Developing local technology to keep the rivers flowing
Sunday, 30 August 2009
Shahiduzzaman Khan
PRIME Minister Sheikh Hasina announced recently that the country's rivers would be restored to their original feature through dredging. She said the government has already started negotiations with the World Bank, the Netherlands and other donor agencies for assistance. The donors have shown their positive attitude in funding such projects. The government is likely to implement two projects at an estimated cost of Tk 11.59 billion to carry out river dredging throughout the country.
The Prime Minister directed the authorities concerned to prepare a complete action plan for dredging the country's silted up rivers. The proposed long-term river dredging project should not be of more than 15 years, as rivers must be given back their navigability immediately. The government plans to start work on the river dredging project through re-excavating the Gorai River.
The Prime Minister also directed the authorities to deploy two full-time dredgers at the estuaries of the Karnaphuli connecting Chittagong seaport and Pashur River linking Mongla seaport to the Bay to keep the channels navigable round the year. There are indications that Dhaleswari, Kapatakkha, Turag, Balu and other rivers will also be dredged in phases. At the same time, maintenance dredging will also be continued periodically.
It is now evident that most of the country's 310 rivers were dying and losing water conservation capacity for lack of dredging. Dredging was not continued regularly in Bangladesh after the World War II, which resulted in the present polluted, silted condition of most of the rivers. According to a report, country's waterway network has been shrinking drastically due to inability of the dredging department of Bangladesh Inland Water Transport Authority (BIWTA) to remove increased siltation from the riverbeds, causing negative impact on overall economy. The waterway routes have reduced to 3,800 kilometres (km) from 5,200 km in winter season, due mainly to successive governments' indifference to strengthen the dredging department of BIWTA over last three decades. In the rainy season, the waterway network is reduced to around 6,000 km from 8,400 km due to siltation.
The waterways have gradually become unfit for navigation as it is not being possible to remove silt by dredging as per demand, hampering navigation, irrigation and fisheries.
It is possible to keep the waterways navigable uninterruptedly for ferry, steamer, launch, cargo and oil tanker if at least 0.5-0.6 million cubic metre dredging is done annually at the ferry and shipping routes. The water transports could carry more passengers and goods at low cost compared to bus, truck, wagon and Biman.
Bangladesh is criss-crossed by a network of 24,000 km of rivers, canals, creeks and Haors. According to a report, five million cusec water and 2.4 billion tonnes silt flow through rivers of Bangladesh each year during the monsoon while all rivers of the world carry 13 billion tonnes silt in a year. It means about 18.50 percent siltation happens through the rivers of Bangladesh. Due to the deposit of heavy silt, most of the rivers in the country are gradually being filled up creating obstacle to navigation.
Experts say it is possible to dredge all rivers and canals in the country using human and technical resources available locally. They say by using traditional methods, it is possible to do dredging work at 'surprisingly low costs'. With slight modifications, traditional 'volgates' currently used to extract sand from the riverbed, could be used to dredge canals and rivers scientifically and thus save valuable foreign currency needed to import conventional dredgers. Volgates are only equipped with suction mechanism but they could be modified to better utilise them.
If the government can equip these volgates with cutting and swinging components, there will no problem in dredging. Conventional dredgers are able to maintain uniformity while dredging the riverbeds. At present, volgates can only lift sand from the riverbed, leaving large ditches in its place, which result in complications for the flow of the river. Some dockyards have been approached to design the volgates to scientifically dredge the dying rivers.
Hundreds of private volgates, however, now lift billions of cubic metres of sand every year from the riverbeds of Meghna, Dhaleshwari and Buriganga rivers. The large amount of sand extracted by them feed the thriving construction sector as well as projects surrounding the metropolis. The government should immediately involve the country's dockyards, and institutions such as Bangladesh University of Engineering and Technology (BUET), to develop local technology for river dredging.
Last year, the BIWTA formed a four-member committee to explore possibilities of dredging the rivers by private entrepreneurs. The committee, comprised of experts from the BIWTA and Water Development Board revealed that dredging of all rivers and canals could be completed almost free of cost under some strict guidelines. The committee formulated a set of policy guidelines for the dredging operations and sent it to the International Union for the Conservation of Nature (IUCN) for further evaluations. IUCN is yet to offer its opinion on the subject.
Coordination among the agencies concerned is vital for river dredging. Drying rivers in northern part of the country need to be dredged by the Water Development Board (WDB), as those rivers are used for irrigation and not for commercial transportation. It is also important to revive the water-transport system for ensuring easier and cheaper communications. At least three to four marine academies should be set up in the country for ensuring modern management of the water-transport system. The government should take up a mega plan to dredge the country's rivers for overall development of water transport system. If 110-kilometre waterways surrounding Dhaka is made navigable for watercraft, it will be effective for reducing huge traffic congestion in the capital. There is also a need for developing the river ports' landing stations and signaling system for safe movement of watercraft, especially at night.
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szkhan@thefinancialexpress-bd.com
PRIME Minister Sheikh Hasina announced recently that the country's rivers would be restored to their original feature through dredging. She said the government has already started negotiations with the World Bank, the Netherlands and other donor agencies for assistance. The donors have shown their positive attitude in funding such projects. The government is likely to implement two projects at an estimated cost of Tk 11.59 billion to carry out river dredging throughout the country.
The Prime Minister directed the authorities concerned to prepare a complete action plan for dredging the country's silted up rivers. The proposed long-term river dredging project should not be of more than 15 years, as rivers must be given back their navigability immediately. The government plans to start work on the river dredging project through re-excavating the Gorai River.
The Prime Minister also directed the authorities to deploy two full-time dredgers at the estuaries of the Karnaphuli connecting Chittagong seaport and Pashur River linking Mongla seaport to the Bay to keep the channels navigable round the year. There are indications that Dhaleswari, Kapatakkha, Turag, Balu and other rivers will also be dredged in phases. At the same time, maintenance dredging will also be continued periodically.
It is now evident that most of the country's 310 rivers were dying and losing water conservation capacity for lack of dredging. Dredging was not continued regularly in Bangladesh after the World War II, which resulted in the present polluted, silted condition of most of the rivers. According to a report, country's waterway network has been shrinking drastically due to inability of the dredging department of Bangladesh Inland Water Transport Authority (BIWTA) to remove increased siltation from the riverbeds, causing negative impact on overall economy. The waterway routes have reduced to 3,800 kilometres (km) from 5,200 km in winter season, due mainly to successive governments' indifference to strengthen the dredging department of BIWTA over last three decades. In the rainy season, the waterway network is reduced to around 6,000 km from 8,400 km due to siltation.
The waterways have gradually become unfit for navigation as it is not being possible to remove silt by dredging as per demand, hampering navigation, irrigation and fisheries.
It is possible to keep the waterways navigable uninterruptedly for ferry, steamer, launch, cargo and oil tanker if at least 0.5-0.6 million cubic metre dredging is done annually at the ferry and shipping routes. The water transports could carry more passengers and goods at low cost compared to bus, truck, wagon and Biman.
Bangladesh is criss-crossed by a network of 24,000 km of rivers, canals, creeks and Haors. According to a report, five million cusec water and 2.4 billion tonnes silt flow through rivers of Bangladesh each year during the monsoon while all rivers of the world carry 13 billion tonnes silt in a year. It means about 18.50 percent siltation happens through the rivers of Bangladesh. Due to the deposit of heavy silt, most of the rivers in the country are gradually being filled up creating obstacle to navigation.
Experts say it is possible to dredge all rivers and canals in the country using human and technical resources available locally. They say by using traditional methods, it is possible to do dredging work at 'surprisingly low costs'. With slight modifications, traditional 'volgates' currently used to extract sand from the riverbed, could be used to dredge canals and rivers scientifically and thus save valuable foreign currency needed to import conventional dredgers. Volgates are only equipped with suction mechanism but they could be modified to better utilise them.
If the government can equip these volgates with cutting and swinging components, there will no problem in dredging. Conventional dredgers are able to maintain uniformity while dredging the riverbeds. At present, volgates can only lift sand from the riverbed, leaving large ditches in its place, which result in complications for the flow of the river. Some dockyards have been approached to design the volgates to scientifically dredge the dying rivers.
Hundreds of private volgates, however, now lift billions of cubic metres of sand every year from the riverbeds of Meghna, Dhaleshwari and Buriganga rivers. The large amount of sand extracted by them feed the thriving construction sector as well as projects surrounding the metropolis. The government should immediately involve the country's dockyards, and institutions such as Bangladesh University of Engineering and Technology (BUET), to develop local technology for river dredging.
Last year, the BIWTA formed a four-member committee to explore possibilities of dredging the rivers by private entrepreneurs. The committee, comprised of experts from the BIWTA and Water Development Board revealed that dredging of all rivers and canals could be completed almost free of cost under some strict guidelines. The committee formulated a set of policy guidelines for the dredging operations and sent it to the International Union for the Conservation of Nature (IUCN) for further evaluations. IUCN is yet to offer its opinion on the subject.
Coordination among the agencies concerned is vital for river dredging. Drying rivers in northern part of the country need to be dredged by the Water Development Board (WDB), as those rivers are used for irrigation and not for commercial transportation. It is also important to revive the water-transport system for ensuring easier and cheaper communications. At least three to four marine academies should be set up in the country for ensuring modern management of the water-transport system. The government should take up a mega plan to dredge the country's rivers for overall development of water transport system. If 110-kilometre waterways surrounding Dhaka is made navigable for watercraft, it will be effective for reducing huge traffic congestion in the capital. There is also a need for developing the river ports' landing stations and signaling system for safe movement of watercraft, especially at night.
........................................................
szkhan@thefinancialexpress-bd.com