NOTICE: This opinion is subject to formal revision before publication in the preliminary print of the United States Reports. Readers are requested to notify the Reporter of Decisions, Supreme Court of the United States, Washington, D. C. 20543, of any typographical or other formal errors, in order that corrections may be made before the preliminary print goes to press.
SUPREME COURT OF THE UNITED STATES
No. 142, Orig.
STATE OF FLORIDA, PLAINTIFF v.
STATE OF GEORGIA
on exceptions to report of special master
[June 27, 2018]
Justice Breyer delivered the opinion of the Court.
This case concerns the proper apportionment of the water of an interstate river basin. Florida, a downstream State, brought this lawsuit against Georgia, an upstream State, claiming that Georgia has denied it an equitable share of the basin’s waters. We found that the dispute lies within our original jurisdiction, and we appointed a Special Master to take evidence and make recommendations.
After lengthy evidentiary proceedings, the Special Master submitted a report in which he recommends that the Court deny Florida’s request for relief on the ground that “Florida has not proven by clear and convincing evidence that its injury can be redressed by an order equitably apportioning the waters of the Basin.” Report of Special Master 3. The case is before us on Florida’s exceptions to the Special Master’s Report.
In light of our examination of the Report and relevant portions of the record, we remand the case to the Master for further findings and such further proceedings as the Master believes helpful.
This original action arises out of a dispute over the division of water from an interstate river basin known as the Apalachicola-Chattahoochee-Flint River Basin. The Basin drains an area of more than 20,000 square miles across the southeastern United States. Three interstate rivers form the heart of the Basin and are central to this case. They are the Chattahoochee River, the Flint River, and the Apalachicola River. It is easiest to think of these three rivers as forming the capital letter “Y,” with each branch starting at a different point in northeastern Georgia near Atlanta and the stem running through the Flor- ida panhandle and emptying into Apalachicola Bay in the Gulf of Mexico. See Appendix, infra
The Chattahoochee River is the western branch of this Y-shaped river system. It runs from the foothills of Georgia’s Blue Ridge Mountains, through most of Georgia, down to Lake Seminole, just north of Florida. The United States Army Corps of Engineers operates several dams and reservoirs along the Chattahoochee where it both stores water and controls the amount of water that flows downstream to Florida in accordance with the terms of its recently revised Master Water Control Manual (Master Manual). As we shall discuss in more detail, Part IV, infra
, the Corps’ operations are important to the resolution of this case.
The Flint River, the eastern branch of the “Y,” runs from just south of Atlanta down to the same lake, namely, Lake Seminole. Unlike the Chattahoochee, there are no dams along the Flint River; it flows unimpeded through southern Georgia’s farmland, where the greatest share of the Basin’s water is consumed by agricultural irrigation.
After water from the Flint and Chattahoochee Rivers mixes at Lake Seminole, the mixed water (now forming the stem of the Y) continues its southward journey. At the southern end of Lake Seminole, it flows through the Woodruff Dam—a dam also controlled by the Corps. The mixed waters then change their name. They are called the Apalachicola River, and under that name they flow 106 miles through the Florida Panhandle and finally empty into the Gulf of Mexico. There, the fresh water of the Apalachicola River mixes with the Gulf’s saltwater, forming Apalachicola Bay, which the United Nations, the United States, and the State of Florida have all recognized as one of the Northern Hemisphere’s most productive estuaries. In total, the Apalachicola River accounts for 35% of the fresh water that flows along Florida’s western coast. See Joint Exh. 168, p. 39.
Florida and Georgia have long disputed the apportionment of the Basin’s waters. Florida contends that Georgia is consuming more than its equitable share of Flint River water. It adds that, were Georgia to consume less water from the Flint River, more water would flow into Lake Seminole, pass through the Woodruff Dam and subsequently flow down the Apalachicola River (the Y’s stem) and into Apalachicola Bay. The additional water that would result from a cap on Georgia’s consumption would, Florida argues, help (among other things) to recover and maintain its oyster industry, which collapsed following a drought in 2012. Georgia believes that it should not have to cut back on its Flint River water consumption because, in its view, it consumes no more than its equitable share.
“This Court has recognized for more than a century its inherent authority, as part of the Constitution’s grant of original jurisdiction, to equitably apportion interstate streams between States.” Kansas
, 574 U. S. ___, ___ (2015) (slip op., at 7). But we have long noted our “preference” that States “settle their controversies by ‘mutual accommodation and agreement.’ ” Arizona
373 U.S. 546
, 564 (1963) (quoting Colorado
320 U.S. 383
, 392 (1943) (Kansas II
)); see also id
., at 392
(“[Interstate] controversies may appropriately be composed by negotiation and agreement, pursuant to the compact clause of the federal Constitution”); Kansas
at ___ (slip op., at 2–3) (describing codification of Republican River Compact); Montana
563 U.S. 368, 372 (2011) (interpreting Yellowstone River Compact); Kansas
543 U.S. 86 (2004) (resolving dispute over Arkansas River Compact).
We recognize that Florida and Georgia (sometimes with the help of the Federal Government) have long tried to do so. But so far they have failed.
In 1992, for example, the States signed a memorandum of agreement in which they “committed to a process for cooperative management and development” of the three-river Basin and agreed to “participate fully as equal partners” in a “comprehensive, basin-wide study” of its waters. Joint Exh. 004, at 1. Five years later, the States signed—and Congress approved—a compact, the Apalachicola-Chattahoochee-Flint River Basin Compact, in which they agreed:
“to develop an allocation formula for equitably apportioning the surface waters of the ACF Basin among the states while protecting the water quality, ecology and biodiversity of the ACF.”
But five years of negotiations under the Compact proved fruitless, and in 2003, the Compact expired.
More than a decade later, in 2014, Congress again recognized the need for an equitable apportionment of Basin waters. See Water Resources Reform and Development Act of 2014, Pub. L. 113–121, §1051(a),
1259. But once again, despite drought, expanding city populations, and a dramatic increase in acreage devoted to agricultural irrigation, no agreement has been reached. The “last effort to reach an amicable resolution of this complex equitable apportionment proceeding” in 2017 was “unsuccessful.” Report 24. The States instead have come to this Court.
In 2013, Florida, the downstream State, sought to sue Georgia, the upstream State, asking us to exercise our “original and exclusive jurisdiction” and issue a decree equitably apportioning the waters of the Basin.
28 U. S. C. §1251(a); see U. S. Const. Art. III, §2; see also this Court’s Rule 17. In its complaint, Florida alleged that Georgia’s consumption of Flint River water “reduce[s] the amount of water flowing to the Apalachicola River at all times,” and noted that “the effects are especially apparent during the low flow summer and fall periods.” Complaint 9, ¶21; see also id.,
at 17, ¶49 (complaining that the impact of Georgia’s water consumption “is significant, particularly during dry periods”). In addition, Florida alleged that “[a]s Georgia’s upstream storage and consumption grows over time, low flow events will become more frequent and increase in severity, diminishing the likelihood that key species will survive and precluding any chance of recovery over the long term.” Id.
, at 20, ¶59. To remedy these harms, Florida seeks a cap on Georgia’s consumption of water from the Flint River. Id.
, at 21.
Georgia filed a brief in opposition, arguing that Florida failed to allege an injury sufficient to warrant this Court’s exercise of original jurisdiction. See State of Georgia’s Opposition to Florida’s Motion for Leave to File a Complaint 31 (“Florida has not pleaded facts plausibly suggesting that it will be able to establish clear and convincing evidence that it suffers substantial injury as a result of Georgia’s consumption of water”). At our request, the United States filed a brief in which it told us that “Florida has pleaded an interstate water dispute of sufficient importance to warrant this Court’s exercise of its original jurisdiction, and no other judicial forum is suitable for resolving the overall controversy.” Brief for United States as Amicus Curiae
12 (Sept. 18, 2014). But, the United States also warned that “[p]ractical considerations . . . weigh against the Court’s resolution of Florida’s claims before the Corps has completed its process of updating the Master Manual for the federal projects in the ACF Basin.” Ibid
. It suggested that the Court could “grant Florida leave to file, but stay or provide for tailoring of any further proceedings until the Corps has issued the revised Master Manual” in March 2017, id.,
at 13 (which Florida has now done, see Brief for United States as Amicus Curiae
3, n. 1, 10–12).
We subsequently agreed to exercise our original jurisdiction and appointed a Special Master “with authority to . . . direct subsequent proceedings,” “take such evidence as may be introduced and such as he may deem it necessary to call for,” and “submit Reports as he may deem appropriate.” 574 U. S. ___ (2014).
At the outset, the United States declined to waive its sovereign immunity from suit in this case. And shortly thereafter, Georgia asked the Special Master to dismiss the case on the grounds that the United States was a necessary party but could not be forced to intervene. See Fed. Rule Civ. Proc. 19(b). The Master concluded that the motion to dismiss Florida’s complaint should be denied. The Master reasoned that a decree binding the Corps might not prove necessary. Order on State of Georgia’s Motion To Dismiss 14–15 (June 19, 2015). Rather, the Master concluded that “the few facts before me at this stage of the proceeding support the conclusion that” a cap on Georgia’s Flint River water consumption could, at least in principle, redress Florida’s injuries either by increasing the amount of water that flows into Florida’s Apalachicola River or by “render[ing] periods of reduced flow releases [into the Apalachicola River] fewer and further between because of the increased reservoir levels that would result from Georgia’s reduced consumption.” Id
., at 14, and n. 5. The Special Master pointed out that Florida would have to show that “a consumption cap is justified and will afford adequate relief.” Id.
, at 13.
The Master then held lengthy discovery and evidentiary proceedings. See Brief for Georgia 11; post,
at 23 (opinion of Thomas, J.) (“During their 18 months of discovery, the parties produced 7.2 million pages of documents”). Ultimately, the Master submitted a 70-page Report to this Court in February 2017. He recommended that the Court dismiss Florida’s complaint. In particular, despite the very large factual record amassed and “the extensive testimony bearing on numerous issues,” the Special Master stated:
“I have concluded that there is a single
, discrete issue that resolves this case: even assuming
that Florida has sustained injury as a result of unreasonable upstream water use by Georgia, can Florida’s injury effectively be redressed by limiting Georgia’s consumptive use of water from the Basin without a decree binding the [Army] Corps [of Engineers]? I conclude that Florida has not proven that its injury can be remedied without such a decree. The evidence does not provide sufficient certainty that an effective remedy is available without the presence of the Corps as a party in this case.” Report 30–31 (emphasis added).
For present purposes, we note that Florida and Georgia agree that the Master’s recommendation “turned on a ‘single, discrete issue’—whether Florida had shown that a cap on Georgia’s consumption would redress its injury if the decree did not bind the Corps as well.” Florida Brief in Support of Exceptions 23–24; see also Georgia’s Reply to Florida’s Exceptions 23 (“The Special Master reserved ruling on any issue other than effective redress”); Brief for United States as Amicus Curiae
19–20 (Aug. 7, 2017) (same).
In reviewing this determination, we do not agree with the dissent’s view that the Master applied the “ordinary balance-of-harms test” that our equitable apportionment cases require. Post,
at 14 (opinion of Thomas, J.); see also Part III–A, infra
, (describing equitable apportionment doctrine). As we shall explain, the dissent’s assertion that “the balance of harms cannot tip in Florida’s favor” is, at best, premature. Post,
at 34–35. That judgment may eventually prove right or it may prove wrong. Here, as we just said, we consider only the “single” and “threshold” question of “redressability” upon which the Master rested his conclusion and which the parties have now argued here. In determining precisely what we now review, we rely upon (and do not go beyond) the Report’s specific and key statements, which include the following:
“As a threshold matter
, equitable apportionment is only available to a state that has suffered ‘real and substantial injury’ as a result of proposed or actual upstream water use” and “the injury must be redressable by the Court
.” Report 24 (emphasis added).
“Florida points to real harm and, at the very least, likely misuse of resources by Georgia. There is little question that Florida has suffered harm from decreased flows in the [Apalachicola] River,” including “an unprecedented collapse of its oyster fisheries in 2012.” Id.,
“Much more could be said and would need to be said on these [and other] issues . . . .” Id.
, at 34.
“I need only address the narrow question
of which party bears the burden of proving injury and redressability
, at 28–29 (emphasis added).
“Florida bears the burden to prove that the proposed remedy will provide redress for Florida’s injury.” Id.
, at 30.
“Florida has not proven by clear and convincing evidence that any additional streamflow
in the Flint River or in the Chattahoochee River would be released from Jim Woodruff Dam into the Apalachicola River at a time that would provide a material benefit to Florida (i.e
., during dry periods)
, thereby alleviating Florida’s injury.” Id.
, at 47 (emphasis added).
“Florida has provided no evidence that a decree in this case could provide an effective remedy during normal (i.e.
, non-drought) periods.” Id.,
“[T]he Corps can likely
offset increased streamflow in the Flint River by storing additional water in its reservoirs along the Chattahoochee River during dry periods [and so] . . . [t]here is no guarantee
that the Corps will exercise its discretion to release or hold back water at any particular time.” Id
., at 69 (emphasis added).
“[W]ithout the Corps as a party, the Court cannot order the Corps to take any particular action.” Id
., at 69–70.
Florida has filed exceptions to the Special Master’s Report. Florida first challenges the legal standard the Master applied in resolving what the Master called the “threshold” question whether Florida had “proven. . . that its injury can be redressed by an order equitably apportioning the waters of the Basin.” Id.,
at 24, 3. The Master wrote that Florida must meet a “clear and convincing evidence” evidentiary burden. Id.
, at 3. Second, Florida argues that, in any event, its showing in respect to redressability was sufficient. We consider each of these exceptions in turn.
We note at the outset that our role in resolving disputes between sovereign States under our original jurisdiction “significantly differs from the one the Court undertakes ‘in suits between private parties.” Kansas
, 574 U. S., at ___ (slip op., at 6) (internal quotation marks and alterations omitted). “In this singular sphere,” we have observed, “ ‘the court may regulate and mould the process it uses in such a manner as in its judgment will best promote the purposes of justice.’ ” Id.
, at ___ (slip op., at 6–7) (quoting Kentucky
, 24 How. 66, 98 (1861)). We must approach interstate disputes “in the untechnical spirit proper for dealing with a quasi-international controversy, remembering that there is no municipal code governing the matter, and that this court may be called on to adjust differences that cannot be dealt with by Congress or disposed of by the legislature of either State alone.” Virginia
v. West Virginia
220 U.S. 1
, 27 (1911) (Holmes, J.).
Where, as here, the Court is asked to resolve an interstate water dispute raising questions beyond the interpretation of specific language of an interstate compact, the doctrine of equitable apportionment governs our inquiry. See Colorado
v. New Mexico
459 U.S. 176
, 183 (1982) (Colorado I
540 U.S. 56, 74, n. 9 (2003) (“Federal common law governs interstate bodies of water, ensuring that the water is equitably apportioned between the States and that neither State harms the other’s interest in the river”). In this realm, we have kept in mind several related but more specific sets of principles.
, as the Special Master pointed out, “the relevant guiding principle in this case” is a simple one. Report 26–27. Given the laws of the States, both Georgia and Florida possess “ ‘an equal right to make a reasonable use
of the waters of the stream’ ”—which, in this case, is the Flint River. Id.,
at 26 (quoting United States
v. Willow River Power Co
324 U.S. 499
, 505 (1945)); see also Colorado I supra
, at 184 (“Our prior cases clearly establish that equitable apportionment will only protect those rights to water that are ‘reasonably required and applied.’ . . . [W]asteful or inefficient uses will not be protected (quoting Wyoming
259 U.S. 419
, 484 (1922))); Idaho ex rel. Evans
462 U.S. 1017
, 1025 (1983) (Idaho II
) (“States have an affirmative duty under the doctrine of equitable apportionment to take reasonable steps to conserve and even to augment the natural resources within their borders for the benefit of other States”); Nebraska
325 U.S. 589
, 618 (1945); Kansas II
, 320 U. S., at 394; Washington
297 U.S. 517
, 522, 527–528 (1936); New Jersey
v. New York
283 U.S. 336
, 342–343 (1931); North Dakota
263 U.S. 365
, 372 (1923) (reaffirming that an upstream State may not “burden his lower neighbor with more than is reasonable”); Kansas
206 U.S. 46
, 102 (1907) (Kansas I
, 24 F. Cas. 472, 474 (No. 14,312) (CC RI 1827) (Story, J.) (setting forth the principle of “reasonable use”).
, our prior decisions emphasize that, when we are confronted with competing claims to interstate water, the Court’s “effort always is to secure an equitable apportionment without quibbling over formulas.” New Jersey
v. New York
, 283 U. S., at 342–343 (Holmes, J.). Where “[b]oth States have real and substantial interests in the River,” those interests “must be reconciled as best they may be.” Id.
, at 342–343. We have added that “[u]ncertainties about the future . . . do not provide a basis for declining to fashion a decree.” Idaho II
, 462 U. S., at 1026; see also ibid.
(“Reliance on reasonable predictions of future conditions is necessary”); Colorado
v. New Mexico
467 U.S. 310
, 322 (1984) (Colorado II
) (requiring “
absolute precision in forecasts . . . would be unrealistic”); North Dakota
at 386 (emphasizing the need to “draw inferences as to the probabilities”); Kansas I, supra
, at 97–98.
, in light of the sovereign status and “equal dignity” of States, a complaining State must bear a burden that is “much greater” than the burden ordinarily shouldered by a private party seeking an injunction. Connecticut
282 U.S. 660
, 669 (1931); see Kansas II
at 392 (“The reason for judicial caution in adjudicating the relative rights of States in such cases is that, while we have jurisdiction of such disputes, they involve the interests of quasi-sovereigns, present complicated and delicate questions, and, due to the possibility of future change of conditions, necessitate expert administration rather than judicial imposition of a hard and fast rule” (footnote omitted)). In particular, “ ‘[b]efore this court can be moved to exercise its extraordinary power under the Constitution to control the conduct of one State at the suit of another,’ ” the complaining State must demonstrate that it has suffered a “ ‘threatened invasion of rights’ ” that is “ ‘of serious magnitude.’ ” Washington
, at 524 (quoting New York
v. New Jerse
256 U.S. 296
, 309 (1921)). The State must make that showing by “ ‘clear and convincing evidence.’ ” Washington
at 522 (quoting New York
v. New Jersey
see also Idaho II
at 1027 (“A State seeking equitable apportionment under our original jurisdiction must prove by clear and convincing evidence some real and substantial injury or damage”); Colorado I
at 187–188, n. 13 (“[A] state seeking to prevent or enjoin [an upstream] diversion by another State” must “bear the initial burden
of showing that a diversion by [the upstream State] will cause substantial injury to [the downstream State’s] interests” (emphasis added)).
In addition, to the extent the Court has addressed the “initial burden” a State bears in respect to redressability, our prior decisions make clear that, as a general matter, “[t]o constitute a justiciable controversy, it must appear that the complaining State has suffered a wrong through the action of the other State, furnishing a ground for judicial redress, or is asserting a right against the other State which is susceptible of judicial enforcement according to the accepted principles of the common law or equity systems of jurisprudence.” Massachusetts
308 U.S. 1
, 15 (1939)); see also Wyoming
502 U.S. 437
, 447, 452 (1992) (same); Maryland
451 U.S. 725
, 735–736 (1981). More specifically, we have said that “it should be clear that [the complaining] State has not merely some technical right, but also a right with a corresponding benefit” as a precondition to any equitable apportionment. Kansas I, supra,
at 109. An effort to shape a decree cannot be “a vain thing.” Foster
v. Mansfield, C. & L. M. R. Co.
146 U.S. 88
, 101 (1892). A State “will not be granted [relief] against something merely feared as liable to occur at some indefinite time in the future,” Connecticut
v. Massachusetts, supra,
674, or when there is “no other or better purpose [at stake] than to vindicate a barren right.” Washington
, at 523; cf. Idaho II, supra,
at 1026 (assessing whether “the formulation of a workable decree is impossible”).
in an interstate water matter, where a complaining State meets its “initial burden of showing ‘real or substantial injury,’ ” Colorado II
at 317 (quoting Colorado I
, 459 U. S., at 188, n. 13), this Court, recalling that equitable apportionment is “ ‘flexible,’ ” not “formu- laic,” will seek to “arrive at a ‘ “just and equitable” apportionment’ of an interstate stream” by “consider[ing] ‘all relevant factors
.’ ” South Carolina
v. North Carolina
558 U.S. 256, 271 (2010) (quoting Colorado I
, 459 U. S., at 183); see also id.,
at 190 (“Whether [relief] should be permitted will turn on an examination of all factors relevant to a just apportionment”); Kansas II
, 320 U. S., at 393–394 (“[I]n determining whether one State is using, or threatening to use, more than its equitable share of the benefits of a stream, all
the factors which create equities in favor of one State or the other must
be weighed”) (emphasis added). These factors include (but are not limited to):
“physical and climatic conditions, the consumptive use of water in the several sections of the river, the character and rate of return flows, the extent of established uses, the availability of storage water, the practical effect of wasteful uses on downstream areas, [and] the damage to upstream areas as compared to the benefits to downstream areas if a limitation is imposed on the former.” Nebraska
325 U. S., at 618.
Because “all the factors
which create equities in favor of one State or the other must
be weighed,” Kansas II, supra
, at 394 (emphasis added), extensive and “specific
factual findings” are essential for the Court to properly apply the doctrine of equitable apportionment. Colorado I
, at 189–190 (emphasis added). And given the complexity of many water-division cases, the need to secure equitable solutions, the need to respect the sovereign status of the States, and the importance of finding flexible solutions to multi-factor problems, we typically appoint a Special Master and benefit from detailed factual findings.
Without the full range of factual findings, we have said, the Court may lack an adequate basis on which to make “the delicate adjustment of interests” that the law requires. Nebraska
v. Wyoming, supra,
at 618; Washington
, 297 U. S., at 519, 523–524 (emphasizing that “the Master’s Report finds the facts fully”);
see also Colorado I
, at 183, 189–190 (remanding “with instructions to the Special Master to make further findings of fact”); Colorado II
, 467 U. S., at 312–315 (explaining that because “the Master’s report [was] unclear,” the Court remanded to the Special Master “for additional factual findings on five specific issues” even after “a lengthy trial at which both States presented extensive evidence” in order “to assist this Court in balancing the benefit and harm”); Texas
v. New Mexico
462 U.S. 554
, 575–576, and n. 21 (1983) (“[W]e return this case to the Special Master for determination of the unresolved issues framed in his pretrial order”); 3 A. Kelley, Water and Water Rights §45.02(c), p. 45–14 (3d ed. 2018) (“If the factual findings in the report are insufficient for the Court to decide whether the master correctly applied the doctrine of equitable apportionment, the Court may refer the case back to the master for additional findings”).
Applying the principles just described, we conclude that the Special Master applied too strict a standard when he determined that the Court would not be able to fashion an appropriate equitable decree. See Report 3 (“Florida has not proven by clear and convincing evidence that its injury can be redressed by an order equitably apportioning the waters of the Basin”); see also id.,
at 31 (“The evidence does not provide sufficient certainty that an effective remedy is available without the presence of the Corps as a party in this case”).
The Special Master referred to the relevant showing that Florida must make in this respect as a “threshold” showing. Report 24. We agree that the matter is “threshold” in one particular sense—namely, the sense that the Master has not yet determined several key remedy-related matters, including the approximate amount of water that must flow into the Apalachicola River in order for Florida to receive a significant benefit from a cap on Georgia’s use of Flint River waters. See infra
, at 28. The Master also wrote that Florida had failed to show “with sufficient certainty that the Corps must (or will choose to) operate its projects so as to permit all
additional flows in the Flint River” or “the entire marginal increase
in streamflow” to reach Florida “without any substantial delay.” Id.,
at 48 (emphasis added); see also id.,
at 24, 70 (similar). He added that there “is no guarantee
” that the Corps will exercise its relevant discretion. Id.,
at 69 (emphasis added). And he said that Florida must show the existence of a workable remedy by “clear and convincing evidence.” Id.,
at 3; see also, e.g., id.,
at 28–29, 47, 51, 69–70.
We believe the Master’s standard, as indicated by these statements, is too strict. In our view, unless and until the Special Master makes the findings of fact necessary to determine the nature and scope of likely harm caused by the absence of water and the amount of additional water necessary to ameliorate that harm significantly, the complaining State should not have to prove with specificity the details of an eventually workable decree by “clear and convincing” evidence. Rather, the complaining State should have to show that, applying the principles of “flexibility” and “approximation” we discussed above, it is likely to prove possible to fashion such a decree. See supra,
To require more definite proof at the outset may well (at least on some occasions) make little sense. Suppose, for example, downstream State A claims that upstream State B wastes at least 10,000 cubic feet per second (cfs) of water. And suppose further that no decree could enforce a 10,000 cfs consumption cap but that it may well prove possible to enforce a lesser requirement. If so, we would have to know at least approximately how much water will significantly ameliorate State A’s water problem before
we could know whether it is possible to shape a workable decree. And the workability of decrees themselves, approximate as they may be, may depend upon more precise findings in respect to the nature and scope of the range of likely harms and likely benefits that a Special Master finds are actually likely to exist. To require “clear and convincing evidence” about the workability of a decree before the Court or a Special Master has a view about likely harms and likely amelioration is, at least in this case, to put the cart before the horse. And that, we fear, is what the Master’s statements, with their apparent references to a “clear and convincing” evidence standard in respect to “redressability” (where that refers to the availability of an eventual decree) have done here. Cf. post
That is also why our cases, while referring to the use of a “clear and convincing” evidentiary standard in respect to an initial showing of “invasion of rights” and “substantial injury,” have never referred to that standard in respect to a showing of “remedy” or “redressability.” See Nebraska
515 U.S. 1
, 8 (1995) (repeating that as a threshold matter, a “ ‘threatened invasion of rights must be of a serious magnitude and it must be established by clear and convincing evidence’ ” without addressing the required initial burden in respect to remedy (quoting New York
v. New Jersey
, 256 U. S., at 309)); Colorado II
, at 317 (describing the “initial burden” a State bears to show “ ‘real or substantial injury’ ” (quoting Colorado I
, 459 U. S., at 187–188, n. 13)); Idaho II
, 462 U. S., at 1027; Colorado I
at 187–188, and n. 13 (“[A] State seeking to prevent or enjoin [an upstream] diversion by another State” must “bear the initial burden
of showing that a diversion by [the upstream State] will cause substantial injury to [the downstream State’s] interests” (emphasis added)); Washington
, 297 U. S., at 522; Connecticut
282 U. S., at 672; New Jersey
v. New York,
283 U. S., at 344–345; Kansas II,
320 U. S., at 393–394. The dissent does not dispute this. See post
, at 12.
As discussed, supra,
at 12–13, our prior decisions have said that the “right” a complaining State asserts must be more than “merely some technical right” and must be “a right with a corresponding benefit
,” Kansas I
, 206 U. S., at 109 (emphasis added)—an effort to shape an equitable apportionment decree cannot be “a vain thing.” Foster
, 146 U. S., at 101; see also Idaho II, supra,
at 1026 (assessing whether “the formulation of a workable decree is impossible”); Washington
at 523. But these statements apply to the general availability
of judicial relief—not to the details
of a final decree or to the workability of a decree that will depend on those details. Cf. Idaho ex rel. Evans
444 U.S. 380
, 392 (1980) (Idaho I
) (explaining that the question whether a State’s proposed remedy will have an “appreciable effect” is a question that “goes to the merits” of the equitable apportionment inquiry). And, of course, to insist upon the use of such a strict standard, in respect to an eventual
decree, runs directly contrary to the statements in, and holdings of, cases to which we have referred when discussing the need for “approximation” and “flexibility.” See supra,
We next address Florida’s exceptions to the Master’s evidentiary determinations. In doing so, we recognize that the record in this case is long. It addresses a number of highly technical matters on a range of subjects—from biology to hydrology to the workings of the Corps’ newly revised Master Manual governing the organization’s complex operations in the Basin. Insofar as the Special Master made findings of fact, those findings “deserve respect and a tacit presumption of correctness.” Colorado II
, 467 U. S.,
at 317. But at the end of the day, “the ultimate responsibility for deciding what are correct findings of fact remains with us.” Ibid.
We have therefore read those portions of the record to which the parties, amici
, or the Master refer, along with several other portions that we have found potentially relevant. Our “independent examination of the record,” Kansas
322 U.S. 213
(1944), leads us to conclude that, at this stage, Florida has met its “initial burden” in respect to remedy. But, we also believe that a remand is necessary to conduct the equitable-balancing inquiry. Cf. Colorado I
, at 183–190.
We reserve judgment as to the ultimate disposition of this case, addressing here only the narrow “threshold” question the Master addressed below—namely, whether Florida has shown that its “injur[ies can] effectively be redressed by limiting Georgia’s consumptive use of water from the Basin without a decree binding the Corps.” Report 30–31. This dispositive threshold question leads us, in turn, to focus upon five subsidiary questions:
, has Florida suffered harm as a result of decreased water flow into the Apalachicola River? (The Special Master assumed “yes.”)
, has Florida shown that Georgia, contrary to equitable principles, has taken too much water from the Flint River (the eastern branch of the Y-shaped river system)? (Again, the Special Master assumed “yes.”)
, if so, has Georgia’s inequitable use of Basin waters injured Florida? (The Special Master assumed “yes.”)
if so, would an equity-based cap on Georgia’s use of the Flint River lead to a significant increase in streamflow from the Flint River into Florida’s Apalachicola River (the stem of the Y)? (This is the basic question before us.)
, if so, would the amount of extra water that reaches the Apalachicola River significantly redress the economic and ecological harm that Florida has suffered? (This question is mostly for remand.)
As our parentheticals suggest, the Special Master assumed that the answer to the first three questions was “yes.” The fourth question is the question before us now. And the fifth question is partly for us now and partly for the Master to answer on remand.
The Report indicates that the Special Master assumed the answer to the first question is “yes.” The Report says that the Special Master reached his conclusion on the “single, discrete issue that resolves this case” by “assuming
that Florida has sustained injury.” Id.,
at 30 (emphasis added); see also id.,
at 2 (repeating Georgia’s argument that “without an order binding the Corps, Florida will not be assured any relief—assuming it has suffered any injury at all
—by a decree entered in this proceeding because the Corps has the ability to impound water in various reservoirs that it maintains in the Basin” (emphasis added)); id.,
at 65 (“Even if there were evidence of harm from other than low-flow conditions . . . ”).
At the same time, the Report states that “Florida points to real harm.” Id.,
at 31. And the Master specified that there is “little question that Florida has suffered harm from decreased flows
in the [Apalachicola] River.” Id.
, at 31 (emphasis added). That harm—caused (at least in part) by increased salinity—includes “an unprecedented collapse of [Florida’s] oyster fisheries in 2012.” Ibid.
at 32 (stating that “the evidence presented tends to show that increased salinity . . . led to the collapse” of Apalachicola Bay’s oysters and “greatly harmed the oystermen of the Apalachicola Region, threatening their longterm sustainability”). Cf. New Jersey
v. New York
, 283 U. S., at 343, 345 (finding redressable harm to oysters caused by diminished water flow and increased salinity). The harms of reduced streamflow may extend to other species in the Apalachicola Region, including in the river and its floodplain, which, as the Master noted, “is home to the highest species density of amphibians and reptiles in all of North America, and supports hundreds of endangered or threatened animal and plant species,” including three “endangered” or “threatened” mussel species, the “[t]hreatened Gulf sturgeon,” and the largest stand of Tupelo trees—of Tupelo Honey fame—in the world. Report 7–8; see also Joint Exh. 168, at 193, 195–196.
The Master also appears to have assumed the answer to the second question is “yes.” The Report reached its key conclusion that Florida’s (assumed) injuries cannot “effectively be redressed” by “assuming
that Florida has sustained injury as a result of unreasonable upstream water use by Georgia
.” Report 30 (emphasis added). But, at the same time, the Master acknowledged that “Florida points to real harm and,
at the very least, likely
misuse of resources by Georgia.
, at 31 (emphasis added). And the Report “provide[s] the Court a brief descriptive background regarding . . . the unreasonableness of Georgia’s consumptive water use.” Ibid.
; see, e.g., id.,
at 32 (“Georgia’s upstream agricultural water use has been—and continues to be—largely unrestrained”); id.,
at 33 (“Despite early warnings of oncoming drought, Georgi[a] . . . chose not to declare a drought in 2011—apparently hoping for the best, and clearly not wishing to incur the cost of preventative action”); id
., at 34 (“Georgia’s position—practically, politically, and legally—can be summarized as follows: Georgia’s agricultural water use should be subject to no limitations, regardless of the long-term consequences for the Basin”).
In respect to the third question, the Master again assumed the answer “yes.” In particular, the Report “assume[s]” that “Florida has sustained injury as a result of
unreasonable upstream water use by Georgia.” Id.
, at 30 (emphasis added). And as relevant to each of the first three questions, the Master added that “[m]uch more could be said and would need to be said about” Florida’s injuries, the reasonableness of Georgia’s water consumption, and “other issues, such as causation,” if the case proceeds. Id.,
at 34. As we have explained, our prior equitable apportionment decisions make clear that “all factors
which create equities in favor of one State or the other must be weighed
.” Kansas II
, 320 U. S., at 393–394 (emphasis added). Thus, a remand is necessary to consider each of the relevant factors, including those upon which the dissent focuses. See infra
, at 27; Nebraska
325 U. S., at 618; cf. Colorado II
, 467 U. S., at 323–324.
We now turn to the fourth question, the basic question before us. Would an equity-based cap on Georgia’s use of the Flint River lead to a significant increase in streamflow from the Flint River into Florida’s Apalachicola River (the stem of the Y)? The answer depends upon (1) the amount of extra water that would flow into Lake Seminole
as a result of a cap on Georgia’s Flint River water consumption; and (2) the amount of water that could actually flow through the Corps-controlled Woodruff Dam at Lake Seminole’s southern end and into Florida’s Apalachicola River
The record shows that Florida’s proposed cap on Georgia’s water consumption could result in the release of considerable extra water into Lake Seminole. Florida’s expert, Dr. David Sunding, testified that the cap would limit the average amount of water that Georgia could use annually and also reduce the amount of water that Georgia could use during drought years, which could “materially reduce [Georgia’s] depletions of river flows . . . by 1,500 to over 2,000 cubic feet per second (cfs) in peak summer months of drought years.” Updated Pre-Filed Direct Testimony (PFDT) of Sunding ¶8; see also id.
, ¶¶88–90. Dr. Sunding added that it would cost Georgia roughly $35 million annually (less than 0.2% of Georgia’s annual bud- get) to reduce streamflow depletions by 2,000 cfs. Id
., ¶113, Table 4. Georgia’s expert, Dr. Robert Stavins, disputed these conclusions. See Direct Testimony of Stavins ¶¶4, 90, 136; see also Brief for Georgia 18. The Master did not make specific findings of fact regarding this aspect of Florida’s proposed remedy. Rather than expressly making any findings, the Master apparently “accept[ed] Florida’s estimates of the increased streamflow that would result from a consumption cap.” Report 67, n. 43. At this stage, we shall do the same.
And as we shall later discuss, the record suggests that an increase in streamflow of 1,500 to 2,000 cfs is reason- ably likely to benefit Florida significantly. See infra,
at 39–40 (citing record evidence of benefits); see also Updated PFDT of J. David Allan ¶¶3d, 26, 67 (Allan) (discussing ecological benefits of increasing streamflow by 300 to 500 cfs); 10 Tr. 2629:7–15 (Kondolf) (detailing benefits of increasing streamflow into the Apalachicola River from 5,000 to 7,000 cfs); 3 id
., at 591:6–593:4, 596:17–598:1 (Allan).
The key question, however, is whether the 1,500 to 2,000 cfs of extra water that will flow into Lake Seminole from the Flint River as a result of a cap on Georgia’s water consumption will flow beyond Lake Seminole, through the Woodruff Dam, and into the Apalachicola River at the relevant times. That is where the Army Corps of Engineers enters the picture. And it is where Florida disagrees with the Special Master and with Georgia. The Special Master and Georgia believe that—at any relevant time—the Corps might “offset” any extra Flint River water that flows into Lake Seminole by simultaneously reducing the amount of water that flows into that lake from the Chattahoochee River. See Report 48–53. Thus, if the 1,500 to 2,000 cfs of extra
water that would reach Lake Seminole from the Flint as a result of Florida’s proposed consumption cap, the question is whether and to what extent the Corps will “offset” that extra streamflow by releasing 1,500 to 2,000 cfs less
water into Lake Seminole from its upstream Chattahoochee reservoirs.
Of course, the Corps might, under certain circumstances, be authorized to “offset” extra streamflow from the Flint River. As the Special Master wrote, “[t]here is no guarantee that the Corps will exercise its discretion to release or hold back water at a particular time.” Id.,
at 69. But as the United States has explained, increased streamflow into Lake Seminole (that is, increased Basin Inflow) “would generally benefit the ACF system by delaying the onset of drought operations, by allowing the Corps to meet the 5000 cfs minimum flow longer during extended drought, and by quickening the resumption of normal operations after drought.” Brief for United States as Amicus Curiae
28 (Aug. 7, 2017). And our reading of the record convinces us it is highly unlikely that the Corps will always reduce the flow in this way; it leads us to believe that, acting in accordance with the its own revised Master Manual, the Corps is likely to permit, and in some cases may be required
to ensure that, material amounts of additional Flint water to flow through the Woodruff Dam and into the Apalachicola River. At the very least, we believe that more proceedings are necessary to reach a definitive determination.
As an initial matter, the Master Manual makes clear that the amount of water the Corps will release turns in part on the amount of water stored in the Corps’ Chattahoochee reservoirs. See U. S. Army Corps of Engineers, Master Manual, Apalachicola-Chattahoochee-Flint River Basin, Florida and Georgia, App. A, pp. 7–4 to 7–5, 7–7. More specifically, the amount of water storage in those reservoirs dictates whether the Corps is conducting one of two possible types of “operations”—namely, “drought operations” or “nondrought operations.” These are technical terms. See id
., at 7–14 to 7–16. The term “drought operations” need not correspond to dry periods, nor need the term “nondrought operations” refer to wet periods. Rather their applicability depends in part upon the amount of water that is stored behind the Corps’ Chattahoochee dams. As the United States explained, “[t]he term ‘drought operations’ refers to more conservative operations that [the Corps conducts, which] are intended to enable the Corps to preserve water and operate its reservoir projects more effectively as drought conditions arise.” Brief for United States as Amicus Curiae
9 (Aug. 7, 2017). We therefore must clearly distinguish what the record tells us about the amount of extra water that could flow into Florida as a result of a consumption cap during each of these two distinct types of Corps operations.
When the Corps is conducting “nondrought operations,” the Master Manual requires the Corps to release into Florida all or some of any extra water that flows from the Flint River into Lake Seminole, where it will then flow through the Woodruff Dam. See App. to Brief for United States as Amicus Curiae
2a (Aug. 7, 2017) (detailing Corps operational protocol). As the United States has explained, when the total streamflow into Lake Seminole is between 5,000 and 10,000 cfs during “nondrought operations,” the following facts are true:
“[A]ny additional basin inflow . . . would generally be passed straight through to Florida. If, for example, the conservation measures advocated by Florida as part of a consumption cap actually resulted in an increased flow in the Flint River of 2,000 cfs, see
Pre-Filed Direct Testimony of David Sunding, Ph. D. at 44, Table 4, then flows into Florida would also increase by roughly that amount.” United States Post-Trial Brief 12–13 (Dec. 15, 2016); see also Brief for United States as Amicus Curiae
18 (Aug. 7, 2017) (reaffirming that under these circumstances “flows in the Apalachicola would increase by the amount of increased Flint River flows” including during summer months).
As far as we can tell, under the Corps’ current operational protocol, the Corps may remain in “nondrought operations” even during the driest summer months of the driest years. For example, in 2007 the Corps conducted “nondrought operations” not only during late autumn, winter, and spring months, but also during the hottest summer and early autumn months “when streamflow is at its lowest.” See Direct Testimony of Phillip Bedient ¶¶48–53 (stating that “[i]f 2007’s Basin Inflow were repeated today and Drought Operations were not triggered,” the Corps would have had 92 days of “nondrought operations,” including 19 days “during summer and fall months, when streamflow was at its lowest” on which 100% of extra water resulting from a consumption cap would reach Florida). We note that these 19 days fell during a period of severe drought in which no extra water (let alone 2,000 cfs of extra water) was flowing into Lake Seminole. And, unsurprisingly, the same trend appears to be true in dry summer months of other years: all or some of the extra water that would result from a consumption cap would also pass through to Florida. See, e.g
., Ga. Exh. 949 (reporting streamflow data indicating several days in 2009 on which extra Flint River water would have passed through to Florida); Joint Exh. 128 (providing link to U. S. Geological Survey data indicating a similar trend based on streamflow into the Apalachicola River, including in 2016 and 2017).
The Corps’ “drought operations” are different. Again, whether the Corps must initiate drought operations is not a matter of discretion; it depends, as we have said, upon the total amount of water the Corps has stored behind the dams it controls along the Chattahoochee River. The Master Manual requires that, when the total amount of water stored in pools behind the Corps’ Chattahoochee dams drops below a certain level, the Corps must reduce the amount of water it releases from the Woodruff Dam to 5,000 cfs, or, in instances of extreme low water levels in the storage pools, to 4,500 cfs. Master Manual App. A, at 7–14 to 7–16. Accordingly, if additional water were to flow into Lake Seminole from the Flint River while the Corps is in drought operations
, the Corps, pursuant to its Master Manual, must reduce the flow of its controlled upstream Chattahoochee water in order to maintain a defined water level in the pools behind its Chattahoochee dams, and no more than 4,500 cfs or 5,000 cfs can flow beyond the Woodruff Dam regardless. Brief for United States as Amicus Curiae
But even then, as we just said, the Corps must make certain that at least 4,500 cfs and more often 5,000 cfs flows though the Woodruff Dam. And, if more water flows from the Flint into Lake Seminole, and if the Corps uses that water to keep the water level high in its Chattahoochee reservoirs, then there will be fewer days in which the Corps is conducting either “drought operations” or “extreme drought operations.” Instead, there will be more “nondrought operations” days where the Corps must pass most or all additional streamflow that exceeds 5,000 cfs through the Woodruff (because there will be more days, given the added Flint water, when its upstream Chattahoochee reservoirs are sufficiently high). The United States adds that “a cap on Georgia’s consumption” could, among other things, generate increased streamflow that
“would provide a cushion during low-flow periods, so that it would be possible to maintain a flow rate of greater than
5,000 cfs for a longer period of time without any alteration of the Corps’ operations.” United States Post-Trial Brief 18–19 (Dec. 15, 2016) (emphasis added); see also Brief for United States as Amicus Curiae
18 (Aug. 7, 2017) (same).
We repeat this point with an example for purposes of clarity. Assume the following: (1) that it is August 13 and the Corps is conducting “drought operations”; (2) that as a result of a cap on Georgia’s consumption, 2,000 cfs more water flows down the Flint and into Lake Seminole; and (3) that, consistent with the Master Manual, 5,000 cfs will flow from Lake Seminole, through the Woodruff Dam, and into Florida’s Apalachicola River. On these three assumptions in all likelihood, as the dissent points out, no extra water
will flow into Florida.
But (and this “but” is key), the extra 2,000 cfs of water that flows into Lake Seminole on August 13 as a result of a cap on Georgia’s from the Flint River water consumption will allow the Corps to store more water behind its upstream Chattahoochee dams (while still complying with the Master Manual’s minimum release requirements). And that fact means that the Corps is likely to remain in “drought operations” for fewer days because whether the Corps remains in “drought operations” depends upon the water level behind the Chattahoochee dams. And the fewer days the Corps conducts “drought operations,” the more days the Corps, consistent with its Master Manual, will allow all (or some) of the 2,000 cfs extra water that would result from a consumption cap to flow through the Woodruff Dam and into Florida’s Apalachicola River. Again, record evidence makes clear that this is not a fanciful possibility. For example, Florida points to record evidence that suggests a consumption cap could have prevented the Corps from entering drought operations in 2011–2012 without departing from the terms of its Master Manual. See, e.g
., Florida Brief in Support of Exceptions 48–49, and n. 12 (citing record evidence, including Ga. Exh. 924 and Fla. Exh. 811, that the Special Master did not address suggesting that Florida’s proposed consumption cap could have helped the Corps to “avoi[d] drought operations entirely” in 2011–2012 without departing from the Master Manual’s requirements).
The upshot is that, even when the Corps conducts its operations in accordance with the Master Manual, Florida’s proposed consumption cap would likely mean more water in the Apalachicola—as much as 2,000 cfs more water when the Corps is conducting normal or “nondrought operations,” which could take place in dry periods, including the driest days of summer, and 500 cfs more on days when the Corps is conducting “drought operations.” And a cap would likely allow the Corps to conduct “nondrought operations” (i.e.
, reservoirs-sufficiently-full operations) more often as well.
We cannot agree with the dissent’s efforts to deny these conclusions. To begin with, the dissent says that our conclusion “depends on the premise that, during droughts, the natural streamflow into Florida is between ‘5,000 and 10,000 cubic feet per second.’ ” Post
, at 29. If the dissent means by “droughts” simply dry days, or summer days, then it is obviously wrong, for pursuant to the Corps’ Master Manual, the Corps must allow all or some of the 2,000 cfs extra water that would flow into Lake Seminole to continue through the Woodruff Dam into Florida during dry summer days when the Corps is not
conducting “drought operations.” This was true, as the dissent concedes, even during 19 summer days in 2007, which was among the driest years in the Basin’s history. Or, does the dissent mean by “droughts” days on which the Corps is conducting “drought operations”? If so, then we agree that on such days, the Corps will normally allow no more than 5,000 cfs to flow into Florida. But, for the reasons just stated in the last few paragraphs, Florida’s proposed consumption cap—which could result in as much as 2,000 extra cubic feet of water per second flowing from the Flint into Lake Seminole—will mean (consistent with the testimony of the very Georgia expert that the dissent so frequently quotes) that there will be significantly fewer such days.
Is there a mistake then in the “concrete example” the dissent offers to support its point? See post,
at 29–30. Invoking a hypothetical posed by Georgia’s expert, the dissent says:
“[I]f the natural flows in the Apalachicola River were 2,600 cubic feet per second, then the Corps would release 2,400 cubic feet per second from its [Chattahoochee] reservoirs . . . . And if a cap on Georgia[ ’s Flint River consumption] increased the River’s natural flow to 4,100 cubic feet per second, the Corps would release 900 cubic feet per second. . . . In either case, the total flow on the Apalachicola River would remain the same: 5,000 cubic feet per second. Thus, so long as the natural flows remain significantly less than 5,000 cubic feet per second, a cap on Georgia would only decrease the amount of water that the Corps releases from storage; it would not increase the overall amount of water flowing into the Apalachicola River.” Id.,
at 29–30 (citing Bedient ¶¶45–47).
If, however, a consumption cap causes 1,500 cfs extra water (from the Flint) to flow into Lake Seminole (as we assume Florida’s proposed cap would), under the dissent’s example, the Corps will reduce
(or “offset”) the amount of water it releases from its upstream Chattahoochee dams from 2,400 cfs to 900 cfs. That is because 2,400 cfs minus 900 cfs is 1,500 cfs. What happens to that 1,500 cfs extra water?
When the Corps is in drought operations, the answer according to the Master Manual is that the Corps must store that water in its upstream Chattahoochee reservoirs. And with that 1,500 cfs extra water each day, the water levels in those reservoirs will rise (or, at a minimum, deplete less rapidly) and allow the Corps to resume “nondrought operations” more quickly. The United States repeats precisely this point—namely, when more water flows into Lake Seminole, it benefits Florida by “quickening the [Corps’] resumption of normal [i.e., “
nondrought”] operations.” Brief for United States as Amicus Curiae
28 (Aug. 7, 2017). (That extra water also means that there will be more days when 5,000 cfs, rather than 4,500 cfs, flows from Lake Seminole into the Apalachicola River). And it means, as no one denies, that on days when the Corps conducts “nondrought operations” (which, as Georgia’s own expert report shows, occur even during dry summer months), more water will reach Florida when Florida needs it.
What about the dissent’s point that Georgia’s expert, Dr. Bedient, said that the extra 2,000 cfs would mean more water for Florida “only 19 days ‘during the summer and fall months when streamflow was at its lowest’ ”? Post,
Dr. Bediant’s exact words, as the dissent points out, were that in “ ‘dry years (e.g.
, 2007 and 2011), . . . even significant changes in Georgia’s consumptive use would lead to virtually no change in state-line flows during the low-flow months (e.g.
, June, July, August, September).’ ” Bedient ¶¶48–53.
At this point, in our view, the dissent has pointed to record evidence with which other record evidence conflicts. It seems from record evidence, from the statements of the United States, from geological data, and from laws of mechanics, that 2,000 cfs extra water flowing into Lake Seminole when, in the dissent’s words, “drought operations were not in effect” would have to mean more water in Florida. Post
, at 30. And the dissent does not dispute that some of these days are in the summer. Ibid
Our own check of the record reinforces the point. In particular, data from the U. S. Geological Survey’s website, which the parties entered into the record at Joint Exh. 128, indicates that between May 2016 and August 2016, streamflow into the Apalachicola River was above 6,000 cfs each day with the exception of two days: August 30, 2016 and August 31, 2016. Nothing in the record suggests that the Corps was in drought operations during these days, and so it appears that under these conditions, any additional streamflow resulting from a cap on Georgia’s Flint River consumption would pass through into Florida. However, without explicit findings, it is neither possible nor prudent for us in the first instance to read through this voluminous record and discover who is right on this matter of how much extra water there will be, when, and how much Florida would benefit from the extra water that there might be. That is why we are sending this case back for more findings.
Finally, while the dissent suggests that “[i]t is incredibly odd to conclude that a Special Master’s merits determination is ‘premature’ after a full trial,” post
, at 17, this Court has repeatedly concluded that remand is “appropriate” to resolve certain issues in an equitable apportionment case even where, as here, there has already been a “lengthy trial at which both States presented extensive evidence.” Colorado II,
467 U. S., at 313; see also Wyoming
, 259 U. S., at 456–457 (explaining that “the evidence was taken” over the course of two years and presented to the Court two years later and that “[t]he case has been argued at bar three times” including because of the “importance of some of the questions involved”). Moreover, we note that adequate factfinding is especially important where, as here, no interstate compact guides our inquiry or sets forth a congressionally ratified water allocation formula. When such a compact exists, as it often does, our effort is relatively simple and focuses upon “declar[ing] rights under the Compact and enforc[ing] its terms.” Kansas
, 574 U. S., at ___ (slip op., at 8) (citing Texas
v. New Mexico
, 462 U. S., at 567); id
., at 567–568 (“If there is a compact, it is a law of the United States, and our first and last order of business is interpreting the compact”). Here, no compact guides our inquiry and it would appear to be important that we approach this complex controversy with the care and thoroughness that our precedent requires.
Our final question is this: Would the amount of extra water that reaches the Apalachicola significantly redress the economic and ecological harm that Florida has suffered? There is evidence indicating that the answer to the question is in the affirmative. See, e.g.,
Allan ¶3d, 26, 67 (“Even relatively modest increases in flows—on the order of 300 to 500 cfs during key periods of the year—could reduce harm to the [Apalachicola Region’s] ecosystem and halt the cycle that is leading to irreversible harm” while “[g]reater increases could make even more dramatic improvements”); Updated PFDT of Patricia Glibert ¶¶5, 28–32, 58–60, and Table 1, Figs. 10, 19b; supra
, at 21–22 (citing record evidence of benefits); see also 10 Tr. 2629:7–15 (Kondolf) (detailing benefits of increasing streamflow from 5,000 to 7,000 cfs); 3 id
., at 591:6–593:4, 596:17–598:1 (Allan). But the Master’s Report does not explicitly answer this question. We consequently must remand the case to find the answer to this question (and others).
* * *
In sum, in respect to the evidentiary questions at issue, the Master assumed that: (1) Florida has likely suffered harm as a result of decreased water flow into the Apalachicola River; (2) Florida has made some showing that Georgia, contrary to equitable principles, has taken too much water from the Flint River; and (3) Georgia’s inequitable use of the water may have injured Florida, but more findings are needed. And in light of the Master’s assumptions, we conclude that: (4) an equity-based cap on Georgia’s use of the Flint River would likely lead to a material increase in streamflow from the Flint River into Florida’s Apalachicola River; and (5) the amount of extra water that reaches the Apalachicola may significantly redress the economic and ecological harm that Florida has suffered. Further findings, however, are needed on all of these evidentiary issues on remand.
We add the following: The United States has made clear that the Corps will work to accommodate any determinations or obligations the Court sets forth if a final decree equitably apportioning the Basin’s waters proves justified in this case. It states in its brief here that if a decree results “in more water flowing to Florida . . . under existing Corps protocols, then the Corps would likely not need to change its operations.” Brief for United States as Amicus Curiae
28 (Aug. 7, 2017). It has added that, in any event, a decree “would necessarily form part of the constellation of laws to be considered by the Corps when deciding how best to operate the federal projects.” Id.,
at 32. And in issuing its revised Master Manual, the Corps stated that it would “review any final decision from the U. S. Supreme Court and consider any operational adjustments that are appropriate in light of that decision, including modifications to the then-existing [Master Manual], if applicable.” Record of Decision 18. The United States has “continually asserted its preparedness to implement, in accordance with federal law, any [agreed-upon] comprehensive water allocation formula.” Id.,
at 4; see also Joint Exh. 124, at 6–35. And, of course, the Administrative Procedure Act requires the Corps to make decisions that are reasonable, i.e
., not “arbitrary, capricious, an abuse of dis- cretion” or “in excess of [the Corps’] statutory jurisdiction.”
5 U. S. C. §706(2).
We recognize that the Corps must take account of a variety of circumstances and statutory obligations when it allocates water. New circumstances may require the Corps to revise its Master Manual or devote more water from the Chattahoochee River to other uses. But, given the considerations we have set forth, we cannot agree with the Special Master that the Corps’ “inheren[t] discretio[n]” renders effective relief impermissibly “uncertain” or that meaningful relief is otherwise precluded. Report 56, n. 38. We cannot now say that Florida has “merely some technical right” without “a corresponding benefit,” Kansas I,
206 U. S., at 109, or that an effort to shape a decree will prove “a vain thing.” Foster
, 146 U. S., at 101. Ordinarily “[u]ncertainties about the future” do not “provide a basis for declining to fashion a decree.” See Idaho II
, 462 U. S., at 1026. And in this case, the record leads us to believe that, if necessary and with the help of the United States, the Special Master, and the parties, we should be able to fashion one.
We keep in mind what our prior decisions make clear: “ ‘The difficulties of drafting and enforcing a decree’ ” do not necessarily provide a convincing “ ‘justification for us to refuse to perform the important function entrusted to us by the Constitution.’ ” Idaho I,
444 U. S., at 390, n. 7 (quoting Nebraska
, 325 U. S., at 616); see also Idaho II
, at 1027 (“Although the computation is complicated and somewhat technical, that fact does not prevent the issuance of an equitable decree”). For this reason and the others we have discussed, we agree with Florida that it has made a legally sufficient showing as to the possibility of fashioning an effective remedial decree.
We repeat, however, that Florida will be entitled to a decree only if it is shown that “the benefits of the [apportionment] substantially outweigh the harm that might result.” Colorado I
, 459 U. S., at 187. In assessing whether that showing has been made, the Master may find it necessary to address in the first instance many of the evidentiary and legal questions the answers to which we have here assumed or found plausible enough to allow us to resolve the threshold remedial question. In order to determine whether Florida can eventually prove its right to cap Georgia’s use of Flint River waters, it may find it necessary for the Special Master to make more specific factual findings and definitive recommendations regarding such questions as: To what extent does Georgia take too much water from the Flint River? To what extent has Florida sustained injuries as a result? To what extent would a cap on Georgia’s water consumption increase the amount of water that flows from the Flint River into Lake Seminole? To what extent (under the Corps’ revised Master Manual or under reasonable modifications that could be made to that Manual) would additional water resulting from a cap on Georgia’s water consumption result in additional streamflow in the Apalachicola River? To what extent would that additional streamflow into the Apalachicola River ameliorate Florida’s injuries? The Special Master may make other factual findings he believes necessary and hold hearings (or take additional evidence) as he believes necessary. Cf. Colorado I
, 459 U. S., at 190, n. 14.
Consistent with the principles that guide our inquiry in this context, answers need not be “mathematically precise or based on definite present and future conditions.” Id.,
at 1026. Approximation and reasonable estimates may prove “necessary to protect the equitable rights of a State.” Ibid.
And the answers may change over time. Cf. New Jersey
v. New York
347 U.S. 995
, 996–1005 (1954); New Jersey
v. New York
, 283 U. S., at 344–346. Flexibility and approximation are often the keys to success in our efforts to resolve water disputes between sovereign States that neither Congress “nor the legislature of either State” has been able to resolve. Virginia
v. West Virginia,
220 U. S., at 27.
We consequently do not dismiss this case. Rather, we remand the case to the Special Master for further proceedings consistent with this opinion.
It is so ordered.