Ganges Delta Salinity: Bangladesh Scaling Pathway & Roadmaps
Increasing river salinity is a rising threat in Bangladesh’s coastal Ganges-Brahmaputra-Meghna Delta, affecting agriculture, livelihoods, and drinking water. Under CGIAR Scaling for Impact, IWMI has developed an AI/ML-driven salinity forecasting and advisory system to help farmers and water managers time sluice gate operations around polders to reduce salinity risk.
Shreya Chakraborthy, Mahesh Jampani, Ahasan Habib, Karthikeyan Matheswaran
Salinity management in the Ganges Delta
Increasing river water salinity trends have been a growing concern in coastal Bangladesh in the Ganges-Brahmaputra-Meghna Delta, with implications for agriculture, livelihoods, and drinking water availability. Shifts in precipitation and sea-level rise, and changes in upstream flow and siltation, together affect river salinity trends with implications for water and food security in the deltaic system. Salinity trends in coastal Bangladesh vary from west to east, and several governmental and non-governmental research and development initiatives have been undertaken to assess and test solutions for salinity issues across the region. The Bangladesh Delta Plan (BDP) 2100 is designed to be a comprehensive techno-economic adaptive plan that deploys interventions across water, land, ecosystems, and the environment to ensure resilient futures for the Ganges Delta. Connecting these siloed interventions can help align them on a shared pathway towards coordinated salinity management efforts in Bangladesh.
Salinity forecasting system for polders
To this end, under the CGIAR Program on Scaling for Impact (building on the foundations laid by the Asian Mega Deltas (AMD) research initiative), the International Water Management Institute (IWMI) jointly with International Rice Research Institute (IRRI) and the Institute of Water Modelling (IWM), have been working to develop an innovative Artifical intelligence/Machine learning (AI/Ml)-driven salinity forecasting system designed to predict river salinity levels around polders and provide advisories to farmers regarding scheduling of sluice gates operations to support freshwater into the polders thereby reducing the risk of higher salinity within the polders. Creating impact at scale from this advisory requires an enabling environment that supports scaling and uptake of the piloted salinity forecast system for wider adoption across polders and operational use. Scaling this innovation requires periodic updates to salinity data, active water management groups to operate sluice gates, desilted canals to hold and drain irrigation water, community awareness, Operations and Maintenance financing systems, equitable water allocation mechanisms, inter-departmental coordination, and strong local governance to ensure transparency and accountability of these processes. IWMI is therefore developing a scaling pathway for the innovation that requires not only innovation-specific support at the community level but also a larger institutional and policy environment roadmap for salinity management in polders across coastal Bangladesh.
Scaling salinity management strategies
The scaling logic is built on three interconnected tiers: Innovation and Co-Design at the field level, Institutional Alignment and Integration, and Policy Uptake and Replication. At the field level, the scaling effort is enabling the adaptation of AI-based salinity forecasting tools to local realities. It includes effective and simple methods for delivering the advisory (phone-based apps, SMS, IVR, public miking, or integration into agricultural extension systems). Institutional Alignment requires the advisory systems to be embedded into the operational workflows of Union Parishads (local government units), the Bangladesh Water Development Board (BWDB), the Department of Agricultural Extension (DAE), and the Department of Environment (DoE) through joint operating procedures, data-sharing platforms, and coordinated gate management. Finally, policy uptake and replication require a national salinity roadmap that integrates lessons and tools from multiple efforts across different organisations in pilot sites across the coastal belt to inform short-, medium-, and long-term solutions and to support coordinated salinity management in coastal Bangladesh. In this context, IWMI organized a national workshop, ‘Roadmap for Strategic Salinity Management in the Coastal Delta of Bangladesh’, together with IWM and IRRI in Dhaka on 02nd December 2025, with participants from important national stakeholders.
Stakeholder-driven scaling pathway and roadmap
Through two structured and participatory stakeholder engagements, organised at the regional (September 2025, Khulna) and national (December 2025, Dhaka) levels, a scaling pathway and a draft roadmap have been developed to align with local institutional and operational contexts and experiences. Stakeholders prioritised short-term actionability by optimizing existing resources while awaiting a slower, large-scale structural overhaul. For instance, they identified that primary data is already being collected by multiple organisations and projects in Bangladesh, and that this can be made accessible and usable by collecting and housing these public primary and secondary databases by Water Resources Planning Organisation (WARPO), Bangladesh Bureau of Statistics (BBS), or BWDB. Similarly, they identified the value of an inventory and a dashboard of actors and interventions operating in the salinity management in the coastal belt to enable the planning institutions to coordinate and align investments and efforts. Stakeholders recognised "committee fatigue" from building issue-specific committees for every issue and therefore recommended repurposing the current District IWRM committees (Integrated Water Resources Management efforts at the district level) for local inter-departmental coordination. Similarly, suggestions emerged around integrating the advisory system into existing extension systems and the DAE's existing ‘Khamari app’, and potentially leveraging existing social safety nets, such as the Vulnerable Group Development (VGD) card system, to incentivise beneficiaries as sluice gate operators.
As salinity concerns in coastal Bangladesh intensify, solutions must be sought at different levels, and scaling pathways for innovations can lead to larger structural changes needed for sustained impact. Moving forward, an evidence-based scaling pathway and salinity management roadmap under development by IWMI will be instrumental in driving improved uptake of the AI-driven salinity advisory system and serve as an effective planning tool for national-level salinity management in coastal Bangladesh.