(A) Constitution of India - Articles 131, 262; Inter-State Water Disputes Act, 1956 - Sections 2(c), 3, 4, 5, 6, 6A, 11 - Inter-State water disputes - Jurisdiction of the court and nature of Tribunal decisions - The jurisdiction of the court under Article 131 is subject to Article 262. Where Parliament has enacted law for the adjudication of water disputes and excluded the jurisdiction of courts, such disputes cannot be entertained under Article 131. However, a suit for the implementation of an already adjudicated award does not constitute a fresh water dispute and is not barred under Section 11 of the Act. (Paras 3, 51-54)

(B) Inter-State Water Disputes Act, 1956 - Definition of "decision" - For a scheme to be considered a "decision" under Section 5(2) of the Act, it must be one that conclusively decides the matter and is capable of being implemented on its own. A scheme that is contingent upon the subsequent agreement of the party states or the enactment of legislation by Parliament to create an administrative authority is not a "decision" and is not binding unless it is specifically notified under Section 6. (Paras 47, 48, 106)

(C) Allocation of Water - Enbloc vs Project-wise allocation - Where a Tribunal provides for mass allocation (enbloc) of water to states, such allocation does not imply project-wise restrictions. States are entitled to utilize the allocated quantity in any manner they find proper within their boundaries, provided the total usage does not exceed the specified limit and does not violate express restrictions. Project-wise assessments used by the Tribunal to determine total needs do not override the final enbloc allocation notified in the Official Gazette. (Paras 156-159)

(D) Submergence of Territory - Dispute regarding the potential submergence of one state's territory due to the executive action of another state in constructing a dam constitutes a "water dispute" under Section 2(c) of the Act. Such grievances must be addressed through a complaint to the central government for the constitution of a Tribunal under Section 3 and cannot be adjudicated under the original jurisdiction of the court under Article 131. (Paras 23, 168-169)

Facts of the case:
Two riparian states filed suits under Article 131 of the Constitution regarding the use and sharing of an inter-state river. One state sought the mandatory notification and implementation of a surplus water sharing scheme and the creation of a monitoring authority based on a Tribunal's report. The other state sought an injunction to prevent the first state from raising the height of a dam beyond a certain level, alleging that such an increase would violate the Tribunal's decision by enabling water utilization beyond the allocated share and adversely affecting downstream flows.

Findings of Court:
The court found that the surplus water sharing scheme was not a binding "decision" as it was not independently implementable without a monitoring authority. It was further held that the Tribunal's allocation of water was enbloc, meaning the state could design its projects as long as the total water used remained within the prescribed limit. Regarding the dam height, while not a direct violation of the award, the court restricted the height to 519.6m based on expert committee reports to balance the needs of all riparian states. Claims regarding the submergence of another state's territory were categorized as fresh water disputes.

Issues: 1. Whether the suit is barred by Article 262(2) of the Constitution read with Section 11 of the Inter-State Water Disputes Act. 2. Whether a proposed surplus sharing scheme, dependent on the creation of an authority, constitutes a "decision" of the Tribunal. 3. Whether the allocation of water by the Tribunal was project-wise or enbloc. 4. Whether the height of a dam can be restricted to protect the interests of other riparian states.

Ratio Decidendi: A "decision" under the Water Disputes Act must be implementable independently. Enbloc allocation provides states with flexibility in project design as long as total usage limits are respected. Disputes concerning executive actions that cause territorial submergence are statutory water disputes requiring adjudication by a specialized Tribunal rather than the court's original jurisdiction.

Result: Suit for implementation of the surplus scheme dismissed; suit for injunction on dam height partially allowed, restricting the height to 519.6m subject to statutory clearances.