Relations Between Union and States
(1) Parliament may by law provide for adjudicating disputes over the use, distribution, or control of inter-State river/river-valley waters. (2) Parliament may by law bar the Supreme Court or any other court from exercising jurisdiction over such a dispute.
River water disputes between states are treated as a special category requiring their own dedicated resolution mechanism (river water tribunals, set up under laws like the Inter-State River Water Disputes Act) rather than ordinary litigation - and notably, Parliament can even completely exclude regular courts (including the Supreme Court) from these specific disputes.
This is the constitutional basis for the various Inter-State River Water Disputes Tribunals (like those addressing the Cauvery or Krishna river disputes) that have historically been set up specifically to resolve contentious water-sharing conflicts between states, outside the ordinary court system.