collection.] Special assessments authorized and made hereunder shall be certified by the secretary of the board of directors of said district to the county assessor of the county or counties where the lands assessed are situated and said assessor shall immediately enter said special assessment on the tax rolls for the year specified in said special assessment whether such roll be in his hands or in the hands of the county treasurer and said special assessment when entered shall be and constitute a first lien upon the lands assessed until paid and shall be collected by the county treasurer at the same time and in the same manner with the same penalties and interest, when in default of payment, as are other levies and assessments of the district collected, or special assessments may be made and included with the regular levies and assessments made by the district for district purposes as now provided by law.