In situ technology has been extensively used in northeastern Brazil, in the Chaco region of Paraguay, and in Argentina. It can be used to augment the water supply for crops, livestock, and domestic use. With the mechanization of agriculture, its use has diminished, but it is still recommended for regions where the volume of rainfall is small and variable. The approach used depends primarily on the availability of equipment, the nature of the agricultural and livestock practices, and the type of soil.
'''Cultural Acceptability'''<br>
In situ rainfall harvesting has been practiced for many years by the agricultural communities of northeastern Brazil, Paraguay, and Argentina. Agricultural communities in other arid and semi-arid regions can readily improve their level of irrigation and increase their production yield using this technique.
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- The effectiveness of the storage area can be limited by evaporation that tends to occur between rains.<br>
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==Design & design limitations, construction==
All rainfall harvesting systems have three components: a collection area, a conveyance system, and a storage area. In this application, collection and storage is provided within the landscape. Topographic depressions represent ideal collection and storage areas. In many situations, such areas are impermeable, being underlain by clay soils that minimize infiltration. Methods of rainwater harvesting in situ, including site preparation of agricultural areas in Brazil, are described below.
