Texas v. New Mexico

P R E L I M I N A R Y P R I N T
Volume 602 U. S. Part 1
Pages 943–990
OFFICIAL REPORTS
OF
T H E S U P R E M E C O U R T
June 21, 2024
REBECCA A. WOMELDORF
reporter of decisions
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N O T I C E : This preliminary print is subject to formal revision before
the bound volume is published. Users are requested to notify the Reporter
of Decisions, Supreme Court of the United States, Washington, D. C. 20543,
pio@supremecourt.gov, of any typographical or other formal errors.

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OCTOBER
TERM, 2023
943
Syllabus
TEXAS, PLAINTIFF v. NEW MEXICO AND
COLORADO
on
exception to third interim report of the special
master
No. 141, Orig. Argued March 20, 2024—Decided June 21, 2024
Approved by Congress in 1938, the Rio Grande Compact is an interstate
agreement that apportions the waters of the Rio Grande River among
Colorado, New Mexico, and Texas. The Compact relies on the Federal
Bureau of Reclamation's operation of an irrigation system called the Rio
Grande Project. Under the Compact, New Mexico must deliver a cer-
tain amount of water to the Elephant Butte Reservoir, located in south-
ern New Mexico. Then, in accordance with agreements called the
“Downstream Contracts,” Reclamation releases specifed amounts of
water from the Reservoir for delivery to two water districts in New
Mexico and Texas.
In 2013, Texas fled suit in this Court against the Compact's other two
signatory States, alleging that excessive groundwater pumping in New
Mexico was depleting supplies of Rio Grande water bound for Texas.
The United States sought to intervene, alleging essentially the same
claims as Texas. In 2018, this Court allowed the United States to inter-
vene, holding that the United States “has an interest in seeing that
water is deposited in the [Elephant Butte] Reservoir consistent with
the Compact's terms,” as that “is what allows the United States to meet
its duties under the Downstream Contracts, which are themselves es-
sential to the fulfllment of the Compact's expressly stated purpose.”
Texas v. New Mexico, 583 U. S. 407, 414. Texas and New Mexico now
seek approval of a proposed consent decree that would resolve this case
and codify a methodology for allocating each State's share of the Rio
Grande's waters. The Special Master recommended that this Court ap-
prove the consent decree, but the United States objected and fled an
exception to the Special Master's report.
Held: Because the proposed consent decree would dispose of the United
States' Compact claims without its consent, the States' motion to enter
the consent decree is denied. Pp. 953–965.
(a) A “court's approval of a consent decree between some of the par-
ties . . . cannot dispose of the valid claims of non-consenting intervenors;
if properly raised, these claims remain and may be litigated by the inter-
venor.” Firefghters v. Cleveland, 478 U. S. 501, 529. Thus, “where
the Government seeks an item of relief to which evidence adduced at

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944 TEXAS
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Syllabus
trial may show that it is entitled, the [court] may not enter a `consent'
judg
ment without the actual consent of the Government.” United
States v. Ward Baking Co., 376 U. S. 327, 334. Pp. 953–954.
(b) The United States has valid Compact claims. Pp. 954–961.
(1) The conclusion that the United States has valid Compact claims
follows directly from the Court's decision six Terms ago “that the United
States [could] pursue the particular claims it has pleaded in this case.”
Texas, 583 U. S., at 413. To start, the Court in 2018 observed that
“the Compact is inextricably intertwined with the Rio Grande Project
and the Downstream Contracts.” Ibid. Indeed, the Compact could
only achieve its goals because, “by the time the Compact was executed
and enacted, the United States had negotiated and approved the Down-
stream Contracts, in which it assumed a legal responsibility to deliver
a certain amount of water to Texas.” Ibid. Second, New Mexico con-
ceded that the United States had its own interests in enforcing the Com-
pact, because it was “ `responsible for . . . delivery of . . . water' as
required by the Downstream Contracts and anticipated by the Com-
pact.” Id., at 414 (alterations in original). Third, the Federal Govern-
ment could not satisfy its treaty obligations to deliver water to Mexico
unless New Mexico complied with its obligations under the Compact.
Ibid. Given these “ `distinctively federal interests,' ” the Court held
that the United States could pursue its claims that New Mexico was
“effectively breaching its Compact duty to deliver water to the Reser-
voir.” Id., at 411, 413. That decision compels the conclusion that the
United States has its own valid claims under the Compact. Pp. 954–957.
(2) The States maintain that the United States has no valid Com-
pact claims because it does not itself receive an apportionment of water.
But the same was true six Terms ago. The States also assert that the
United States failed to allege a “1938 baseline,” that is, that New Mexi-
co's groundwater pumping should be restricted to levels in effect when
the Compact was enacted. But whether the complaint uses the term
“1938 baseline” is beside the point. What matters is that the United
States, like Texas, pleaded that New Mexico was pumping more ground-
water than the Compact contemplates, and the United States still seeks
to pursue that same claim.
The States further maintain that any interest the United States has
in the Compact is strictly derivative of the States' interests. But as
the Court explained in 2018, the United States has “distinctively federal
interests” in the Compact's operations. Texas, 583 U. S., at 413. Addi-
tionally, although the United States must generally comply with state
law when impounding water for use in a federal irrigation project, see
California v. United States, 438 U. S. 645, 647, the United States does
not seek to skirt any state law here. Rather, its position is that the

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945
Syllabus
Compact itself imposes a duty of noninterference on New Mexico.
Pp
. 957–961.
(c) The consent decree would also dispose of the United States' Com-
pact claims. Pp. 961–965.
(1) In proceedings before the Special Master, the States conceded
that the consent decree would resolve all parties' claims, and the Special
Master agreed. Those concessions make sense because the consent de-
cree would, indeed, dispose of the Federal Government's claims. The
United St ates a l leges that New Mexico's groundwater pumpi ng
breaches the State's Compact duty not to interfere with the Project,
and it seeks an injunction against New Mexico to prohibit that interfer-
ence. The proposed consent decree would neither impose that duty on
New Mexico nor enjoin New Mexico from allowing excessive pumping.
To the contrary, the consent decree's proposed new metric for measuring
New Mexico's compliance with the Compact would take for granted the
very increase in groundwater pumping that the United States maintains
violates New Mexico's Compact duties. See Third Interim Report 75.
Accordingly, were the consent decree adopted, the United States would
be precluded from claiming what it argues now—that New Mexico is in
violation of the Compact when it permits groundwater pumping at those
increased levels. Pp. 961–963.
(2) The States argue that rejecting the consent decree would un-
justly expand the scope of this original action and that the United States
should instead litigate its claims in another forum. But the scope of
this action is the same as it was in 2018. The United States asserts the
same claim and seeks the same relief now as it did then. That Texas
has chosen to compromise does not mean that, by staying the course,
the United States is expanding this action. And, because the consent
decree would effectively preclude the United States from arguing that
the Compact itself forecloses New Mexico's current rates of groundwa-
ter pumping, the Court does not see how the United States could vindi-
cate that claim elsewhere. Pp. 964–965.
Exception sustained.
Jackson, J., delivered the opinion of the Court, in which Roberts, C. J.,
and Sotomayor, Kagan, and Kavanaugh, JJ., joined. Gorsuch, J., fled
a dissenting opinion, in which Thomas, Alito, and Barrett, JJ., joined,
post, p. 966.
Frederick Liu argued the cause for the United States on
exception to the Third Interim Report of the Special Master.
With him on the briefs were Solicitor General Prelogar, As-
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946 TEXAS
v. NEW MEXICO
Counsel
sistant Attorney General Kim, Deputy Solicitor General
Kneed
ler, Judith E. Coleman, and Jennifer A. Najjar.
Lanora C. Pettit, Principal Deputy Solicitor General of
Texas, argued the cause for Texas on exception to the Re-
port. With her on the briefs were Angela Colmenero, for-
mer Provisional Attorney General of Texas, Ken Paxton, At-
torney General of Texas, Brent Webster and Grant Dorfman,
First Assistant Attorneys General, James Lloyd, Deputy At-
torney General, Kellie E. Billings-Ray, Aaron L. Nielson,
Solicitor General, William F. Cole, Assistant Solicitor Gen-
eral, Beth Klusmann, Assistant Solicitor General, Stuart L.
Somach, Theresa C. Barfeld, and Sarah A. Klahn, by Philip
J. Weiser, Attorney General of Colorado, Shannon Steven-
son, Solicitor General, Scott Steinbrecher, Deputy Attorney
General, Lain Leoniak, First Assistant Attorney General,
Chad M. Wallace, Second Assistant Attorney General, and
Preston V. Hartman, Senior Assistant Attorney General,
and by Raúl Torrez, Attorney General of New Mexico, James
Grayson, Chief Deputy Attorney General, Julie Ann Meade,
Assistant Attorney General, Jeffrey J. Wechsler, Shelly Dal-
rymple, Kaleb W. Brooks, Bennett W. Raley, Lisa M. Thomp-
son, Michael A. Kopp, John B. Draper, and Corinne E.
Atton.
Jeffrey J. Wechsler argued the cause for New Mexico on
exception to the Report.*
*Briefs of amici curiae were fled for the State of Utah et al. by Sean
D. Reyes, Attorney General of Utah, Melissa Holyoak, Solicitor General,
Chr istopher A. Ba tes, Deputy Solicitor General, and Wendy Bowden
Crowther, Assistant Attorney General, and by the Attorneys General for
their respective States as follows: Treg R. Taylor of Alaska, Kris Mayes
of Arizona, Tim Griffn of Arkansas, William Tong of Connecticut, Ashley
Moody of Florida, Christopher M. Carr of Georgia, Raúl Labrador of
Idaho, Theodore E. Rokita of Indiana, Brenna Bird of Iowa, Kris Kobach
of Kansas, Jeff Landry of Louisiana, Dana Nessel of Michigan, Lynn Fitch
of Mississippi, Austin Knudsen of Montana, Michael T. Hilgers of Ne-
braska, Ellen F. Rosenblum of Oregon, Michelle A. Henry of Pennsylva-
nia, Alan Wilson of South Carolina, Marty J. Jackley of South Dakota,
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as: 602 U. S. 943 (2024)
947
Opinion of the Court
Justice Jackson delivered the opinion of the Court.
The
Rio Grande River begins in Colorado, fows through
New Mexico into Texas, and then courses along the Texas-
Mexico border. The Rio Grande Compact (Compact)—an
interstate agreement between Colorado, New Mexico, and
Texas—governs the “equitable apportionment” of the waters
of the Rio Grande among those three States. To ensure that
Texas receives its share of water, the Compact relies on the
United States Bureau of Reclamation to operate the Rio
Grande Projec t, an irr igati on system i n souther n New
Mexico.
In 2013, Texas fled suit against the other two signatory
States, alleging that, in violation of the Compact, excessive
groundwater pumping in New Mexico was depleting supplies
of Rio Grande water bound for Texas. The United States
sought to intervene, and in a decision we issued six Terms
ago, we allowed it to do so. See Texas v. New Mexico, 583
U. S. 407 (2018). In our opinion, we explained that the Fed-
eral Government has its own distinct interests in holding
New Mexico to its obligations under the Compact, as the
Compact is “inextricably intertwined” with the United
States' operation of the Rio Grande Project. Id., at 413.
Now, Texas and New Mexico have agreed to a proposed
consent decree that would resolve this case and codify a
methodology for determining each State's allocation of the
Rio Grande's waters. But the United States opposes the
proposed consent decree, contending that it would dispose of
Jonathan Skrmetti of Tennessee, Jason S. Miyares of Virginia, and
Bridget Hall of Wyoming; for the Albuquerque Bernalillo County Water
Utility Authority et al. by Jay F. Stein, James C. Brockmann, Charles W.
Kolberg, and Christopher P. Melendrez; for the Elephant Butte Irrigation
District by Samantha R. Barncastle; for New Mexico Pecan Growers
et al. by Tessa Davidson and Arnold J. Olsen; for New Mexico State
University et al. by John W. Utton and Stacey Goodwin; and for Water
Law Professors by Burke W. Griggs, Noah Hall, Rhett Larson, and Jesse
J. Richardson, Jr., all pro se, and by Sam Kalen.
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the Federal Government's claims that New Mexican ground-
water
pumping is violating the Compact.
We agree with the United States. “[P]arties who choose
to resolve litigation through settlement may not dispose of
the claims of a third party.” Firefghters v. Cleveland, 478
U. S. 501, 529 (1986). The United States still advances the
same claims as it did in 2018, backed by the same unique
federal interests we identifed then. Through the consent
decree, the States would settle all parties' Compact claims
and, in the process, cut off the United States' requested relief
as to New Mexican groundwater pumping. Because our
precedent does not permit that result, the States' motion to
enter the consent decree is denied.
I
A
The Rio Grande springs from the San Juan Mountains just
east of the Continental Divide in southwestern Colorado.
After tumbling out of the Rocky Mountains, the river cuts
south through the deserts of New Mexico before crossing
into Texas near the city of El Paso. From there, the river
snakes its way southeast, marking the border between the
United States and Mexico and eventually spilling into the
Gulf of Mexico at the city of Brownsville, Texas.
Of course, when a river touches so many jurisdictions, dis-
putes about water rights are bound to follow. The Rio
Grande is no exception. In the late 19th century, Mexico
began to voice concerns about water shortages caused by
increased use of the Rio Grande's upstream waters in the
United States. See National Resources Committee, Re-
gional Planning: Part VI—The Rio Grande Joint Investiga-
tion in the Upper Rio Grande Basin in Colorado, New Mex-
ico, and Texas, 1936–1937, pp. 7–8 (1938). In 1906, the
United States and Mexico settled that dispute and entered
into a treaty, with the United States promising to provide
Mexico 60,000 acre-feet of Rio Grande water each year. See
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Opinion of the Court
Convention Between the United States and Mexico Provid-
i
ng for the Equitable Distribution of the Waters of the Rio
Grande for Irrigation Purposes, May 21, 1906, 34 Stat. 2953,
T. S. No. 455. To deliver on that promise, the United States
needed to harness the river's irregular ebb and fow brought
on by alternating dry spells and foods. Accordingly, the
Federal Government resolved to construct a new dam and
reservoir at Elephant Butte in New Mexico, about 100 miles
north of the Texas-New Mexico border. Among the frst ir-
rigation projects authorized by the Reclamation Act of 1902,
the dam and reservoir constituted an essential component of
the new Rio Grande Project, an irrigation system imple-
mented by the United States Bureau of Reclamation (Recla-
mation). See Act of Feb. 25, 1905, ch. 798, 33 Stat. 814.
Thanks to the Rio Grande Project, the United States had
harnessed the Rio Grande's water. But that raised another
question: What to do with it? Enter the “Downstream Con-
tracts,” a series of agreements between the United States
and two irrigation districts in New Mexico and Texas. First
signed in 1906 and later renegotiated in the 1930s, the Down-
stream Contracts provided that, after allocating Mexico's
share of Rio Grande water under the 1906 Treaty, the United
States would deliver apportionments of water to the two po-
litical subdivisions—the Elephant Butte Irrigation District
in New Mexico (EBID) and El Paso County Water Improve-
ment District No. 1 in Texas (EP1). Specifcally, Reclama-
tion agreed to supply water to 88,000 irrigable acres in EBID
and 67,000 irrigable acres in EP1, amounting to shares of
about 57% and 43% of the reserved water, respectively.
Letter from S. Somach to Special Master, p. 36 (May 8, 2018).
That left the competing water-rights claims of Colorado,
New Mexico, and Texas. To resolve that dispute, those
States looked to the U. S. Constitution's Compact Clause,
which permits States to enter into agreements among them-
selves, with the consent of Congress. Art. I, § 10, cl. 3.
While contractual in nature, an interstate compact “ `is not
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950 TEXAS
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Opinion of the Court
just a contract,' but also `a federal statute enacted by Con-
gress'
that preempts contrary state law.” New York v. New
Jersey, 598 U. S. 218, 224 (2023) (quoting Alabama v. North
Carolina, 560 U. S. 330, 351 (2010)). Once Congress gives
its stamp of approval, an interstate compact becomes the law
of the land, much like any other federal statute.
In 1938, with Congress's endorsement, Colorado, New
Mexico, and Texas agreed to the Rio Grande Compact, which
“effect[ed] an equitable apportionment” of the Rio Grande's
waters among the three States. Act of May 31, 1939, 53
Stat. 785. For the upstream States, the Compact imposed
certain delivery obligations. It required Colorado to deliver
a particular amount of water to the New Mexican border.
Id., at 787–788. “But then, instead of similarly requiring
New Mexico to deliver a specifed amount of water annually
to the Texas state line, the Compact directed New Mexico to
deliver water to the [Elephant Butte] Reservoir.” Texas,
583 U. S., at 410–411. That “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.”
Id., at 411. In other words, the Compact relied on Reclama-
tion to apportion water through its contractual obligations
to EBID and EP1.
Although the Rio Grande's waters were plentiful in the
1930s, drought conditions set in beginning in the late 1940s
and early 1950s. As a result, entities in southern New Mex-
ico below the Elephant Butte Reservoir began pumping
groundwater at increasing levels to support local agriculture.
That groundwater pumping had important hydrological im-
plications for the Rio Grande Project.
Here's why: When Reclamation releases water from Ele-
phant Butte, the water fows into the bed of the Rio Grande,
and then to a series of canals and ditches, eventually reach-
ing irrigated farms, its fnal destination. Some of the water
runs off of the felds or percolates into the ground, returning
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951
Opinion of the Court
to the river through drains or seepage. Due to these “re-
tur
n fows,” water trickles back to the Rio Grande riverbed,
where it proceeds farther downstream to other irrigation
destinations. But groundwater pumping in southern New
Mexico interrupts that process, both by drawing water away
from the river and by intercepting the return fows that
would otherwise replenish it. Put simply, the more ground-
water pumping between the Elephant Butte Reservoir and
Texas, the more water Reclamation has to release from the
reservoir to comply with its delivery obligations.
Reclamation dealt with these changing circumstances by
developing an equation known as the D2 Curve. Using
Project data from 1951 to 1978—the so-called D2 Period that
witnessed New Mexico's ramped-up groundwater pumping—
Reclamation devised a linear regression model to help it pre-
dict how much water would be available to EBID and EP1
based on a given release of water from the Elephant Butte
Reservoir.
The extent of groundwater pumping in New Mexico none-
theless remained a point of contention, and in 2013, Texas
fled an original action in this Court against New Mexico.
1
Among other things, Texas alleged that New Mexico was
violating the Compact by permitting local entities to pump
groundwater at levels exceeding those contemplated in 1938,
intercepting water bound for the Lone Star State. Texas
requested declaratory, injunctive, and monetary relief, in-
cluding an injunction commanding New Mexico to cease all
interference with the United States' operation of the Rio
Grande Project.
The United States sought to intervene in Texas's suit and
fled its own complaint in 2014. Like Texas, the Federal
Government took issue with New Mexico's groundwater
1
Texas's complaint also names Colorado as a signatory to the Compact,
but because this dispute concerns the allocation of water downstream from
Colorado, the only claims at issue here are against New Mexico. Texas's
Complaint 2, ¶¶4–5.
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952 TEXAS
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Opinion of the Court
pumping, explaining that excessive water interception below
Elephant
Butte could reduce Project effciency “to a point
where 43% of the available water could not be delivered to
[EP1], and 60,000 acre-feet per year could not be delivered
to Mexico.” Intervening Complaint 4, ¶15. For relief, the
United States sought a declaration and an injunction requir-
ing New Mexico to stop in-state entities from interfering
with the Project's delivery of water to EBID, EP1, and Mex-
ico. Id., at 5.
The Special Master appointed to adjudicate this case rec-
ommended dismissing the United States' complaint. But
this Court allowed the United States to intervene. Specif-
cally, we held that “the federal government has an interest
in seeing that water is deposited in the [Elephant Butte]
Reservoir consistent with the Compact's terms,” as that “is
what allows the United States to meet its duties under the
Downstream Contracts, which are themselves essential to
the fulfllment of the Compact's expressly stated purpose.”
Texas, 583 U. S., at 414.
B
The litigation continued. After the Special Master denied
summary judgment and held the frst phase of trial, Texas
and New Mexico negotiated a proposed consent decree. The
consent decree would make “[c]ompliance with th[e] Decree”
suffcient to show “compliance with the Compact with re-
spect to the division of Rio Grande water below Elephant
Butte Reservoir.” Third Interim Report of the Special
Master Addendum 8, ¶7 (Third Interim Report Addendum).
The centerpiece of the proposed consent decree would be
the establishment of the Effective El Paso Index (EEPI), a
new method of determining the allotment of Rio Grande
water New Mexico must deliver downstream into Texas.
The EEPI's calculations of water allocations would be based
on conditions during the D2 Period, when New Mexico was
actively depleting return fows through groundwater pump-
ing. That is, the EEPI would permit levels of pumping “re-
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953
Opinion of the Court
fected in the 1951–1978 timeframe rather than [requiring] a
str
ict return to a pumping condition as existed in 1938.”
Third Interim Report 75. The EEPI would then rely on the
El Paso Gage, a fow indicator near the New Mexico-Texas
border, to measure New Mexico's delivery of water into
Texas. Finally, the consent decree would require Reclama-
tion to transfer water between EBID and EP1 as needed to
maintain a specifed allotment.
The States moved the Special Master to approve the pro-
posed consent decree, but the United States objected. As
relevant here, the United States maintained that the consent
decree would impermissibly dispose of its Compact claims
without its consent. The Special Master disagreed, how-
ever, and issued a Third Interim Report recommending that
this Court approve the consent decree. The United States
fled an exception to the report, and we set the case for
argument.
II
A consent decree “embodies an agreement of the parties
and thus in some respects is contractual in nature.” Rufo
v. Inmates of Suffolk County Jail, 502 U. S. 367, 378 (1992).
But it is also “an agreement that the parties desire and ex-
pect will be refected in, and be enforceable as, a judicial
decree.” Ibid.
In Firefghters v. Cleveland, 478 U. S. 501, we described
the rules that apply when parties wish to settle via consent
decree over the objection of a nonconsenting intervenor.
“[W]hile an intervenor is entitled to present evidence and
have its objections heard . . . on whether to approve a con-
sent decree,” it generally cannot block a decree that would
settle the other parties' claims “merely by withholding its
consent.” Id., at 529.
That rule does not apply, however, when the parties' set-
tlement would also affect the intervenor's claims. Under
those circumstances, parties “who choose to resolve litigation
through settlement may not dispose of the claims of a third
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954 TEXAS
v. NEW MEXICO
Opinion of the Court
party . . . without that party's agreement.” Ibid. In other
words,
a “court's approval of a consent decree between some
of the parties . . . cannot dispose of the valid claims of noncon-
senting intervenors; if properly raised, these claims remain
and may be litigated by the intervenor.” Ibid.
Consequently, and as we explained 20 years before Fire-
fghters, “where the Government seeks an item of relief to
which evidence adduced at trial may show that it is entitled,
the [court] may not enter a `consent' judgment without the
actual consent of the Government.” United States v. Ward
Baking Co., 376 U. S. 327, 334 (1964).
III
With these legal rules in mind, we must now decide
whether to approve the States' proposed consent decree over
the Federal Government's objection. The relevant ques-
tions under our precedents are whether the United States
has valid Compact claims and whether the proposed consent
decree would dispose of those claims. Because the answer
to each of those questions is yes, the consent decree cannot
be approved without the United States' consent.
A
1
Conventional wisdom posits that, because time changes all
things, no one can step into the same river twice. This case
may be an exception, though, for the same considerations
that convinced us to let the United States intervene six
Terms ago also lead us to conclude that the United States
still has valid Compact claims today.
In 2014, the United States asked to intervene in this ac-
tion, asserting “essentially the same claims Texas already”
pleaded. Texas, 583 U. S., at 409. Namely, the United
States alleged that New Mexico was impermissibly “siphon-
[ing] off water below the Reservoir in ways the Downstream
Contracts do not anticipate.” Id., at 411. The Special Mas-

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955
Opinion of the Court
ter recommended that we dismiss the United States' com-
plai
nt, reasoning “that the Compact does not confer on the
United States the power to enforce its terms.” Ibid. But
in its exception to that report, the United States maintained
that “it may pursue claims for violations of the Compact it-
self.” Id., at 412.
We agreed with the United States. Although interstate
compacts are (as the name suggests) agreements between
States, “we have sometimes permitted the federal govern-
ment to participate in compact suits to defend `distinctively
federal interests' that a normal litigant might not be permit-
ted to pursue in traditional litigation.” Id., at 412–413
(quoting Maryland v. Louisiana, 451 U. S. 725, 745, n. 21
(1981)). Examining the nature of the United States' claims
and the Rio Grande Project's unique relationship to the Com-
pact, we ticked through “several considerations” persuading
us that the United States “may pursue the particular claims
it has pleaded in this case.” 583 U. S., at 413.
First, “the Compact is inextricably intertwined with the
Rio Grande Project and the Downstream Contracts,” both
carried out by the Federal Government. Ibid. The pur-
pose of the Compact, recall, was to “ `effec[t] an equitable
apportionment' ” of the Rio Grande's waters among the sig-
natory States. Ibid. (alteration in original). But it “can
achieve that purpose only because, by the time the Compact
was executed and enacted, the United States had negotiated
and approved the Downstream Contracts, in which it as-
sumed a legal responsibility to deliver a certain amount
of water to Texas.” Ibid. The United States, therefore,
“might be said to serve, through the Downstream Contracts,
as a sort of `agent' of the Compact,” responsible for ensuring
Texas and New Mexico receive their apportionments. Ibid.
(some internal quotation marks omitted). Or, put another
way, “the Compact could be thought implicitly to incorporate
the Downstream Contracts by reference.” Ibid. “However
described,” the bottom line was that the “federal govern-
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956 TEXAS
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ment has an interest in seeing that water is deposited in the
Reservoir
consistent with the Compact's terms.” Id., at
414. And although running parallel with Texas's asserted
interests, the United States' interest was “distinctively fed-
eral.” Id., at 413 (internal quotation marks omitted). If
New Mexico interfered with the Project, for instance, Recla-
mation might prove unable “to meet its duties under the
Downstream Contracts, which are themselves essential to
the fulfllment of the Compact's expressly stated purpose.”
Id., at 414 (emphasis added).
Second, along similar lines, we stressed that New Mexico
had “conceded that the United States plays an integral role
in the Compact's operation” and so had its own interests in
this litigation. Ibid. Specifcally, New Mexico had argued
that the Federal Government was “an indispensable party”
because it was “ `responsible for . . . delivery of . . . water' as
required by the Downstream Contracts and anticipated by
the Compact.” Ibid. (quoting New Mexico's Brief in Oppo-
sition to Texas' Motion for Leave to File Complaint 33
(Mar. 11, 2013) (2013 BIO); alterations in Texas). For that
reason, the “ `entry of a Decree in accordance with Texas'
Prayer for Relief would necessarily affect the United States'
interests.' ” 583 U. S., at 414 (quoting 2013 BIO 33; empha-
sis added).
Third, we also took note of the Federal Government's obli-
gations under the 1906 Treaty. As explained above, the
United States must deliver 60,000 acre-feet of water from
the Elephant Butte Reservoir to Mexico, but the United
States can “fll that Reservoir” only if New Mexico complies
with its obligation “to deliver a specifed amount of water
to the facility.” 583 U. S., at 414. Thus, the United States'
ability to deliver water to Mexico depends on New Mexico's
compliance with “its Compact obligations,” and “a breach of
the Compact could jeopardize the federal government's abil-
ity to satisfy its treaty obligations.” Ibid. “Permitting the
United States to proceed” with its own Compact claims
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would “allow it to ensure that those obligations are, in fact,
honored.
” Id., at 415.
2
In light of these “ `distinctively federal interests,' ” we held
that the United States could validly claim that New Mexico
was “effectively breaching its Compact duty to deliver water
to the Reservoir.” Id., at 411, 413. Our 2018 decision leads
inexorably to the same conclusion today: The United States
has its own, uniquely federal claims under the Compact. If
it did not, one might wonder why we permitted the Federal
Government to intervene in the frst place.
2
Our 2018 decision is also all but dispositive of the States'
arg uments that the United States lacks va lid Compact
claims today.
For starters, the States contend that the United States
has no valid Compact claims because it does not itself receive
an apportionment of water under the Compact. Joint Reply
2
Alongside these justifcations for the United States' intervention, we
also noted that the Federal Government sought “substantially the same
relief ” as Texas, without that State's objection. Texas, 583 U. S., at 415.
Citing this portion of our 2018 opinion, the dissent repeatedly asserts that,
back then, we reserved the question whether the United States could
bring Compact claims of its own. See post, at 970–971, 985–986 (opinion
of Gorsuch, J.). To the contrary, we repeatedly stated that the United
States could “pursue the Compact claims it has pleaded in this original
action.” Texas, 583 U. S., at 415; accord, id., at 409, 413. And that is
exactly what we permitted the United States to do. After all, the effect
of our decision was to allow the United States to fle its complaint. Id.,
at 412–413. The issues we reserved were much narrower, namely,
“whether the United States could initiate litigation” to enforce the Com-
pact (had a suit not already been pending between the States) and
whether the United States could “expand the scope of an existing ” law-
suit. Id., at 415 (emphasis added); see also Tr. of Oral Arg. 13–14 (Jan. 8,
2018). As with our 2018 decision, today's opinion says nothing about
whether the United States could have initiated a Compact suit on its own,
and, as explained below, nothing about our decision here expands the scope
of this litigation either. See in fra, at 964.
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to Exception of the United States by the State of Texas et al.
29
–31 (Joint Reply). But the United States did not receive
an apportionment of Rio Grande water in 2018 any more than
it does now. Rather, as we explained, its claims arise from
the Compact's incorporation of the Downstream Contracts
and the attendant risk that New Mexico's interference with
the Project could leave Reclamation unable to meet its con-
tractual and treaty obligations.
The States and the dissent also assert that the United
States failed to allege a “1938 baseline”—a shorthand for the
claim that New Mexico's groundwater pumping should be re-
stricted to levels in effect when the Compact was enacted.
See id., at 36–37; post, at 982–988, and nn. 2–3 (opinion of
Gorsuch, J.). But that argument, too, is foreclosed by our
prior decision. There, we explained that Texas had alleged
New Mexico was “breaching its Compact duty” by allowing
downstream water “users to siphon off water . . . in ways the
Downstream Contracts do not anticipate.” Texas, 583 U. S.,
at 411; see Texas's Complaint 10, ¶18 (alleging that current
pumping “changed the conditions that existed in 1938”).
And we recognized that the United States asserted “essen-
tially the same claims Texas already has.” Texas, 583 U. S.,
at 409; see id., at 411 (United States' claims “parallel Tex-
as's”); id., at 415 (United States seeks “substantially the
same relief ” as Texas). Whether the United States' com-
plaint uses the term “1938 baseline” is beside the point.
Both Texas and the United States pleaded that New Mexico
was violating the Compact by pumping more groundwater
than the Compact contemplates, and that is still the claim
that the United States wishes to pursue now.
3
3
At times, the dissent suggests that the United States' past briefng in
this Court eschewed a 1938 baseline. See post, at 970, 982, n. 2, 986, n. 3,
987–988. It did not. The United States merely observed that a ruling in
New Mexico's favor—that New Mexico does not violate the Compact by
allowing excessive groundwater pumping—would likely affect how Recla-
mation operated the Rio Grande Project, including by undermining a 2008
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Last, we are not persuaded by the States' reliance on our
decisi
ons in Hinderlider v. La Plata River & Cherry Creek
Ditch Co., 304 U. S. 92 (1938), and California v. United
States, 438 U. S. 645 (1978). The States maintain that they
alone represent EBID's and EP1's interests in an allocation
of Compact water; accordingly, they say, any interest Recla-
mation has in fulflling the Downstream Contracts is strictly
derivative of the States' interest in how the water is appor-
tioned. Joint Reply 31–36; see post, at 978, 982. For sup-
port, they rely on Hinderlider, which held that a Colorado
ditch company had no right to water that the State of Colo-
rado had agreed to apportion to New Mexico under the La
Plata River Compact. 304 U. S., at 106–108. “[T]he
States,” we explained, “had power to bind by compact their
respective appropriators,” id., at 108, notwithstanding the
ditch company's pre-existing right under Colorado law to a
certain apportionment of water, id., at 98.
The States' argument here fails for at least two reasons.
First, our decision in 2018 is incompatible with the sugges-
tion that the Federal Government's interest is either entirely
derivative of the States' interests (as with the relationship
between the Colorado ditch company and the State of Colo-
rado in Hinderlider) or merely a stand-in for the interests
of the water districts. See post, at 984. Our reasons for
fnding that intervention was warranted—(1) the United
States' duties under the Project and the Downstream Con-
tracts, (2) the United States' integral role in the Compact's
operation, and (3) the United States' treaty obligations—
agreement that calculated water allocations using a D2 Period baseline.
Memorandum in Support of Motion of United States to Intervene as Plain-
tiff 6 (Feb. 27, 2014); accord, U. S. Brief in Opposition 19 (June 16, 2014).
Nowhere in that briefng did the United States purport to take any defni-
tive position on what groundwater-pumping baseline the Compact should
ultimately be read to require. See Reply Brief for United States 20 (July
28, 2017) (“[I]t remains to be seen whether the interests of Texas and the
United States are completely aligned” regarding the correct baseline).
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stemmed from “ `distinctively federal interests' ” the United
St
ates has, independent of Texas, “in seeing that water is
deposited in the Reservoir consistent with the Compact's
terms.” Texas, 583 U. S., at 413–414 (emphasis added). As
it did then, the United States continues to claim that New
Mexico's interference with the Project's delivery of water vio-
lates the Compact. That Texas's litigation strategy has since
changed, such that it is now willing to accept a greater degree
of groundwater pumping, does not erase the United States'
independent stake in pursuing claims against New Mexico.
Second, because Hinderlider was based on a compact that
is different from the one at issue here, its reasoning is inap-
posite. Different compacts divide state and federal author-
ity differently. Hinderlider's analysis of the States' “con-
clusive” power to determine their citizens' shares of water
was a function of the specifcs of the compact in that case,
which gave the States the sole authority over and responsi-
bility for apportionments of the La Plata River. 304 U. S.,
at 96–98, 107. Here, by contrast, the United States “plays
an integral role in the Compact's operation.” Texas, 583
U. S., at 414. Reclamation's operation of the Project, and
the United States' obligations to EBID and EP1 under the
Downstream Contracts, are the means by which the States
chose to effectuate the apportionment of water in the Com-
pact. Rather than “requiring New Mexico to deliver a spec-
ifed amount of water annually to the Texas state line,” the
Compact instead “directed New Mexico to deliver water to
the” Elephant Butte Reservoir. Id., at 410–411. That
choice made sense only because the “Downstream Contracts
. . . promised Texas water districts a certain amount of
water” via the operation of the Project. Id., at 411. Ac-
cordingly, the Federal Government has its own “interest in
seeing that water is deposited in the Reservoir consistent
with the Compact's terms” and not “siphon[ed] off . . . in
ways the Downstream Contracts do not anticipate.” Id., at
411, 414.
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For similar reasons, our continued recognition of the
U
nited States' valid Compact claims would not, as the States
assert, “tur[n] on its head the hierarchy of authorities gov-
erning the distribution of water within a federal irrigation
project.” Joint Reply 34. Relying on California v. United
States, 438 U. S. 645, the States maintain that the Federal
Government must “comply with state water laws in oper-
ating its federal Reclamation projects.” Joint Reply 34.
True, so far as it goes. California held that § 8 of the Recla-
mation Act required the United States to comply with state-
imposed permit requirements when impounding water from
the Stanislaus River for use in a federal irrigation project.
438 U. S., at 647–650. But the United States is not seeking
to skirt any state law here.
Again, the United States' position is that the Compact it-
self imposes a duty of noninterference on New Mexico.
That claim is not at odds with California's holding that the
Secretary of the Interior must “comply with state laws, not
inconsistent with congressional directives, governing use of
water employed in federal reclamation projects.” Califor-
nia v. FERC, 495 U. S. 490, 504 (1990) (discussing California
v. United States, 438 U. S. 645). The United States' claims
rest on its interpretation of the Compact, and the Compact
trumps state water law. See Texas, 583 U. S., at 412
(“[O]nce Congress gives its consent, a compact between
States—like any other federal statute—becomes the law of
the land”); New York, 598 U. S., at 224.
4
B
1
Because the United States has valid Compact claims and
has not agreed to the proposed consent decree, the only re-
4
Accordingly, and notwithstanding the dissent's suggestions to the con-
trary, see post, at 966–967, 983–984, 988–989, nothing in today's decision
affects either this Court's state water law jurisprudence or the Federal
Government's general obligation to comply with state water law.
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maining question is whether the consent decree would dis-
pose
of those claims. Firefghters, 478 U. S., at 529. We
conclude it would.
To start, the States have conceded as much. In their
briefng before the Special Master, the States acknowledged
that the consent decree would “resolv[e] all of the Compact
claims stated by any party.” States' Joint Motion To Enter
Consent Decree 33 (Nov. 14, 2022) (emphasis added). Like-
wise, in their reply, the States reaffrmed that “upon entry
of the Consent Decree, the United States will have no re-
maining Compact claims.” States' Joint Reply in Support
of Joint Motion To Enter Consent Decree 7 (Feb. 3, 2023)
(emphasis added). The Special Master agreed, explaining
that the consent decree would “resolv[e] the dispute over
the Texas and downstream New Mexico apportionments.”
Third Interim Report 2.
And those concessions state an obvious proposition, be-
cause the consent decree would in fact resolve the United
States' claims in this action. The United States maintains
that New Mexico's pumping breaches that State's alleged
duty under the Compact not to interfere with the Project.
Intervening Complaint 4–5. And the United States seeks
an injunction against New Mexico that would prohibit that
interference. Id., at 5. The proposed consent decree, how-
ever, would dispose of that legal claim and the associated
prayer for relief without addressing the United States' con-
tentions, as it neither imposes the duty of noninterference
that the United States seeks nor enjoins New Mexico from
allowing groundwater pumping beyond 1938 levels. To the
contrary, the consent decree would incorporate New Mexi-
co's groundwater pumping into the Compact by adopting a
new method for apportioning Rio Grande water—the EEPI.
As explained above, the EEPI would establish “an index-
based methodology” to assess New Mexico's compliance with
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Opinion of the Court
during the D2 Period,” from 1951 to 1978. Third Interim
Repor
t Addendum 9, 23, 25. Those decades coincided with
the onset of drought conditions in the Rio Grande Basin and
an accompanying increase in groundwater pumping in New
Mexico. Measuring New Mexico's compliance with the con-
sent decree (and, by extension, its compliance with the Com-
pact) against D2 Period conditions would therefore take for
granted the very increase in groundwater pumping that the
United States maintains violates New Mexico's duty of non-
interference. See Third Interim Report 75 (“Undisputedly,
the Consent Decree's reliance on the D2 period seeks to limit
pumping to an average amount as refected in the 1951–1978
timeframe rather than a strict return to a pumping condition
as existed in 1938”).
Were the consent decree adopted, the United States would
be precluded from claiming what it argues now—that New
Mexico's present degree of groundwater pumping violates
the Compact. Indeed, the consent decree would settle that
question by deeming New Mexico compliant with the Com-
pact, even as it allows pumping at the D2 levels. And that
legal determination would “be refected in, and be enforce-
able as, a judicial decree.” Rufo, 502 U. S., at 378.
The proposed consent decree, therefore, would have the
effect of “cutting [the United States] off from a remedy to
which” it alleges it is entitled. Lawyer v. Department of
Justice, 521 U. S. 567, 579 (1997).
The United States' argument that groundwater pumping
at D2 levels violates the Compact may or may not ultimately
prevail at trial. But we “may not enter a `consent' judgment
without the actual consent of the Government” when “the
Government seeks an item of relief to which evidence ad-
duced at trial may show that it is entitled.” Ward Baking
Co., 376 U. S., at 334. Because the consent decree here
would have that effect, we cannot approve it over the United
States' objection.

964 TEXAS
v. NEW MEXICO
Opinion of the Court
2
The
States and the dissent nevertheless argue that reject-
ing the consent decree would unjustly expand the scope of
this original action and that the United States can and
should litigate its claims in another forum instead. Joint
Reply 38–45; post, at 978–986. Neither argument holds up.
The frst objection boils down to the unremarkable fact
that the United States' and Texas's interests have now di-
verged. As we explained in 2018, both Texas and the
United States at that point asserted “essentially the same
claims” and sought “substantially the same relief ”—an end
to New Mexico “siphon[ing] off water below the Reservoir in
ways the Downstream Contracts do not anticipate.” Texas,
583 U. S., at 409, 411, 415. The United States still asserts
that same claim today and seeks that same relief. That
Texas has chosen to compromise does not mean that, by stay-
ing the course, the United States is expanding this action.
What is more, this Court was well aware in 2018 that the
States' interests might diverge from those of the United
States. See, e. g., New Mexico's Reply to Exceptions of the
United States and Colorado 25 (July 28, 2017); Reply Brief
for United States 18 (July 28, 2017).
The second objection turns on a mischaracterization of the
United States' claims. The States maintain that the Federal
Gover nment's qua lms w ith New Mexico's groundwater
pumping pose only “an intrastate dispute between the
United States and New Mexico” that is better left to existing
litigation in other courts. Joint Reply 43–45. For the rea-
sons already explained, however, the United States' claims
are not limited to “issues related to reclamation law, Project
operations, or the details of New Mexico water administra-
tion.” Id., at 43. Rather, the United States maintains that
New Mexico's groundwater pumping contravenes the Com-
pact itself. Nothing in the consent decree prohibits that al-
leged breach of the Compact; to the contrary, compliance
with the consent decree would instead constitute compliance
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Opinion of the Court
with the Compact. We therefore do not see how the United
St
ates could elsewhere vindicate its claim that the Compact
itself bars New Mexico's allegedly excessive groundwater
pumping.
5
***
Our decision today follows directly from our prior recogni-
tion of the United States' distinct federal interests in the Rio
Grande Compact. Having acknowledged those interests,
and having allowed the United States to intervene to assert
them, we cannot now allow Texas and New Mexico to leave
the United States up the river without a paddle. Because
the consent decree would dispose of the United States' Com-
pact claims without its consent, the United States' exception
is sustained, and the States' motion to enter the consent de-
cree is denied.
It is so ordered.
5
The dissent suggests that, even if we were to adopt the proposed con-
sent decree, the United States could continue to litigate the meaning of
the Compact in another forum and later seek modifcation of the decree.
Post, at 978–984. Perhaps the United States could argue elsewhere that
some source of law aside from the Compact independently bars current
levels of New Mexican groundwater pumping. But what matters here is
that the consent decree would settle that question as far as the Compact
is concerned. It would thus eliminate the United States' claim that New
Mexico is breaching a duty under the Compact. Indeed, at oral argument,
counsel for Texas conceded that the consent decree would be “binding on
the United States” with respect to “the baseline against which the Com-
pact is judged.” Tr. of Oral Arg. 41 (Mar. 20, 2024). That position makes
sense. And it is diffcult to understand why the States would care so
much about this Court's approval of the consent decree if the United
States could turn right around and undo it tomorrow in another court.
Moreover, the dissent's reliance on Firefghters v. Cleveland, 478 U. S. 501
(1986), for this contention is mistaken. See post, at 979–980. The reason
the labor union in Firefghters “remained free to bring its own independ-
ent . . . claims in separate litigation” was that the consent decree there
did “not purport to resolve any claims the [u]nion might have,” as the
union had “failed to raise any substantive claims” in the frst place. 478
U. S., at 530. As already explained, the same cannot be said here.
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966 TEXAS
v. NEW MEXICO
Gorsuch, J., dissenting
Justice Gorsuch, with whom Justice Thomas, Justice
Alito,
and Justice Barrett join, dissenting.
Texas and New Mexico ask us to approve a consent decree
resolving their decade-long original jurisdiction dispute over
the Rio Grande Compact. The decree would fairly appor-
tion water from the Rio Grande River between those two
States and leave federal reclamation operations in the area
running the way they have run for decades. A Special Mas-
ter we appointed to consider the dispute has recommended
approving the proposed decree, concluding that it is “diffcult
to envision a resolution to this matter that might be supe-
rior.” Third Interim Report of the Special Master 15 (Third
Interim Report). The States' dispute resolved, and the
basis for our original jurisdiction gone with it, the Special
Master also recommends dismissing without prejudice any
claims the United States, an intervenor in the case, might
hold.
Still, the Court denies entry of the consent decree. Why?
Because the federal government demands as much. Not
content with receiving what it asked for when it intervened
in this litigation—the protection of its existing federal recla-
mation operations—the United States now seeks to advance
a theory about how water should be distributed between
Texas and New Mexico so aggressive that New Mexico fears
it could devastate its economy. In the process, the federal
government seeks to prolong this original jurisdiction dis-
pute, a form of litigation usually reserved for disputes be-
tween States, over the objection of both Texas and New
Mexico. And it does so despite the fact the consent decree
would leave the federal government free to pursue any
claims it believes it has in the lower courts, where disputes
between the federal government and States are normally
tried.
The Court's decision is inconsistent with how original ju-
risdiction cases normally proceed. It defes 100 years of this
Court's water law jurisprudence. And it represents a seri-
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967
Gorsuch, J., dissenting
ous assault on the power of States to govern, as they always
have
, the water rights of users in their jurisdictions. The
Special Master issued a detailed 115-page report laying all
this out. His views were wise, his recommendations sound,
and, respectfully, we should have done as he suggested.
I
A
Beginning its journey high in the San Juan Mountains, the
Rio Grande runs through Colorado, New Mexico, and Texas
before fowing into Mexico and eventually the Gulf of Mexico.
Along the way, the river serves as a vital irrigation source
for crops as varied as the terrain through which it passes,
nourishing everything from pecans to the justly famous
green chiles of the Hatch Valley. See El Encanto, Inc. v.
Hatch Chile Co., 825 F. 3d 1161 (CA10 2016).
To ensure “an equitable apportionment” of the Rio Gran-
de's waters, Colorado, New Mexico, and Texas entered into
the Rio Grande Compact in 1938. 53 Stat. 785. Congress
approved it the following year. Ibid.; see U. S. Const., Art.
I, § 10, cl. 3 (requiring congressional approval for a State's
“Compact with another State”). The Compact directs Colo-
rado to deliver a specifed amount of water to the New
Mexico-Colorado border. 53 Stat. 787–788. New Mexico
must then deliver water to Elephant Butte Reservoir, lo-
cated about 100 miles north of the Texas line, in order to
ensure Texas receives its share of the river's waters. Id.,
at 788.
The United States Bureau of Reclamation operates the
Reservoir as part of the federal Rio Grande Project. That
Project serves two roles relevant here. First, pursuant to
contracts with New Mexico and Texas water districts (serv-
ing areas around Las Cruces and El Paso), the Project sup-
plies water from the Reservoir to those districts using a
roughly 57%–43% split between New Mexico and Texas.
Texas v. New Mexico, 583 U. S. 407, 410 (2018) (Texas I). We
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968 TEXAS
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Gorsuch, J., dissenting
have called these the Downstream Contracts, and they es-
sentia
lly work to supplement the Compact, which is silent
as to the precise quantity of water owed Texas. Id., at
410–411. Second, the Project ensures the delivery of a set
amount of water to Mexico to satisfy treaty obligations to
that country. Id., at 410.
Over the better part of a century, this arrangement has
worked reasonably well. Yes, disagreements occasionally
arise, sometimes leading to the fling of a complaint in this
Court. But, invariably, these disputes have settled before
the Court reached the merits. See, e. g., Texas v. New Mex-
ico, 308 U. S. 510 (1939); Texas v. Colorado, 474 U. S. 1017
(1985).
B
In the early 2000s, another disagreement arose. The
causes? The 100-mile-long journey water must travel from
Elephant Butte Reservoir to Texas, and the increase in
groundwater pumping along that route. Groundwater and
surface water (like the Rio Grande) are often connected,
drawing from and feeding back into one another. Because
of this connection, pumping by New Mexicans downstream
of the Reservoir (that is, between Elephant Butte and Texas)
reduces the amount of Project water that reaches Texas's
water district. Texas saw this as a violation of the Com-
pact. So in 2013, it sought to fle a bill of complaint in this
Court against New Mexico. (Colorado, as a signatory to the
Compact, joined as a defendant). We agreed to exercise our
original jurisdiction over the case and appointed a Special
Master to aid in our consideration of it. Texas I, 583 U. S.,
at 411.
In brief, here is how Texas framed its claim. It argued
that the Compact implicitly guarantees that the State's
water district will receive a certain minimum quantity of Rio
Grande water from New Mexico. And, Texas contended, we
should calculate the amount of that water based on the “con-
ditions” in and around the river “that existed in 1938 at the
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969
Gorsuch, J., dissenting
time the Rio Grande Compact was executed.” Texas's Com-
plai
nt 5, ¶10. Back in 1938, there was hardly any groundwa-
ter pumping. So adopting 1938 conditions as our baseline
would have the effect of giving Texas' water district more
water. See id., at 8–10, ¶18.
New Mexico resisted Texas's claim. Among other things,
New Mexico observed that the Compact is silent about how
to measure water due Texas. N. M. Brief in Opposition 14–
15 (Mar. 11, 2013). And New Mexico stressed that, since
approximately 1980, the federal government has relied on
data about Rio Grande conditions between 1951 and 1978—
the so-called D2 Period, when groundwater pumping was
more prevalent—to calculate the amount of water due Tex-
as's water district under the Downstream Contracts. See
N. M. Counterclaims 10–11, ¶¶40–41 (May 22, 2018); Joint
Reply to Exception of the United States by the State of
Texas et al. 5–6. New Mexico stressed, too, that Texas had
not previously objected in this Court to that practice—a
sign, New Mexico said, that Texas understood it to be en-
tirely consistent with the Compact. N. M. Answer 10–11,
¶36 (May 22, 2018).
Abandoning decades of practice and mutual understand-
ing, New Mexico continued, wou ld threaten dire conse-
quences for its economy. Farming along the Rio Grande,
New Mexico explained, relies in part on groundwater pump-
ing for irrigation. And replacing the D2 Period with a 1938
baseline, when pumping was all but nonexistent, could put
at risk nearly 50,000 jobs (in a State of 2 million people) and
up to 10% of the State's gross domestic product. See 1 Tr.
of Proceedings before the Special Master 47 (Oct. 4, 2021).
In short order, the United States moved to intervene and
“fled a complaint that presented the federal government's
interests.” Tr. of Oral Arg. 4 (Jan. 8, 2018) (2018 Tran-
script). For its part, the United States agreed with Texas
about the bottom line—that New Mexican groundwater
pumping below the Elephant Butte Reservoir was “interfer-
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970 TEXAS
v. NEW MEXICO
Gorsuch, J., dissenting
ing with the equitable apportion[ment of] water to Texas.”
Id
., at 29–30. But it disagreed with Texas about the appro-
priate method for calculating the amount of water owed
Texas. A holding for Texas that the Compact required the
use of a 1938 baseline, the federal government worried,
would require it to alter its longstanding use of the D2 Pe-
riod when assessing what deliveries were due under the
Downstream Contracts. Reply Brief for United States 20
(July 28, 2017) (2017 Reply). Intervention, as the federal
government put it, would allow it to protect its interest “in
the Project's operation” as well as its interest in ensuring
suffcient water reaches Mexico to satisfy its treaty obliga-
tions. Id., at 11–12, 18.
The United States also fagged for us a procedural issue:
Because the federal government wasn't a signatory to the
Compact, it wasn't clear on what basis it could press any
Compact claims separate from the claims held by the signa-
tory States. This raised the question whether the United
States “could go forward” with claims in its own right “if
Texas's complaint were dismissed” or the parties settled.
2018 Transcript 14. The government speculated that it
might be able to bring an independent claim as a “third-
party benefciary,” id., at 19, or perhaps had some “implied
right of action” under general “equitable” principles, id., at
20. But because Texas's complaint was “going forward,” the
government asked us not to “reach that” issue. Id., at 14.
After hearing argument, in 2018 we “permitted the federal
government to participate in [this] compact sui[t].” Texas I,
583 U. S., at 412. In our decision, we accepted the federal
government's suggestion that there was no need to decide
whether it had valid, independent Compact claims of its own.
Id., at 415. Instead, we held, four “considerations taken col-
lectively persuade[d] us” that the government's participation
was appropriate. Id., at 413. First, we recognized the fed-
eral government's “duties under the Downstream Contracts”
afforded it an “interest in seeing that water is deposited in

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the Reservoir consistent with the Compact's terms.” Id.,
at
414. Second, we gave weight to New Mexico's conces-
sion that the Project “plays an integral role in the Compact's
operation.” Ibid. Third, we said that “[p]ermitting the
United States” to intervene would “allow it to ensure” its
treaty obligations to Mexico were “honored.” Id., at 415.
Fourth, we emphasized that we had no reason to decide
whether the government could press Compact claims inde-
pendently of the States because “the United States ha[d] as-
serted its Compact claims in an existing action brought by
Texas, seeking substantially the same relief and without that
State's objection.” Ibid.
At the same time, we expressly warned that “permission”
to intervene “should not be confused for license.” Id., at
413. In particular, we stressed, “[t]his case does not present
the question whether the United States could initiate [its
own] litigation . . . under the Compact or expand the scope of
an existing controversy between [the] States.” Id., at 415.
And, we added, “[n]othing in our opinion should be taken to
suggest whether a different result would obtain in the ab-
sence of any of the considerations” we had laid out, “or in the
presence of additional, countervailing considerations.” Ibid.
C
Once the case returned to the Special Master, it appeared
to be heading in the same direction as prior disputes about
the Rio Grande Compact. After completing an “initial
phase” of a trial, months-long negotiations followed. Third
Interim Report 35. Ultimately, those discussions culmi-
nated in a settlement and proposed consent decree in 2022.
In the decree, the parties agreed to continue using the D2
Period to measure the amount of water due Texas's water
district. Id., at 42; see Addendum to Third Interim Report
8–11 (Addendum). But they also agreed Elephant Butte—
over 100 miles from the Texas border—wasn't the appro-
priate place to measure the amounts due Texas in light of
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the New Mexican groundwater pumping between the Reser-
voir
and state line. Instead, the States resolved to measure
water fows into Texas at a federally operated gauge near El
Paso, Texas, by the border between the two States. Third
Interim Report 7; Addendum 8–9.
In short, as with any settlement agreement, each side gave
something up to gain something it wanted. Through the use
of the El Paso gauge, Texas received a guarantee that de-
liveries to its water district would be protected from exces-
sive New Mexican groundwater pumping between Elephant
Butte and the state line. And through the continued use of
the D2 Period as the baseline, New Mexico won its water
users the right to maintain at least some of that pumping.
Colorado, as a signatory to the Compact, gave its assent.
For the United States, the consent decree promised busi-
ness as usual. That's because “the [c]onsent [d]ecree essen-
tially adopt[ed]” the federal government's “own method of
operating.” Third Interim Report 107. The government
would continue to use the D2 Period for measuring the
amounts it distributed to Texas's and New Mexico's water
districts, just as it had sought when it intervened and as it
has done “for approximately the last 40 years.” Id., at 42.
The federal government would not even have to establish a
new water gauge at El Paso, for it already operates one.
See id., at 107. It was undisputed, too, that the consent de-
cree would protect water due Mexico under this country's
treaty with that nation. Id., at 94, n. 10.
The federal government objected to the decree's entry
anyway. In an unexpected and still-unexplained move, the
United States abandoned its position, held for over 40 years,
that its own D2 Period data supply the correct method for
measuring the amount of water it must deliver to Texas and
New Mexico water districts. Instead, the federal govern-
ment began advocating for something similar to what Texas
had once urged—the “broad elimination of New Mexican
[groundwater] pumping through a return to a 1938” baseline.
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Id., at 14. Unlike Texas, however, the federal government
had
never alleged in its complaint that the Compact required
the use of the 1938 baseline. In fact, it still has not sought
to plead such a claim. Perhaps even stranger yet, despite
its new litigating position, the United States continued (and
still continues) to deliver water to the water districts using
the D2 Period as its guide.
D
In a detailed 115-page report, the Special Master recom-
mended we approve the consent decree. He advised that it
was “diffcult to envision a resolution to this matter that
might be superior” to it. Id., at 15. In particular, the Spe-
cial Master observed that the States and federal government
had long used the D2 Period to measure the apportionment
of water due each State. And nothing in the voluminous
submissions he received suggested that they had to do other-
wise. As he put it, no evidence suggested that “the Com-
pacting States believed [in 1938] they were locking in . . .
any particular condition of development,” such as a certain
amount of groundwater pumping, for determining what
water was due Texas or New Mexico. Id., at 76–77.
That left the question what to do with any claims the fed-
eral government might believe it has and wishes to pursue
as a result of its newfound views. Our decision in Texas
I, the Special Master recalled, did not decide whether the
government had viable, independent Compact claims of its
own. And rather than undertake that assessment himself,
he recommended dismissing any claims the government
might have without prejudice. Third Interim Report 115.
The Court, he reasoned, had taken the rare step of exercising
its original jurisdiction because the case involved a dispute
between two States. Id., at 11. That dispute was now re-
solved. And, he said, the federal government could pursue
any claims it might have against the States or other water
users as it normally does, “in one of several ongoing or any
new lower court actions.” Id., at 99. In fact, as the Special
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Master alluded to, the federal government is already in-
volved
in Compact-related litigation with New Mexico in
federal district court. See New Mexico v. United States,
No. 1:11–cv–00691 (DNM).
Though the States' agreement and the Special Master's
recommendations promised to bring to an end a decade of
litigation, the United States fled an exception to those rec-
ommendations. It asked us to reject the proposed decree
and order the Special Master to conduct further proceedings
yet. We agreed to hear oral argument on the federal gov-
ernment's request.
II
A
The principles that guide our analysis in original jurisdic-
tion water disputes like this one are long settled. The
“power to control navigation, fshing, and other public uses
of water,” we have said, “is an essential attribute of [state]
sovereignty.” Tarrant Regional Water Dist. v. Herrmann,
569 U. S. 614, 631 (2013) (internal quotation marks omitted).
But in our federal system, one State may not exercise its
sovereignty in ways that deny another State the capacity to
exercise its own. So to prevent upstream States from
wholly draining rivers that would otherwise reach their
downstream neighbors, this Court many years ago developed
the doctrine of equitable apportionment—the notion “that
States have an equal right to make a reasonable use of a
shared water resource.” Mississippi v. Tennessee, 595 U. S.
15, 24 (2021) (internal quotation marks omitted); see Kansas
v. Colorado, 206 U. S. 46 (1907).
Time and again, we have urged States to effect this appor-
tionment “by mutual accommodation and agreement” rather
than through litigation. Florida v. Georgia, 585 U. S. 803,
809 (2018) (internal quotation marks omitted) (collecting
cases). Agreements of that kind usually take the form of an
interstate compact. Once approved by Congress, compacts
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gain the status of federal law. Texas I, 583 U. S., at 412.
And
because States' authority over their waters is an essen-
tial attribute of their sovereignty, a compact's apportionment
of water between two or more States “is binding upon . . .
all water claimants” in those States, “even where [a] State
had granted the water rights before it entered into the com-
pact.” Hinderlider v. La Plata River & Cherry Creek
Ditch Co., 304 U. S. 92, 106 (1938). So, for example, a com-
pact between Texas and New Mexico allocating water be-
tween them binds their respective water districts that con-
tract for water with the federal government, along with all
other water users in their jurisdictions.
Notably, compacts also bind the federal government when
it distributes water from its reclamation projects pursuant
to agreements like the Downstream Contracts. Compacts
do so not only because they are federal law. Texas I, 583
U. S., at 412. They do so as well because Congress has
specifcally directed federal reclamation projects to “follow
state law as to water rights” unless that law conficts with
some other “explicit congressional directive.” California v.
United States, 438 U. S. 645, 673 (1978); see 43 U. S. C. § 383.
As we have put it, Congress has “subject[ed] to the authority
of ” the States “[a]ll of the acts of the [federal] Reclamation
Bureau in operating [its] reservoirs.” Nebraska v. Wyo-
ming, 295 U. S. 40, 42 (1935) (Nebraska I). So an interstate
water rights compact “necessarily bind[s]” the government
as it would “any other appropriator in th[e] [S]tate.” Id., at
43. We have referred to this aspect of congressional water
policy as a form of “ `cooperative federalism.' ” California,
438 U. S., at 650.
While compacts provide a highly valuable tool for resolv-
ing water disputes, disagreements about the meaning of their
terms arise from time to time. The Constitution vests this
Court with original jurisdiction to adjudicate these inter-
state disputes, an “ `awkwar[d]' ” arrangement where we sit,
in effect, as a trial court, a court of frst (and last) review.
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South Carolina v. North Carolina, 558 U. S. 256, 267 (2010).
D
ecide though we may, our general “ `preference' ” is for
States to negotiate to resolve their differences. Florida,
585 U. S., at 809. When those negotiations bear fruit, the
product is often a proposed consent decree containing “de-
tailed mechanisms to promote compliance with the [c]om-
pact's terms.” E. g., Kansas v. Nebraska, 574 U. S. 445, 451
(2015).
Because a consent decree in a water rights case seeks sim-
ply to provide more “detailed mechanisms” to implement a
compact, it bears the same force as one. Just like a compact,
a consent decree is binding on all those in the affected States,
regardless of their “participation” in the case, Nebraska v.
Wyoming, 515 U. S. 1, 22 (1995), or their “assent or dissent,”
Hudson County Water Co. v. McCarter, 209 U. S. 349, 355
(1908). And, once more, the same holds true when it comes
to federal reclamation projects that distribute water to users
in the affected States. They must operate consistently with
a decree's terms unless doing so conficts with some other
explicit congressional directive. See Nebraska I, 295 U. S.,
at 43; California, 438 U. S., at 674.
Still, our approval of a consent decree is hardly a given.
The parties may not use a settlement to rewrite a compact,
for a new compact requires new congressional approval.
See Kansas, 574 U. S., at 455–456. So, when presented, as
we are here, with a request to approve a proposed consent
decree, two considerations guide our decisionmaking. First,
we ask whether the decree is “consistent with the compact
itself.” Id., at 455. In answering that question, we do not
require the States' proposal to be perfect. Rather, we will
“give [a settlement] effect” as long as it is not “wholly con-
trary to relevant evidence, . . . even if we would reach a
different conclusion upon the same evidence.” New Hamp-
shire v. Maine, 426 U. S. 363, 369 (1976). Second, because
the parties' agreement is the driving force behind the decree,
we consider whether the decree purports to bind third par-
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Gorsuch, J., dissenting
ties the States have no authority to represent. In particu-
lar
, we confrm that a proposed settlement does not improp-
erly impose duties or obligations on those third parties
without their consent or dispose of the valid claims they
enjoy. Firefghters v. Cleveland, 478 U. S. 501, 529 (1986).
B
With these rules in mind, I see no sound basis on which
we might refuse to adopt the Special Master's recommenda-
tion to approve the States' consent decree.
First, the decree is consistent with the Compact. All
agree the Compact implicitly guarantees Texas some mini-
mum amount of Rio Grande water each year. Third Interim
Report 75–76, and n. 6. In their settlement, the States pro-
pose to calculate that amount by reference to the D2 Period
and measure it at a water gauge at El Paso. Both terms
are entirely appropriate. The States have relied on the D2
Period for decades. And in making distributions to those
States' water districts pursuant to the Downstream Con-
tracts, so has the federal government. These longstanding
practices are “highly signifcant evidence of [everyone's] un-
derstanding of the [C]ompact's terms.” Tarrant Regional
Water Dist., 569 U. S., at 636 (internal quotation marks omit-
ted). All agree, too, that the Compact expressly authorizes
representatives from each compacting State to choose gauge
locations. See Third Interim Report 69–70. So use of the
El Paso gauge is consistent with the Compact as well. In-
deed, by using that gauging station rather than one 100 miles
upstream from the Texas border at the Elephant Butte Res-
ervoir, the decree ensures Texas's water district is protected
from excessive groundwater pumping in New Mexico be-
tween the Reservoir and the state line.
Second, the consent decree does not impose any new im-
proper duty or obligation on the federal government or deny
it the ability to pursue any valid claim it may have. Yes,
under the decree, reclamation authorities must measure
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water they distribute to Texas's and New Mexico's water dis-
tr
icts using the D2 Period. And they must use the El Paso
gauging station to do so. But, again, the federal govern-
ment has employed the D2 Period to measure the water it
distributes for decades, and it has long maintained the El
Paso gauging station. The government cannot sensibly sug-
gest that it would be improper to require it to continue doing
as it has long done.
Nor is there anything unusual about any of this. As we
have seen, under longstanding federal law, a consent decree
between the States “will necessarily bind” “the Reclamation
Bureau” because “[a]ll of [its] acts . . . in operating the [Proj-
ect] so as to impound and release waters of the river are
subject to the [States'] authority.” Nebraska I, 295 U. S., at
42–43; see Part II–A, supra. Accordingly, Texas and New
Mexico are entitled to decide what water rights their govern-
mental water districts are due, and the federal government's
reclamation project is bound to honor what the States say
on the subject. See ibid.; California, 438 U. S., at 675. Of
course, a consent decree would be improper if it left the fed-
eral government unable to meet some other “explicit con-
gressional directive.” Id., at 673. But the government
does not argue anything of the sort here, never suggesting,
for example, that the proposed decree would risk its obliga-
tions under its treaty with Mexico. To the contrary, it is
undisputed that compliance with the decree would “protect
the [t]reaty water.” Third Interim Report 94, n. 10 (empha-
sis added).
Think about it this way. A federal reclamation project
may not decide that state water districts are entitled to dif-
ferent water rights than States have specifed in their com-
pacts and consent decrees. Those agreements bear the
force of federal law, as Congress has directed and our cases
have long recognized. And were there any possible remain-
ing room for doubt, the Downstream Contracts themselves
dispel it. They direct the contracting parties (the federal
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Gorsuch, J., dissenting
government and the water districts) to apply two sources of
law
when allocating water: that of the States and the federal
Reclamation Act of 1902—the same statute that instructs the
federal government to defer to the States in allocating water
rights among their users and to operate reclamation projects
consistent with what state law requires. See 4 Tex. App. in
Support of Partial Summary Judgment 593; 2 id., at 911–912;
43 U. S. C. § 383.
Nor does the consent decree dispose of any valid claims
the federal government may possess in its own right,
whether under the Compact or any other source of law. To
be sure, to the extent the federal government seeks to pur-
sue a claim “wholly derivative” of the States (or their water
districts), those claims necessarily “rise or fall with the
claims of the States,” and the federal government has no
independent right to press them. Alabama v. North Caro-
lina, 560 U. S. 330, 357 (2010). But, to the extent the federal
government thinks it has any independent claims of its own,
the Special Master recommends dismissing them without
prejudice.
That is “an entirely appropr iate”—and our long-
preferred—“means of resolving whatever questions remain”
after the resolution of an interstate dispute. California v.
Nevada, 447 U. S. 125, 133 (1980). After all, once a dispute
between the States comes to an end, so does the basis for
our exclusive original jurisdiction—jurisdiction we exercise
only “ `sparingly.' ” South Carolina, 558 U. S., at 267; see
28 U. S. C. § 1251. A dismissal without prejudice allows the
federal government to pursue any valid independent claims
it may have in the ordinary course in lower courts. And,
naturally, should the federal government prevail in that liti-
gation in a way that affects the consent decree, it may return
to this Court and seek a modifcation of that decree.
Our consent-decree decisions outside the water-rights con-
text confrm as much. Take Firefghters v. Cleveland, a
Title VII discrimination suit brought by “an organization of
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black and Hispanic frefghters” against their employer, the
city
of Cleveland. 478 U. S., at 504. Under the terms of a
proposed consent decree, the city sought to revise an alleg-
edly discriminatory promotion exam and otherwise make up
for its “assertedly limited minority advancement.” Id., at
505; see id., at 510. An intervenor, the union “represent-
[ing] a majority of Cleveland's frefghters,” objected on the
ground that the remedy would harm its “ `non-minority' ”
members. Id., at 506, 512. Affrming the entry of the de-
cree, we noted that the union remained free to bring its own
independent Title VII or Fourteenth Amendment claims in
separate litigation. Id., at 530. “[W]hether [those] claims
have merit [is a] questio[n] that must be presented in the
frst instance to the [d]istrict [c]ourt.” Ibid. Until then,
city employees, including union members, would be subject
to the consent decree's promotion provisions. If the union
members won on their statutory or constitutional challenges,
however, the decree would have to be modifed to bring it in
line with those laws. See id., at 526–528. So too here.
1
III
Despite reaching a different result, the majority has little
to say in response. It does not dispute the above account of
our settled water law jurisprudence. Nor does it identify
any inconsistency between the proposed consent decree and
1
The majority notes that, in Firefghters, the union had not raised any
claims at the time the district court confrmed the consent decree; it had
merely raised its objections when resisting that decree. Ante, at 965, n. 5.
But in that particular, too, this case parallels Firefghters, for the United
States still has not alleged a 1938 baseline, instead pressing that point in
its objections to the States' proposed decree. The majority fnds “diffcult
to understand” Firefghters' recognition that a consent decree may be en-
tered even if an intervenor might later prevail in a separate suit in a
manner requiring the modifcation of the decree. Ante, at 965, n. 5. But
there is nothing diffcult to understand, or even unusual, about any of that:
Many years and millions of dollars into a dispute, even less-than-ideal (and
perhaps short-lived) settlements often may prove appealing to the parties
and legally permissible for a court to approve.
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the Compact's terms. Instead, bypassing all that, the ma-
jor
ity proceeds in two steps. First, it suggests, the United
States may have valid, independent Compact claims of its
own that the consent decree extinguishes; second, the major-
ity insists, holding otherwise would be inconsistent with our
decision in Texas I, where we allowed the federal govern-
ment to participate to protect its interests. Neither argu-
ment is sound.
A
Primarily, the majority contends the decree risks dis-
posing of valid, independent claims that may belong to the
federal government. To advance its position, the majority
relies on supposed “concessions” by Texas and New Mexico
before the Special Master that, if the consent decree were
confrmed, the federal government would be left with “ `no
remaining Compact claims.' ” Ante, at 962 (emphasis de-
leted); see also ante, at 965, n. 5 (treating a similar assertion
by Texas at oral argument as a “conce[ssion]”). This argu-
ment is wrong for a number of reasons.
First, the majority's telling omits what happened next.
Far from “agree[ing]” with the States, ante, at 962, the Spe-
cial Master recommended we dismiss any claims the federal
government might have in its own right “without prejudice
to being asserted in other fora,” Third Interim Report 11.
Th is recommendati on appl ied, he said, “regardless of
whether the United States bases its claims on Reclamation
law, state law, the Compact, or some other source of author-
ity.” Ibid. Because the States did not fle an exception to
this recommendation, we may treat them as having acceded
to it. See Texas v. New Mexico, 592 U. S. 98, 105 (2020).
That alone is enough to answer the majority.
Second, the majority does not explain why the usual
course of dismissing a third party's claims without prejudice
wouldn't be “entirely appropriate” here, as it ordinarily is in
our original jurisdiction cases. California, 447 U. S., at 133;
see ante, at 962–963. The majority does not, for example, ex-
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plain why the federal government could not press whatever
i
ndependent Compact claims it believes it has in lower courts
and return here, if necessary, to seek modifcation of the
States' consent decree. See Third Interim Report 99–100.
The majority does not offer any such explanation because it
cannot. See supra, at 980–981, and n. 1. Until the govern-
ment had the case stayed to participate in this one, the United
States was already involved, as we have seen, in Compact liti-
gation with New Mexico in federal district court. See Memo-
randum Opinion and Order in New Mexico v. United States,
No. 1:11–cv–00691 (DNM, Mar. 29, 2013), ECF Doc. 193,
pp. 5–6. Perhaps the government thinks it more convenient
to remain here than to return for decree modifcation should
it prevail in that suit or another. But that “do[es] not pro-
vide a basis for declining to [approve] a decree.” Idaho ex
rel. Evans v. Oregon, 462 U. S. 1017, 1026 (1983).
Third, the majority struggles to spell out how the govern-
ment might possibly hold Compact claims in its own right—
that is, independent of the States' claims. Yes, the majority
describes the government's present “position”—namely that
the Compact imposes a 1938 baseline—and repeats the
observation that “the Compact trumps state water law.”
Ante, at 961. But the majority does not suggest, as the gov-
ernment once did, that the United States may sue as a third-
party benefciary of the Compact or under some ill-defned
equitable cause of action. See ante, at 957, n. 2, 959–960;
Part I–B, supra; 2018 Transcript 19–20. Nor does the ma-
jority purport to identify anything in the Compact that
might entitle the federal government the right to sue to de-
mand a 1938 baseline. See Tarrant Regional Water Dist.,
569 U. S., at 632 (“silence in compacts” must be read in favor
of “the States' authority to control their waters”). In fact,
the majority does not dispute that the United States still has
yet even to plead such a claim of its own.
2
2
The most the majority can muster in response is the assertion that,
around the time it intervened, the United States did not affrmatively “es-
che[w] a 1938 baseline.” Ante, at 958, n. 3. The federal government, the

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Fourth, the majority conspicuously avoids the lessons of
our
water law jurisprudence. So, for example, the majority
expresses surprise that the government might be bound to
honor the terms of the consent decree until and unless it
prevails in other litigation on its own claims and then returns
here to seek revision of the decree. Ante, at 965, n. 5; n. 1,
supra. But about that there should be no surprise. Few
rules in water law are more settled than that federal recla-
mation projects must comply with any Compact, state water
law, or consent decree term “not inconsistent with clear con-
gressional directives respecting the project.” California,
438 U. S., at 672; see also Part II, supra. And here, no one,
the majority included, has identifed any congressional direc-
tive, much less a clear one, inconsistent with the consent de-
cree before us.
Fifth, the majority's reasoning doesn't withstand scrutiny
even under ordinary consent-decree principles. Suppose, as
the majority does (incorrectly), that approval of the decree
would necessarily preclude the United States from claiming
in any other forum “that New Mexico's present degree of
groundwater pumping violates the Compact.” Ante, at 963.
Even so, the majority is mistaken when it claims that the
proposed consent decree “would have the effect of `cutting
[the United States] off from a remedy to which' it alleges it
majority continues, did not “purport to take any defnitive position on
what groundwater-pumping baseline the Compact should ultimately be
read to require.” Ibid. But even this tepid defense proves too much for
the record to bear. Time and again, the United States represented that
one factor warranting its participation in the suit was its interest in con-
tinuing to use the D2 Period in its Project operations—an interest neces-
sarily incompatible with a 1938 baseline. See, e. g., Memorandum in Sup-
port of Motion of United States to Intervene as Plaintiff 5–6 (Feb. 27,
2014); U. S. Brief in Opposition 18–19 (June 16, 2014); 2017 Reply 19–20.
Does the majority believe the government was asserting an interest in
violating the Compact? We need not speculate. In support of its as-
serted interest, the United States pointed to an operating agreement with
the water districts to use the D2 Period. And that agreement holds itself
out as Compact compliant. See N. M. Exh. 510, pp. 5, 14.
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is entitled.” Ante, at 963 (quoting Lawyer v. Department of
J
ustice, 521 U. S. 567, 579 (1997)). It is undisputed that the
government's present “prayer for relief ” in this case seeks
only to “prohibit th[e] interference” with the Project caused
by excess groundwater pumping in New Mexico. Ante, at
962. All agree, too, that at the time the United States inter-
vened, the government determined how much pumping was
too much by reference to the D2 Period; the government did
not allege—and still has not alleged—in its complaint that
the Compact mandates a 1938 baseline. Part I–B, supra.
To complete the majority's clipped quotation, then, the
decree would “dispos[e] of [the government's] claim not in
the forbidden sense of cutting [it] off from a remedy” to
which it alleges it is entitled, “but only in the legiti-
mate sense of granting [the government] the very relief [it]
had sought.” Lawyer, 521 U. S., at 579; see infra, at
987–988.
Instead of answering any of these problems, the majority
changes the subject. It replies by observing that the fed-
eral government's deliveries under the Downstream Con-
tracts play a central role in effectuating the Compact by en-
suring certain Rio Grande waters reach New Mexico and
Texas water districts. Ante, at 959–960. That may be so,
but it is no answer for reasons we have already seen. Those
contracts do not promise water districts that the 1938 condi-
tions will be used in measuring the water due them. Nor
may the federal government seek to vindicate the contrac-
tual rights of the States' own water districts. Rather, Con-
gress's instructions, a century's worth of this Court's prece-
dents, and the Downstream Contracts themselves teach that
the compacting States get to decide what water rights those
and other water users in their jurisdictions enjoy. And a
federal reclamation project is bound to honor those decisions
absent some clear congressional command to the contrary.
See Part II, supra.
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Gorsuch, J., dissenting
B
A
t this point, the majority retreats. Perhaps what I have
laid out above would hold true in any other case, it replies,
but this one is special. Special, the majority asserts, be-
cause in Texas I we allowed the United States to participate
in this case. And that ruling, the majority says, necessarily
means the United States may pursue, independently of
Texas, a claim that the Compact requires use of the 1938
conditions. Ante, at 957–960.
This argument is mistaken, too. Recall that, in Texas I,
the government suggested it might be able to sue in its
own right under third-party-benefciary or equitable-cause-
of-action theories. See Part I–B, supra. But recall, too,
that the federal government asked us not to “reach” the
question whether it could independently bring claims of its
own under these theories or any others. Ibid.; 2018 Tran-
script 14. It said answering the question whether it could
sue in its own right was needless because Texas's claims
were live. Ibid. We proceeded in express reliance on that
representation, stressing that we were not resolving either
“the question whether the United States” could sue inde-
pendently of Texas “under the Compact” or the question
whether it could otherwise “expand the scope of an existing
controversy between States.” Texas I, 583 U. S., at 415.
Really, there was no way we could have passed on the
federal government's current assertion that it has a right to
pursue a claim that the Compact requires the use of a 1938
baseline. As the majority concedes, Texas I “repeatedly”
cabined our permission to intervene to “ `the Compact claims
[the United States] has pleaded in this original action.' ”
Ante, at 957, n. 2 (quoting 583 U. S., at 415). As the majority
admits, too, the government has never pleaded the existence
of a 1938 baseline. Ante, at 958, and n. 3. Instead, when it
sought to intervene, the government took just the opposite
view, arguing that its longstanding use of the D2 Period was
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consistent with the Compact. Allowing the government to
re
verse course now is not required by anything in Texas I.
More nearly, it defes that decision by “expand[ing] the
scope” of the parties' litigation. Ante, at 964. In fact, it is
hard to imagine anything that might do more to expand the
scope of this dispute than forcing the States to continue to
litigate when they have already resolved their differences.
Cf. Town of Chester v. Laroe Estates, Inc., 581 U. S. 433
(2017) (intervenor expands the scope of a case when it re-
quests a money judgment different from the one sought by
plaintiff ).
3
The truth is, this Court has “often permitted the United
States to intervene” even without a valid claim of its own.
Maryland v. Louisiana, 451 U. S. 725, 745, n. 21 (1981).
Texas I was simply of a piece with that practice. See 583
U. S., at 413 (citing that portion of Maryland). Far from
holding the federal government could pursue a claim in its
own right, we permitted it to “participate . . . to defend . . .
interests that a normal litigant might not be permitted to
pursue in traditional litigation.” 583 U. S., at 412–413 (in-
ternal quotation marks omitted); accord, ante, at 955. And
allowing intervention in that posture is anything but a hold-
ing that the government may pursue an independent claim
of its own. Cf. Fed. Rules Civ. Proc. 24(a)–(b) (setting out
different Rules for intervention depending on whether an
individual has “an interest” or “a claim”).
3
In response, the majority wishfully asserts that “nothing about [its]
decision here expands the scope of this litigation.” Ante, at 957, n. 2 (cit-
ing ante, at 964). Why? Because the United States “asserts th[e] same
claim[s]” “and seeks th[e] same relief ” “today” as it did “in 2018.” Ante,
at 964. Of course, if that were true and the United States were “staying
the course,” ibid., it would be agreeing with the States that use of the D2
Period is permissible. But admitting as much would require the majority
to do what it will not—recognize that the government's late-stage about-
turn in demanding a 1938 baseline remains unpleaded and alters the consid-
erations that informed Texas I. See ante, at 958, 964 (highlighting Texas's
change of position, but dismissing the government's as “beside the point”).
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Gorsuch, J., dissenting
Beyond that faw with the majority's reading of Texas I
l
ie others. In deciding to take the rare step of permitting
intervention, we stressed that multiple “factors” “taken col-
lectively persuade[d] us” to do so. 583 U. S., at 413, 415.
At the same time, we stressed that “[n]othing in our opinion
should be taken to suggest” the same result “would obtain
in the absence of any of the[m] . . . or in the presence of
additional, countervailing considerations.” Id., at 415.
Factors present then, however, are absent now. And addi-
tional considerations have indeed arisen. In fact, through
the consent decree, the federal government promises to re-
ceive everything it initially sought. Cf. Campbell-Ewald
Co. v. Gomez, 577 U. S. 153, 178 (2016) (Roberts, C. J.,
dissenting) (“When a plaintiff fles suit seeking redress for
an alleged injury, and the defendant agrees to fully redress
that injury, . . . there is no longer any necessity to expound
and interpret the law” (emphasis deleted; internal quotation
marks omitted)).
Take the treaty. One of the factors we cited as favor-
ing intervention concerned the then-live possibility that “a
breach of the Compact could jeopardize [the federal govern-
ment's] treaty obligations” to Mexico requiring it to deliver
certain Rio Grande waters. 583 U. S., at 414. Now, how-
ever, everyone agrees the consent decree will do nothing to
interfere with those obligations, but will instead “protect the
[t]reaty water.” Third Interim Report 94, n. 10.
Next, consider the federal government's concern in 2018
that litigation over the Compact could ultimately require it
to use the 1938 conditions in its distributions to water dis-
tricts, as Texas then sought. That development, the gov-
ernment worried, could interfere with its longstanding use
of the D2 Period in its operations at the Reservoir and the
Downstream Contracts. 2017 Reply 20; see 2018 Transcript
30–31 (Texas highlighting this as an example of where
“Texas and the United States are not exactly going to be
raising the same arguments”). But that, too, is no longer
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a worry. Under the proposed settlement, operations may
conti
nue at the Reservoir as they have for over 40 years.
Finally, recall that, when it intervened, the federal govern-
ment disagreed with Texas about the use of the 1938 baseline
but “substantially” agreed that groundwater pumping in
New Mexico below the Reservoir interfered with the Texas
water district's receipt of water to which it was entitled.
Texas I, 583 U. S., at 415. The parties' proposed decree ad-
dresses this concern, as well, by ensuring the water due
Texas (again, calculated using the government's D2 Period
data) is measured near the state line, at the El Paso gauging
station, and not over 100 miles upstream, along a course
where New Mexico users pump groundwater from the Rio
Grande.
Here's the bottom line: Texas I did not hold—nor could it
have held—that the United States could pursue an independ-
ent Compact claim to enforce a 1938 baseline. To the con-
trary, the government's disagreement with Texas about the
appropriateness of a 1938 baseline was one of the considera-
tions that led us to permit intervention. At the same time,
the interests the federal government did assert then have
been satisfed now by the States' agreement. To conclude,
as the majority does, that the government at this late hour
may assert essentially any Compact-related claims—even
unpleaded ones—is to ignore all this and the many caveats
that accompanied our decision. Where Texas I warned the
United States not to “confus[e]” “our permission” to inter-
vene “for license,” id., at 413, the Court now reverses course
and allows the government to exercise squatter's rights over
our original jurisdiction.
IV
“The history of the relationship between the Federal Gov-
ernment and the States,” we once observed, contains a “con-
sistent thread of . . . continued deference to state water law
by Congress.” California, 438 U. S., at 653. By “den[y-
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ing]” the Special Master's recommendation to approve the
St
ates' consent decree “without [the] consent” of the federal
government, ante, at 965, the Court disregards this long, un-
broken practice. Not to ensure the federal government can
comply with some statutory directive at odds with the de-
cree. Not to protect the interests the government identifed
when it entered the case. Certainly not to avoid impermis-
sibly disposing of a valid claim. No, the majority defes Con-
gress's directions and a century of our precedent all in aid of
a position that the federal government has never pleaded,
one that works against the government's decades-old, real-
world interests. And the majority does so even when the
consent decree would permit the government to raise any
valid, independent claims of its own in a different forum.
Where does that leave the States? After 10 years and
tens of millions of dollars in lawyers' fees, their agreement
disappears with only the promise of more litigation to follow.
All because the government won't accept a settlement pro-
viding it with everything it once sought, and now seeks to
promote the use of an alternative 1938 baseline that no party
seeks and New Mexico represents could cost it tens of thou-
sands of jobs and a large segment of the State's economy.
“ `[C]ooperative federalism' ” that is not. California, 438
U. S., at 650.
Looking beyond this case to future ones does not brighten
the prospect. When the federal government sought to enter
the case, it did so “without [Texas's] objection,” a consider-
ation that carried weight with us. Texas I, 583 U. S., at 415.
But in light of the veto power the Court seemingly awards
the government over the settlement of an original action,
what State in its right mind wouldn't object to the govern-
ment's intervention in future water rights cases? If, as hap-
pened here, even heavily caveated permission to intervene
may end up federalizing an interstate dispute, what State (or
Court) would ever want to risk letting the nose make it
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under the tent? In that way, too, I fear the majority's short-
sighted
decision will only make it harder to secure the kind
of cooperation between federal and state authorities recla-
mation law envisions and many river systems require.
With respect, I dissent.
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Reporter’s Note
The attached opinion has been revised to refect the usual publication
and citation style of the United States Reports. The revised pagination
makes available the offcial United States Reports citation in advance of
publication. The syllabus has been prepared by the Reporter of Decisions
for the convenience of the reader and constitutes no part of the opinion of
the Court. A list of counsel who argued or fled briefs in this case, and
who were members of the bar of this Court at the time this case was
argued, has been inserted following the syllabus. Other revisions may
include adjustments to formatting, captions, citation form, and any errant
punctuation. The following additional edits were made:
None