1 (Slip Opinion) OCTOBER TERM, 2017

Syllabus

NOTE: Where it is feasible, a syllabus (headnote) will be released, as is being done in connection with this case, at the time the opinion is issued. The syllabus constitutes no part of the opinion of the Court but has been prepared by the Reporter of Decisions for the convenience of the reader. See United States v. Detroit Timber & Lumber Co., 200 U. S. 321, 337.


## SUPREME COURT OF THE UNITED STATES

Syllabus

TEXAS v. NEW MEXICO ET AL

.

ON EXCEPTIONS TO REPORT OF SPECIAL MASTER

No. 141, Orig. Argued January 8, 2018—Decided March 5, 2018

To resolve their disputes over water rights in the Rio Grande, Colorado,

New Mexico, and Texas, with Congress’s approval, signed the Rio Grande Compact. The Compact requir es Colorado to deliver a speci

fied amount of water annually to New Mexico at the state line and directs New Mexico to deliver a specified amount of water to the Ele

phant Butte Reservoir. The Reservoir was completed in 1916 as part
of the Federal Government’s Rio Gr ande Project and plays a central role in fulfilling the United States’s obligations to supply water under a 1906 treaty with Mexico as well as under several agreements with downstream water districts in New Mexico and Texas (Downstream Contracts). Texas brought this original action complaining that New Mexico

has violated the Compact by allowi ng downstream New Mexico users to siphon off water below the Reservoir in ways not anticipated in the
Downstream Contracts. The United States intervened and filed a complaint with parallel allegations. The Special Master filed a report recommending that the United Stat es’s complaint be dismissed in part because the Compact does not confer on the United States the power to enforce its terms. This Court agreed to hear two exceptions to the report concerning the scope of the claims the United States can assert here: The United States says it may pursue claims for Com

pact violations; Colorado says the United States should be permitted to pursue claims only to the exte nt they arise under the 1906 treaty

with Mexico.

Held : The United States may pursue th e Compact claims it has pleaded

in this original action. This Cour t, using its unique authority to mold original actions, see Kansas v. Nebraska , 574 U. S. ___, ___, has sometimes permitted the federal government to participate in com

pact suits to defend “distinctively federal interests” that a normal lit

-2 TEXAS v. NEW MEXICO

Syllabus

igant might not be permitted to pursue in traditional litigation, Mary

land v. Louisiana , 451 U. S. 725, 745, n. 21. While this permission should not be confused with license, several considerations taken col

lectively lead to the conclusion th at the United States may pursue the particular claims it has pleaded in this case. First, the Compact is inextricably intertwined with the Rio Grande Project and the Downstream Contracts. Second, Ne w Mexico has conceded in plead

ings and at oral argument that the United States plays an integral role in the Compact’s operation. Third, a breach of the Compact could jeopardize the federal government’s ability to satisfy its treaty obligations to Mexico. Fourth, th e United States has asserted its Compact claims in an existing action brought by Texas, seeking sub

stantially the same relief and withou t that State’s objection. This case does not present the question whether the United States could initiate litigation to force a State to perform its obligations under the Compact or expand the scope of an existing controversy between States. Pp. 4–7.

United States’s exception sustained; all other exceptions overruled; and

case remanded.

G ORSUCH , J., delivered the opinion for a unanimous Court._________________

_________________ 1 Cite as: 583 U. S. ____ (2018)

Opinion of the Court

NOTICE: This opinion is subject to formal revision before publication in the preliminary print of the United States Reports. Readers are requested to notify the Reporter of Decisions, Supreme Court of the United States, Wash

ington, D. C. 20543, of any typographical or other formal errors, in order that corrections may be made before the preliminary print goes to press.


## SUPREME COURT OF THE UNITED STATES

No. 141, Orig.

STATE OF TEXAS, PLAINTIFF v. STATE OF
NEW MEXICO AND STATE OF COLORADO

ON EXCEPTIONS TO REPORT OF SPECIAL MASTER

[March 5, 2018]

J USTICE G ORSUCH delivered the opinion of the Court.
Will Rogers reportedly called the Rio Grande “the only river I ever saw that needed irrigation.” In its long jour

ney from the Colorado Rockies to the Gulf of Mexico, many and sometimes competing demands are made on the riv

er’s resources. In an effort to reconcile some of those demands, Colorado, New Mexico , and Texas, acting with the federal government’s assent, signed the Rio Grande Compact in the 1930s. In today’s lawsuit, Texas claims
that New Mexico has defied the Compact. But at this stage in the proceedings we face only a preliminary and narrow question: May the United States, as an intervenor, assert essentially the same claims Texas already has? We believe it may. Like its namesake, the Rio Grande Compact took a long and circuitous route to ratification. Its roots trace perhaps to the 1890s, when Mexico complained to the United States that increasing demands on the river upstream left little for those below the border. The federal government responded by proposing, among other things, to build a reservoir and guarantee Mexico a regular and regulated release of water. Eventually, the government identified a2 TEXAS v. NEW MEXICO

Opinion of the Court

potential dam site near Elephant Butte, New Mexico, about 105 miles north of the Texas state line. The gov

ernment presented this suggestion to representatives of
Mexico and the affected States in a 1904 “ ‘Irrigation Con

gress,’ ” where it was “‘heartily endorse[d] and ap

prove[d].’ ” Official Proceedings of the Twelfth National Irrigation Congress 107 (G. Mitchell ed. 1905). So, in 1906, the United States agreed by treaty to deliver 60,000 acre-feet of water annually to Mexico upon completion of
the new reservoir. Convention Between the United States and Mexico Providing for the Equitable Distribution of the Waters of the Rio Grande for Irrigation Purposes, 34 Stat. 2953. After obtaining the necessary water rights, the United States began construction of the dam in 1910 and completed it in 1916 as part of a broader infrastructure development known as the Rio Grande Project. But that still left the problem of resolving similar dis

putes among the various States. After a number of interimagreements and impasses, the affected parties eventually (and nearly simultaneously) negotiated several agreements. And here again the Rio Grande Project and its Elephant Butte Reservoir played a central role. In the first set of agreements, the federal government promised to supply water from the Rese rvoir to downstream water districts with 155,000 irrigable acres in New Mexico and Texas. In turn, the water districts agreed to pay charges in proportion to the percentage of the total acres lying in each State—roughly 57% for New Mexico and 43% for Texas. We will call those agreements the “Downstream Contracts.” Additionally, Colorado, New Mexico, and Texas concluded the Rio Grande Compact, which Congress approved in 1939. Act of May 31, 1939, 53 Stat. 785. In the Compact, the parties indicated that nothing in their agreement should be “construed as affecting” the federal government’s treaty duties to deliver promised water to Mexico, but only as resolving disputes among themselves.3 Cite as: 583 U. S. ____ (2018)

Opinion of the Court

Id. , at 792. Toward that end, the Compact required Colo

rado to deliver a specified amount of water annually to

New Mexico at the state line. Id. , at 787–788. But then, instead of similarly requiring New Mexico to deliver a specified amount of water annually to the Texas state line, the Compact directed New Mexico to deliver water to the

Reservoir. Id. , at 788.* In isolation, this might have seemed a curious choice, for a promise to deliver water to a

reservoir more than 100 miles inside New Mexico would seemingly secure nothing for Te xas. But the choice made all the sense in the world in light of the simultaneously negotiated Downstream Contracts that promised Texas

water districts a certain amount of water every year from
the Reservoir’s resources. Fast forward to this dispute. Texas filed an original action before this Court comp laining that New Mexico has violated the Compact. According to Texas, New Mexico is effectively breaching its Compac t duty to deliver water to the Reservoir by allowing do wnstream New Mexico users to siphon off water below the Reservoir in ways the Down

stream Contracts do not antic ipate. After we permitted the United States to intervene, it also filed a complaint with allegations that parallel Texas’s. In response to these complaints, New Mexico f iled a motion to dismiss. A Special Master we appointed to consider the case receivedbriefing, heard argument, and eventually issued an interim report recommending t hat we deny New Mexico’s motion to dismiss Texas’s complaint. We accepted that recommendation. At the same time, the Master recom

-

——————

* To be precise, the Compact originally required New Mexico to deliver water to a measuring station at San Marcial, New Mexico, upstream of the Elephant Butte Reservoir. 53 Stat. 788. But the Compact also established something called the Ri o Grande Compact Commission and gave it the power to administer the Compact in various ways. Id. , at

791. In 1948, that Commission relocated the spot for measuring the delivery obligation from the measurin g station to the Reservoir itself.4 TEXAS v. NEW MEXICO

Opinion of the Court

mended that we dismiss in part the complaint filed by the United States. The Master reasoned, in pertinent part, that the Compact does not confer on the United States the power to enforce its terms. In response to the Master’s report, the parties filed a number of exceptions. We agreed to hear two of these exceptions—one by the United States and one by Colorado—concerning the scope of the claims the United States can assert in this original action. The United States says it may pursue claims for violations of the Compact itself; Colorado says the United States should be permitted to pursue claims only to the extent they arise under the 1906 treaty with Mexico. Our analysis begins with the Constitution. Its Compact Clause provides that “[n]o State shall, without the Con

sent of Congress, . . . enter into any Agreement or Com

pact with another State.” Art. I, §10, cl. 3. Congress’s approval serves to “prevent any compact or agreement between any two States, which might affect injuriously the
interests of the others.” Florida v. Georgia, 17 How. 478, 494 (1855). It also ensures that the Legislature can “check any infringement of the rights of the national govern

ment.” 3 J. Story, Commentaries on the Constitution of the United States §1397, p. 272 (1833) (in subsequent editions, §1403). So, for example, if a proposed interstate agreement might lead to friction with a foreign country or injure the interests of another region of our own, Congress may withhold its approval. But once Congress gives its consent, a compact between States—like any other federal
statute—becomes the law of the land. Texas v. New Mexico

, 462 U. S. 554, 564 (1983). Our role in compact cases di ffers from our role in ordi

nary litigation. The Constitution endows this Court with original jurisdiction over disp utes between the States. See Art. III, §2. And this Court’s role in these cases is to serve

“ ‘as a substitute for the diplomatic settlement of contro

versies between sovereigns and a possible resort to force.’ ”5 Cite as: 583 U. S. ____ (2018)

Opinion of the Court

Kansas v. Nebraska , 574 U. S. ___, ___ (2015) (slip op., at 6) (quoting North Dakota v. Minnesota , 263 U. S. 365, 372–373 (1923)). As a result, the Court may, “[i]n this singular sphere, . . . ‘regul ate and mould the process it uses in such a manner as in its judgment will best pro

mote the purposes of justice.’” 574 U. S., at ___–___ (slip op., at 6–7) (quoting Kentucky v. Dennison , 24 How. 66, 98 (1861)). Using that special authority, we have sometimes per

mitted the federal government to participate in compact suits to defend “distinctively federal interests” that a normal litigant might not be pe rmitted to pursue in tradi

tional litigation. Maryland v. Louisiana , 451 U. S. 725, 745, n. 21 (1981). At the same time, our permission
should not be confused for license. Viewed from some sufficiently abstract level of generality, almost any com

pact between the States will touch on some concern of the national government—foreign affairs, interstate com

merce, taxing and spending. No doubt that is the very reason why the Constitution requires congressional ratifi

cation of state compacts. But just because Congress en

joys a special role in approving interstate agreements, it does not necessarily follow that the United States has blanket authority to interven e in cases concerning the construction of those agreements. Still, bearing in mind our unique authority to mold original actions, several cons iderations taken collectively persuade us that the United States may pursue the par

ticular claims it has pleaded in this case:

First , the Compact is inextricably intertwined with the Rio Grande Project and the Downstream Contracts. The Compact indicates that its purpose is to “effec[t] an equi

table apportionment” of “the waters of the Rio Grande”
between the affected States. 53 Stat. 785. Yet it can achieve that purpose only be cause, by the time the Com

pact was executed and enacted, the United States had6 TEXAS v. NEW MEXICO

Opinion of the Court

negotiated and approved the Downstream Contracts, in which it assumed a legal respon sibility to deliver a certain amount of water to Texas. In this way, the United States might be said to serve, through the Downstream Con

tracts, as a sort of “ ‘agent’ of the Compact, charged with assuring that the Compact’s equitable apportionment” to Texas and part of New Mexico “is, in fact, made.” Texas’s Reply to Exceptions to the First Interim Report of the Special Master 40. Or by way of another rough analogy, the Compact could be thought implicitly to incorporate the Downstream Contracts by reference. Cf. 11 R. Lord, Wil

liston on Contracts §30:26 (4th ed. 2017). However de

scribed, it is clear enough t hat the federal government has an interest in seeing that wa ter is deposited in the Reser

voir consistent with the Compact’s terms. That is what
allows the United States to meet its duties under the Downstream Contracts, which are themselves essential to the fulfillment of the Compact’s expressly stated purpose.
Second , New Mexico has conceded that the United States plays an integral role in the Compact’s operation. Early in these proceedings, it argued that the federal government was an indispensable party to this lawsuit because it is “responsible for . . . delivery of . . . water” as required by the Downstream Co ntracts and anticipated by the Compact. Brief in Opposition 33; ibid. (“[T]he entry of

a Decree in accordance with Te xas’ Prayer for Relief would necessarily affect the United States’ interests in the [Rio Grande] Project” contract). And at oral argument, New
Mexico contended that the fede ral government is so inte

grally a part of the Compact’ s operation that a State could sue the United States under the Compact for interfering with its operation. Tr. of Oral Arg. 59.

Third , a breach of the Compact could jeopardize the federal government’s ability to satisfy its treaty obliga

tions. See Sanitary Dist. of Chicago v. United States , 266
U. S. 405, 423–425 (1925) (recognizing the strong interests7 Cite as: 583 U. S. ____ (2018)

Opinion of the Court

of the United States in preventing interference with its treaty obligations). Our treat y with Mexico requires the federal government to deliver 60,000 acre-feet of water annually from the Elephant Butte Reservoir. And to fill that Reservoir the Compact ob liges New Mexico to deliver a specified amount of water to the facility. So a failure by New Mexico to meet its Comp act obligations could directly impair the federal government’s ability to perform its obligations under the treaty. Now the Compact says plainly that it may not be “construed as affecting the obligations of the United States of America to Mexico” under existing treaties. 53 Stat. 792. But that means only that the Compact seeks to avoid impairing the federal government’s treaty obligations. Permitting the United States to proceed here will al low it to ensure that those obligations are, in fact, honored.

Fourth , the United States has asserted its Compact claims in an existing action brought by Texas, seeking substantially the same relief and without that State’s objection. This case does not present the question whether the United States could initiate litigation to force a State to perform its obligations under the Compact or expand the scope of an existing controversy between States. Taken together, we are persuaded these factors favor allowing the United States to pursue the Compact claims it has pleaded in this original action. Nothing in our opinion should be taken to suggest whether a different result would obtain in the absence of any of the considera

tions we have outlined or in the presence of additional, countervailing considerations. The United States’s excep

tion is sustained, all other exceptions are overruled, and the case is remanded to the Special Master for further proceedings consistent with this opinion.

It is so ordered.