Neither state shall amend its legislation or any agreement authorized thereby without the consent of the other in such manner as to substantially adversely affect the rights of the other state or its people hereunder, or as to substantially impair the rights of the holders of any bonds or notes or other evidences of indebtedness then outstanding or the rights of an interstate school district to procure the means for payment thereof. Subject to the foregoing, any reference herein to other statutes of either state shall refer to such statute as it may be amended or revised from time to time.   [PL 1981, c. 693, §§ 5, 8 (NEW).]