If at any time after the final construction of said improvements the same shall become out of repair, obstructed, inefficient, or defective from any cause, the said board of supervisors may order an assessment upon the lands in said drainage district for the purpose of placing the same in proper and suitable condition for drainage purposes, using the original assessment upon the property in said district as a basis to ascertain the ratio that each separate tract or lot of land or property bears to the whole amount to be levied and said board shall fix and determine the amount of the assessment or tax that shall be levied against each separate piece of property in said district, and to meet the requirements of this act, which said assessment shall be limited to the amount necessary to make and complete said repairs, remove said obstruction or remedy any such defect or defects, and shall be levied and collected in the same manner as other assessments provided for in this act for the location, construction and operation of said system of drainage are collected and expended: Provided, That if the repair is made necessary by the act or negligence of the owner of any land through which such improvement is constructed, or by the act or negligence of his agent or employee, or if the same is filled and obstructed by the cattle, hogs or other stock of such owner, employee or agent then the cost thereof shall be assessed and levied against the lands of such owner alone.