(a) In any levee or drainage district, if the original assessment of benefits was made by assessors, then the board of directors or commissioners of the district shall have the power to fill any vacancies in the board of assessors.
(b) If, however, in any such district the power of the board of assessors was exhausted on making the original assessment, the board of commissioners or directors of the district shall have the power to appoint a new board of assessors composed of the same number and with the same qualifications as the original board, the new board to have all powers to make the reassessments provided for in this section as were conferred on the original board of assessors.