20. Whenever it shall come to the notice of the Collector that any permanent boundary-mark erected under the provisions of this Act has been injured, destroyed or removed, or requires repairs, the Collector may cause such boundary-mark to be re-erected, restored or repaired, and may recover any expenses incurred in respect of such re-erection, restoration or repair, in such proportions as he shall think fit, from the zamindars and tenure-holders to whom such boundary-mark may have been assigned in that respect under the provision of section 29; and all such expenses shall be recoverable as provided in section 57.