ON EXCEPTIONS TO REPORT OF SPECIAL MASTER.
White, J., delivered the opinion of the Court, in which all other Members joined, except Stevens, J., who took no part in the consideration or decision of the case.
JUSTICE WHITE delivered the opinion of the Court.
This original case, which is here for the fourth time, involves the construction and enforcement of the 1949 Compact*fn1 between New Mexico and Texas dividing the water of the Pecos River between the two States. Because of the irregular flow of the Pecos River, the Compact did not specify a particular amount of water to be delivered by New Mexico to Texas each year. Instead, Article III(a) of the Compact provides that "New Mexico shall not deplete by man's activities the flow of the Pecos River at the New Mexico-Texas state line below an amount which will give to Texas a quantity of water equivalent to that available to Texas under the 1947 condition." Pecos River Compact, S. Doc. No. 109, 81st Congress, 1st Sess., Art. III(a) (1949). The parties have had different views with respect to the "1947 condition" as well as other matters that could not be resolved through the Pecos River Commission, which Article V of the Compact established to carry out its provisions and which can effectively act only by mutual agreement of the two States.*fn2 After years of relatively fruitless negotiation, Texas filed this original action in June 1974. We granted leave to file the
complaint, 421 U.S. 927 (1975), and appointed a Special Master, 423 U.S. 942 (1975), the Honorable Jean Breitenstein, now deceased, who was then a judge of the Court of Appeals for the Tenth Circuit and a recognized expert in western water law.
In 1979, the Special Master filed a report defining "the 1947 condition" and proposed a river routing study and adoption of a new inflow-outflow manual to be used in determining how much water Texas should be expected to receive over any particular period for any particular level of precipitation under the consumption conditions prevailing in New Mexico in 1947. We adopted that report in its entirety. 446 U.S. 540 (1980). When the case was next here, we decided against attempting to restructure the Commission to enable it to determine the method for allocating river water, preferring that the case continue in the litigation mode.*fn3 462 U.S. 554 (1983). On June 11, 1984, we summarily approved the Special Master's report specifying the inflow-outflow methodology to be used in calculating Texas' entitlement.*fn4 467 U.S. 1238.
Special Master Charles Meyers, Judge Breitenstein's successor, 468 U.S. 1202 (1984), then held hearings on the question whether New Mexico had fulfilled its obligation under Article III(a) of the Compact. He issued a report containing his findings and conclusion that for the years 1950-1983, New Mexico should have delivered 340,100 acre-feet more water at the state line than Texas had received over those years. The Master recommended that in addition to performing its ongoing obligation under the Compact, New Mexico be ordered to make up the accumulated shortfall by delivering
,010 acre-feet of water each year for 10 years, with a penalty in kind, i. e., "water interest," for any bad-faith failure to deliver these additional amounts.
Both sides excepted to the Master's report, and we have heard oral argument. We find no merit in and reject the exceptions filed by Texas and New Mexico with respect to the Master's calculation of the shortfall that is chargeable to New Mexico.*fn5
New Mexico also excepts to the proposed remedy for the short deliveries in past years. We find no merit in its submission that we may order only prospective relief, that is, requiring future performance of compact obligations without a remedy for past breaches. If that were the case, New Mexico's defaults could never be remedied. This was not our approach when the case was here in 1983. We then affirmed our authority to hear and decide Texas' claim and remanded the case to the Master for a determination of the shortfall. As we said then, a compact when approved by Congress becomes a law of the United States, 462 U.S., at 564, but "[a] Compact is, after all, a contract." Petty v. Tennessee-Missouri Bridge Comm'n, 359 U.S. 275, 285 (1959) (Frankfurter, J., dissenting). It remains a legal document that must be construed and applied in accordance with its terms. West Virginia ex rel. Dyer v. Sims, 341 U.S. 22, 28 (1951); 462 U.S., at 564. There is nothing in the nature of compacts generally or of this Compact in particular that counsels against rectifying a failure to perform in the past as well as ordering future performance ...