TIRUNELVELI: The ever-growing number of infiltration wells and bore wells in the district has again turned the focus on groundwater conservation, and thereby on the Thamirabarani River. With rapid urbanisation and swelling population, the water requirement, and also its exploitation is at their peak.
The rampant drilling of infiltration and bore wells to tackle this scarcity may soon sound like the death knell for the perennial Thamirabarani river. Hundreds of infiltration wells are active on the river bed and thousands of borewells are coming up in the district.
On the other hand, a large number of old wells have dried up and remain unused. They might become point sources of pollutants and hazardous substances in the future. Official sources confirmed there are 236 active infiltration wells, supplying water for just Tirunelveli district.
Further, there are lots of wells supplying water to Tenkasi, Thoothukudi, and Virudhunagar districts. Environmentalists say nearly thousands of wells, including bore wells and abandoned infiltration wells, are scattered across the river.
A Nambi, a resident of Ambasamudram who has been recording the river's flow over the years, said, "In the stretch between Ambasamudram and Pathamadai, there are over 40 infiltration wells, including many that have been left unused for more than a decade with algae covering its walls."
Speaking to TNIE, Collector V Vishnu said various steps have been taken towards the preservation and conservation of such wells. Besides, there have been many schemes implemented to store rainwater and restore the water bodies in the district with the help of MNREGA workers.
"There are 204 village panchayats in the district. We have instructed the block level officials to identify abandoned borewells. As most of the bore wells are installed in water soak pits next to check dams, we plan to recharge the borewells so that the soaking rainwater could recharge the groundwater level," he added.
Vishnu also said a water recharging map has been designed and a rainwater harvesting method would be used to channel water underground. With at least 10 abandoned borewells in a village panchayat, a total of 2,040 wells can be transformed into rainwater harvesting structures.
ATREE's Agasthyamalai Community Conservation Centre Senior Research Associate M Mathivanan said, "Too many man-made structures in the river will affect the aquatic life and also its flow of the river. Invasive plants grow in the abandoned well and affect the water ecosystem. Unused infiltration wells should be taken care of before sinking another one as piling of silt will affect the groundwater table."
Officials sources said the TWAD Department has schemes, and funds have been allocated to rejuvenate infiltration wells if it stops pumping water out. Most of the abandoned wells come under the local bodies near Oorkadu and Veeravanallur.
To date, there is no procedure or norm to remove an unused well."Demolishing one will leave debris, and pulling the entire well out would lead to quicksand deposition in the river. New technology must be introduced to safely remove the infiltration wells," he added.