Quick search by citation:

42 U.S. Code § 1962d–11a - Potomac River water diversion structure

(a) Consent of Congress for construction; written agreement providing schedule for allocation among parties for withdrawal of waters
(1)
Subject to paragraph (2) of this subsection, the consent of Congress is granted under section 401 of title 33 to the Washington Suburban Sanitary Commission to construct a water diversion structure, with an elevation not to exceed one hundred and fifty-nine feet above sea level, from the north shore of the Potomac River at the Washington Suburban Sanitary Commission water filtration plant to the north shore of Watkins Island.
(2)
The structure authorized by paragraph (1) of this subsection, may not be constructed until the Secretary of the Army, acting through the Chief of Engineers, and the State of Maryland, the Commonwealth of Virginia, the Washington Suburban Sanitary Commission, and such other governmental authorities as the Secretary of the Army, the State of Maryland, and the Commonwealth of Virginia deem desirable signatories enter into a written agreement providing an enforceable schedule for allocation among the parties to such agreement for the withdrawal of the waters of that portion of the Potomac River located between Little Falls Dam and the farthest upstream limit of the pool of water behind the Chesapeake and Ohio Canal Company rubble dam at Seneca, Maryland, during periods of low flow of such portion of such river.
(b) Authorization of Secretary of the Army to enter written agreement; amendments or revisions

The Secretary of the Army, acting through the Chief of Engineers, is authorized to enter into the agreement referred to in subsection (a)(2) of this section and any amendment to or revision of such agreement.

(c) Riparian rights or other authority of Maryland, Virginia, political subdivisions; authority of District of Columbia

Except as may be provided in the agreement referred to in subsection (a)(2) of this section, nothing in this section shall alter any riparian rights or other authority of the State of Maryland, or any political subdivision thereof, the Commonwealth of Virginia, or any political subdivision thereof, or the District of Columbia, or authority of the Corps of Engineers existing on October 22, 1976, relative to the appropriation of water from, or the use of, the Potomac River.

Editorial Notes
Codification

Section was enacted as part of the Water Resources Development Act of 1976, and not as part of the Water Resources Planning Act which comprises this chapter.

Amendments

1980—Subsec. (a)(2). Pub. L. 96–292 struck out cl. “(A)” designation and cl. (B) which prohibited construction of the Potomac River water diversion structure should such structure be in conflict with the report of the Secretary of the Army, acting through the Chief of Engineers, issued in connection with a study of water resources development.