If flood control or management, were to be adopted the control of the Ganges and the Brahmaputra would be of the utmost importance. Because of the sheer volume of water flowing though Bangladesh, one method of flood control would be to construct levees on every river and control the flow between each channel. This is an extremely difficult task; rivers, lakes and swamps take up 10% of the land, so the sheer cost of levying every potential channel that could act as a flood risk is extremely expensive. The amount of time required plan test and construct such flood defences could be up to 100 years, so there is no “quick fix”. The maintenance cost of such a defence once built would follow into billions of dollars a year, the maintenance of defences of the Mississippi flood plain are 85 million dollars a year. These defences being on a much smaller scale than those that would needed on rivers in Bangladesh. Bangladesh might struggle to reach prosperity once defences of such magnitude were built. Another problem is that flood defences of such size have never been built and so engineers simply do not know what will happen after construction. The sheer size of levees, that would be required would be huge, and how would engineers plan for huge floods such as that of the 1993 Mississippi on rivers the size of the Ganges and Brahmaputra would be extremely difficult cost wise.
The problem being is that should the defences be constructed to ensure Bangladesh’s development. With flood defences and river management would could more efficient farming. The river would be narrowed and so land reclaimed and possibly alleviating overcrowding. The rivers are so long that they could be well used for transporting industrial goods. Water management would enable irrigation and crops such as high yield rice, which would produce a much more cost-effective crop, yield to be produced. This high production crop is believed would boost the economy bringing in much needed income to the country. There would be fewer famines as the 7.16 hectares of crops destroyed each year would be saved. The growth rate of Bangladesh is also huge, the population is expected to increase by 60 million in the next 10 years. With such a large growth rate Bangladesh certainly needs flood defences, as with an increasing population when there is a catastrophic flood huge numbers of people will die. Many arguments against construction of defences are based upon the successes of the Mississippi River defences and the great flooding of 1993. Opposition against construction of similar defences view that rivers simply cannot be controlled. The case is though that the Mississippi defences did work, they prevented many floods from flooding onto the flood plain. When the great flood did occur, catastrophic flooding occurred because the defences couldn’t control something they were not designed to defend against.
There are many arguments on why the flood defences should not be constructed. One view is that man should simply not mess with the sheer forces of nature and water. One problem is that of the deforestation in the Hamalayas and Tibet. Huge amounts of silt are eroded and washed down in the rivers. Present flood defence methods would inevitably cause the change in the cycle of transportation and deposition. With levees constructed the rivers would silt up raising water levels and increasing the likely hood of flooding. Each year the floods fertilise the ground with fertile soil eroded from the mountains. With levees the water and silt would be contained in the channel and not fertilise the soil, the ground losing its productivity and fertiliser required. Fishing in the main river channels and also minor rivers of Bangladesh is very important. It provides an important source of income and provides a much-needed balance to the diet. River control could effect the fish stocks in the river and so remove a valuable asset of the country. The rivers are also very holy so people would be reluctant to change its natural flow because of this.
My view is that Bangladesh is in a very great need of flood defences. This will encourage growth in the country and allow for more permanent development. At the present time I feel it is very risky to construct defences on such huge rivers when the understanding of the processes are very limited. Without a good understanding of the nature of the river the consequences could cause a ‘man made’ flood at such great magnitude that millions would probably be killed. The co-operation of the surrounding countries is also in much needed as flooding will be increased in magnitude if the river levels rise from silting. The reduction in deforestation would stop river channels from raising their levels. Reforestation would make a huge reduction in erosion but presently the co-operation of this scale is unlikely. The price of the defences is also a hot issue but put in context with the anount of damage caused - 3 billion in the flood of 1976, the defences would be well worth it and the price of which would be recovered in a few floods.