Chennai reservoirs record significant boost in storage after nine days of rain

  Nine days of rainfall boosted Chennai’s drinking water reserves by 984.98 million cubic feet, taking combined storage to 5,470.66 mcft. The six reservoirs now hold 41.38 per cent of capacity, with Red Hills recording the largest increase 

Chennai: Nine days of sustained rainfall have boosted Chennai’s drinking water reserves, adding nearly one thousand million cubic feet (TMC) to the six reservoirs supplying the city as the northeast monsoon gathers strength.

Combined storage rose by 984.98 million cubic feet (mcft), from 4,485.68 mcft on October 15 to 5,470.66 mcft on October 24. The reservoirs now hold 41.38 per cent of their total capacity of 13,222 mcft, improving the city’s water availability ahead of further monsoon rainfall.

---

The additional water amounts to approximately 27.89 billion litres. This is equivalent to nearly 29 days of the current withdrawal from reservoirs, or about 23 days of Chennai’s total daily supply when other sources are included.

The Chennai Metropolitan Water Supply and Sewerage Board (CMWSSB) supplies 1,237.71 million litres a day (MLD), including 61.29 MLD for industries, bulk consumers and municipal requirements.

Reservoirs contribute 968.41 MLD, accounting for approximately 78 per cent of the overall supply. Other sources include two desalination plants at Nemmeli, which together provide 200 MLD. Quarries contribute 28 MLD, wells and borewells supply 16 MLD, sources in the added areas provide 14 MLD, and Porur contributes another five MLD.

Red Hills registered the largest increase among the six reservoirs, reinforcing its position as a major source of drinking water for Chennai. Its storage climbed by 539 mcft, from 1,876 mcft on October 15 to 2,415 mcft in the latest figures provided. The reservoir has reached 73.18 per cent of its capacity of 3,300 mcft. Its gain accounts for more than half the overall increase recorded across the six waterbodies during the period.

Chembarambakkam also recorded a substantial improvement, with storage rising from 1,319 mcft to 1,497 mcft. Veeranam’s reserves increased from 526.68 mcft to 677.56 mcft, making it another significant contributor to the improvement in combined storage.

Poondi’s storage rose from 412 mcft to 490 mcft, while Cholavaram increased from 120 mcft to 144 mcft. Kannankottai-Thervoy Kandigai recorded a smaller gain, with its reserves moving from 232 mcft to 247 mcft. The widespread gains have strengthened the reservoir network on which Chennai depends for most of its daily water requirements.

However, combined storage remains below half the total capacity, leaving considerable room for further replenishment during the northeast monsoon, even after the recent spell of persistent rain across the region.