The neighbouring state has responded "positively" to a letter written by Mr Vijayan to his counterpart, K. Palaniswami, seeking discussion on PAP.
"The state government recently sent a letter to the Tamil Nadu chief minister seeking discussion over the issue. And now, the neighbouring state has agreed for a discussion. This is a positive development," Mr Vijayan said.
However, he said the "violation" of agreement by Tamil Nadu on release of water under the PAP to Kerala is "continuing". But, at the same time, due to the Kerala government's repeated and effective intervention, "the state received more quantity of water during this water year than what it got in earlier times," Mr Vijayan said.
Mr Vijayan said the Central government had said at a recent meeting of the National Water Development Authority or NWDA that any final decision on linking of Pampa-Achakovil with Vypar river in Tamil Nadu would be taken only after Kerala's consent.
Mr Vijayan was replying to a notice seeking adjournment motion by the Congress-led United Democratic Front or UDF over closure of the state government's Cauvery cell, which was functioning at Kerala House in New Delhi.
Mr Vijayan said it was only related to official work deployment. "It will not affect any of the pending inter-state water dispute cases including Mullaperiyar, Cauvery water sharing, Neyyar and so on in Supreme Court cases," Mr Vijayan said.
Rejecting opposition UDF charges that the decision to close the two-decade-old cell was "mysterious" and had some "ulterior motives", the Kerala chief minister said a new committee has been formed under the chairmanship of former water resources secretary VJ Kurien with technical experts as members.
Besides this, two nodal officers in law and irrigation departments have been appointed for effective coordination to handle cases and ensure technical support. "What the government has done is to form a new mechanism to deal effectively with the inter-state water dispute cases," Mr Vijayan said.
Seeking notice for a debate on the matter, former water resources minister and Congress leader Thiruvanchoor Radhakrishnan said the closure of the water cell, which offered technical support to deal with cases of inter-state water disputes, was suspected to be under the influence of some "external force".
As the Speaker denied the opposition's demand for a discussion on the issue, the opposition members staged a walkout from the assembly. Opposition leader Ramesh Chennithala said the closure had caused concern about the future conduct of the water dispute cases.
However, he said the opposition was not against shifting any non-performing officers and staff. But the closure of the water cell, which played a key role in the inter-state water dispute cases, was not "justifiable", Mr Chennithala said.
In the letter, Mr Vijayan had asked Tamil Nadu to release water under the PAP agreement to tide over drinking water shortage in northern Palakkad district, which is facing an acute drought.