Climate Proofing Infrastructure in Bangladesh: The Incremental Cost of Limiting Future Flood Damage

Abstract

Bangladesh is one of the most flood prone countries in the world. Two thirds of the country is less than 5 m above sea level. Past monsoon flood records indicate that about 21% of the country is subject to annual flooding and an additional 42% is at risk of floods with varied intensity. Although annual regular flooding has traditionally been beneficial, providing nutrient-laden sediments and recharging groundwater aquifers, the country often experiences severe flooding during a monsoon that causes significant damage to crops and properties with adverse impacts on rural livelihoods and production. The 1998 flood inundated two thirds of the land area, resulting in damages and losses of over US$2 billion, or 4.8% of GDP. Climate models suggest increased precipitation, higher transboundary water flows, and sea-level rise will all increase the destructive power of monsoon floods. Using climate change scenarios out to 2050, hydrological and hydrodynamic models, this article estimates an incremental cost to climate-proof roads and railways, river embankments protecting productive agricultural lands, and drainage systems and erosion control measures for major towns of US$2,671 million initially and US$54 million in annual recurrent costs.