Despite various plans, ambitious projects and programmes undertaken by the authorities over the years, the residents of low-lying areas in the capital and its surroundings still suffer from waterlogging during the monsoon.
The city dwellers face extensive waterlogging from May to October every year, which experts say is a result of rapid and unplanned urbanisation in Dhaka city and its outskirts.
This hazard creates adverse financial, physical and environmental impacts in the city.
According to a World Bank study published in November 2015, the potential damages from waterlogging between 2014 and 2050 will be Tk11,000 crore in Dhaka, if climate change is not considered. In a changing climate with more intense rainfalls, the loss will be Tk13,900 crore between 2014 and 2050.
Waterlogging in Dhaka occurs even after small amounts of rain due to the poor, inadequate and unplanned drainage networks that are regulated by three local government bodies – Dhaka Water Supply and sewerage Authority, Dhaka North City Corporation and Dhaka South City Corporation.
Experts also point out the many failures of the city development authority Rajuk to implement properly any of the city's development plans including the Dhaka Detailed Area Plan (DAP). Reports over the years show a large number of drainage channels, water reservoir and flood flow zones inside Dhaka city and its surroundings have been taken over by construction activity.
Rajuk is accused of irregularities and corruption in the implementation of city plans, and on the other hand this state-run agency also faces obstructions and constant pressures from developer companies and land grabbers.
Dhaka Wasa, the two city corporations, the deputy commissioner's office, Rajuk, Water Development Board, Bangladesh Inland Water Transport Authority and Dhaka Cantonment Board are involved in resolving waterlogging in Dhaka city and the surrounding areas.
Prime Minister Sheikh Hasina has recently directed her cabinet and the concerned agencies to address waterogging problems in the capital as soon as possible.
City's existing drains
Wasa and the two city corporations provide services directly to resolve waterlogging in around 128 square kilometres of the city. Wasa covers 370km drains, while the DNCC and DSCC together have around 2,000 km.
This amount drains is not sufficient for the dense mega city, and these existing drains are unable to discharge rainwater swiftly as the 26 drainage canals they are connected to have been encroached by land grabbers.
[caption id="attachment_107831" align="aligncenter" width="800"]
People having to use whatever they can to get by the waterlogged streets Mehedi Hasan/Dhaka Tribune
Status of water bodies
The capital city's drainage network was designed to discharge storm water to the surrounding four rivers – Buriganga, Balu, Turag and Shitalakhya - through the existing 26 canals.
According to Wasa, Dhaka used to have 65 canals but the number has come down to 43 over time. Of the existing ones, around 20 canals have also nearly vanished because of encroachment, Wasa officials said.
In a bid to ensure sustainable delivery of storm water drainage and waste water disposal from the city, the government in September 2008 approved the Dhaka Water Supply and Sanitation Project (DWSSP), in association with the World Bank.
As part of the project, Dhaka Wasa took steps to reclaim 26 canals from illegal occupation by building walkways, channels, lining and planting trees along the canals’ embankments, but the project has not succeeded.
The government has reviewed the new DAP due to pressures from developer companies, sources said.
The four rivers are under threat as grabbers are still occupying and filling up various river bank areas. On the other hand developer companies and owners of different industries have grabbed the flood flow zones on both sides of the rivers.
In the past 25 years, urban planners had pointed out several times that rapid urbanisation of Dhaka city had resulted in substantial increase in impervious area, created obstruction to natural drainage patterns, and reduced the detention basins, which in turn led to the shortening of the runoff concentration time and an increase of the peak flow.
"It could not be said that the DAP was fully successful. A large number of land developers continue to fill up flood flow zones and grab embankment of rivers around Dhaka," said Prof Jamilur Reza Choudhury, who headed the DAP expert team.
He said structural and industrial disasters might occur repeatedly since the city's development has largely ignored the official plan.
"The DAP remains far from being implemented due to negligence of the authorities concerned. Land developers are using the land in violation of the Rajuk plan," Jamilur added.
[caption id="attachment_108003" align="aligncenter" width="800"]
In the past 25 years, urban planners had pointed out several times that rapid urbanisation of Dhaka city had resulted in substantial increase in impervious area, created obstruction to natural drainage patterns, and reduced the detention basins, which in turn led to the shortening of the runoff concentration time and an increase of the peak flow Mehedi hasan/Dhaka Tribune
Study and recommendations
The authorities concerned recently asked two private research organisations – Centre for Environmental and Geographical Information Services and the Institute of Water Modeling - to find out the ways to relieve waterlogging in Dhaka. Both the research institutions recommended that all encroached water bodies be freed up.
After their surveys, both research groups recommended widening rivers and flood flow zones surrounding the city.
The study papers say 50-metre to 400-metre buffer zones on both banks of the four rivers would facilitate uninterrupted flood flow run-off, keeping the capital’s drainage undisturbed until end of the new DAP in 2036.
To ward off rapid occupation of natural drainage channels, the studies recommended banning development activities which could affect all the water bodies.
The reports also pointed out that filling-up of countless wetlands in Ashulia, Banasree, Aftabnagar, Bashundhara, Meradia, Baunia, Badda, Amin Bazar and Hatirjheel had increased waterlogging across the capital.
Urban planner Prof Nazrul Islam said: "To resolve waterlogging, the drainage network needs to be always kept clear. This work needs to be done jointly.
"The problem will not be solved unless the concerned agencies cooperate."
[caption id="attachment_108023" align="aligncenter" width="800"]
Two research groups recommended that 50-metre to 400-metre buffer zones on both banks of the four rivers surrounding Dhaka would facilitate uninterrupted flood flow run-off, keeping the capital’s drainage undisturbed until end of the new DAP in 2036 Mahmud Hossain Opu/Dhaka Tribune
DNCC Mayor Annisul Huq said they will take charge of all the city canals to maintain them properly.
DSCC Mayor Mohammad Sayeed Khokon said his corporation had been working on the storm water drainage system in the city's waterlogged areas.
"We will take responsibility all the drainage network if Dhaka Wasa hands them over to us," he assured.
Mayor Khokon has previously slammed Wasa for its failure to address the problem.
But Wasa Managing Director Taqsem A Khan counters by blaming the water-logging on waste congestion in the drainage system.
"The capacity of storm water drainage lines and canals are significantly reduced because of clogging with solid garbage, and the two city corporations were supposed to clean that up.
"Flood plains around the capital were filled up by real estate companies," he added.
The Wasa chief further said a master plan has been launched up to 2035 to develop sewerage system and storm water drainage networks.
City corporations to play main role in future
The Ministry of Local Government and Rural Development has handed over the maintenance of the city's drainage system from Wasa to the two Dhaka city corporations, accusing Wasa of failing to properly take care of the canals.
Addressing a joint meeting between different government stakeholders at the DNCC office in Gulshan on July 16, Local Government Minister Khandkar Mosharraf Hossain said they had taken the decision with a view to recovering Dhaka’s 26 canals from grabbers, which are a crucial part of the drainage system.
[caption id="attachment_108037" align="aligncenter" width="800"]
The government in September 2008 approved the Dhaka Water Supply and Sanitation Project (DWSSP), in association with the World Bank. As part of the project, Dhaka Wasa took steps to reclaim 26 canals from illegal occupation by building walkways, channels, lining and planting trees along the canals’ embankments, but the project has not succeeded Mahmud Hossain Opu/Dhaka Tribune
The maintenance responsibility of the canals had been lying with the Wasa for years though they are owned by the office of the Dhaka deputy commissioner.
DNCC Mayor Annisul Huq presided over the meeting attended by Housing and Public Works Minister Mosharraf Hossain, Water Resources Minister Anisul Islam Mahmud, lawmaker AKM Rahmatullah and Dhaka Wasa Managing Director Taqsem A Khan.
"Wasa has been unable to resolve Dhaka’s water-logging crisis. So, the responsibility should be vested in public representatives as they are well informed of the people’s needs," the LGRD minister said.
"The projects taken earlier did not succeed in effectively addressing the water-logging problem. Therefore, all bodies including the two city corporations, Wasa, Rajuk, Water Development Board and Bangladesh Inland Water Transport Corporation will have to engage in collaborative work and devise a master plan to resolve the problem," he added.