The 1996 Ganges Water Sharing Treaty was an important breakthrough in solving disputes over sharing Ganges water between India and Bangladesh. This study evaluates cooperation reflected in the Treaty by performing a quantitative analysis on available water sharing data. The study recognized that inaccurate projection of future flow and the obligation of allocating guaranteed 991 m3/s flows perpetuate the ongoing water sharing conflicts. The provision of guaranteed minimal flow alternately to India and Bangladesh during critical periods leads to frequent occurrences of low-flow events. Results indicated that the Treaty underestimated the impact of climate variability and possibly increasing upstream water abstraction. Statistical analysis of the post-Treaty data (1997–2016) also indicated that 65% of the time Bangladesh did not receive its guaranteed share during critical dry periods with high water demand. It is advised to project the reliable water availability using a combination of modelling and improved observation of river flows. In addition, the condition of minimum guaranteed share should be removed to reduce the frequency of low-flow events in future. Although our analyses show a number of weaknesses, the Treaty could still enhance the future regional cooperation if some adjustments are made to the current terms and conditions.