CHENNAI: The monsoon has arrived. Despite the fact that rain has caused flooding, Tamil Nadu is almost always short of water. This is exacerbated by the lack of a groundwater policy.
In a survey done last year, the public works department’s ground and surface water resources wing discovered groundwater is overexploited (with more than 100 percent extraction) in 435 revenue firkas (sub-divisions within taluks) across the state, according to an order passed last week.
At least 26 firkas in the Chennai district have been over-exploited, including those in the Egmore-Nungambakkam, Fort-Tondiarpet, Mambalam-Guindy, Mylapore-Triplicane, Purasawalkam-Perambur, Ambattur, Maduravoyal, and Tiruvottiyur sectors. Alandur, Sholinganallur, and Pallikaranai are the few places that are safe.
Thanjavur, the core delta region, and Salem are the most over-exploited districts. Only the fact that the number of over-exploited and critical firkas has decreased from 462 and 79 in 2017 provides some comfort. Since the last assessment, 99 firkas have improved, according to the study. Government agencies’ sustained efforts in recent years to strengthen bunds and replenish wells, restore water bodies, and inspect dams may have helped, but the state’s situation remains dangerous.
After Punjab and Haryana, experts claim TN is the third worst state for groundwater exploitation. “First and foremost, the state must capture rainfall and use it wisely. The majority of our basins are ‘closed,’ which means demand can no longer be met. With increased population and urbanisation, demand continues to rise while rainfall remains constant. Climate change has resulted in more heavy rainfall over a shorter period of time, according to B V Mudgal, director of the Anna University Centre for Water Resources, who has called for steps to conserve as much rainwater as possible.
The groundwater table in Tirupur, Namakkal, Tuticorin, and Dharmapuri districts has dropped significantly.
Due to the scarcity of ground water in rural regions, delivering household tap water is a pipe dream. K N Nehru, the minister of municipal administration and water supply, and K R Periakaruppan, the minister of rural development, recently met with Union Jal Shakti minister Gajendra Singh Shekhawat to discuss funding for drinking water projects. Rapid urbanisation has had a negative impact on the state, which is heavily reliant on neighbouring states for irrigation and drinking water.
“Everyone wants to get rid of the runoff as soon as possible.” The government has tried to remedy this by encouraging people to collect rainwater on their roofs. However, we must look further and include a Sustainable Urban Drainage System (SUDS). Rainfall and runoff are intercepted at many levels using the SUDS technique. It provides enough time and space for possible penetration and replenishment.
“In the recently laid out integrated storm water drains in Chennai, recharge shafts embedded within storm water drains is a great innovation. However, in order to increase groundwater level, quality, and prevent floods, the scale of SUDS adaptation in storm water drains must begin at the planning stage. “Building standards should be enforced to guarantee that there are undeveloped areas in every project to permit water infiltration into the earth,” says Balaji Narasimhan, an environmental and water resources engineering professor at IIT Madras. In the Union Jal Shakti ministry, Narasimhan was involved in the establishment of a water resources information system.
Groundwater extraction in Chennai and 304 villages in Kancheepuram and Tiruvallur is currently regulated under the Chennai Metropolitan Area Ground Water (Regulation) Act. “The government is drafting a groundwater bill, which will be tabled in the legislature soon.” There is no mechanism in place to monitor irrigated extraction, which accounts for 70% of overall extraction. “There is a plan to cap the power of irrigation motors or limit the hours of extraction,” a senior government official stated.
The proposed law is expected to establish a statutory water regulatory authority, led by the chief secretary and comprised of officials from government institutions such as the TWAD Board and Metrowater. It will levy penalties for noncompliance and impose groundwater use limitations.