Here is a 10-point primer on the water sharing dispute:
"Keeping in view the severe drinking water problem in Belgaum and parts of Dharwad, Bagalkote and the agitation over there, the state government and the legal team agreed that we should not agree for an extension of time for the tribunal. This is the demand of the people. They are already frustrated and the matter has been going on for the last 600-odd days," said irrigation minister M B Patil.
The rain-fed Mahadayi river -- about 110 kilometres long -- originates in Karnataka but the bulk of it (nearly 75 kilometres) runs through Goa. It passes briefly through Maharashtra before emptying into the Arabian Sea in Panaji.
Trouble began in the 1980s when Karnataka wanted to build a network of dams and canals under the Kalasa-Banduri Nala project to channel nearly 7.56 thousand million cubic feet of the Mahadayi's waters to the parched Dharwad, Gadag and Belagavi districts located in the northern parts of the state. Goa strongly objected, saying any such diversion would affect the coastal state's ecosystem.
In 2002, Goa requested the centre to form a tribunal under the Inter-State River Water Disputes Act, 1956 to settle the issue of water sharing. Subsequent efforts by the centre to find a way out by getting the chief ministers of the three states to engage in negotiations failed. In 2006, Goa approached the Supreme Court, seeking the constitution of a tribunal.
The Mahadayi Water Disputes Tribunal was effectively formed by the central government on August 21, 2013 and was told to give its report in three years. It has subsequently been given two extensions of one year each, and is due to give its report by August 20 this year.
Urging the central government to resolve the dispute soon, there have been several rounds of protests by farmers and pro-Kannada across Karnataka of late. A bandh called for February 4, the day Prime Minister Narendra Modi was in Bengaluru for a BJP rally, was termed unconstitutional by the high court.
In December last year, Karnataka BJP chief BS Yeddyurappa took up the issue with Goa Chief Minister Manohar Parrikar, asking him to consider Karnataka's drinking water needs. Mr Parrikar replied to Mr Yeddyurappa, saying he was open to the idea on "humanitarian grounds".
The Karnataka chief minister took offence to Mr Parrikar responding to Mr Yeddyurappa and not to him. Goa Water Resources Minister Vinod Palienkar declared that the state will not share "a drop of water" with Karnataka. He even called Mr Parrikar's gesture a "political stunt".
Later, there were protests outside the BJP office in Bengaluru by farmers who said Mr Yeddyurappa had gone back on his promise of solving the water dispute by December 2017.
On Wednesday, Mr Parrikar told reporters that the tribunal would decide on the water sharing issue, adding that all other discussions were only of "academic interest".