Whenever it is necessary to determine the limitations on the amount of nonelectoral debt or nonelectoral debt plus lease rental debt that may be incurred by any local government unit, the appropriate percentage limitations of section 8022 (relating to limitations on incurring of other debt) shall be applied to the borrowing base of the local government unit. The certificate as to the borrowing base shall be made a part of all proceedings for the sale of bonds or notes, for the guaranty of authority obligations or for the incurring of lease rental debt and a copy shall be filed with the department as a part of all proceedings required to be filed for its approval. The borrowing base set forth in the certificate and a similar certificate as to net nonelectoral debt or net lease rental debt outstanding shall be conclusive as to the respective figures for the purposes of this subpart, upon the approval of the proceedings by the department, unless contested within the specified time limits as provided in this subpart.