Floods are one of the most dangerous natural disasters, causing great destruction, damage, and even fatalities worldwide. Flooding is the phenomenon of a sudden increase or even slow increase in the volume of water in a river or stream bed as the result of several possible factors: heavy or very long precipitation, melting snowpack, strong winds over the water, unusually high tides, tsunamis, or the failure of dams, gages, detention basins, or other structures that hold back water. To gain a better understanding of flooding, it is necessary to examine evidence, search for ancient wisdom, and compare flood-management practices in different regions in a chronological perspective. This study reviews flood events caused by rising sea levels and erratic weather from ancient times to the present. In addition, this review contemplates concerns about future flood challenges and possible countermeasures. Thus, it presents a catalogue of past examples in order to present a point of departure for the study of ancient floods and to learn lessons for preparation for future flood incidents including heavy rainfalls, particularly in urbanized areas. The study results show that ancient societies developed multifaceted technologies to cope with floods and many of them are still usable now and may even represent solutions and measures to counter the changing and increasingly more erratic weather of the present.

This paper uses pragmatic findings and lessons learned from three case studies to deduce that community-based rainwater harvesting (CB-RWH) is an innovative solution to develop sustainable drinking water supply systems in developing countries, especially in Africa and Asia. Taking advantage of traditional community-based activities in African and Asian villages, the water supply system can be significantly improved with the introduction and implementation of CB-RWH systems. Furthermore, sustainable, safe water sources in Africa and Asia can be brought to fruition when transparent self-regulatory management systems are supported through comprehensive design and maintenance guidelines and funded from private and public sources. To this end, the potential for CB-RWH to lead toward greater resilience and sustainability was investigated. Based on case studies of three successful demonstration projects in Africa and Asia, this paper identifies 14 innovative solutions resolving technical, economic, and social problems which have been barriers preventing the wide implementation of CB-RWH in developing countries, especially in Africa and Asia. It also recommends strategies to promote CB-RWH in African and Asian villages, which include the following: implementation of more pilot projects at local levels; promotion of and education in rainwater preservation and harvesting at all levels of the education system; and innovation in micro-funding systems in cooperation with corporate social responsibility activities. These strategies will promote the implementation of CB-RWH as a mainstream and high-priority technique for national, regional, and global water strategies.