Guwahati: Asian Development Bank (ADB) is helping Assam to become a disaster-resilient state by enhancing climate-resilient flood and riverbank erosion risk mitigation systems along the Brahmaputra River.
“Of India’s states and union territories, Assam has the seventh greatest likelihood of natural hazards occurring and has one of the lowest achievements in meeting the Sustainable Development Goals. The rankings largely result from the unpredictable and highly dynamic erosion processes of the Brahmaputra River. Since 1980, devastating events have become more frequent, and the Brahmaputra Valley is among the areas with the highest projected increase in extreme flood events because of climate change,” the Bank says while approving a $200 million loan to strengthen flood and riverbank erosion risk management along the 650 kilometers (km) long main stem of the Brahmaputra River in Assam.
The project will apply a holistic, integrated, and risk-informed approach to scale up investment in flood and riverbank erosion risk management and its long-term planning, while intensifying support for climate and disaster resilience and food security. “By optimising co-benefits and empowering women through disaster-resilient economic activities, the project will benefit about 1 million people and increase crop production over 50,000 hectares,” the bank says.
The project will (i) develop and implement climate-resilient flood and riverbank erosion risk mitigation measures; (ii) strengthen key agencies’ capacity in flood forecasting and warning systems, surveys, erosion and embankment breach modeling, asset management, risk-sensitive land-use planning, and nature-based solutions; and (iii) support the livelihood and disaster resilience of the poor and destitute living in flood embankments.
Riverbank erosion is one of the most prominent causes of disasters in Assam due to the highly dynamic morphology of the Brahmaputra River and its tributaries. Since the Great Assam Earthquake in 1950, the river has widened from about 6 kilometers (km) to 9 km along its 650 km course in Assam, eroding about 5.5% of Assam cultivable area, destroying roads, homesteads, crops, and flood embankments. Since 1954, around 427,000 hectares of land (equivalent to about 7% of Assam’s area) have been eroded at an average annual erosion rate of 8,000 hectares. Between 2000 and 2018, 93 locations eroded along the main stem of the Brahmaputra River in Assam, causing damages to a total length of more than 400 km.
About 40% of the state (i.e., about 9.4% of the national flood-prone area) is inundated on average annually during the monsoon by the Brahmaputra River and its tributaries, resulting in damages and loss of assets and crops.
“Riverbank erosion disproportionately affects the poor, who face significant social hardships, such as loss of homesteads, lands, and crops, and are often displaced to fringe lands or urban slums. Disaster risks increase as the population grows, and the high population density of the state hinders people from moving away from disaster-prone areas,” the Bank says.
By stabilizing 60 km of banks, installing 32 km of pro-siltation measures, and building 4 km of climate-resilient flood embankments in five high-priority districts (Dibrugarh, Goalpara, Kamrup Rural, Morigaon, and Tinsukia), the project will secure living spaces, support livelihoods, create employment opportunities, and ultimately enhance the navigability of the river.
Chronic flooding along the Brahmaputra damages fisheries, agriculture, homes, private and public infrastructure, and lives. Since 1950, large floods have impacted the project area in 1954, 1962, 1972, 1977, 1984, 1988, 1998, 2002, 2004, 2008, 2014, 2017, 2020 and most recently, in 2022.
“Flooding is exacerbated by the ubiquitous riverbank erosion along the Brahmaputra. Riverbank erosion not only destroys land and assets, it also erodes embankment lines, leading to breaches and costly embankment retirements. The combination of high discharges and sediment loads result in a morphologically dynamic river that swiftly laterally shifts within the floodplain,” the Bank says.
Various reports say climate impacts are projected to worsen, compounding recurrent flooding and continual riverbank erosion from the Brahmaputra. Natural hazards and remoteness have led to long-term development slower than the national average, despite similar population growth and density.
The Flood and River Erosion Management Agency of Assam will lead, manage, and coordinate the project activities. The Water Resources Department of the Government of Assam will implement the works, and the Assam Agroforestry Development Board will use nature-based solutions. The Brahmaputra Board, the Assam State Disaster Management Authority, and the Assam Inland Water Transport Development Society will be partner agencies of the project.
