Vested drainage rights as defined by chapters 46A-10A to 46A-13, inclusive, shall be excluded from the operation of this chapter, until such a time as the operation of any drainage district can be absorbed by the watershed district, to the satisfaction of the then controlling board of county commissioners, or board of commissioners appointed by the county commissioners, or the board of trustees elected by the people of the district.
SDCL 46A-14-46