Water conservation is key

March 22 (Saturday) was this year's World Water Day and the theme of the day is Glacier Preservation. But what has a tropical country, Bangladesh, to do with glacier, which is a big mass of dense ice very slowly sliding downhill under the pull of gravity over the millennia in the cold parts of the Earth? Since the Ganges-Brahmaputra river system, the source of our major rivers is lying in the Himalayan glaciers, Bangladesh has definitely a stake in what happens to these glaciers. The Ganges' headwater flows from the Gangotri Glacier in Uttarkhand in India, while the Brahmaputra originates from Chemayungdung glacier in Tibet.

So, preserving those glaciers is obviously vital to the sustenance of Bangladesh's river system. But the glaciers in the Himalayas as well as those in the Arctic and the Antarctic regions are also retreating due to climate change. Abnormal depletion of the Himalayan glaciers is producing more water than has been flowing through the Ganges-Brahmaputra river system since time immemorial. This is resulting in the unpredictability of the water cycle leading to avalanches, landslides and floods, leading to the devastations to the human settlements on the mountainside or in the valley below.  However, the worse is yet to come. Unless further retreating of the Himalayan glaciers are halted, there will be a time when the Himalayan glaciers will vanish and there will be no water in river systems they (the glaciers) feed. As a  result, the rivers will dry up. That will be the end of the civilization on the Ganges-Brahmaputra basin of which Bangladesh is a part. Himalayan glaciers apart, melting of the polar ice is also causing the sea level to rise and flooding of the coastal areas and intrusion of saline water causing pollution of the freshwater ecosystem of the coastal regions, destruction of crops, livestock and aquatic life and in the end making life impossible for coastal populations who would then migrate in droves to other parts of, for instance, the South Asia  including Bangladesh.  This is but going to be one side of the coin of human misery, unless timely actions are taken to change their lifestyle and, especially, production, management and use of energy. However, these issues relate to global impact of the climate change.

Now, narrowing the focus, let us see the usage of water, which is already scare in Bangladesh. A recent report published in the local media warns that one of the major sources of water that people in Bangladesh depend on for drinking, irrigation as well as for industrial use, groundwater, is drying up alarmingly. Experts as well as members of the public who are concerned since the tube wells are running dry. They have to drive the water pipes hundreds of feet down the ground level, if they are lucky, to access water. This is clearly a sign that the water table is declining due to its overuse. In Dhaka and its surrounding areas alone more that1,260 deep tube wells have been sunk by the Dhaka Water Supply and Sewerage Authority (WASA). As reported, quoting WASA officials, these  deep tube wells draw water from the aquifer as deep as 400 to 1200 feet below the earth surface. This is not all. Some 2,000 privately owned deep tube wells are also, reportedly, in operation in the capital city alone. The WASA meets 70 per cent of the capital city's need for drinking water from these deep tube wells while the rest 30 per cent comes from some five water treatment plants that purify water from the rivers around Dhaka including Buriganga, Dhaleswari and Padma. This is the picture of only the capital city. But hundreds of such deep tube wells are operating all across the country including the bigger cities like Chattogram, Rajshahi, and Khulna. All these deep tube wells are using groundwater in an unplanned way. This is not only causing water table to drop to a further lower level. But as the deep tube wells are nowadays sinking deeper and deeper below the ground in search of water, they are not only risking  lifting arsenic contaminated water, but also subsidence of earth due to hollowed-out groundwater reservoirs of water or aquifers. Nothing can be a worse scenario than that.

The water table, according to experts, could be accessed just around a yard below the earth surface in Dhaka in the 1970s. But now one has to dig some 70 metres deep to find  groundwater in certain areas of the capital city.  However, in the areas adjacent to rivers, the groundwater can be accessed half that depth down the surface. But the way the rivers of Bangladesh are also drying up due to barrages, dams and other water control structures built upstream in Indian portion of most transboundary rivers, water crisis may turn more acute in the future. In that case, what is urgent is planned use of available water either from surface or underground. At the same time, the government will have to take water conservation measures which include creating large reservoirs at the mouth of rivers in upstream of which the neighbouring country has built dams and barrages. The government needs to be bold enough to take measures  to protect Bangladesh and its people's interests. Also, big ponds and artificial lakes should be excavated all across the country to conserve rainwater during the rainy season. Households in every village and city in the country should be encouraged and incentivised to harvest rainwater. Awareness is required to be raised among the public to use purified surface water for drinking and discourage the use of groundwater. Reducing use of groundwater will enable aquifers to recharge.  There is a need to use both groundwater and surface water sustainably. This is not just an option but an imperative for everyone in Bangladesh considering the prospect of freshwater crisis getting worse in the coming days.

sfalim.ds@gmail.com