415 (1964); McClellan v. Carland, supra, at 281; Cohens v. Virginia, 6 Wheat. 264, 404 (1821) (dictum). Given this obligation, and the absence of weightier considerations of constitutional adjudication and state-federal relations, the circumstances permitting the dismissal of a federal suit due to the presence of a concurrent state proceeding for reasons of wise judicial administration are considerably more limited than the circumstances appropriate for abstention. The former circumstances, though exceptional, do nevertheless exist.

It has been held, for example, that the court first assuming jurisdiction over property may exercise that jurisdiction to the exclusion of other courts. Donovan v. City of Dallas, supra, at 412; Princess Lida v. Thompson, 305 U. S. 456, 466 (1939); United States v. Bank of New York Co., 296 U. S. 463, 477 (1936). But cf. Markham v. Allen, 326 U. S. 490 (1946); United States v. Klein, 303 U. S. 276 (1938). This has been true even where the Government was a claimant in existing state proceedings and then sought to invoke district-court jurisdiction under the jurisdictional provision antecedent to 28 U. S. C. § 1345. United States v. Bank of New York Co., supra, at 479. But cf. Leiter Minerals, Inc. v. United States, 352 U. S. 220, 227-228 (1957). In assessing the appropriateness of dismissal in the event of an exercise of concurrent jurisdiction, a federal court may also consider such factors as the inconvenience of the federal forum, cf. Gulf Oil Corp. v. Gilbert, 330 U. S. 501 (1947); the desirability of avoiding piecemeal litigation, cf. Brillhart v. Excess Ins. Co., 316 U. S. 491, 495 (1942); and the order in which jurisdiction was obtained by the concurrent forums, Pacific Live Stock Co. v. Oregon Water Bd., 241 U. S. 440, 447 (1916). No one factor is necessarily determinative; a carefully considered judgment taking into account both the obligation to exercise jurisdiction and the combination of factors counselling against that exer

cise is required. See Landis v. North American Co., supra, at 254–255. Only the clearest of justifications will warrant dismissal.

Turning to the present case, a number of factors clearly counsel against concurrent federal proceedings. The most important of these is the McCarran Amendment itself. The clear federal policy evinced by that legislation is the avoidance of piecemeal adjudication of water rights in a river system. This policy is akin to that underlying the rule requiring that jurisdiction be yielded to the court first acquiring control of property, for the concern in such instances is with avoiding the generation of additional litigation through permitting inconsistent dispositions of property. This concern is heightened with respect to water rights, the relationships among which are highly interdependent. Indeed, we have recognized that actions seeking the allocation of water essentially involve the disposition of property and are best conducted in unified proceedings. See Pacific Live Stock Co. v. Oregon Water Bd., supra, at 449. The consent to jurisdiction given by the McCarran Amendment bespeaks a policy that recognizes the availability of comprehensive state systems for adjudication of water rights as the means for achieving these goals.

As has already been observed, the Colorado Water Rights Determination and Administration Act established such a system for the adjudication and management of rights to the use of the State's waters. As the Government concedes 24 and as this Court recognized in Eagle County and Water Div. 5, the Act established a single continuous proceeding for water rights adjudication which antedated the suit in District Court. United States v. District Court for Eagle County, 401 U. S., at 525; United States v. District Court for Water Div. 5,

24 See Brief for United States 46-49.

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401 U. S., at 529. That proceeding "reaches all claims, perhaps month by month but inclusively in the totality.” Ibid. Additionally, the responsibility of managing the State's waters, to the end that they be allocated in accordance with adjudicated water rights, is given to the State Engineer.

Beyond the congressional policy expressed by the McCarran Amendment and consistent with furtherance of that policy, we also find significant (a) the apparent absence of any proceedings in the District Court, other than the filing of the complaint, prior to the motion to dismiss,25 (b) the extensive involvement of state water rights occasioned by this suit naming 1,000 defendants, (c) the 300-mile distance between the District Court in Denver and the court in Division 7, and (d) the existing participation by the Government in Division 4, 5, and 6 proceedings. We emphasize, however, that we do not overlook the heavy obligation to exercise jurisdiction. We need not decide, for example, whether, despite the McCarran Amendment, dismissal would be warranted if more extensive proceedings had occurred in the District Court prior to dismissal, if the involvement of state water rights were less extensive than it is here, or if the state proceeding were in some respect inadequate to resolve the federal claims. But the opposing factors here, particularly the policy underlying the McCarran Amendment, justify the District Court's dismissal in this particular case.

26

25 As we have observed, the complaint was filed in District Court on November 14, 1972. The Federal Government was served in the state proceedings on January 3, 1973. Shortly thereafter, on February 13, 1973, a motion to dismiss was filed in District Court. Up to this point, it does not appear the District Court dealt in any other manner with the suit pending before it.

26 Whether similar considerations would permit dismissal of a water suit brought by a private party in federal district court is a question we need not now decide.

800

STEWART, J., dissenting

The judgment of the Court of Appeals is reversed and the judgment of the District Court dismissing the complaint is affirmed for the reasons here stated.

It is so ordered.

MR. JUSTICE STEWART, with whom MR. JUSTICE BLACKMUN and MR. JUSTICE STEVENS concur, dissenting.

The Court says that the United States District Court for the District of Colorado clearly had jurisdiction over this lawsuit. I agree.1 The Court further says that the McCarran Amendment "in no way diminished" the District Court's jurisdiction. I agree. The Court also says that federal courts have a "virtually unflagging obligation . . . to exercise the jurisdiction given them." I agree." And finally, the Court says that nothing in the abstention doctrine "in any of its forms" justified the District Court's dismissal of the Government's complaint. I agree. These views would seem to lead ineluctably to the conclusion that the District Court was wrong in dismissing the complaint. Yet the Court holds that the order of dismissal was "appropriate." With that conclusion I must respectfully disagree.

1 "Except as otherwise provided by Act of Congress, the district courts shall have original jurisdiction of all civil actions, suits or proceedings commenced by the United States . . . ." 28 U. S. C. § 1345.

2 Nothing in the McCarran Amendment or in its legislative history can be read as limiting the jurisdiction of the federal courts. That law operates as no more than a pro tanto waiver of sovereign immunity. United States v. District Court for Eagle County, 401 U. S. 520; United States v. District Court for Water Div. 5, 401 U. S. 527.

3 See England v. Medical Examiners, 375 U. S. 411, 415-416; Meredith v. Winter Haven, 320 U. S. 228.

4 See ante, at 813-817.

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424 U.S.

In holding that the United States shall not be allowed to proceed with its lawsuit, the Court relies principally on cases reflecting the rule that where "control of the property which is the subject of the suit [is necessary] in order to proceed with the cause and to grant the relief sought, the jurisdiction of one court must of necessity yield to that of the other." Penn General Casualty Co. v. Pennsylvania ex rel. Schnader, 294 U. S. 189, 195. See also Donovan v. City of Dallas, 377 U. S. 408; Princess Lida v. Thompson, 305 U. S. 456; United States v. Bank of New York Co., 296 U. S. 463. But, as those cases make clear, this rule applies only when exclusive control over the subject matter is necessary to effectuate a court's judgment. 1A J. Moore, Federal

Practice 0.214 (1974). Here the federal court did not need to obtain in rem or quasi in rem jurisdiction in order to decide the issues before it. The court was asked simply to determine as a matter of federal law whether federal reservations of water rights had occurred, and, if so, the date and scope of the reservations. The District Court could make such a determination without having control of the river.

The rule invoked by the Court thus does not support the conclusion that it reaches. In the Princess Lida case, for example, the reason for the surrender of federal jurisIdiction over the administration of a trust was the fact that a state court had already assumed jurisdiction over the trust estate. But the Court in that case recognized that this rationale "ha[d] no application to a case in a federal court... wherein the plaintiff seeks merely an adjudication of his right or his interest as a basis of a claim against a fund in the possession of a state court. . . ." 305 U. S., at 466. The Court stressed that "[n]o question is presented in the federal court as to the right of any person to participate in the res or as to the quantum of his interest in it." Id., at 467. Similarly, in the