In a letter to her Andhra counterpart Y S Rajasekhara Reddy, she said any attempt to withhold water in the river would be a 'serious breach' of the existing inter-state water agreement.

"This will also be a body blow to the farmers of Tamil Nadu, besides seriously affecting even the basic drinking water supply position in northern districts of Tamil Nadu," she said.

The people living downstream in the northern districts of the state, who are totally dependent on the river even for drinking water, apart from their livelihood, are very agitated over the new development, she said.

"It is most unfortunate that this attempt at impounding waters of the Palar is being made," she said.

Palar is an inter-state river and was also one of the rivers mentioned in Schedule A annexed to the 1892 agreement which it was in force. As per a clause of the agreement, the upstream state should not build any new dam or any structure to obstruct, divert, or store waters of the rivers without the consent of the downstream state, she said.

Andhra Pradesh had not so far approached Tamil Nadu with any proposal and had not furnished any information on the project as required, she said.

She urged Dr Reddy to stop the execution of any such plan to construct a reservoir across Palar river.