When it appears that any tract of land within any drainage district has been assessed with fifteen percent (15%) or more excess acreage, the owner of any such tract of land may by bill filed against the district and directors have the mistake corrected and the assessment changed, and the chancery court shall in the decree correcting the mistake determine whether it is necessary for the district to levy a special assessment to meet the deficiency caused by the correction of the mistake. If a special assessment is needed, the chancery court shall determine its amount, and the directors are authorized to, and shall, as soon as any such cause is determined, proceed to levy such special assessment, and it shall be spread upon the tax books and collected as other assessments.