Harvested Rainwater Quality of Dhaka and Its Importance as the Alternative to Surface and Groundwater

Dhaka, like many other megacities in southern Asia, has been struggling with urban flooding and droughts. The main reason behind the problem is thought to be the propagation of the city's built-up area and a significant decrease in rainwater infiltration in the capital. On the contrary, the continuous safe water supply in Dhaka is becoming an impossible task for the authority as the ground and surface water is being depleted over the years. In this regard, proper rainwater management, even at the individual plot level, has the potential to bring up a significant difference in the present crisis. In this report, the total physiochemical quality assessment of the harvested rainwater from Dhaka city has been presented and compared with that of the World Health Organization (WHO) standard. For the first time, this study reveals the applicability of this harvested rainwater to be used in several aspects including drinking, cooking, agricultural, industrial, and household purposes.