Water table in most parts of the city has witnessed a minimal dip in January this year compared to the previous month.
Chennai’s average groundwater level stood at a depth of 3.98 metre in January this year. The level had dropped by 0.05 metre in the city compared to December 2022, according to the data available with the Chennai Metropolitan Water Supply and Sewerage Board (CMWSSB).
Similarly, the groundwater level has fallen by 68 cm compared to last January when the average level in the city stood at a depth of 3.31 metres. Sources in the CMWSSB said the city may have recorded a dip in water table this month.
Chennai recorded normal rainfall during the northeast monsoon last year. But in 2021, the rainfall was 74% excess. Prolonged dry weather and relatively less rainfall last year could have caused a minimal dip in water table, officials said. The average annual rainfall in the city last year turned out to be in normal range. Chennai received more than double its yearly share of rain in 2021, they pointed out.
The dip in water level was marginal as residents’ dependence on groundwater was less. The daily water supply of about 1,000 million litres a day meant less groundwater extraction in several areas, the officials said.
According to the data, water level in five zones in north Chennai recorded a slight rise this month. Thiru Vi Ka Nagar recorded an increase in water table by nearly 2.75 metres this January. This could be because of an improved piped water supply in areas and quicker percolation of rainwater because of the sandy nature of the soil, the officials said.
Valasaravakkam zone has recorded the maximum dip in water level by 1.40 metres among the 15 zones in the past one month, indicating rise in groundwater consumption. Officials said the process was on to provide piped water connection to residents of the zone. Once the added areas are covered with water supply infrastructure, water table would improve in those localities, they assure. The water agency had initiated action against over-exploitation of groundwater through borewells based on complaints, the officials added.
