The Siliguri Municipal Corporation (SMC) said the supply was hit due to the shifting of main water pipelines at Fulbari, near the city, on account of ongoing work of the Asian Highway II.
"For three days there is no drinking water. Suddenly the supply of water was cut short and the mayor never intimated the citizens. There was no press conference or any circular in the local newspapers," said Trinamool leader Nantu Pal.
He warned the siege will not be withdrawn unless water supply resumed as early as possible.
Mayor Asok Bhattacharya, of the Communist Party of India-Marxist, however clarified that people were notified of the move.
"It could happen in any city and it is unfortunate. We will resume water supply shortly," he said.
The city in north Bengal (under SMC area) sources its water supply from the Teesta canal after it is purified at the water treatment plant in Fulbari.
