Water supply to large parts of south Calcutta, including Bhowanipore, Kalighat, Gariahat, Jadavpur, Tollygunge and Behala, will be suspended from 10am on Saturday as the Garden Reach water treatment plant will be shut down for upkeep, Calcutta Municipal Corporation officials said.

The supply will resume on Sunday morning, the officials said.

Maheshtala and Budge Budge, in South 24-Parganas, will be affected, too, as they get their daily potable water from the Garden Reach plant.

The CMC goes for one of two shutdowns of water supply every year to repair leaks or for general maintenance. This is the first time since the pandemic hit in March that the Garden Reach network will be shut down, CMC engineers said.

The Tallah network, which supplies water to the entire north Calcutta and parts of central and south Calcutta and Bidhanangar, faced a similar shutdown last month to repair a leak.

An engineer said portions of southern suburbs, especially along EM Bypass, that receive water from the Dhapa water treatment plant will not be affected.

A statement issued by the CMC mentioned that Garden Reach, Jadavpur, Tollygunge, Behala, Maheshtala and Budge Budge will not receive water from 10am on Saturday. “Parts of Bhowanipore and Kalighat will also be impacted,” said a CMC engineer.

All places in boroughs X (Tollygunge, Jadavpur, Golf Green, Jodhpur Park and Dhakuria), XI (Garia, NSC Bose Road, Ranikuthi and Bansdroni), XIV (Behala) and XV (Garden Reach) will be impacted, the statement said.

Parts of boroughs VIII (Ballygunge and Gariahat), IX (Alipore, Chetla and Kidderpore), XII (Kasba and Garfa) and XVI (Joka) will be affected, the statement said.

A senior CMC engineer said the shutdown was necessary to undertake repairs as well as maintenance work. “There are several booster pumping stations in the Garden Reach water supply network. The motors and pumps in these stations, as well as in the Garden Reach water treatment plant, work throughout the year. They need some break for maintenance. Suspension of water supply for some hours allows the maintenance work,” the engineer said.

“We will also replace the valves, which help regulate water supply, in 60-inch diameter water transmission lines. These are high diameter water pipes and called transmission main lines. In some places we will also connect two such main transmission lines during Saturday’s shutdown,” said the engineer.

Linking two lines makes the water supply network more integrated, the engineer said.