The compensation made to any reclamation district, levee district or drainage district shall be applied and credited pro rata toward the payment of the balance remaining unpaid upon the assessments levied by the board against the land respectively situated within the reclamation district, levee district or drainage district, as part of the assessment out of which the compensation is to be made, based upon the total amount of the assessment charges against the lands in such reclamation district, levee district or drainage district.