This part shall not apply to any de minimis structure position discrepancy on public lands, as defined in § 171-2, or to such encroaching improvements incident to shoreline boundaries. If real property subject to this section is owned by a county, any improvement within a de minimis structure position discrepancy shall be removed at the expense of the property owner who constructed the improvement, or the property owner’s successor in interest, upon notice, in accordance with the respective county procedures or ordinances.