(a) Tax increment base.--Upon the creation of a tax increment district or the adoption of any amendment to a project plan subject to subsection (c), the tax increment base of the district shall be determined.

(b) Determination of base.--Upon application in writing by the finance officer of the municipality which created the district, the assessor for that municipality shall determine, according to its best judgment from all sources available to it, the full aggregate market value of the taxable property in the district as of the date on which the district was created. The finance officer of the municipality may determine the sales tax base or any other tax increment base contemplated hereby in any manner which is reasonable and prudent and meets sound business practice.

(c) Amendment of plan.--If the original project plan for any district is amended and the amendment includes additional project costs for which tax increments may be received by the municipality, to the extent reimbursement of previously incurred costs and debt has been made as described in section 7(a), the tax increment base for the district shall be redetermined pursuant to subsection (b) within 90 days following the effective date of the amendment. The tax increment base, as redetermined under this subsection, is effective for the purposes of this act only if it exceeds the original tax increment base.

(d) Rebuttable presumption.--It is a rebuttable presumption that any property within a tax increment district acquired or leased as lessee by the authority within one year immediately preceding the date of the creation of the district was so acquired or leased in contemplation of the creation of the district. The presumption may be rebutted by the authority with proof that the property was leased or acquired primarily for a purpose other than to reduce the tax increment base. If the presumption is not rebutted, in determining the tax increment base of the district, but for no other purpose, the taxable status of the property shall be determined as though such lease or acquisition had not occurred.

(e) Identification.--The assessor for the municipality which created the district shall identify upon the assessment roll, returned and examined in accordance with law, those parcels of property which are within each existing tax increment district, specifying the name of each district. A similar notation shall also appear on the tax roll made by the finance officer for the municipality creating the district and by the finance officer for any municipality or school district that participates in a tax increment district.