Plastics
in Water Management
Plastics
Pipes, Tanks & Rainwater Harvesting
It
is high time, we need to wake up and make a strategy and action plan
for a perfect water management with due focus on Rainwater Harvesting.
Plastics have a decisive role to play in its success.
| "Water
is likely to become one of the limiting resources of the next
century, as well as one with multiple, often conflicting uses."
(UN Commission for Sustainable Development, Second Session, New
York, 1994). Situation of fresh water world over is so critical,
that United Nations had declared 2003 as a year of fresh water. |
 |
Water
seems abundant on this planet: three quarters of its area is covered
by water. The 1400 million km3 of water present can cover the entire
area of the earth to a depth of 3000 meters. However, around 98% of
the water is in the oceans. Only 2.7% is fresh water; of this 75%
lies frozen in the polar regions; 22.6 % is present as groundwater,
some of which lies too deep; only a small fraction is to be found
in rivers, lakes, atmosphere, soil, vegetation and exploitable underground
aquifers, and this is what constitutes the fresh water resources of
the world. We must clearly understand two fundamental points of the
hydrological cycle. The first is that water in all its forms (snow,
rain, soil moisture, glaciers, rivers, lakes, other surface water
bodies, and groundwater) constitutes a unity. The second is that there
is a finite quantity of water on earth, and this is neither added
to nor destroyed. We cannot create new water, and whatever quantity
is used up in any manner reappears though perhaps not always in a
re-usable form and hence, water for use of human being is extremely
limited. Apart from increase in the population, the processes of urbanization
and `development' are also expected to result in a vast increase in
the demand for fresh water. It is this, which leads to projections
of water scarcity, which could be severe in some parts of the world.
Any country having annual per capita water availability below 1000
cubic meter is considered as ‘Water Scarce Country’ and
28 countries all over the world now fall under this category.With
a population that is 16% of the world, India has 2.45% of the world's
land resources and 4% of its water resources. The situation in India
is not very encouraging. We have 1869 BCM of water available with
us, but only 1122 BCM is usable. Within the usable water, 690 BCM
is available to us in the form of surface water, rest being the ground
water. With rising population and depletion of water resource, per
capita availability of water will come down and projections show that
by 2050, it will be as low as 748 BCM. Time is not far when India
will be another Water Scarce Country. As per IWMI estimates, by 2025
one third of India's population will live under absolute water scarcity.
The urban water scarcity has assumed critical dimension in many of
the cities including metros. The urban water supply and sanitation
sector in the country is suffering from inadequate levels of service,
an increasing demandsupply gap, and poor sanitary conditions. According
to Central Public Health Engineering Organization (CPHEEO) estimates
that as on 31 March 2000, 88 per cent of urban population has access
to a potable water supply.
But this supply is highly erratic and unreliable. Water supply networks
are old and poorly maintained. Consequently physical losses are typically
high, ranging from 25 to over 50 per cent. Low pressures and intermittent
supplies allow back siphoning, which results in contamination of water
in the distribution network. Water is typically available for only
2-8 hours a day in most Indian cities. The situation is even worse
during summer when water is available only for a few minutes, sometimes
not at all.
A World Bank study, of the 27 Asian cities with populations of over
1,000,000, places Chennai and Delhi as worst performing metros in
terms of hours of water availability per day, while Mumbai is ranked
as second worst performer and Calcutta fourth worst (Source: Background
Paper - International Conference on New Perspectives on Water for
Urban & Rural India - 18- 19 September, 2001, New Delhi.) In most
of the cities, centralized...
....contd.
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