Va. Code § 62.1-69
The Potomac River Basin Commission of Virginia shall, if and when it shall come into existence as hereinabove provided, act jointly with commissions appointed for a like purpose by the states of West Virginia and Maryland, the Commonwealth of Pennsylvania and the District of Columbia, or by such of the same as shall enter into the compact and with an additional three members to be appointed by the President of the United States, as a unit of the Interstate Commission on the Potomac River Basin which shall be constituted as provided by the compact hereinabove mentioned. The Potomac River Basin Commission of Virginia shall perform such further duties as shall be provided by the compact.
No provision of this chapter or application thereof shall operate to repeal, limit, affect or impair any provision or application of Chapter 3.1 (§ 62.1-44.2 et seq.) of Title 62.1; and no provision of this chapter shall have any effect upon the powers and duties of the State Water Control Board created by Chapter 3.1 (§ 62.1-44.2 et seq.) of Title 62.1 and the operation of such Board over the waters of the Commonwealth subject to its jurisdiction. Members of the Potomac River Basin Commission of Virginia are prohibited from voting in favor of any measure before the Interstate Potomac River Basin Commission which might have any effect upon the powers and duties of the State Water Control Board without the consent of such Board first had and obtained. Members of the Potomac River Basin Commission of Virginia are prohibited from voting in favor of the construction, with public funds, of any dam or other structure upon the Potomac River or its tributaries in Virginia, which dam or other structure is used or is capable of being used, directly or indirectly, in whole or in part and whether as a single or multiple purpose, for the production by any government or any agency or instrumentality thereof, of electric power and energy.
Va. Code § 62.1-69