In many areas, readily available water is in short supply. Although the total annual rainfall in an area may be enough to sustain needs such as farming, it is often distributed very unevenly so that long dry periods are interspersed with periods of intense rainfall.
Water harvesting techniques gather water from an area termed the ‘catchment area’ and channel it to wherever it is required, for instance, a cropping area. Water harvesting also involves the collection of rainfall-runoff for subsequent beneficial use
Water harvesting, storage and processing technologies are key water-related interventions with the potential to contribute to rapid improvements in the provision of water for domestic use, livestock, manufacturing and agriculture among other uses. Secure access to water with reliable storage has boosted economic growth in many countries worldwide. In many cases, water storage simultaneously serves multiple purposes, such as irrigation, energy generation and flood control.
Dams, both small and large, and associated reservoirs and tanks, can store water for later use, provide hydropower, and offer a certain level of protection against extreme precipitation events. Well-designed dams make water available at times when, in their absence, it would be lacking.
By integrating water harvesting, storage and processing structures in water landscape in a planned and systematic manner, it is possible to create a “water buffer” that helps reduce vulnerability to outages, drought and seasonal variations in rainfall and in effect achieve a water-secure society. It is imperative to harvest and store water when it is plentiful and make it available when it is scarce.
