What is the Indus Waters Treaty? How will its abeyance affect India and Pakistan?

India on Wednesday suspended the Indus Waters Treaty of 1960, as part of a series of strict measures against Pakistan, following the Pahalgam terror attack on April 22.

“The Indus Waters Treaty of 1960 will be held in abeyance with immediate effect, until Pakistan credibly and irrevocably abjures its support for cross-border terrorism,” Foreign Secretary Vikram Misri said on Wednesday evening.

At least 26 were killed and several others were injured after gunmen opened fire at Pahalgam's Baisaran meadow.

What is the Indus Water Treaty?
The Indus Waters Treaty (IWT) was signed in Karachi on September 19, 1960, after nearly nine years of talks between India and Pakistan. The treaty includes 12 main articles and 8 annexures, labeled from A to H.

Under the terms of the treaty, India has full rights to use the water from the Eastern Rivers of the Indus system — Sutlej, Beas, and Ravi — without restrictions. On the other hand, Pakistan is entitled to the water from the Western Rivers — Indus, Jhelum, and Chenab. The Indus system of rivers comprises the main river, the Indus, along with its five left-bank tributaries: the Ravi, the Beas, the Sutlej, the Jhelum, and the Chenab. The right bank tributary, the Kabul, does not flow through India.

What is the potential impact of its abeyance?
Pradeep Kumar Saxena, who served as India's Indus Water Commissioner for over six years and has been associated with work related to the IWT, said India, as an upper riparian country, has multiple options.

Saxena added that this could be the first step towards abrogating the treaty, if the government so decides. "Although there is no explicit provision in the treaty for its abrogation, Article 62 of the Vienna Convention on Law of the Treaties provides sufficient room under which the treaty can be repudiated in view of the fundamental change of circumstances which has occurred with regard to those existing at the time of conclusion of the treaty," he said.

Last year, India sent a formal notice to Pakistan, seeking the "review and modification" of the treaty.

Listing out the steps India could take, Saxena said in the absence of the treaty, India is under no obligation to follow the restrictions on the "reservoir flushing" of the Kishanganga reservoir and other projects on western rivers in Jammu and Kashmir. The Indus Water Treaty currently prohibits it.

Flushing can help India desilt its reservoir, but then filling the entire reservoir could take days. Under the treaty, reservoir filling after flushing has to be done in August, during the peak monsoon period, but with the pact in abeyance, it could be done at any time.

Doing it during sowing season in Pakistan could be detrimental, especially since a large part of Punjab in Pakistan relies on the Indus and its tributaries for irrigation.

According to the treaty, there are design restrictions on building structures like dams on the Indus and its tributaries. In the past, Pakistan has raised objections over the designs, but in future, it will not be obligatory to take the concerns on board.

In the past, almost every project has been objected to by Pakistan.

Notable are Salal, Baglihar, Uri, Chutak, Nimoo Bazgo, Kishenganga, Pakal Dul, Miyar, Lower Kalnai and Ratle.

Following the 2019 Pulwama terror attack, the government cleared eight additional hydropower projects in Ladakh. The objections may no longer apply to the new projects.

There are also operational restrictions on how reservoirs are to be filled and operated. With the treaty in abeyance, these are no longer applicable.

Saxena said India can stop sharing flood data on the rivers. This could also prove detrimental to Pakistan, especially during the monsoon when rivers swell.

India will now have no restrictions on storage on western rivers, particularly the Jhelum, and the country can take several flood control measures to mitigate floods in the Valley, he said.

The tours of the Pakistan side to India, which are mandatory under the treaty, may now be stopped.
(With PTI inputs)