The government's decision twenty years ago, made on the suggestion of the country's international donors, to convert the capital's canals into box culverts was 'suicidal' for the city's drainage system, according to the Dhaka Water and Sewerage Authority's managing director and other experts.
The failure to take into consideration the need for constant maintenance of the culverts has resulted in additional blockage in the drainage system of the city, said Taqsem A Khan, Dhaka WASA's managing director.
Urban planner Professor Nazrul Islam agreed with Khan. 'We have destroyed the natural drainage system by converting the large canals into box culverts.'
Terming the capital's current drainage system a 'disaster', Dhaka WASA's managing director, along with other experts, also blamed encroachment on the canals by private and public builders and developers and a total lack of coordination amongst different government bodies for the destruc-tion of the city's natural drainage system.
'Dhaka used to have a wonderful natural drainage system, but due to unplanned urbanisation and encroachment, the rivers, natural canals and water bodies are on the verge of extinction, giving rise to a manmade drainage disaster,' he said.
'We now have to try and mitigate the water congestion problem artificially during the rainy season, which can never be a replacement of the natural drainage system that we had,' he told New Age.
Professor Sarwar Jahan, a teacher at the Department of Urban and Regional Planning at the Bangladesh University of Engineering and Technology, agreed with them, adding that in the current scenario it is not possible to have a good drainage system as we have destroyed the natural drains and there is not enough space to create an artificial drainage system because of unplanned urbanisation.
At present, many roads in Dhaka city become submerged in water and remain so for four hours even after a normal shower of 50mm, since the existing drainage system in the city can only remove 12mm of water per hour.
The situation is even worse after a heavy shower of over 200mm, which sometimes happens during the monsoon.
The city, which once had 65 canals, has now only a handful of functioning ones.
Five of the big canals that flowed across the city were the first to go when, in the early 1990s, the Asian Development Bank and JICA funded the conversion of four big canals into box culverts.
The canals — Shegunbagicha Khal, Dhanmondi Khal (now Panthopath), Paribagh Khal and Basabo Khal — had a total length of 6.2 kilometres.
Subsequently further 4 kilometres of canals, under the jurisdiction of Dhaka WASA, were converted into boxed culverts.
The World Bank also funded the DCC to convert the 4.2 kilometre Dholai Khal, located in Old Dhaka, into another uninterrupted box culvert.
The idea was to retain the canals as a drainage system, whilst allowing the city to develop roads above them.
The problem was that the project never considered the issue of how to clean and maintain the box culverts and, as a result, they got blocked up with dirt and waste and drastically slowed down the drainage of water.
'The decision to convert the natural canals to box culverts was just suicidal. It was akin to declaring war on nature. Now it's a great challenge for us to keep these channels open', said Dhaka WASA's managing director.
'We are struggling to keep this large number of box culverts clean,' he added. Many of his fellow officers said that WASA does not have the special equipment necessary to clean up the culverts.
Most of the city's other smaller canals, which were useful for drainage have also become inoperative due to indiscriminate dumping of waste and the construction of roads by local government and housing companies, said the chairman.
'Most of those canals are now no more than small ditches,' he said.
Dhaka Wasa, established in 1963, in 1989 took over responsibility for the drainage and sanitation of the city from the Department of Public Health and Engineering, following a study carried out by the Japan International Cooperation Agency on the creation of a Flood Action Plan after the city was subjected to serious flooding in 1988.
The study also resulted in JICA funding the construction of embankments on the west and north of Dhaka, and four other pump stations in various locations.
However this conversion, which changed what was a gravity-based drainage system into a pump-based one, has only had partial success.
Even after two decades the required pumps, pipelines and water storage ponds — known as 'retarding ponds' — adjacent to the pumps have not been installed or built, as was required by the study, a senior official told New Age.
'There is only one retarding pond in Kalyanpur, but it is not yet complete,' he said. 'There should be three other such ponds, but work on them has not yet been started.'
Moreover, the conversion process, to the extent that it has taken place at all, has only occurred on the Western side of the city.
It has not been co-ordinated with the eastern part of the city which includes Khilgaon, Badda and the Bushandara Housing Complex where the drainage system remains gravity-based.
This is a major cause for water-logging in the centre of the city, said the official.
Another problem is that a significant number of areas in Dhaka are still completely outside the coverage of Dhaka WASA's drainage system.
According to a study carried out by Institute of Water Modelling in 2004, Greater Dhaka has an area of 350 square kilometres but Dhaka WASA services only 140 square kilometres.
Gulshan, Banani, Baridhara, Mirpur and other newly developed areas of the city still remain outside the area covered by WASA, the senior official told New Age.
In these areas other agencies like the DCC, Rajuk and the Bangladesh Water Development Board have constructed feeder channels that drain water mostly into the canals, and also sometimes into the WASA's drainage lines.
'If WASA claims that there was no provision for maintenance in its projects, then those agreements were definitely faulty. Now, the agency must include this provision in its budget,' said Professor Nazrul Islam.
'WASA must also strive to solve other problems immediately, such as constructing drainage lines in the areas not covered by it, for improving the drainage system for a mega-city like Dhaka,' he added.
He also called for a single authority, instead of so many different agencies having various kinds of responsibility, to handle the drainage issue.
The infrastructure of the drainage system has been developed in an unplanned manner by four different government agencies on an ad hoc basis, without co-ordinating with other agencies, with the aim of mitigating the immediate crisis, he observed.
At present five different agencies — WASA, DCC, Rajuk, the district administration and the Water Development Board — have the responsibility to maintain the existing 54 canals, eleven having been completely destroyed.
Dhaka WASA's managing director, however, claimed that the agency was now working on a drainage master plan, referring to various ongoing projects funded by the government and the World Bank.
This is, however, just the latest attempt to devise a drainage and sewerage master plan. Other studies were undertaken in 1968, 1976, 1978, 1981, 1983, 1985, 1987 and again in 2004 to develop a master plan, but none succeeded in producing a plan.
Professor Muntasir Mamun, a teacher of the Department of History in Dhaka University, said, 'Why should we only blame WASA only? Has Rajuk developed drainage systems in its model town projects?'
'Unless and until the policymakers respond effectively to the crisis, none of the agencies will be able to discharge their duties effectively. I believe the local government should be empowered properly and the charters of the utility agencies should be reviewed immediately before the situation goes totally out of control,' he added.
DCC Mayor Sadeq Hossain Khoka, on the other hand, told New Age that all the utility agencies should be under the corporation for ensuring proper co-ordination and better service.
Source : New Age