Battling Riverbank Erosion: Saving Lives and Livelihoods in West Bengal
By Indrajit Pala, Debamitra Basub, Neshma Tuladhara, Nilay Pramanickb, Anirban Mukhopadhyay c, Ayush Baskotaa
* aDisaster Preparedness, Mitigation and Management, Asian Institute of Technology, Thailand and bScience for Sustainability, India.
Morning sunrise in Sunderbans delta, West Bengal (Suprabhat Dutta from Getty Images)
For decades, riverbank erosion has been one of India's most pressing environmental challenges. Almost all of India's rivers face the threat of erosion along their banks, a problem worsened by a mix of natural and human drivers. In West Bengal, the Bhagirathi-Hooghly Riverbank experiences significant erosion, leading to distressing situations in the villages within the Ganges Brahmaputra Meghna Delta.
In 2023, we published 'Upstream River Erosion vis-a-vis Sediments Variability in Hugli Estuary, India: A Geospatial Approach,' a study which uses satellite data to assess the extent of river-shoreline changes, through erosion and deposition, losses incurred, and to identify the hotspots and vulnerable areas in the river basin. Here, we discuss the trends of riverbank erosion discovered in the study and the potential impacts on local livelihoods and vulnerability.
Trends and Impacts
Riverbank erosion has led to ecological disturbances across the basin. We have found an alarming trend erosion; more than two-thirds of farmers in Matiari and around half in Rukumpur have lost over 90% of their agricultural lands. Residents in Ganjadanga and Akandanda face similar challenges and a quarter of the land in the Kaliachak II block has eroded.
Alongside riverbank erosion, residents face regular seasonal flooding and prolonged waterlogging as the natural embankments are often breached. This leads to a myriad of cascading socio-economic impacts on the delta residents. One of the most intense impacts is the loss of agricultural land and assets, leading to reduced income and subsequently prompting out-migration as people relocate to seek safe housing and sustainable livelihoods. This displacement starts a chain reaction of challenges, from unemployment and economic insecurity to social disparity, crime, child labour, and a decline in socio-cultural fabric. Addressing these complex issues requires comprehensive strategies to tackle the multifaceted challenges arising from riverbank erosion and flooding-induced human displacement.
In flood-prone areas like the Ganga-Brahmaputra-Meghna delta, the current situation is unsustainable due to population growth and economic development, which add more pressure to the region. The riverine areas are often over-exploited, both for human settlements and agricultural activities. River basin farms produce higher yields than upland farms (due to fertile grounds and an abundance of water), which leads to excessive cultivation, inadequate land management and removal of natural protection such as trees and shrubs. Furthermore, infrastructure in upstream cities alters the water and sediment flow, which also aggravates erosion.
Overall sustainability and resilience can only be preserved through technological developments, effective government policies, and the awareness amongst the population.
Diverse adaptive initiatives - ecological, technical, institutional, and economic - can be utilised to improve the sustainability and resilience of the flood-affected region. In India, efforts to combat riverbank erosion and flooding mainly focus on ecological and technical solutions, such as constructing and restoring dams, barrages, and embankments, implementing early warning systems, investing in flood shelters, and developing necessary infrastructure like floating houses.
Policies and Initiatives for Risk Management
A series of policies and projects are playing a pivotal role in safeguarding these landscapes. Let's delve into some key initiatives that underscore the importance of erosion control and river management.
The 2012 National Water Policy focuses on protecting land from erosion caused by rivers. It suggests well-planned structures like revetments, embankments, and spurs to be constructed and maintained based on studies of the river's shape to avoid irreversible damage. The Policy on Sediment Management (2017) addresses sediment control, providing a foundation for effective strategies. Additionally, the National Water Mission, part of the National Action Plan on Climate Change, stresses the importance of designing erosion control measures that consider a 50-year return period flood. There is an increasing sense for strategic river management, particularly with the looming threat of projected changes to glacial flow, tidal hydrology and precipitation due to climate change. Similarly, the 2008 National Disaster Management Guidelines for Floods advocates anti-erosion measures like revetments, slope pitching, and spurs using traditional or geosynthetic materials. These measures are designed to safeguard towns, cities, villages, and critical infrastructure from river erosion.
State Governments are at the forefront of managing floods and erosion, addressing issues based on their priorities. The Union Government supports these initiatives by providing technical advice and financial aid, mainly through the Brahmaputra Board and the Flood Management Programme (FMP) led by the Ministry of Jal Shakti (Water Management). In West Bengal, over 300 million USD is currently invested by the State and Central Governments to combat erosion along the banks of the Bhagirathi-Hooghly River. City-level master plans guide the implementation of these measures, encouraging collaboration with local authorities. Additionally, projects like coastal dams in the Sundarbans region are underway.
The Farakka Barrage Project is another significant initiative aimed at river training and flood control along the Ganges River. However, its construction alters river flow, requiring the construction of retired embankments. Approximately 20 million USD has been invested in strengthening the riverbanks, and these measures are helping to protect the lives and assets of thousands of people.
To counteract the multi-dimensional impact of riverbank erosion, the Mahatma Gandhi National Rural Employment Guarantee Scheme emphasizes canal and river restoration, vetiver plantation, and preserving riverbank embankments, often involving local communities. Additional efforts involve identifying vulnerable areas, initiating building projects, and conducting training and awareness programs. Investments in early warning systems through mobile devices and alarms have further enhanced response capabilities in the face of embankment breaches and flooding.
Final thoughts
Addressing the intricate challenge of riverbank erosion along the Bhagirathi-Hooghly River basin demands a comprehensive approach that acknowledges the dual impact of climate change and human activities. The consequences on local lives and livelihoods underscore the urgency of action.
The over-exploitation of riverine areas in the GBM delta region, coupled with inadequate land management, worsens the issue, while upstream urban development further disrupts natural flow patterns, intensifying erosion.
The Union, State and Local governments are proactive in risk mitigation and response; yet challenges remain. Structural interventions like barrages and embankments have proven insufficient in mitigating the problem alone, so there is a need to shift towards a holistic approach in conjunction with non-structural solutions. Community preparedness and social engineering emerge as pivotal strategies to minimise the devastating effects of riverbank erosion and associated floods. Our research in the Living Deltas Hub, focusing on erosion hotspots, climate change and urbanisation impacts, and the efficacy of protective measures, aims to foster informed discourse and decision-making.
By understanding local contexts through community-based activities and field research, we strive to unravel the intricacies of community resilience. This knowledge is paramount for crafting structured, localised, and inclusive adaptation strategies that align with the Sustainable Development Goals (SDGs). Through these efforts, we aspire to fortify livelihoods, enhance food security, improve economic status, and foster sustainable infrastructure development. In pursuit of these goals, we envision a future where the Bhagirathi-Hooghly River basin thrives, resilient to the challenges posed by riverbank erosion, and where the well-being of communities remains at the forefront of our collective endeavours.
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