This report advocates a strategic framework for preparing integrated flood management plans. Our research, using river basins in Bihar and Odisha as case studies, provides clear insights into bottlenecks as well as promising interventions that would reduce the losses and burdens of millions of people currently affected by floods. Mathematical modelling as well as social surveys proved to be key to unravel the intricacies of the problem: to quantify what needs to be quantified and to qualify the needs from the grassroots level. Major conclusions can be drawn from these basins which in many ways can be regarded representative for many others:
- As per our model calculations for both river basins it was found that by providing the 1:25 safety standard for rural areas around 90% of the average annual damage could be avoide; this implies that the marginal extra benefits quickly diminish beyond this safety standard.
- In terms of flood hazards, climate change is expected to cause heavier rainfall events and can lead to significant increases in flood extent (in the order of 25% in 2040 and perhaps 30% in 2080 in the case of the Brahmani-Baitarani).
- Upstream structural flood control measures, such as dams and river diversions, would lead to a significant reduction in flood hazard.
- Flood embankments are currently and will remain the major flood control measure and the preferred option of a majority of the people.
- Non-structural measures necessarily complement structural measures, as is well understood by all key stakeholders.
Marchand, M.; Sethurathinam, S.; Dahm, R.; Lal, M.; Ekande, T.G.; Kumar Manhacheri, V.; Upadhyay, V.; Muralikrishna, M.; Singh, U.; Nansey, J.; Dhar, S. Operational Research to Support Mainstreaming of Integrated Flood Management under Climate Change. ADB, Manila, Philippines (2015) 187 pp.