Neb. Rev. Stat. §§ 31-364
If at any time after the final construction of such improvement the same shall become out of repair, obstructed, inefficient, or defective from any cause, except such as are the result of the use of said improvements as a joint outlet for other systems of drainage improvements, the board of supervisors, if in its discretion it is practicable and feasible to make such repairs, remove such obstructions, and correct such inefficiencies, may order an assessment upon the lands and property benefited by the drainage system, for the purpose of placing the same in proper and suitable condition for drainage purposes, using the original assessment upon the property in the 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. The board shall fix and determine the amount of the assessment or tax that shall be levied against each separate piece of property in the district, which assessment shall be limited to the amount necessary to make and complete such repairs, remove such obstructions, or remedy any such defect or defects, and shall be levied and collected in the same manner as the other assessments for the location, construction and operation of said system of drainage are levied and collected as provided in sections 31-301 to 31-369; Provided, however, the board of supervisors of any such district, if it deems advisable, or is ordered so to do by a majority vote at a landowners meeting of the district, instead of proceeding as above mentioned, shall, when it is found that funds are necessary for minor repairs and maintenance of its drains or ditches, or for the administration of the affairs of the district, or for upkeep or protection of its tools and machinery, levy a tax annually, sufficient in amount to pay for such items of expense, without the estimate of an engineer, and certify the same to the proper authorities, and the same shall be extended on the tax rolls of the county and collected as other taxes. All such annual assessments shall be based upon the original apportionment of benefits to the lands and property within the district, and apportioned as the original assessment. The board of supervisors shall also determine and certify to the said authorities at that time the amount each tract of land or separate property shall pay as its proportion of the funds so found necessary, and levied for said purposes. If the repair is made necessary by the act or negligence of the owner of any land or other property through which the improvement is constructed or by the act or negligence of his or its 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 or property of such owner alone.
Neb. Rev. Stat. §§ 31-364