A. Any person diverting or transferring or having substantially under construction facilities to divert or transfer five percent of the seven-day, ten-year low flow or one million gallons or more of water a day from one river basin and using or discharging all or any part of the water in a different river basin on the effective date of this chapter may continue the transfer subject to the following conditions:

1. (1) The transfer must be registered with the department within six months of the effective date of this chapter.
2. (2) The total amount of the transfer daily shall not exceed the larger of (i) the capacity of the facilities used to transfer water on December 1, 1984, or (ii) facilities to transfer water substantially under construction on December 1, 1984, or (iii) any water withdrawal project under contract approved by the Federal Energy Regulatory Commission prior to December 1, 1984.
3. (3) Any increase in water transferred over the amount authorized in item (2) of this section must be reviewed and permitted in accordance with Section 49-21-20.

4. (4) In any event, a transfer authorized under this section must be reviewed under the criteria of Section 49-21-30 upon the occurrence of any of the following conditions:

   1. (i) the cessation of the transfer for any reason for a continuous period of three years;

   2. (ii) following a period from the effective date of this chapter no longer than the longest of the following:

      1. (a) twenty years, or
      2. (b) a period found by the department to be reasonable based upon review of all relevant facts and circumstances pertaining to the existing water transfer, but the period may be not longer than forty years, or

      3. (c) for existing transfers pursuant to item (2) of subsection A of Section 49-21-50, upon conclusion of the maximum useful life of the transfer facilities or water withdrawal project under contract not to exceed forty years from December 1, 1984.

         B. The provisions of this chapter shall take precedence over any other state regulatory provision pertaining to the subject of this chapter.