The Hindu         10.06.2013

Perils of poor water planning

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 ‘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.

As the city grows, it not only needs to find new ways to augment supply but also to take care of existing resources