Tenn. Code Ann. § 67-5-803

When assessing for public taxes any tract of land lying partly within the limits of a drainage district, special school district or other special taxing district, and partly outside the limits of such district, an assessor shall assess that part of such tract lying within the limits of such district as one (1) independent tract, and that part of any such tract lying outside of the limits of such district as another independent tract, to the end that the amount of the taxes due to each taxing district may be definitely known.