1. 2nd
International Conference on Emerging Trends in Engineering & Technology, April12-13, 2013
College of Engineering, Teerthanker Mahaveer University.
1
WATER CONSERVATION: A GLOBAL CONCERN
Priyank Gupta1
, Mohd. Danish1
, Javed Alam2
, Mohd. Muzammil3
Water is a basic necessity for life on the globe. It is used for many purposes in one way or other such as for drinking,
irrigation, recreation, and generation of electricity, industrial and commercial purposes etc. Its careless use has
resulted in the depletion of its good quality and also quantity. The total volume of water on Earth is about 1.4 billion
km3
. The volume of freshwater resources is around 35 million km3
. Out of these fresh water resources, about 24
million km3
is in the form of ice and permanent snow cover in mountainous regions. Around 30% of the world’s
freshwater are stored underground in the form of groundwater. This constitutes about 97% of all the freshwater that
is potentially available for human use. Freshwater lakes and rivers contain an estimated 0.3% of the world’s fresh
water. The Earth’s atmosphere contains approximately 13,000 km3
of water. The total freshwater supply for
ecosystem and humans is about 200,000 km3
of water which is less than 1% of all freshwater resources. Among
various continents, Asia has the worse position with 36% of the available fresh water reserves, with over 60% of the
world population where water is a scarce commodity. As the population is increasing at an exponential rate and
fresh water reserves are depleting so this resource need to be conserved for our future generations. This paper
presents various ways and means of water conservation adopted in various countries so far with a focus on India.
Keywords: Water Conservation, Rainwater Harvesting, Grey Water, Water Resource
1. Introduction
In most regions of Asia and the Pacific, water
availability has rapidly decreased. While Asia has the
world’s highest rate of increase of water withdrawal,
water availability per capita ranks as least in the world
4,200m3
/capita per year. In 2025, water availability per
capita in the region will be between 15 and 35 percent
less than that of 1950 [1] as shown in Fig. 1. In South
Asia, which has the lowest level of water resources per
capita, water availability per capita has already
decreased by almost 70 percent since 1950. Other sub
regions have also experienced drops in water
availability per capita, with North Asia having lost 60
percent and Southeast Asia 55 percent since 1950. It is
well-known that Iran and Afghanistan suffer chronic
water shortages. The Pacific countries also experience
water shortages despite good rainfall because of the
lack of appropriate investment and technology for water
storage. At the same time, more than half of the
population in the region lacks access to adequate
1. M.Tech. Students, Zakir Hussain College of Engineering &
Technology, Aligarh Muslim University, Aligarh, India.
Email:priyank9092@gmail.com,Email:mohd.danish999@gmail.com
2. Associate Prof., Department of Civil Engineering, Zakir
Hussain College of Engineering & Technology, Aligarh
Muslim University, Aligarh, India. E-mail:
javed_alig2000@yahoo.co.in
3. Prof. , Department of Civil Engineering, Zakir Hussain
College of Engineering & Technology, Aligarh Muslim
University, Aligarh, India. E-mail: muzammil786@rediffmail.com
sanitation systems Water scarcity impacts, food
availability, human health, livelihoods and also
economic development. It is said that the poor are the
most vulnerable to the impact of this water crisis. For a
region which is home to about 60 percent of world’s
population and about 70 percent of the world’s poor, the
conservation and environmentally-sound, use of
freshwater resources is the crucial element for socio-
economic development and poverty alleviation.
Reflecting the importance of sound water management
in the promotion of sustainable development in the
region, recent international and regional conferences
highlight freshwater issues as a priority area for
achieving sustainable development.
Ministerial
Fig.1 Decline in Water Resource Per Capita (1950-
2025)

2. 2nd
International Conference on Emerging Trends in Engineering & Technology, April12-13, 2013
College of Engineering, Teerthanker Mahaveer University.
2
Conference on Environment and Development in Asia
and the Pacific (MCED) in 2000 identified conservation
and integrated management of freshwater resources as
one of the eight priority areas for the region. The High-
level Regional Meeting for the World Summit on
Sustainable Development held in Phnom Penh in
November 2001 also paid special attention to freshwater
resource management as one of the key issues for
sustainable development in the region. The Ministerial
Declaration issued at the International Conference on
Freshwater held at Bonn in December 2001 also made a
call to the Secretary General of the UN to strengthen the
coordination and coherence of activities within the UN
system on water issues in an inclusive manner. How can
the needs of the increasing population of Asia and the
Pacific are fully met without sacrificing the
sustainability of the region’s finite and vulnerable
freshwater resource.
In the Asia-Pacific region where about 70 percent of the
world’s poor live, the needs of the poor should be
primarily reflected in water development and
management policies. The region’s water policy should
be linked closely with poverty alleviation policy.
2. Global Water Available
The total volume of water on Earth is about 1.4 billion
km3
. The volume of freshwater resources is around 35
million km3
, or about 2.5% of the total volume. Out of
these fresh water resources, about 24 million km3
or
70% is in the form of ice and permanent snow cover in
mountainous regions, the Antarctica and Arctic regions.
Around 30% of the world’s freshwater is stored
underground in the form of groundwater. This
constitutes about 97% of all the freshwater that is
potentially available for human use. Freshwater lakes
and rivers contain an estimated 105000 km3
or around
0.3% of the world’s fresh water. The Earth’s
atmosphere contains approximately 13,000 km3
of
water. The total freshwater supply for ecosystem and
humans is about 200,000 km3
of water which is less
than 1% of all freshwater resources [2].
Among various continents, Asia has 36% of the
available fresh water reserves, with over 60% of the
world population where water is a scarce commodity. In
fact compared to Asia, Africa is in a better situation,
where 13% of the population has access to 11 % of the
fresh water reserves. Australia have plenty of water with
1 % population owning 5% of the fresh water reserves,
followed by North and Central America, with 8%
population and 15% water reserves and South America
with 6% global population and 26% fresh water
reserves. Since generations, the pattern of water use in
different countries is mostly dependent on their culture,
lifestyle and industrial development, as availability of
water was not a serious concern [3].
3. WATER RESOURCES IN INDIA
India receives a fair amount of rainfall well distributed
over 5-6 months in the year. The average annual rainfall
in the country is 1170 mm with a wide range between
100 mm in desert areas of Rajasthan to 10000 mm in
Cherapunji. The total available sweet water in the
country is 4000 billion m3
per annum. Out of this, over
1047 billion m3
water is lost due to evaporation,
transpiration and runoff, reducing the available water to
1953 billion m3
and the usable water to 1123 billion m3
.
It is disturbing to note that only 18% of the rainwater is
used effectively while 48% enters the river and most of
which reaches the ocean. Out of the total usable water,
728 billion m3
is contributed from surface water and
395 billion m3
is contributed by replenish able ground
water. Against the above supply, the water consumed
during the year 2006 in India was 829 billion m3
which
is likely to increase to 1093 billion m3 in 2025 and 1047
billion m3 in 2050, as estimated by the Government of
India (2009).
Table 1. Per Capita Water Availability in India
(source: Government of India 2009)
Year
Population
(million)
Per Capita
Water
availability
(m3/year)
1951 361 5177
1955 395 4732
1991 846 2209
2001 1027 1820
2025 1394 1341
2050 1640 1140
4. Need For Water Conservation
Due to the changing scenario and various initiatives
taken by Government of India and other countries
people now came to know the importance of water and
concern about the fresh water resources. As we know
the population is increasing at an exponential rate and
fresh water reserves are depleting by the same rate so
this resource need to be conserved for our future

3. 2nd
International Conference on Emerging Trends in Engineering & Technology, April12-13, 2013
College of Engineering, Teerthanker Mahaveer University.
3
generations. As can be seen in above table, the per
capita water availability in 1951 was 5177 m3
per year
when the total population was only 361 million. In
2001, as the population increased to 1027 million, the
per capita water availability reduced drastically to 1820
m3
per year. By 2025, the per capita water availability
will further dropdown to 1341 m3
and to 1140 m3
in
2050. As the water available within the country varies
widely as a result of rainfall, ground water reserve and
proximity to river basins, most of the Indian States will
have reached the water stress condition by 2020 and
water scarcity condition by 2025. This paper is related
to various methods available for its conservation and
proper use.
5. Methods For Water Conservation
There are several methods available for water
conservation, some of which are -
5.1. Grey Water Reuse
It is water generated from bathroom sinks, showers, and
washing machines. It is not water that has come into
contact with faeces, toilet. Grey water may contain
traces of dirt, food, grease, hair, and certain household
cleaning products. While grey water may appear
“dirty,” it is a safe and can be used as source of
irrigation water in a yard (as shown in fig. 2). If released
into rivers, lakes, or estuaries, the nutrients in grey
water become pollutants, but to plants, they are valuable
fertilizer. Not only it helps in saving water and reusing
it, keeps it out of the sewer or septic system, so it helps
in reducing the chance that it will pollute local water
bodies. We can easily use grey water by connecting it
through pipe directly outside and use it to water our
plants or fruit trees. Grey water can be used directly on
vegetables as long as it doesn't touch edible parts of the
plants. In any grey water system, it is advised not to use
water which contains bleach, dye, bath salts, cleanser,
shampoo with unpronounceable ingredients, and no
products containing boron, which is toxic to plants. It is
crucial to use all biodegradable soaps whose ingredients
do not harm plants. Most of the powdered detergent,
and a few liquid detergent, is sodium based, which can
keep seeds from sprouting and destroy the structure of
clay soils so we have to choose salt-free liquid soaps.
While using these products, we have to make sure that
these products must not contain substances toxic to
humans, including parabens, stearalkonium chloride,
phenoxyethanol, polyethelene glycol (PEG), and
synthetic fragrances.
Fig. 2 Grey Water Reuse Experimental Setup
5.1.1.Basic Grey water Guidelines
There are certain guidelines to use grey water which are
different from fresh water and are as follows-
Never store grey water (more than 24 hours)
because the nutrients in it will start to break
down, creating bad odours.
Water discharge system should be designed in
such a way that grey water containing
pathogens (human faeces) should be allowed to
get soaked separately and should not be
available for drinking purpose for animals and
humans.
Do not allow pooling of grey water as it is the
breeding place for moquitoes which can lead to
several diseases.
Our grey water system should be as simple as
possible because simple systems last longer,
require less maintenance, require less energy
and cost less money.
Septic water should be discharged separately.

4. 2nd
International Conference on Emerging Trends in Engineering & Technology, April12-13, 2013
College of Engineering, Teerthanker Mahaveer University.
4
5.1.2. Types of Simple Systems
From the Washing Machine –Washing
machines are a very good source of grey water
as each washing machine has an internal pump
that automatically pumps out the water which
can be connected directly to water our plants.
From the Shower-Showers are a great source of
grey water they usually produce a lot of
relatively clean water. To have a simple,
effective shower system we require a gravity-
based system (no pump). If our yard is located
uphill from the house, then we require a
pumped system.
If the volume of grey water produced is more than we
need for irrigation, a constructed wetland can be
incorporated into your system to "ecologically dispose"
of some of the grey water. Wetlands absorb nutrients
and filter particles from grey water, enabling it to be
stored or sent through a properly designed drip
irrigation system (a sand filter and pump will also be
needed- this costs more money) [4].
5.2. Rainwater harvesting
Rainwater harvesting is an effective way to deal with
water crisis as it provides a method to store rainwater
from households, factories, schools and offices to
overcome their problems of irregular and inadequate
water supply or water supply of poor quality. This
process involves storing rainwater that falls within one’s
premises and re-using it after basic treatment. There are
certain simple instruments which are easily available to
divert the rainwater towards existing underground tanks
or terrace fitted tanks and then supplied to the taps. This
water is then treated by using certain purification
techniques and this treated rainwater is safe not just for
cleaning and washing but also for cooking and personal
consumption.
We know that water is very precious resource for the
survival of humans, animals, plants etc. A large amount
of water goes waste into gutters during monsoon season.
We can collect the rain water into the tanks and prevent
it from flowing into drains and being wasted. It is
practiced on the large scale in the metropolitan cities.
Rain water harvesting comprises of storage of water and
water recharging through the technical process. In the
long run, rainwater harvesting will replenish the India’s
rapidly depleting ground water levels, and lead to water
security and sustainability.
5.2.1. Methods of Rainwater Harvesting
Broadly there are two ways of harvesting rainwater
Surface runoff harvesting
Roof top rainwater harvesting
5.2.2.Surface Runoff Harvesting
In urban area rainwater flows away as surface runoff.
This runoff could be caught and used for recharging
aquifers by adopting appropriate methods.
5.2.3.Roof top rainwater harvesting (RTRWH)
In rooftop harvesting, the roof becomes the catchments
(as shown in fig. 3), and the rainwater is collected from
the roof of the building. It can either be stored in a tank
or diverted to artificial recharge system. This method is
less expensive and very effective and if implemented
properly helps in maintaining the ground water level of
the area.
Fig. 3 Roof top rainwater harvesting (source:
MPPCB)
5.2.4.Methods of Roof Top Rainwater Harvesting
5.2.4.1. Storage of Direct use
In this method rain water collected from the roof of the
building is diverted to a storage tank. The storage tank
has to be designed according to the water requirements,
rainfall and catchment availability. Each drainpipe
should have mesh filter at mouth and first flush device
followed by filtration system before connecting to the
storage tank. It is advisable that each tank should have
excess water over flow system. Excess water could be
diverted to recharge system. Water from storage tank
can be used for secondary purposes such as washing and
gardening etc. This is the most cost effective way of
rainwater harvesting. The main advantage of collecting
and using the rainwater during rainy season is not only
to save water from conventional sources, but also to
save energy incurred on transportation and distribution
of water at the doorstep. This also conserves

5. 2nd
International Conference on Emerging Trends in Engineering & Technology, April12-13, 2013
College of Engineering, Teerthanker Mahaveer University.
5
groundwater, if it is being extracted to meet the demand
when rains are on.
5.2.4.2. Recharging ground water aquifers
Ground water aquifers can be recharged by various
kinds of structures to ensure percolation of rainwater in
the ground instead of draining away from the surface.
Commonly used recharging methods are:
Recharging of bore wells
Recharging of dug wells
Recharge pits
Recharge Trenches
Soak ways or Recharge Shafts
Percolation Tanks
Recharging from Roads
5.2.5.Benefits of Rainwater Harvesting
Rainwater harvesting is one of the best methods
available for water conservation first of all it increases
water security as it meets the water demands during low
discharge periods especially during summer and it also
helps to meet water requirements especially in the areas
which do not have sufficient water resources. It helps in
improving the quality of the ground water and
increasing the ground water level. It reduces the loss of
top layer of the soil. If we capture the water directly we
need not to depend much on the water storage dams. It
is the good solution to the increasing water crises. Rain
water harvesting reduces the flooding on roads and
further prevents it from contamination.
6. Simple Ways for Water Conservation
There are many effective ways to conserve water in and
around your home, apartment, villa, office etc.
Following are simple ways for water conservation [6].
When washing dishes by hand, don’t let the
water run while rinsing. Fill one sink with wash
water and the other with rinse water.
Run your clothes washer and dishwasher only
when they are full. You can save up to 1,000
gallons a month.
Install covers on pools and spas and check for
leaks around your pumps.
Monitor your water bill for unusually high use.
Your bill and water meter are tools that can help
you discover leaks.
Encourage your family to keep looking for new
ways to conserve water in and around your
home.
Housing Society or Apartment owners
association must adopt rainwater harvesting.
Turning the water off while you lather the soap
can save as many as 5 gallons of water each
time you wash. Use one glass of water for
brushing teeth instead of running the tap.
Use dual piping one pipe for drinking, bathing
and utensil cleaning where other pipe will bring
in rain water and treated water for toilet, lawns
etc.
Shorten your shower by a minute or two and
you’ll save up to 150 gallons per month.
Teach your children to turn off faucets tightly
after each use.
A water leak detector or water leak detection
system can alert you of any possible plumbing
malfunctions in your home or apartment. Even
a small leakage can cause huge water losses.
Wash your vehicle with bucket of water and
sponge than using a hose.
Toilet is one of the source wastes water
unnecessarily. Upgrade your toilet with new
water efficient models.
A trained property manager can manage water
systems such as saving water in swimming
pool, proper management of waste water,
detection of leakage etc.
The practice of installing individual water
meters on multi-family apartment units and
billing based on actual consumption results in
water savings 8,000 gallons per year.
Everyday water is wasted, while bathing and
other activities, therefore all new buildings
should implement the systems to collect and
recycle used water.
One must check usage by maids and domestic
servants, since it is these people who are the
end users of the resource in apartments, villa,
office etc.
7. Conclusion
For India’s future generations to be ensured of a reliable
water supply, sustainable management practices must be
implemented to preserve the nation’s dwindling
groundwater resources. For more than one billion
people of India, though hidden from the naked eye,
groundwater depletion is a real and serious issue
deserving of political and humanitarian attention. The
present study reviews and suggests the concept of using
greywater and rainwater harvesting in various possible
fields and thus, making fresh water demand within
control. The use of these methods is in their initial stage
in India. Though, various developed countries are

6. 2nd
International Conference on Emerging Trends in Engineering & Technology, April12-13, 2013
College of Engineering, Teerthanker Mahaveer University.
6
already utilizing these new water potential after some
preliminary treatments depending upon the type of use.
References
[1] Asian Development Bank, “Water for All: The
Water Policy of the Asian Development Bank”
[2] United Nations Environment Programme (UNEP).
[3] Hegde N. “Water scarcity and security in India”,
BAIF-Indian Science Congress, 2012.
[4] greywateraction.org/content/about-greywater-reuse.
[5] http://www.mppcb.nic.in/RWH.htm
[6] http://www.commonfloor.com/guide/20-simple-
ways-for-water-conservation-1857.html