Va. Code Ann. § 15.2-7421

The Commonwealth and, by participating in the Authority, each participating political subdivision pledge to and agree with the holders of any bonds issued by the Authority that neither the Commonwealth nor any participating political subdivision will limit or alter the rights hereunder vested in the Authority to fulfill the terms of any agreements made with said holders or in any way impair the rights and remedies of said holders until such bonds are fully met and discharged. The Authority is authorized to include this pledge and agreement in any contract with the holders of the Authority's bonds.