The five reservoirs, including Red Hills and Chembarambakkam, have a combined storage of 5,124 million cubic feet (mcft) against their total capacity of 11,757 mcft. File

City’s major reservoirs have less storage this November compared to previous four years

WRD expects northeast monsoon to boost resources before it winds down this year  

by · The Hindu

Water storage in reservoirs that feed drinking water to Chennai is lower this November compared to the previous four years. However, the Water Resources Department (WRD) expects the northeast monsoon to boost resources before it winds down this year.

The five reservoirs, including Red Hills and Chembarambakkam, have a combined storage of 5,124 million cubic feet (mcft) against their total capacity of 11,757 mcft. The waterbodies have a storage of nearly 43.58% as on Thursday.

According to WRD records, this is much less than the reservoirs’ storage on the same day last year. The water bodies had a storage of nearly 74.3% then. “We need to have a minimum of 8,000 mcft in reservoirs to maintain a comfortable daily water supply in the city throughout the year,” said a WRD official.  

While the reservoirs had considerable storage in 2022 and 2020 too, they were well-replenished in November 2021 with a higher storage of nearly 84.23%. Heavy inflows particularly into Poondi reservoir had significantly increased the storage in 2021.

Officials of the WRD noted that the catchment areas of the reservoirs are yet to receive adequate rain to generate floodwater to fill the waterbodies so far during this NE monsoon.

“We need at least two or three wet spells bringing 7-8 cm of rainfall spread over two or three days to bring inflow into the water bodies and stave off possibility of water crisis next year. With many weeks remaining for monsoon to end, we hope to receive sufficient inflow in waterbodies,” said an official.

The reservoirs contribute to nearly 748 million litres of water drawn daily (mld) to provide drinking water supply to Chennai. The city is now being provided nearly 1,113 mld of water drawn from multiple sources, including desalination plants.

Officials noted that Krishna water from Andhra Pradesh has been a vital source for city water supply and has added nearly 1,218 mcft of storage into reservoirs since September 23. Veeranam tank in Cuddalore district was another significant source that augmented water supply.

With Kancheepuram, Chengalpattu and Tiruvallur districts experiencing a rain deficit so far this monsoon, many tanks in districts around the city are also waiting to be replenished. Only 40 tanks among the 929 tanks in Chennai and its three neighbouring districts are full. A total of 136 tanks have touched a storage above 76% so far this month, officials said.

Citing various measures to improve storage capacity in major reservoirs, a senior official noted that the department prioritised water conservation efforts along with flood mitigation strategies to combat the cycle of floods and droughts.

Published - November 14, 2024 07:57 pm IST