Upon the allowance of such petition a certified copy of the order of the board of directors authorizing such change, and a plat of such district showing such change, certified by the president and the secretary of the district, shall be filed for record in the office of the county clerk of each county in which shall be situated any of the lands of the district; and the district shall remain a drainage district as fully to every intent and purpose as if the lands excluded by change of the boundaries as aforesaid had not been excluded therefrom. Provided, in case contract has been made between the district and the United States as in this act N.M. Stat. Ann. § 73-8-1 to 73-8-60 provided, no change shall be made in the boundaries of the district, and the board of directors shall make no order for any such change until the written assent of the secretary of the interior shall have been filed with the board of directors as aforesaid. Upon the filing of such written assent, however, the lands excluded from any such district shall be discharged of and free of liens in favor of the United States under any contract with the United States, or under bonds deposited with its agents.