The Supreme Court has ordered Punjab to finish construction of the Sutlej Yamuna Link, a canal on which work began 40 years ago to bring Ravi and Beas water to Haryana. Forty-two Congress MLAs, who account for more than a third of the entire legislative assembly, have resigned in protest over the decision.

Congress MLAs from 42 of Punjab’s 117 assembly constituencies resigned

The apex court's order has reignited a years-long dispute that has been a political flashpoint between the two states. Here's how the SYL canal controversy unfolded.

November 1, 1966

Haryana is carved out of Punjab. Leaders from the two states disagree on how to share extra water from the Ravi and Beas river system. Haryana claims 4.8 million acre feet (MAF) of water per year out of the total 7.2 MAF.

1968

The Centre decides that Ravi-Beas water will be shared among Punjab, Rajasthan and the newly-formed Haryana. The Bhakra Beas Management Board starts delivering 0.8 MAF of the surplus water to Haryana.

1976

After years of disagreement between the states, the central government intervenes, allocating 3.5 MAF of surplus Ravi-Beas waters to Haryana. All parties agree to build the Sutlej Yamuna Link canal (SYL). Haryana pays Punjab ₹1 crore to begin construction on its side. By the end of the year, Haryana starts construction on its end.

1978

Haryana pays Punjab another ₹1.5 crore for the timely construction of the canal.

June 1980

The construction of the Haryana portion is completed. The state spends ₹250 crore for the construction of the distribution network, in addition to ₹55.81 crore that the canal cost. Punjab hasn’t even started.

December 31, 1981

Prime Minister Indira Gandhi meets with the chief ministers of Punjab, Haryana and Rajasthan. Punjab is instructed to finish the construction in the next two years.

April 8, 1982

Indira Gandhi breaks ground to mark the start of construction for the canal in Punjab.

August 1982

The Akali Dal leads statewide protests against the canal.

July 24, 1985

Prime Minister Rajiv Gandhi and Akali Dal chief Sant Harchand Singh Longowal sign an agreement to bring an end to Alkali Dal agitation. As part of the “Rajiv-Longowal Accord,” they agree to complete construction of the canal by August 1986.

June 1990

Punjab completes more than 114 km of the 121-km-long portion in its territory (it would later fill portions of it with dirt and return the land to farmers). By now, the state has spent ₹750 crore on the project. Government abandons work after militants kill 35 labourers and two engineers engaged in the construction.

Incomplete portion of canal Completed portion of canal Bhakra Dam Nangal Dam Gobind Sagar Chandigarh Punjab 121 KM Haryana 91 KM Karnal

Incomplete portion of canal Completed portion of canal Bhakra Dam Nangal Dam Gobind Sagar Chandigarh Punjab 121 KM Haryana 91 KM Karnal

November 23, 1990

The central government hands over the pending work to the Border Roads Organisation. No progress has been made since.

1996

Haryana moves to the SC against Punjab, seeking resumption of canal construction.

January 15, 2002

The SC directs Punjab to complete construction.

July 12, 2004

Former Punjab Chief Minister Amarinder Singh gets the assembly to pass the Punjab Termination of Agreements Act 2004, annulling the 1981 agreement and all subsequent ones. In response, the Haryana assembly passes a resolution urging the Centre to intervene to get the canal completed. The Centre seeks the apex court’s opinion on the validity of the law through a Presidential reference.

February 29, 2016

After almost 12 years, the SC resumes the Presidential reference.

March 2016

Punjab farmers start filling the canal, following the state cabinet’s approval to return 5,376 acres of land acquired from farmers for the link. Punjab returns Haryana ₹192 crore. Supreme Court instructs Punjab to stop returning land acquired for SYL. Haryana quickly sends back the money.

November 10, 2016

The SC passes a verdict on the Presidential reference deeming the Punjab Termination of Agreements Act invalid. 42 MLAs from the Congress, in addition to Lok Sabha member Amarinder Singh, resign in protest. The Punjab state government asks President Pranab Mukherjee to disagree with the SC’s advisory. Deputy chief minister Sukhbir Badal declares that “not a single drop of water from Punjab rivers would be allowed to go out of the state.”

Navneet Sharma and Chitleen Sethi contributed to this story.