- The court says watertightness must be based on actual operational hydrological data.
- Installed capacity and expected load must be realistic and evidence-based.
- India cannot justify a higher weighting by assumptions.
ISLAMABAD: The Government of Pakistan welcomed a new ruling by the Court of Arbitration under the Indus Waters Treaty (IWT), saying it reinforces key limitations on India’s use of western rivers and strengthens Pakistan’s legal position in ongoing hydropower disputes.
“The Government of Pakistan notes with utmost satisfaction the supplementary award of the Arbitration Tribunal on maximum tightness, issued on May 15, 2026, in the IWT proceedings arising from the disputes over the design of the Ratle hydropower plant and the Kishenganga hydropower project,” according to a statement.
The award, he said, was a testament to the country’s position that the treaty imposes substantial limits on India’s water control capabilities and that these restrictions are applied at the design and planning stage of hydropower projects.
“The Award affirms Pakistan’s core position that the Treaty imposes substantial limits on India’s water control capacity in western rivers, and these limits are not formalities.
“They are applied at the planning and design stage and cannot be satisfied simply with a later guarantee of operational restraint.
“The pond for a run-of-the-river plant must be justified by the actual needs of the project, the actual expected operation, the hydrology of the site, the hydraulic conditions, the requirements of the power system, and the information and explanation required under the Treaty.”
Referring to previous proceedings, the statement said the ruling follows a decision from August 2025 and reinforces the requirement that installed capacity and projected energy demand be based on realistic operational and technical assessments.
“Building on the Tribunal’s General Issues Award of August 8, 2025, the Supplementary Award gives practical effect to the standard that installed capacity and anticipated load must be realistic, well-founded and defensible.
“The installed capacity must correspond to the actual expected operation, to the hydrological and hydraulic data and to the requirements of the Treaty.
“The planned load must correspond to the expected actual operation and projected needs of the electrical system that the plant is intended to serve.”
The statement further said the ruling addresses concerns about what it described as attempts to justify increased water storage capacity without an adequate technical basis.
“This addresses a fundamental concern of the Treaty. India cannot justify increased tightness through imagined capacity, artificial loading curves, unrealistic peak assumptions, or simple assertions of compliance with paragraph 15 release limits.
“Paragraph 15 remains an operational limitation, but is no substitute for an evidence-based justification of the water control capability sought, while any different operational pattern must be supported by specific information and underlying data produced by India.”
The government said the decision also strengthened Pakistan’s right to review the details of the project and demand full disclosure under treaty obligations.
“The Award also strengthens Pakistan’s review rights. India must provide Pakistan with sufficient information and explanations to assess compliance with the Treaty.
“If India does not do so, it fails to meet its burden of establishing that the proposed Maximum Pondage satisfies paragraph 8(c) of Annex D.”
He added that minimum environmental flow requirements should also be taken into account in hydropower design calculations where applicable.
“The Court further confirmed that any applicable minimum flow obligation must be taken into account when calculating the required weightage for firm power where such an obligation exists and is not otherwise met.
“The release requirements of paragraph 15 do not automatically satisfy that obligation.”
According to the statement, the Court’s rulings are binding and will be presented in other ongoing treaty mechanisms.
“Pakistan also takes note of the Court’s earlier decision that the awards of an Arbitral Tribunal are final and binding on the Parties and otherwise have determinative legal effects on subsequent Treaty bodies on relevant issues of Treaty interpretation.
“Pakistan will present these interpretations to the Neutral Expert process, in accordance with Treaty procedures and applicable confidentiality agreements.”
Reaffirming its broader policy stance, the government said Pakistan remains committed to the peaceful resolution of water disputes under the treaty.
“The country remains committed to the Indus Waters Treaty, its dispute resolution procedures and the peaceful resolution of water-related differences.
“Pakistan will continue to protect its rights under the IWT and will use all legal and diplomatic means to ensure that hydropower projects on western rivers are designed and operated strictly within the limits of the Treaty.”
The statement concluded that the ruling “is a strategic consolidation of Pakistan’s position in the Treaty,” emphasizing that maximum tightness must be “realistic, evidence-based, hydrologically substantiated, justified by the energy system, compatible with the Treaty and incapable of inflation through artificial assumptions.”
