Waterlogging worsens as remedial steps stagnant

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Inadequate and faulty drainage network, filling up of drainage canals and lack of proper cleaning of drains are the main reasons behind waterlogging in the capital, experts said.

The drainage system in the city was not upgraded keeping pace with the rapid urbanisation while around half the canals in the city dried up or have been illegally filled in and occupied over the last two decades causing waterlogging in many parts of the city during the rainy season.

According to experts, Water Supply and Sewerage Authority (Wasa) has to deal with 150 square km of the capital, less than half the actual city size, and it requires around 350km of rainwater drainage pipes. It, however, only has 265km of drainage pipes.

“About 90km more rainwater drainage lines are needed at different areas of the city to strengthen the drainage system. The width of the existing pipes should also be increased,” said an official of Wasa.

Dhaka Wasa had 135km of drainage lines in 1990 and it has been extended to 265km. However, the population of the capital city was 68.44 lakh in 1991 and now it is 1.20 crore. The number of houses in the city has more than doubled, said officials at Wasa and Rajdhani Unnayan Kartripakkha (Rajuk).

Experts say that the drainage system was inadequate in the late 80s and early 90s but the waterlogging problem was not that visible since the canals, jheels and other water bodies had not been filled up then.

Most parts of Uttara, Gulshan, Banani, Badda, Manda, and large sections of Khilgaon, Bashabo and Rampura are still outside the Wasa’s drainage system coverage, officials said.

In places where there is no drainage network of Dhaka Wasa, the Dhaka City Corporation (DCC) covers the area with drainage pipes or surface drains, they said.

Due to the lack of proper cleaning of the existing drainage systems of both Wasa and the DCC the network does not function properly, experts say.

Even though Wasa is mainly responsible for maintaining the city’s drainage system and cleaning the drains once a year, most of the time nearly half the drains remain clogged as the cleaning is done manually and improperly, said Architect Iqbal Habib, member secretary of Urbanisation and Good Governance Committee of Bangladesh Paribesh Andolan.

Dhaka Wasa took over the city’s water and sewage management from the Directorate of Public Health in 1989 with a 135-km drainage network that covers a 60-square-km area, said an official of Wasa. The Department of Public Health developed the 135km drainage network between 1964 and 1989 under eight projects, the official said.

According to official figures of Wasa, it now has 265km drainage pipes and 75km of canals of which 10km is box culverts. The DCC has 999.47km of surface drains and 1052.20km of drainage pipes.

Dhaka Wasa is the custodian of drainage system as the main lines of drainage are maintained by Wasa and the surface drains of DCC are linked to those lines.

Sources in Wasa and DCC say that a lack of coordination between the activities of Wasa and DCC is hampering drainage management in many areas. The drainage system should be brought under one authority to make the system more effective, an official of Wasa said.

DCC Mayor Sadeque Hossain Khoka repeatedly demanded that the government brings the utility-providing agencies, including Wasa, under the DCC for better coordination in their activities and to form a metropolitan government.

An official of Wasa said a committee, formed to prepare national drainage guidelines during the tenure of BNP-led four-party alliance government, in a meeting suggested bringing all the drainage lines of DCC under Dhaka Wasa as it is the custodian of the drainage system and it maintains the main drainage lines.

However, no initiatives were taken by the government to bring the drainage lines under one organisation, the official said.

Eighty percent of the canals and water bodies, the major means for water to recede, have been filled up during the last two decades. This has increased pressure on drains of Wasa and DCC, said Chairman of Save the Environment Movement Abu Naser Khan.

The waterlogging situation was much better 15 years ago, even though the number of drains was much less, because canals and other water bodies helped water to recede, he said.

Seventeen out of 43 canals in the city have already been filled up entirely while the rest 26 have narrowed down due to unplanned urbanisation, an Wasa official said.

As the water bodies and canals in different areas have been filled up either partially or entirely, the pressure on pump houses to pump out water has increased. The capability of pump houses needs to be improved and the number of pump houses across the city has to be increased, the official said.

The capacity of pump-house reservoirs, where water comes from different parts of the city to be pumped out into rivers, is also reducing due to unplanned urbanisation, the official added.

There are two permanent pump houses of Wasa, one at Dholai Khal and another at Kalyanpur. Another pump house at Goran Chatbari in Mirpur is run by Bangladesh Water Development Board (WDB). There are two temporary pump houses at Rampura and at Janapath in Kamalapur, the Wasa official said.

Architect Iqbal Habib said it is necessary to monitor the drains all round the year but Wasa has no monitoring system. In foreign countries electronic sensors are used for monitoring the drainage systems of large cities.

Since setting up this system in Dhaka would be costly, he suggested forming a team to monitor the rainwater drainage lines round the year and forming of another team to clean them.

“Wasa becomes alert about the drains clogging in the rainy season and starts cleaning them but it needs to unclog the drains during the dry season,” he said.

The drains are cleaned during the rainy season so that the contractors have to do less work for their pay as most clogs are flushed out with the rainwater, he said. The garbage extracted from drains and box culverts are kept on the side which in many cases fall back into the drains and culverts and back into the cycle.

Habib said faulty design of drains at different parts of the city is also a reason for waterlogging. He said the drainage lines under the central reservations of Rokeya Sarani, Monipuripara and Gulshan Avenue were done wrongly. The drains should have been on the two sides of the streets, he said.

However, an official of Wasa said just because the drainage lines were built near the central reservations of a street does not mean there are faulty. He, however, acknowledged that there are a number of construction faults at places.

Managing Director (MD) of Wasa Raihanul Abedin said about 50 workers clean the drains round the year as part of Wasa’s routine work and they also monitor drains. He said they hire workers for cleaning the drains especially before the rainy season.

“We try to manually clean the drains as much as possible,” he said, adding, “We are trying to buy modern drain-cleaning equipment in the hope of improving the situation.”

“We are going to take up a $150 million project financed by World Bank and when implemented most of the important areas of Dhaka will come under the Wasa drainage system and 13 canals will be developed,” said Raihanul, adding that two permanent pump houses at Rampura and Janapath will also be completed under this project.

World Bank delegates completed the detailed planning for implementing the project on July 29. The delegates and Wasa officials have finalised the implementation arrangement for the project, said an Wasa official.

Another pump house will be constructed at Kalyanpur under a Tk 78-crore project. Japan has granted Tk 53 crore for this. The project is scheduled to finish by June, 2009.

The Wasa MD said they cleaned 150km of drain pipes, 21km of canals–Kalyanpur main canal, Kalyanpur branch canals Ka, Kha, Gha, Uma and Cha and Katasur, Ramchandpur, Segunbagicha and Jirani canals–and 7km of box culverts for the current rainy season.

Thirteen canals have also been cleaned after they were freed from illegal encroachers in the current season, he said.

Chief Waste Management Officer of DCC Maksudur Rahman Chowdhury said they conducted a three-month-long special cleaning drive of surface and pipe drains before this rainy season in addition to their regular cleaning activities.

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