Idaho Code § 42-5250

Upon a change of the boundaries of a district becoming effective, a copy of the order of the board of directors ordering such change, certified by the president and secretary of the board, shall be filed for record in the recorder’s office of each county within which are situated any of the lands of the district, and thereupon the district shall be and remain a ground water district, as fully and to every intent and purpose as if the lands which are included in the district by the change of the boundaries had been included therein at the original organization of the district.