After a dry spell that lasted a week, heavy rains lashed most parts of the city on Wednesday evening.
However, more rains are needed for the storage in the city’s reservoirs to swell.
Tuesday’s low pressure area over southwest Bay of Bengal is expected to result in good rains till Friday. However, it will begin to recede by Saturday, said S.R. Ramanan, director, Area Cyclone Warning Centre.
After overnight showers, there had been only a pleasant drizzle during the day on Wednesday. But as dusk fell over the city, several areas experienced heavy rains.
Within two hours, Chennai received about 30 mm of rains.
November is considered the wettest month of the year in Tamil Nadu. But since the beginning of this month, Chennai has received only 60 mm of rains, far below its average monthly share of 407 mm. Meenambakkam has received just 44 mm since November 1.
Meteorologists say the phenomenon of long, dry spells interspersed with heavy showers is a common characteristic of the northeast monsoon.
Despite a lull the past few days, the season’s rainfall in the city still stands above the average because of the heavy downpour in October.
Since October 1, Chennai has received 497.3 mm of rainfall, which is 21.7 mm more than the average rains for the season.
But, this has not reflected much in the storage at the four reservoirs that provide drinking water to Chennai.
The reservoirs have just 2,506 mcft, which is less than 25 per cent of their capacity.
Officials of the Water Resources Department said there has not been much rain in the catchment areas.
“We need spells of intense rainfall for the storage to increase. There have been days when the reservoirs have recorded up to 300 mm of rains in a single day. But this year, the highest volume at Cholavaram reservoir was just 99 mm,” said an official.
Krishna water crucialAt present, distribution to the city is managed with Krishna water supply. Officials said they expected the reservoirs to fill up, with another month-and-a-half of the northeast monsoon season left.
