Abstract: The Southwest Coastal people of Bangladesh have introduced Tidal River Management (TRM) as an environmentally acceptable water resource management practice based on their indigenous knowledge of water logging of low lying coastal land. TRM helps to address problems resulting from different anthropogenic and structural development activities, and it has been successful in helping coastal communities to adapt to climate change and rising sea level vulnerability by forming new land in Tidal Basins. Hence, it is essential to measure sustainability impacts of TRM from the environmental, socio-economic and institutional perspectives. Therefore, firstly, the study identifies sustainability indicators of TRM considering ecosystem services and secondly, develops an inclusive conceptual framework to understand the important impacts of each indicator at various spatial and temporal scales. The conceptual framework is followed by the construction of a Sustainability Index of Tidal River Management (SITRM). It has advantages over the Ramsar Convention framework (2007) and the World Meteorological Organization (WMO) framework (2012) to measure water sustainability as it includes a sustainable model to project future vulnerability of the community, river and Tidal Basin, emphasizing on climate change issues. It also involves trade-offs analysis, livelihood analysis and SWOT (Strengths, Weaknesses, Opportunities and Threats) analysis for a complete impact assessment to enable decision-makers to focus on those services most likely to be of risks and weaknesses or opportunities and strengths for the sustainability of TRM. Moreover, the framework is a useful guide for policymakers in identifying the sustainability impacts of TRM so that they can choose best coping strategies for coastal people to effectively deal with adverse effects of water-logging and undesired climatic events as well as environmental and socio-economic changes in coastal areas.