The southwest delta region of Bangladesh is one of the most vulnerable areas in the world to the impacts of climate change. The region is characterized by low-lying areas, with a complex network of rivers, estuaries, and tidal channels that are affected by both monsoonal and tidal flooding. Livelihoods in the region are under increasing pressure from changes in the physical environment, compounded by socio-economic dynamics such as population growth and a decreasing income from traditional agriculture. 

Over the last 50 years experts and engineers have been trying to deal with these adverse trends by developing a series of coastal embankment projects and optimized, rationalized polders following the Dutch examples. However, these embankments and polder developments have also caused unintended consequences, such as waterlogging, salinity intrusion, and ecological degradation.

Local populations are less and less content with the solutions that were promised by the development of the polders. In recent events local farmers have breached the embankments around the polders to improve the drainage situation of their inundated lands. Farmers are increasingly resorting to shrimp farming as an alternative way to make a living, but bringing in more and more salinity. These dramatic dynamics are further enhanced by a top-down approach to water management: communication and exchange of ideas between experts and local communities is almost absent.

The negative impacts of the coastal embankments and polder development on local communities have been significant, with loss of livelihoods and displacement being common. As a response, Tidal River Management (TRM) has emerged as an alternative approach to embankment-based flood control. This TRM aims to work with the natural flow of tidal rivers and their associated wetlands, rather than against them, to reduce flood risk and improve water management. 

Although the approach looks promising, balancing social benefits and costs seem to be very challenging. Compensation schemes for the farmers being affected by the return of tidal wetlands have repeatedly failed, and so central decision makers seem to return favoring the engineering approaches such dredging. We are still a long way from finding dedicated, locally adjusted, social-inclusive solutions. 

The real challenge in improving livelihoods is in handling the complex interaction between many diverse actors. Agriculture is recognized as one of the important stakeholder sectors, but the agricultural sector itself is heterogeneous, consisting of diverse groups ranging from large landowners to subsistence farmers and landless seasonal laborers. All these actors have individual stakes, incentives and thus individual perspectives and behavior towards the dynamic changes in land use and water management.

The 'Tidal River Water Custodian' decision making framework is about resilient livelihoods in the next 50 years in changing deltas such as South-West Bangladesh. Decision making is a process that needs careful design and a strong focus on the inclusion of all relevant stakeholders in the decision making process. The current limited focus on the geo-physical environment and an optimization of infrastructure and control structure misses the ultimate goal of defining adaptation strategies to improve the livelihoods of the local communities.

With our approach we enhance current decision-making processes with inclusion of a mapping of the diversity of local communities and their vulnerability profiles, by recognising a multitude of stakeholders with a large variation in stakes and incentives. The approach aims at explicitly include these local actors and their characteristic stakes in the decision making process. To this end we develop a decision support process and decision support tool with explicit reference to the stakeholders.

We developed a Serious Game approach that incorporates mental models of the community into the game design. Our serious gaming helps stakeholders to better understand the complex social, economic, and environmental factors that influence water management decisions in the Tidal River region. 

Local communities are often the most affected by water management decisions, yet their voices and perspectives are not always heard or fully understood by decision-makers. The Tidal River Water Custodian approach helps to bridge this gap by allowing stakeholders (both the decision makers and the local communities) to explore different scenarios and understand the consequences of their decisions on the community and the environment.

A Decision Support System is not a tool, but its always a process that needs careful design.

We developed a tailor made decision support system (DSS) that includes local communities' mental models and that can help facilitate effective decision-making in Tidal River water management. By integrating these mental models, the DSS provides a more comprehensive understanding of the complex water systems, capture the diverse perspectives and values of stakeholders, and improve communication and collaboration among them. 

The DSS allows for scenario planning and sensitivity analysis, which helps the users and decision makers to anticipate and prepare for potential future scenarios. The use of the DSS can ultimately lead to more sustainable and equitable water management decisions, by ensuring that stakeholders' voices and perspectives are incorporated into the decision-making process.