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Water conservation
Our ancient
religious texts and epics give a good insight into the water storage
and conservation systems that prevailed in those days.
Over the years rising populations, growing industrialization, and
expanding agriculture have pushed up the demand for water. Efforts
have been made to collect water by building dams and reservoirs and
digging wells; some countries have also tried to recycle and desalinate
(remove salts) water. Water conservation has become the need of the
day. The idea of ground water recharging by harvesting rainwater is
gaining importance in many cities.
In the forests, water
seeps gently into the ground as vegetation breaks the fall. This groundwater
in turn feeds wells, lakes, and rivers. Protecting forests means protecting
water 'catchments'. In ancient India, people believed that forests
were the 'mothers' of rivers and worshipped the sources of these water
bodies.
Some ancient Indian
methods of water conservation
The Indus Valley Civilization, that flourished along the banks of
the river Indus and other parts of western and northern India about
5,000 years ago, had one of the most sophisticated urban water supply
and sewage systems in the world. The fact that the people were well
acquainted with hygiene can be seen from the covered drains running
beneath the streets of the ruins at both Mohenjodaro and Harappa.
Another very good example is the well-planned city of Dholavira, on
Khadir Bet, a low plateau in the Rann in Gujarat. One of the oldest
water harvesting systems is found about 130 km from Pune along Naneghat
in the Western Ghats. A large number of tanks were cut in the rocks
to provide drinking water to tradesmen who used to travel along this
ancient trade route. Each fort in the area had its own water harvesting
and storage system in the form of rock-cut cisterns, ponds, tanks
and wells that are still in use today. A large number of forts like
Raigad had tanks that supplied water.
 In ancient times, houses
in parts of western Rajasthan were built so that each had a rooftop
water harvesting system. Rainwater from these rooftops was directed
into underground tanks. This system can be seen even today in all
the forts, palaces and houses of the region.
Underground baked earthen
pipes and tunnels to maintain the flow of water and to transport it
to distant places, are still functional at Burhanpur in Madhya Pradesh,
Golkunda and Bijapur in Karnataka, and Aurangabad in Maharashtra.
Rainwater harvesting
In urban areas, the construction of houses, footpaths and roads has
left little exposed earth for water to soak in. In parts of the rural
areas of India, floodwater quickly flows to the rivers, which then
dry up soon after the rains stop. If this water can be held back,
it can seep into the ground and recharge the groundwater supply.
 This
has become a very popular method of conserving water especially in
the urban areas. Rainwater harvesting essentially means collecting
rainwater on the roofs of building and storing it underground for
later use. Not only does this recharging arrest groundwater depletion,
it also raises the declining water table and can help augment water
supply. Rainwater harvesting and artificial recharging are becoming
very important issues. It is essential to stop the decline in groundwater
levels, arrest sea-water ingress, i.e. prevent sea-water from moving
landward, and conserve surface water run-off during the rainy season.
Town planners and civic
authority in many cities in India are introducing bylaws making rainwater
harvesting compulsory in all new structures. No water or sewage connection
would be given if a new building did not have provisions for rainwater
harvesting. Such rules should also be implemented in all the other
cities to ensure a rise in the groundwater level.
Realizing the importance of recharging groundwater, the CGWB (Central
Ground Water Board) is taking steps to encourage it through rainwater
harvesting in the capital and elsewhere. A number of government buildings
have been asked to go in for water harvesting in Delhi and other cities
of India.
All you need for a water
harvesting system is rain, and a place to collect it! Typically, rain
is collected on rooftops and other surfaces, and the water is carried
down to where it can be used immediately or stored. You can direct
water run-off from this surface to plants, trees or lawns or even
to the aquifer.
Some of the benefits
of rainwater harvesting are as follows
Increases water availability
Checks the declining water
table
Is environmentally friendly
Improves the quality of
groundwater through the dilution of fluoride, nitrate, and salinity
Prevents soil erosion and
flooding especially in urban areas
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Rainwater harvesting:
a success story
Once Cherrapunji
was famous because it received the largest volume of rainfall
in the world It still does but ironically, experiences acute
water shortages. This is mainly the result of extensive deforestation
and because proper methods of conserving rainwater are not used.
There has been extensive soil erosion and often, despite the
heavy rainfall and its location in the green hills of Meghalaya,
one can see stretches of hillside devoid of trees and greenery.
People have to walk long distances to collect water.
In the area surrounding
the River Ruparel in Rajasthan, the story is different - this
is an example of proper water conservation. The site does not
receive even half the rainfall received by Cherrapunji, but
proper management and conservation have meant that more water
is available than in Cherrapunji.
The water level
in the river began declining due to extensive deforestation
and agricultural activities along the banks and, by the 1980s,
a drought-like situation began to spread. Under the guidance
of some NGOs (non-government organizations), the women living
in the area were encouraged to take the initiative in building
johads (round ponds) and dams to hold back rainwater. Gradually,
water began coming back as proper methods of conserving and
harvesting rainwater were followed. The revival of the river
has transformed the ecology of the place and the lives of the
people living along its banks. Their relationship with their
natural environment has been strengthened. It has proved that
humankind is not the master of the environment, but a part of
it. If human beings put in an effort, the damage caused by us
can be undone.
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Agriculture
Conservation of water in the agricultural sector is essential since
water is necessary for the growth of plants and crops. A depleting
water table and a rise in salinity due to overuse of chemical fertilizers
and pesticides has made matters serious. Various methods of water
harvesting and recharging have been and are being applied all over
the world to tackle the problem. In areas where rainfall is low and
water is scarce, the local people have used simple techniques that
are suited to their region and reduce the demand for water.
In India's arid and semi-arid
areas, the 'tank' system is traditionally the backbone of agricultural
production. Tanks are constructed either by bunding or by excavating
the ground and collecting rainwater.
Rajasthan, located in the
Great Indian Desert, receives hardly any rainfall, but people have
adapted to the harsh conditions by collecting whatever rain falls.
Large bunds to create reservoirs known as khadin, dams called johads,
tanks, and other methods were applied to check water flow and accumulate
run-off. At the end of the monsoon season, water from these structures
was used to cultivate crops. Similar systems were developed in other
parts of the country. These are known by various local names ¾
jal talais in Uttar Pradesh, the haveli system in Madhya Pradesh,
ahar in Bihar, and so on.
Reducing water demand
Simple techniques can be used to reduce the demand for water. The
underlying principle is that only part of the rainfall or irrigation
water is taken up by plants, the rest percolates into the deep groundwater,
or is lost by evaporation from the surface. Therefore, by improving
the efficiency of water use, and by reducing its loss due to evaporation,
we can reduce water demand.
There are numerous methods to reduce such losses and to improve soil
moisture. Some of them are listed below.
Mulching, i.e., the application
of organic or inorganic material such as plant debris, compost, etc.,
slows down the surface run-off, improves the soil moisture, reduces
evaporation losses and improves soil fertility.
Soil covered by crops,
slows down run-off and minimizes evaporation losses. Hence, fields
should not be left bare for long periods of time.
Ploughing helps to move
the soil around. As a consequence it retains more water thereby reducing
evaporation.
Shelter belts of trees
and bushes along the edge of agricultural fields slow down the wind
speed and reduce evaporation and erosion.
Planting of trees, grass,
and bushes breaks the force of rain and helps rainwater penetrate
the soil.
Fog and dew contain substantial
amounts of water that can be used directly by adapted plant species.
Artificial surfaces such as netting-surfaced traps or polyethylene
sheets can be exposed to fog and dew. The resulting water can be used
for crops.
Contour farming is adopted
in hilly areas and in lowland areas for paddy fields. Farmers recognize
the efficiency of contour-based systems for conserving soil and water.
Salt-resistant varieties
of crops have also been developed recently. Because these grow in
saline areas, overall agricultural productivity is increased without
making additional demands on freshwater sources. Thus, this is a good
water conservation strategy.
Transfer of water from
surplus areas to deficit areas by inter-linking water systems through
canals, etc.
Desalination technologies
such as distillation, electro-dialysis and reverse osmosis are available.
Use of efficient watering
systems such as drip irrigation and sprinklers will reduce the water
consumption by plants.
Water conservation
The most important step in the direction of finding solutions to issues
of water and environmental conservation is to change people's attitudes
and habits¾this includes each one of us. Conserve water because
it is the right thing to do. We can follow some of the simple things
that have been listed below and contribute to water conservation.
Try to do one thing each
day that will result in saving water. Don't worry if the savings are
minimal¾every drop counts! You can make a difference.
Remember to use only the
amount you actually need.
Form a group of water-conscious
people and encourage your friends and neighbours to be part of this
group. Promote water conservation in community newsletters and on
bulletin boards. Encourage your friends, neighbours and co-workers
to also contribute.
Encourage your family to
keep looking for new ways to conserve water in and around your home.
Make sure that your home
is leak-free. Many homes have leaking pipes that go unnoticed.
Do not leave the tap running
while you are brushing your teeth or soaping your face.
See that there are no leaks
in the toilet tank. You can check this by adding colour to the tank.
If there is a leak, colour will appear in the toilet bowl within 30
minutes. (Flush as soon as the test is done, since food colouring
may stain the tank.)
Avoid flushing the toilet
unnecessarily. Put a brick or any other device that occupies space
to cut down on the amount of water needed for each flush.
When washing the car, use
water from a bucket and not a hosepipe.
Do not throw away water
that has been used for washing vegetables, rice or dals¾use
it to water plants or to clean the floors, etc
You can store water in
a variety of ways. A simple method is to place a drum on a raised
platform directly under the rainwater collection source. You can also
collect water in a bucket during the rainy season.
For more information
on Water harvesting link to
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