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Understanding Dhaka's water crisis: What can we do sustain our water usage?

  • Published at 02:28 pm October 24th, 2019
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A portion of a lake in Dhaka city Mahmud Hossain Opu/Dhaka Tribune

Ensuring equitable and affordable access to safe water to this increasingly large population is going to be a monumental challenge

Cities in both developing and developed countries around the world are gradually moving towards an inevitable water crisis. Cape Town in South Africa has already had to face the horror of “Day Zero,” when most of the city’s water taps were switched off and residents stood in line to collect just 25 litres of water per capita a day. 

According to a report from the NITI Aayog, an Indian government think tank, 21 cities in India including Delhi, Bengaluru, Chennai, and Hyderabad will run out of groundwater by 2020, affecting 100 million people; 40% of India’s population will have no access to drinking water by 2030. Other major cities across the world are also seeing their water resources shrink at an alarming rate. 

Dhaka is the largest and fastest-growing urban centre in Bangladesh with a population density of 44,500/km2. One-tenth of the country’s population and a third of its urban population (36%) live in this city. According to the Dhaka Structural Plan 2016-2035, its population will reach 22.79 million by 2035. Ensuring equitable and affordable access to safe water to this increasingly large population is going to be a monumental challenge.

Dhaka Water Supply and Sewerage Authority (Wasa), the sole legal entity to develop and maintain a water supply system for Dhaka metropolitan and its surrounding areas estimates that per capita water demand in Dhaka is 150 litres per day.  

A study by Brac Institute of Governance and Development (BIGD), Brac University found that, on average, per capita water usage is 310 litres per day among the households in the formal settlements—more than twice as high as the estimation.

Meanwhile, per capita usage is just 85 litres per day among the households in informal settlements (e.g. slums) with metered Dhaka Wasa connections. Furthermore, inequality increases with increasing wealth, for example, areas such as Gulshan and Banani have by far the highest per capita usage—509 litres.  The study findings not only demonstrate the wide inequality in water usage between households in the formal and informal settlements but also indicate to huge inefficiency in water usage in formal settlements.

A number of factors are responsible for such high level of water usage. One of the most prominent factors is the current holding-based metering and billing system. In this system, one water meter is given to an entire building, which is used to calculate the water used by all the households within that building. Water bill of the entire building is equally divided among the households, irrespective of family size and actual usage. As a result, households with fewer members subsidize the cost of households with more members. We also found that per capita income and water usage go up simultaneously. 

In households with per capita income less than Tk3,000, per capita water usage is less than 200 litres, whereas with per capita income of 9,000 and above, usage is 441 litres. 

This is because households with higher income tend to use more water-dependent appliances that increase their water usage. 

For instance, 61% of households with per capita income higher than Tk9,000 possess shower and flushing toilets and among these households, per capita water usage is almost 100 litres higher than those without. 

Given the current economic trend, average income of the citizens of Dhaka is expected to increase continuously, further increasing their water usage.

Changing weather patterns also affect consumers’ water usage. 85% of the surveyed respondents said that their water usage reaches its peak in summer (March-June). According to Shourav et al. 2018, “most climate models predict that the temperature in Bangladesh will rise sharply because of climate change,” leading to longer summers and an increase in water demand. Additionally, the cities are becoming increasingly concentrated and the resultant “urban heat island” impact is likely to trap more heat and add to the rising temperature.

Growing and increasingly wealthier population, climate change and the urbanization process itself will cause steep growth in water demand in Dhaka city in the coming days. Can Dhaka Wasa sustainably meet the increasing demand for water in Dhaka? 

78% of Dhaka Wasa water comes from underground—which leads to incremental depletion of groundwater. Due to this over-extraction, the land in Dhaka is predicted to subside by 6.4cm between 2010 and 2020. Moreover, groundwater depletion is driving up the cost of extraction and reducing the operational lifespan of pumps. In this condition, reducing groundwater dependence and switching to surface water is the only way forward.

There are five rivers and 43 canals inside and around Dhaka which can potentially serve the purpose of retaining rainwater. But they are fast disappearing. 

For instance, the Dhaka Detailed Area Plan (DAP) 2010 identified 5,523 acres of water retention areas. A Rajuk study in 2017, however, found the existence of only 1,744 acres of water retention areas. 

Around 43% of Dhaka’s floodplain has been filled in between 2003-2017. And existing water retention bodies are being polluted because of unchecked industrial effluents, dumping of solid waste, and low-level of sewerage treatment. All the six rivers around Dhaka—Buriganga, Shitalakkhya, Dhaleshwari, Turag, Bongshi, and Balu—have turned nearly untreatable, DWASA found in 2016. 

With huge inefficient usage in formal settlements and unmet demand among the poor on one hand, and dwindling sources of water on the other, water demand management is the most important way of ensuring sustainability of water supply . 

First, a standard recommendation for water usage for decent living should be set to measure efficiency; currently there are none. There should be awareness campaigns for water conservation and to make citizens aware of the dire situation of our water sources. Shockingly, only one-fifth of the surveyed respondents expressed their concerns about groundwater depletion while 35% said that they are worried about surface water pollution.

Campaigns such as “Let’s Not Waste Precious Water,” “Safe Water Campaign” and water conservation courses in high schools have already proven to be effective and brought positive changes in Singapore. Also, water-saving technologies and products can make an important contribution to conservation efforts. And finally, monetary incentives should be created for water conservation. Household-level water metering could influence household members to use water accountably. Progressive tariff, i.e. water pricing as per usage, is a popular and successful measure used in many countries to manage water demand. A refined form of progressive tariff is Increasing Block Tariff (IBT) which specifies the rate charged for each additional block (volume) of water used—higher rate for a higher block.

To move towards these directions, we need a multi-stakeholder partnership that brings together the public and the private sectors with community and people. The government should come up with policies incentivizing conservation, the private sector should bring in necessary technologies and the citizen must actively conserve water, so that we may never have to observe a ‘Day Zero.’

Mohammad Sirajul Islam is Program Manager at Brac Institute of Governance and Development, Brac University and lead author of the study State of Cities 2018:  Water Governance in Dhaka