Abstract : Water harvesting is a traditional conservation technique, and there is general agreement that conserving water will promote agricultural production, especially in arid and semi-arid regions. The high competition for water and land has led to scarcity of water resources, and it has also threatened the world's food security. Recent technological developments have led to improvements in rainwater harvesting techniques, which will help guarantee the availability of food for the growing population. However, problems always occur with the implementation of any advanced technology, and this is also the case for the water harvesting system. This system, in combination with other factors, has a great potential to improve food security, especially in developing countries.This paper presents are view of more than 60 recent articles on water harvesting that were published between 1990 and 2012.
? Water harvesting provides a means to supply non-potable water for reuse without putting additional strain on existing sources.
? There is a common agreement that whatever the soil and water conservation measures are they must first of all support a positive economic alternative to existing conditions in order to get farmers’ acceptance.
? Water harvesting can improve the vegetative cover, increase the carrying grazing capacity of rangeland and help halt environmental degradation.
? RWH minimizes some of the problems associated with irrigation, such as the competition for water between various uses and users, low water use efficiency, and environmental degradation.
? The plastic used to mulch the ridges also poses environmental problems, therefore biodegradable plastic film should be used.
? Farmers' participation in construction and maintenance can prevent check-dams from becoming defunct if technical problems occur during operation, because farmers understand how to overcome these problems.
• Water harvesting techniques have been applied in settlements on a small scale for domestic and municipal purposes, and in the large, broad acre farm setting for productive use of the water.
• In the context of artificial harvesting, it can be inferred that following collection, water is stored and subsequently used for some purpose, from potable supply to less obvious uses such as abatement of flooding.
• Water for irrigation purposes should be sourced from supplies unsuitable for potable use.
? The important components of the physical design elements for water harvesting are precipitation, soil type, soil characteristics, runoff area ratio, runoff efficiency, and vegetation type.
? Rainwater harvesting in India is done via a traditional method for runoff catchment; this method is a managed aquifer recharge technique that increase the groundwater supply; it is also used to collect and store runoff during the heavy downpours of the Indian monsoon season.
? To overcome the contouring difficulties, semi-circular and trapezoidal bunds are usually used.
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