are characterized by active erosion and sedimentation processes. These river systems have a total catchment area of 1.72 million km\({}^{2}\), only 7% of which lies in Bangladesh [11; 12]. Bangladesh is a tropical monsoon country characterized by warm, humid summers, relatively cold, dry winters, and heavy monsoonal rainfall. About 80% of the total rainfall occurs in the five monsoon months [8]. The topography of Bangladesh is mainly low-lying, flat floodplain, which experiences frequent floods. The main water problems in Bangladesh are related to high flow (flooding) during monsoons and a prolonged dry period in winter (lasting about six months). In Bangladesh, about 80% of the water is used for agricultural purposes. About 97% of the total population of Bangladesh has access to water; however, the quality of water is a major concern [13]. Drinking water is often contaminated, and hence, water-borne diseases are common in Bangladesh. None of its city water supplies are reliable, and hardly any person would like to drink mains water without further in-house treatment such as filtering or boiling. [PERSON] [14] tested 53 tube-well water samples across the country and found that 81.2% of the samples contained coliforms. [PERSON] et al. [15] detected a high concentration of pathogenic bacteria in the water samples of the Dhaka Water and Sewerage Authority (WASA). Surface water is generally highly contaminated by numerous sources such as untreated industrial effluents, domestic waste, and agricultural runoff. Groundwater, used for drinking by rural people, has been contaminated with a high level of arsenic, affecting about 30 million people [16]. Water and sanitation problems are attributed to about 8.5% of the total deaths in Bangladesh [17]. The salinity level in the soil and water has been increasing due to high water abstraction by India from the international rivers and due to climate change. Bangladesh is ranked sixth on the Global Climate Risk Index, and the vast majority of Bangladesh could be under water due to sea-level rise within the next few hundred years. Major water issues in Bangladesh are illustrated in Figure 1, which shows that Bangladesh water research and developments are dominated by floods, climate change, water contamination, water sharing, and transparency. Figure 1: Illustration of major water issues in Bangladesh. [PERSON] et al. [18] stated that over 35 million people living in the coastal zone of Bangladesh are being affected by increased flood risk, salinization, and waterlogging. By a modeling exercise, they demonstrated that improved drainage is more effective than embankment rehabilitation in improving agricultural production in Bangladesh. [PERSON] et al. [19] noted that increased salinity in the coastal areas of south-western Bangladesh has caused a crisis in drinking water. As per this study, the development of a community-based model is needed to solve drinking water problems, which should incorporate all levels of governments, non-government organizations (NGOs), and community people. [PERSON] et al. [20] investigated investment scenarios to provide safe drinking water in coastal areas of Bangladesh, which have been badly affected by a high level of salinity. They compared several options, including deep tube wells, desalination plants, and piped systems, and the results of this study can inform investment in the water supply in the coastal region of Bangladesh. [PERSON] et al. [21] noted that in 2018 there were USD 253 million private investments in tube wells, accounting for about 65% of the total water and sanitation sector's household-level investment. This indicates that a 'private-public blended financial model' could potentially solve the drinking water crisis in coastal Bangladesh. [PERSON] et al. [22] noted that 20.1% of the shoreline in Bangladesh is highly vulnerable to sea-level rise, while 21.5% is moderately vulnerable.