As the city digs deeper for water, groundwater levels have been steadily dipping.
Chennai has received 153.1 mm of rainfall against the normal of 179.8 mm so far this Southwest monsoon, since June 1.
Residents of several areas are either sinking new borewells or deepening the existing borewells to tide over the water crisis.
Open wells in some areas like Ambattur and Mylapore have dried up as residents rely more on groundwater even as Metrowater has reduced its drinking water supply for the past several months.
According to a study by Rain Centre, the water level varied between 5.3 metres and 11 metres below ground level across the city this July.
The water quality has also deteriorated and the total dissolved solids level remains at 900 ppm to 1,100 ppm in some areas such as Saligramam and Kotturpuram.
However, residents are hoping rain spells since Tuesday night would help in recharging groundwater.
On Wednesday, Nungambakkam received nearly 2 cm of rainfall till 7 p.m.
Officials of the Meteorological department said two weather systems were influencing rainfall over the State.
Cyclonic circulation
Besides an upper air cyclonic circulation over Southwest Bay of Bengal off north Tamil Nadu coast, another trough runs from Telangana to Comorin area across Rayalaseema and interior Tamil Nadu. “Scattered rainfall would continue over the State on Thursday. After a lull, there will be an increase in rainfall from August 7,” said an official.
Chennai will continue to experience thunder showers for two days.
But, the day temperature will be around 36 degree Celsius, which is one degree Celsius above normal for the month.
