The board of water quality, oil and gas may, from time to time after giving due notice and conducting a public hearing, determine and delineate such basins or portions of basins where the demands upon supply made by water users have developed or threaten to develop to such a degree as to create a water shortage and any such areas may be designated as “protected areas.” The water quality control board, whenever it determines that such shortage no longer exists, shall terminate the protected status of such area and shall give public notice of such termination.