“Despite raining in the city for two days, there was no sufficient rain in the catchment areas of the lakes. Due to this, the city lakes could not leverage from the unexpected rains,” a Metrowater official said.

On Wednesday, Chennai saw significant rains as Nungambakkam and Meenambakkam weather stations had recorded 19.3 mm and 24.6 mm rainfall respectively. Inundation occurred in the southern periphery of the city, where normal life was hit.

According to Chennai Metropolitan Water Supply and Sewerage Board (Metrowater) data, the four lakes ‑— Poondi, Cholavaram, Red Hills and Chembarambakkam had a combined storage of 4,543 mcft against their total storage of 11,257 mcft. Among the four lakes, Red Hills lake has the highest storage of 2,524 mcft, whereas Chembarambakkam has 1,860 mcft of water.

It may be noted that during the same period on the previous year, the four lakes had a combined storage of mere 16 mcft, sending the city helter-skelter for drinking water. The official added that the vast portion of present storage is from Krishna River water from Andhra Pradesh.

“We have received around 8 TMC of water from Krishna River so far this year. The Andhra Pradesh government has promised additional supply of 4 TMC once the southwest monsoon brim the reservoirs in the State. The neighbouring State should share 12 TMC of water every year,” the official added.

When asked the official whether the present storage would last throughout this year, the official explained that the water in the lakes would last till December.

“Also, we will receive rain from Northeast monsoon during November and December. This would help post December but that depends on the amount of rain in the catchment areas,” he said.