CHENNAI: Thanks to good rain since October, groundwater levels across Tamil Nadu have risen by an average of three metres, officials said. From 17.5 m in May, it has come up to 14.5 m across the State. Officials said this data was put together by collecting information from 1286 monitoring wells between May 19 and November 1.
Data released by Tamil Nadu Water Supply and Drainage Board (TWAD) on Wednesday showed that in some districts such as Salem, Tiruchy, Tiruvarur, Perambalur and Namakkal, levels have gone up by almost six metres. Vellore topped the list with a whopping 11.5 metre rise. In Perambalur, levels dipped by almost 10m this summer. Now, a healthy rise of 6.1 m was recorded.
Due to scanty or no rain in many southern districts, water was not found even at 1000 ft in many places three months ago. As northeast monsoon set in, on an average, the State received 255 mm which is close to normal rainfall rate of 272 mm, according to meteorological department. “As of November 12, only Dindigul, Madurai and Kancheepuram had deficit rain, while Tirunelveli and The Nilgiris recorded excess rain. All other districts received normal rainfall,” a TWAD official said.
Installation of more rainwater harvesting and recharge wells has also contributed to the rise, said officials. Last month at Vellore, two water bodies were revived. “Though Kancheepuram received less rain it has the highest number of 308 RWH structures put up by the board along river courses, out of which 152 are check dams. Similarly in Vellore, though only hard rock is present, recharge wells increase water percolation,” added the official.
With respect to Kancheepuram, a healthy increase of 6.3m was observed, but levels have gone down by 1.6 m in Tiruvallur.
According to data with Chennai Metro Water Board, there was an average increase of 4.84 m across the city in October. Officials said information from 40-odd observation wells will be collected again by November end. “As Metro Water has increased its supply to 630 MLD from 550 MLD, people will reduce usage of water from borewells. This in turn will stabilise groundwater levels. We expect the levels not to decrease too much,” said an official.
Rise in levels