As the city grows, it not only needs to find new ways to augment supply but also to take care of existing resources
Chennai is not a well-serviced city when it comes to water supply. It hardly meets the norms. Against the demand of 1,009 million litres, it manages to supply only about 766 million liters per day (mld) through the pipeline and lorries. The per capita water supply is about 114 litres per capita per day (lpcd) when it should be 135 to 150 lpcd. In slums and suburbs, the supply is even less — about 25 and 40 lpcd respectively.
The city also falls short of other service level benchmarks: 24 x7 water supply and 100 per cent water supply connection. Every summer, when the conditions deteriorate, the inadequacy is glaringly exposed. Chennai has none to blame, but its own poor planning for its water woes. Unable to meet the demands from local sources, the city first tapped into Veeranam tank, which is about 220 km away, and then it sought Krishna water from Andhra Pradesh. In another two decades, the demand will exceed 1500 mld, and without new sources, the city will face a severe crisis. To tide over this, Chennai is now looking to get 900 mld water from Cauvery River. Whether the farmers in Cauvery delta would agree to this, is another question.
There is no doubt that the city, as it grows, needs new sources to augment supply; but it has first to take care of its own resources. The bore wells in Chennai together account for about 225 mld water, and most of the houses depend on them. Mindless extraction in places such as Minjur in North Chennai has severely depleted the wells there. As the Central Ground Water Board (CGWB) report states, excessive extraction has led to the reversal of hydraulic gradient and consequent saline water intrusion.
The CGWB studies point out that wells located as far as Chitamur costal block in Kancheepuarm district are endangered. They also cautioned about the contamination of groundwater along the Buckingham Canal and the ‘adverse impact on ground water regime’ along the GST road. They insist on a ‘close monitoring’ of water extraction in places such as Besant Nagar and Thiruvanmiyur to prevent any irreversible damage to the aquifers. The Tamil Nadu Groundwater Development and Management) Act meant to protect groundwater and prevent over exploitation has hardly delivered.
The government, which initiated the successful domestic rainwater harvesting, has neither shown enthusiasm to protect public water bodies nor has carefully integrated urban development with resource protection. Building rules and master plans in Chennai have hardly related to the landscape and water potential of different zones. For instance, the alluvial area south of Tiruvanmiyur, along the coast, has been one of the important aquifer recharge areas in the city. For more than three decades, the government did not permit development on this tract. However, a few years ago, it allowed construction in the aquifer area unmindful of the impact.
Lakes in Chennai, barring Red Hills, are not protected by regulations that prevent constructions in their catchment area. This has seriously impaired the surface runoff and water collection. The vanishing of water bodies has impoverished groundwater and adversely affected bore wells. It is time to conserve and rejuvenate public water bodies.