This chapter may be amended by the voters of the District in the manner prescribed for petitions under subchapter 5 of this chapter, or by the Board under this section. The Board at any regular or special meeting may adopt a resolution expressing the intention to amend the chapter. A copy of such resolution shall be mailed to the legislative bodies of the members and to each supervisor at least 10 days prior to the meeting scheduled to act on the amendment. Unless a majority of the legislative bodies requests, in writing, on or before the date of the meeting scheduled to act on the amendment, that the Board hold a special meeting of the District to vote on the amendment, the Board may adopt the amendment. Within 10 days of the adoption of the amendment by the Board or by the voters of the District, the Clerk of the District shall certify to the Secretary of State each proposal of amendment. Section 510 of this chapter, relating to reconsideration and rescission of vote, shall apply to an amendment adopted by a vote of the Board or the voters under this section. The Secretary of State shall then proceed as with municipal charter amendments under section 17 V.S.A. § 2645. No amendment shall be made which shall substantially impair the rights of the holders of any bonds or other notes or other evidence of indebtedness or substantially affect any obligations under long-term contracts of the District then outstanding or in effect, or the rights of the District to procure the means for payment, continuation, or termination thereof.