that conclusion also seems questionable. The line between procedural and substantive law is hazy but no one doubts federal power over procedure. Wayman v. Southard, 10 Wheat. 1. The Judiciary Article and the "necessary and proper" clause of Article One may fully authorize legislation, such as this section of the Judiciary Act.

In this Court, stare decisis, in statutory construction, is a useful rule, not an inexorable command. Burnet v. Coronado Oil & Gas Co., 285 U. S. 393, dissent, p. 406, note 1. Compare Read v. Bishop of Lincoln, [1892] A. C. 644, 655; London Street Tramways Co. v. London County Council, [1898] A. C. 375, 379. It seems preferable to overturn an established construction of an Act of Congress, rather than, in the circumstances of this case, to interpret the Constitution. Cf. United States v. Delaware & Hudson Co., 213 U. S. 366.

There is no occasion to discuss further the range or soundness of these few phrases of the opinion. It is sufficient now to call attention to them and express my own non-acquiescence.

HINDERLIDER, STATE ENGINEER, ET AL. v. LA PLATA RIVER & CHERRY CREEK DITCH CO.

APPEAL FROM THE SUPREME COURT OF COLORADO. No. 437. Argued February 10, 11, 1938.-Decided April 25, 1938. 1. The water of an interstate stream, used beneficially in each of the two States through which it flows, must be equitably apportioned between the two. P. 101.

The claim that on interstate streams the upper State has such ownership or control of the whole stream as entitles it to divert all the water, regardless of any injury or prejudice to the lower State, has been consistently denied by this Court. P. 102.

2. A decree of a state court can not confer a right in the water of an interstate stream in excess of the State's equitable portion of such water. P. 102.

3. A decree of a state court adjudicating to a local user a right in the water of an interstate stream in excess of the State's equitable portion thereof is not res judicata as to another State and its citizens who claim the right to divert water from the stream in such other State, and who were not parties to the proceedings. P. 103. 4. It is not essential to the validity of a compact between States for the apportionment of the water of an interstate stream that there be judicial or quasi-judicial decision in respect of existing rights. P. 104.

5. Whether the apportionment of the water of an interstate stream be made by compact between the upper and lower States with the consent of Congress or by a decree of this Court, the apportionment is binding upon the citizens of each State and all water claimants, including grantees whose rights antedate the compact or decree. P. 106.

6. A compact between two States for apportionment of the water of an interstate stream may provide for division of the water at times, and at other times for the use of the entire flow by one State or the other in alternating periods; and authority may validly be delegated to the States' engineers to determine when the use should be rotated. P. 108.

So held where the evidence conclusively established that, at the times when rotation was determined upon, the stream could in that way be more efficiently used.

7. No vitiating infirmity being here shown in the proceedings preliminary to the La Plata River Compact or in its application, the apportionment made by it between Colorado and New Mexico of the water of the La Plata River could not be held to deprive a Colorado appropriator of any vested right, even though a right had previously been adjudicated to him in a water proceeding in a court of that State. P. 108.

8. The assent of Congress to the La Plata River Compact between Colorado and New Mexico does not make the compact a "treaty or statute of the United States" within the meaning of § 237 (a) of the Judicial Code, and a decision of the state court against its validity is not appealable to this Court. P. 109.

9. A claim based on the equitable interstate apportionment of water, like one based on the proper location of a state boundary, is not within the provisions of § 237 (a) of the Judicial Code. P. 109. 10. The decision of the Supreme Court of Colorado in this case, restraining the State Engineer from taking action required by the La Plata River Compact, denied an important claim under the

Constitution and is reviewable by this Court on certiorari under § 237 (b) of the Judicial Code. P. 110.

11. Whether the water of a stream must be apportioned between the two States through which it flows is a federal question, upon which neither the statutes nor decisions of either State can be conclusive. P. 110.

12. That the States which are parties to a compact are not parties to the suit and can not be made so, does not deprive this Court of jurisdiction to determine the validity and effect of the compact. P. 110.

101 Colo. 73; 70 P. 2d 849, reversed.

APPEAL from the affirmance of a judgment requiring water officials of Colorado to permit diversion of water from the La Plata River by the respondent Ditch Company, notwithstanding contrary provisions of the La Plata River Compact. Appeal dismissed; certiorari granted.

Messrs. Ralph L. Carr and Byron G. Rogers, Attorney General of Colorado, with whom Messrs. Shrader P. Howell, R. F. Camalier, and Jean S. Breitenstein were on the brief, for appellants.

Mr. Charles J. Beise, with whom Mr. Reese McCloskey was on the brief, for appellee.

Attorney General Cummings filed a memorandum by which he sought to maintain that, within the meaning of the Act of Aug. 24, 1937, c. 754, 50 Stat. 751, this Court is "a court of the United States" and the state compact here in question, approved by Congress, is an "Act of Congress affecting the public interest," the constitutionality of which is drawn in question on the appeal. The Attorney General and Acting Solicitor General Bell also filed a memorandum suggesting the interest of the United States in interstate water compacts and interstate compacts generally.

92

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Opinion of the Court.

Messrs. Percy Warren Green, Attorney General of Delaware, Herbert R. O'Conor, Attorney General of Maryland, David Wilentz, Attorney General of New Jersey, John J. Bennett, Jr., Attorney General, Henry Epstein, Solicitor General, of New York, Julius Henry Cohen, T. Harry Rowland, Adrian Bonnelly, Austin T. Tobin, and Daniel B. Goldberg, appearing as amici curiae, by leave of Court, filed on behalf of their respective States and certain state agencies a memorandum taking issue with the views of the Attorney General of the United States as expressed in the first of his memoranda above mentioned. Mr. Abram P. Staples, Attorney General of Virginia, appearing by leave of Court as amicus curiae, joined with the other States in this matter.

MR. JUSTICE BRANDEIS delivered the opinion of the Court.

The La Plata River and Cherry Creek Ditch Company, a Colorado corporation, owns a ditch by which it diverts from that river in Colorado water for irrigation. On July 5, 1928, it brought in the District Court for La Plata County a suit which charged that since June 24, 1928, the defendants, Hinderlider, State Engineer of Colorado, and his subordinates have so administered the water of the river as to deprive the plaintiff of water which it claims the right to divert. A mandatory injunction was sought.

The defendants admit that in administering the water of the stream during the period named they shut the headgate of the Ditch Company so as to deprive it of water for purposes of irrigation; but assert that they did so pursuant to the requirements of the La Plata River Compact entered into by the States of Colorado and New Mexico with the consent of the Congress of the United States.

Opinion of the Court.

304 U.S.

The Compact provides that each State shall receive a definite share of water under the varying conditions which obtain during the year, and, among other things:

1

"1. At all times between the 1st day of December and the 15th day of the succeeding February each State shall have the unrestricted right to the use of all water which may flow within its boundaries.

"2. By reason of the usual annual rise and fall, the flow of said river between the 15th day of February and the 1st day of December of each year shall be apportioned between the States in the following manner:

"(a) Each State shall have the unrestricted right to use all the waters within its boundaries in each day when the mean daily flow at the interstate station is one hundred cubic feet per second, or more.

"(b) On all other days, the State of Colorado shall deliver at the interstate station a quantity of water equiv

1

The Compact had its inception in 1921 when the legislature of each state authorized the appointment of a commissioner who shall represent the State "upon a Joint Commission . . . to be constituted by said states for the purpose of negotiating and entering into a compact or agreement between said states, with the consent of Congress, respecting the future utilization and disposition of the waters of the La Plata River, and all streams tributary thereto, and fixing and determining the rights of each of said states to the use, benefit and disposition of the waters of said stream, provided, however, that any compact or agreement so entered into on behalf of said states shall not be binding or obligatory upon either of said states or the citizens thereof, unless and until the same shall have been ratified and approved by the Legislatures of both states, and by the Congress of the United States." Colo. Session Laws, 1921, p. 803; Session Laws of New Mexico, 1921, p. 322.

The compact drafted by the commissioners was ratified by the General Assembly of New Mexico on February 7, 1923 (Session Laws of New Mexico, 1923, p. 13) and by the General Assembly of Colorado on April 13, 1923 (Colorado Session Laws, 1923, p. 696.)

The consent of Congress was granted by Act of January 29, 1925, 43 Stat. 796.