Section 1. Section 11-36a-305 is amended to read:11-36a-305. Calculating impact fees.(1)In calculating an impact fee, a local political subdivision or private entity: (a)may include:(a)(i)the construction contract price;(b)(ii)the cost of acquiring land, improvements, materials, and fixtures;(c)(iii)for services provided for and directly related to the construction of the system improvements, the cost for planning and surveying, and engineering fees;(d)(iv)for a political subdivision, debt service charges, if the political subdivision might use impact fees as a revenue stream to pay the principal and interest on bonds, notes, or other obligations issued to finance the costs of the system improvements; and(e)(v)one or more expenses for overhead.; and(b)shall comply with Subsections (2) and (3), as applicable.(2)In calculating an impact fee, eacha local political subdivision or private entity shall base amounts calculated under Subsection (1) on realistic estimates, and the assumptions underlying those estimates shall be disclosed in the impact fee analysis.(3)(a)As used in this Subsection (3), "plumbing fixture" means a receptacle or device that is connected to a water supply system or that discharges to a drainage system or both.(b)In calculating an impact fee for a single-family residential use development activity, a local political subdivision or private entity shall use the number of plumbing fixtures shown in the building plans for the single-family residential unit to determine the development activity's proportionate share.