Integrated Water Resource Management for Mega City: A Case Study of Dhaka City, Bangladesh

Khalid Md. Bahauddin1, Nasir Hossain2

 

 

¹ Bangladesh Society of Environmental Scientists, Bangladesh

² Khulna University, Bangladesh; E-mail: This e-mail address is being protected from spambots. You need JavaScript enabled to view it

 

 

 

Abstract

Dhaka, the capital of Bangladesh, is facing a serious water scarcity problem due to the big gap between demand and supply of the water system. When accelerating water scarcities and pollution in and around urban centers are superimposed on issues like continuing urbanization, lack of investment funds for constructing and maintaining water infrastructures, high public debts, inefficient resources allocation processes, inadequate management capacities, poor governance, inappropriate institutional frameworks and inadequate legal and regulatory regimes, water management in the megacities poses a daunting task in the future. To overcome these water related problems, water can be a designing element for structuring future development with the combination of sustainable approaches for social and physical transformation, open up opportunities for a water management system. Therefore an integrated approach such as an integrated water resource management (IWRM) system, which responds to problems that are all interrelated, is required. Alternate supply and demand management tools such as ground water recharge, rainwater harvesting, effective water pricing and reclaimed water use are suggested to meet the deficit of the current supply system through the efficient use of the scarce resources available. Institutional reform and improved water planning are required to facilitate economic growth and social development. Finally, human resource development is identified as a key factor for the sustainable effective management of this valuable resource.

Keywords: Dhaka, Water Supply and Demand, IWRM, Institutional Reform, Human Resource Development

 

 

Introduction

 

Water is a key element in the development of society and a vital necessity for any living being. A growing population, urbanization, increasing pressure on land and water resources by different competing usage and degradation of scarce resources, challenge the extraction, management and protection of the water resources throughout the entire country such as Bangladesh.

Bangladesh is one of the most densely populated countries in the world. More than 130 million people live in an area of 147 540 km2 and the population is increasing at a rate of around 1.6% annually. Approximately 44% of the population lives below the poverty line. Dhaka, the capital city of Bangladesh, is a megacity with a population of about 16 million that is growing at an annual rate of around 5%, one of the highest amongst Asian cities.

Dhaka will be the second largest city of the world by the year 2015. The huge population puts forth massive pressure on the water supply system and causes a huge amount of deficit every year. Various sectors such as urban households, industries, agriculture and the ecosystem are experiencing competition for the share of water. Unplanned urbanization, economic development, as well as huge population, have caused increased interaction among different water uses, changed the water environment of Dhaka, polluted the river bodies and ecosystem, lowered the ground water table and altered the water and sediment regime.

In this context, it has been realized that integrated water resources management (IWRM) should be the guiding principle to address these culminating problems. IWRM is a process which promotes the coordinated development and management of water, land and related resources, in order to maximize the resultant economic and social welfare in an equitable manner without compromising the sustainability of vital ecosystems.

Dhaka City and Water Issues

It is not easy to imagine a more water-affluent megacity than Dhaka. Dhaka receives 2000mm of rainfall annually. It is located close to the convolution of the mighty Ganges, Brahmaputra and Meghna rivers and it is frequently flooded, often catastrophically. These three rivers constitute the world's second biggest river system with an annual discharge 25 times that of the Nile. However, Dhaka is one of the most challenging megacities in its water management.

Dhaka is the political and economic centre of Bangladesh. The country has more than 130 million people in an area of 147 540 km2 making it extremely crowded. Dhaka's population is approaching 16 million with a growth rate of around 5% per year.

Bangladesh is one of the poorest countries of the world with 44% of the people living below the poverty line. It has been estimated that around one-quarter of Dhaka's population live in slums.

The water supply and sewerage services have been allocated to one single public authority. It now supplies 0.51 km3 of water per year against the demand of 0.73 km3, serving around 72% of the city dwellers. The quality of the supplied water is very much in question. Almost 1000 private wells abstract another 0.35 km3 of groundwater per year, mainly for industrial purposes. Groundwater is used far beyond the sustainable rate and this groundwater mining puts a serious strain on the environment. The groundwater table has gone down 20 to 30 m in the past three decades and continues to sink 1 to 2 m per year.

Seventy percent of the population has adequate sanitation and 30% are served by sewer networks. Only one sewage treatment plant exists, with a treatment capacity of 49 000 domestic connections. This is not a great part for a megacity the size of Dhaka. Over one-quarter of the population lacks adequate sanitation altogether. The share of unaccounted for water is around 53%. It has gradually decreased from the level of 75% in 1980. There are currently important discussions on various water management issues such as the cost recovery of water services through tariff regulation, increased involvement of the private sector in water management, etc. in order to bring more efficiency and transparency to the water sector of Dhaka.

Serious surface and groundwater pollution with detrimental effects on public health follow from the massive infrastructure shortcomings in water supply and sanitation. They are reinforced by occasional and often dramatic flooding, which raises the water level to streets and dwellings. Storm water management systems have been developed but not at a rate that can keep pace with the growing population, particularly in the eastern part of Dhaka with a population of 3 million. Several decades ago, the city was covered by a canal network of 24 canals and included a large natural wetland area. This system was able to keep flood damage fairly low. The unplanned and largely illegal sprawl of the city ever since, has led to the situation in which no proper storm water infrastructure exists. The most important flood protection system today is the Dhaka Western Embankment which is able to keep about half of the city area virtually flood-free.

 

Situation of Water Availability and Accessibility in Dhaka City

The Dhaka Water Supply and Sewerage Authority (DWASA) is primarily responsible for providing water to about 90% of the Dhaka metropolitan area (DMPA). The remaining 10% depends on private wells. It is necessary to mention that 90% coverage of the DMPA does not mean that all people in this area get continuous DWASA supplied water. About 91% of the total water served by DWASA is utilized to meet the domestic water demand and about 9% is supplied to industrial and commercial sectors. Around 1794.44 million liters per day (MLD) of water is produced by DWASA, as per May 2008. More details are given in table 1. About 1540 MLD of this supply is abstracted from 471 deep tube wells (DTW) situated in Dhaka City and 14 DTWs in Narayanganj. The remaining 254.44 MLD is produced through two surface water treatment plants (SWTP) in Dhaka (Saidabad & Chandighat) and one SWTP in Narayanganj (Godnail). About 223.1 MLD is solely produced by the Saidabad SWTP. In addition to this, around 1179 DTWs are currently operated by the private agencies in order to meet the city's present water demand. About 585 private DTWs supply water for domestic use and 562 DTWs for industrial and commercial use.

 

Table 1: Water production per day in Dhaka City
Tab01