-121

Each estimate under §§ 4-6-118 — 4-6-123 may include a contingent fund, not to exceed three percent (3%) of the total amount for maintenance for the period of the estimate, for which no detailed account need be given in the estimate, but such funds shall be drawn upon only in due form as provided in this chapter and under the rules of the commissioners of correction and finance and administration.