Kansas and Colorado entered into the Arkansas River Compact (Compact) in 1949, but disagreements over the equitable distribution of the river's upper waters persisted. In 1985, Kansas charged that Colorado had violated the Compact by drilling new irrigation wells that, in Compact Art. IV-D's words, "materially depleted" the river water otherwise available "for use" by Kansas' "water users." Accepting the recommendation set forth in the First Report of the Special Master to find that Colorado had unlawfully depleted the river in violation of Art. IV-D, this Court remanded the case for remedies. Kansas v. Colorado, 514 U. S. 673, 694 (Kansas I). In proposing remedies in his Second and Third Reports, the Master said that Colorado's Compact violation had occurred between 1950 and 1994; recommended that Colorado pay Kansas damages; divided the water losses into six categories, calculating damages somewhat differently for each; and urged that Kansas be awarded prejudgment interest on damages for losses incurred from 1969 through 1994 (the judgment's date). The Court subsequently adopted these recommendations with one exception: It held that prejudgment interest would run from 1985 (not 1969). Kansas v. Colorado, 533 U. S. 1, 15-16 (Kansas III). The Master has now filed a Fourth Report setting forth his resolution of the remaining issues. Kansas takes exception to several of his recommendations.

Held:

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