43 U.S.C. § 666
Section 666 · Suits for adjudication of water rights
Amended 1 time on record
Applied in 207 court decisions — leading case Moses H. Cone Memorial Hospital v. Mercury Construction Corp. (1983)
Most recently applied in Municipio de Río Grande y otro v. Adquisición de Finca 27.661 de la Urbanización Industrial Las Flores, del Término Municipal de Río Grande y otros (April 2025)
Applied most in the Ninth Circuit Circuit (35 decisions)
Cases citing this section usually also cite 28 U.S.C. § 1346 · 28 U.S.C. § 1345 · 28 U.S.C. § 1331
How often courts cite this section
Court decisions citing this, by year.Markers show enactment, consequential amendments, and circuit splits over this section — watch for a citation surge after a change or a disagreement. The dip in the last several years is a data-coverage gap, not a real trend — our corpus holds fewer opinions from the most recent years, so recent citations are undercounted.
Consent is given to join the United States as a defendant in any suit (1) for the adjudication of rights to the use of water of a river system or other source, or (2) for the administration of such rights, where it appears that the United States is the owner of or is in the process of acquiring water rights by appropriation under State law, by purchase, by exchange, or otherwise, and the United States is a necessary party to such suit. The United States, when a party to any such suit, shall (1) be deemed to have waived any right to plead that the State laws are inapplicable or that the United States is not amenable thereto by reason of its sovereignty, and (2) shall be subject to the judgments, orders, and decrees of the court having jurisdiction, and may obtain review thereof, in the same manner and to the same extent as a private individual under like circumstances: Provided, That no judgment for costs shall be entered against the United States in any such suit.
Summons or other process in any such suit shall be served upon the Attorney General or his designated representative.
Nothing in this section shall be construed as authorizing the joinder of the United States in any suit or controversy in the Supreme Court of the United States involving the right of States to the use of the water of any interstate stream.
Editorial notes U.S. Code · Office of the Law Revision Counsel
Codification
Section is comprised of subsections (a) to (c) of section 208 of act July 10, 1952. Subsection (d) of section 208 is omitted as it referred to the limitation on the use of any appropriation in act July 10, 1952 to prepare or prosecute the suit in the U.S. District Court for the Southern Division of California, by the United States v. Fallbrook Public Utility Corporation.
Federal Rules of Civil Procedure
Service of summons upon the United States, see Rule 4, Title 28, Appendix, Judiciary and Judicial Procedure.
Cross References
Costs against the United States, see section 2412 of Title 28, Judiciary and Judicial Procedure.