Fresh water for Buriganga: Project underway to get Jamuna water into the highly polluted river during lean period

The government has finally started dredging the Turag river in efforts to bring fresh water to the highly polluted Buriganga river.

The dredging is part of its Tk 945-crore project to connect the Buriganga with the Jamuna river through Turag-Bangshi-Pungli and then the new Dhaleshwari near Bangabandhu Bridge.

The first-phase dredging, which began last month, will cover a 6.5-kilometre stretch of the Turag--from Rustampur point to the Pungli canal. The Turag meets the Buriganga near Aminbazar, on the outskirts of the capital.

Water Development Board, the implementing agency of the project, will dredge 162.5 kilometres of rivers and canals in different phases.

Titled "Buriganga River Restoration", the project was planned to be completed in December 2013. It might take more time now as the work started a year late, said officials.

"Once the project is implemented, the Buriganga will get an additional 141 cubic metres of water per second during the lean period," said Project Director Sunil Baran Dev Roy.

"The fresh flow of water will decrease the level of pollution and increase the amount of dissolved oxygen in the Buriganga," he added.

The main objective of the project is to raise the level of dissolved oxygen (DO) to 4 micrograms per litre from almost zero in dry season now. Aquatic life forms cannot survive if the DO level drops below 4.

Experts, however, say this project alone will not be enough to make the Buriganga healthy and clean. The government must relocate the tanneries and stop the industrial units in Savar and Gazipur dumping untreated waste into the rivers in and around the capital.

The water flow in Dhaka's river systems remains almost stagnant for seven months a year including the lean period. To make matters worse, millions of gallons of highly toxic industrial and human waste are dumped into the rivers.

In the second phase of the project, 29 kilometres of Turag-Bangshi will be dredged. A proposal to that end has already been submitted to the purchase committee for approval, Project Director Sunil Roy told The Daily Star.

In later phases, around 63 kilometres of the new Dhaleshwari will be extensively excavated, as this portion of the river is totally silted since Bangabandhu Bridge was built.

Besides, a sluice gate will be set up at the Jamuna confluence to control floodwater during monsoon. "We will not divert any water during the monsoon," Sunil continued.

The idea is to divert around 300 cm of water per second towards the city's river systems. Some water, however, will be taken off for irrigation purposes on the way.

"If 141 cubic metres of water per second is added to the Buriganga during the dry season, pollutants will be automatically flushed out," he observed.

Experts from the Institute of Water Modelling (IWM), which did the feasibility study on the project in 2003, believe diverting water will not affect the environment as over 2,000 cubic metres of water flows through the Jamuna every second.

Asked about rampant river pollution, Sunil said the Water Development Board is responsible only for the river water restoration project. The environment and forest ministry will ensure installation of effluent treatment plants to check pollution.

Hasan and Brothers, a local firm, is conducting the dredging work on the Turag.

IWM will give them technical support.

Source : The Daily Star