Water experts have long been sounding alarms against receding ground water level in the country. If things continue like this we are in for a grave danger. The importance of water in all living beings is too well-known to elaborate. Water covers 71 per cent of the Earth's surface. On earth, 96.5 per cent of water is found in seas and oceans, 1.7 per cent in groundwater, 1.7 per cent in glaciers and the ice caps of Antarctica and Greenland, and another small fraction in other large water bodies.
The water content in the bodies of human beings, birds and animals, insects and plants is 60 to 95 per cent. In an adult human being the volume of water is 57-60 per cent. The water content in children below one year is 75 to 78 per cent.
On the other hand, the total quantity of water in the world is 1400 million cubic litres, 97 per cent of which is from saline water in the seas. Only 2.5 per cent of this water is fresh water, of which 30.1 per cent comes from underground water, 67.8 per cent from glacier and iceberg and only 0.3 per cent from surface water and 0.9 per cent from other sources of sweet water. Of the 0.3 per cent of sweet water, 2.0 per cent is found in rivers, 11 per cent in other water bodies and 87 per cent can be found in different lakes.
Less than 0.3 per cent of all fresh water is in rivers, lakes, and the atmosphere, and an even smaller amount of the Earth's fresh water (0.003 per cent) is found within biological bodies and manufactured products. A greater quantity of water is found in the earth's interior where large lakes are located, for example, in Canada, Mongolia, Russia and lonely regions of Africa. The lake of North America contains 21 per cent of water and only 33 million people live along its shores.
Bangladesh contains only a fraction of the sweet water in the world. Most of its sweet water requirement is met from underground sources. Nearly 87 per cent of underground water is used for agriculture. About 300 litres of water is required to produce I kg of Ufshi rice. 250 tons of water is required to produce 1 ton of paper while 40,000 gallons of water are required at different stages of a motor car manufacture.
Coming back to receding water level, it owes a lot to indiscriminate use. The population of Dhaka is over 15 million and if according to WASA standard, 150 litres of water is required per head per day, a total of 2250 million litres of water is required every month in Dhaka alone. The current water supply of WASA is close to this requirement, but the way the level is going down, many of the tube wells are going to be dry soon. WASA had 440 deep tube wells which rose to 460 in 2010, 634 in 2013 and 705 in 2016.
It has not been like this before. For example, in Motijheel water level in 2004 was 52 metres below the ground and that in Gulshan was 43 metres below. Currently water level in Dhaka city is going down by 2 to 3.5 litres per year and the average amount of recharge is only over I litre per year. The amount of water lifted is more than the amount recharged. In this way ground water is level is going down further and saline water from the south will infiltrate into ground water and make it unfit for drinking as well as farming.
Apart from causing a perpetual scarcity of water, the diminishing water level is also a major cause of land slides at ground level of up to 16 mm per year which is alarming. That has necessitated WASA to reverse its strategy for water supply in Dhaka. WASA that currently supplies 78 per cent of underground water and 22 per cent of surface water, now aims at supplying 70 per cent of surface water and 30 per cent of underground water.
Four water plants including the water treatment plant at Saidabad was set up in 2002. Two more plants in Saidabad and one each at Pagla and Khikhet are going to be set up soon. More than setting up more water treatment plants, the crying need of the hour is to reduce wastage of water. We must realize the imminent danger of water crisis in near future. If we had been careful from the beginning, the water level would have been where it was in 1960. In Dhaka city water is mostly used for domestic purposes and the domestic consumption of water is unfortunately is more than three to four times than is actually required.
We all have the experience of water crisis during a power failure or as the lift pump runs out of order. The amount of water that we spend in a situation like that is our actual requirement. We overspend water on rest of the occasions. The common people must be made aware of the imminent danger of diminishing ground water level and the urgency of making efficient use of water. Research should be conducted to reduce water use in agriculture. Campaigns should be stepped up highlighting the dangers of extravagant use of water. On the industrial side, Effluent Treatment Plant (ETP) should be set up along side conducting research works to ensure correct use of water. Arrangement should also be made to preserve rain water and waste water should be recycled. Water used in household should be reverted back through underground pipes. All these should be done in an integrated manner along side enactment of necessary laws regarding use of underground water.
Last but not least, austerity in water use has become a necessity as the world prepares to fight the effects of climate change.
As a precaution the following instances may be cited:
- If people had access to clean water and adequate sanitation and practised good hygiene, 2.4 million deaths could be prevented each year.
- Almost 1.0 billion people lack access to safe water, and about 2.6 billion people do not have improved sanitation.
- 1 out of 5 children under the age of 5 die each day from waterborne diseases - one every 21 seconds as a direct result of contaminated water and poor sanitation.
It is evident from the above statistics that water is vital not only for survival of all known forms of life, judicious use of water will help prevent many more catastrophes in future necessitating the significance of preventing wastage of water at any cost. Our Prime Minister also called for a global fund that will be utilised for research, innovation and technology transfer to achieve sustainable development on water.