Generally this technology is simple and easy to use. Governmental organizations and the agricultural community generally work together to support and promote the in situ rainwater storage. Educational and information programs should be provided to inform users of the benefits of this technology, and the means of implementing rainwater harvesting while preventing soil loss.
==Design, suitable Suitable conditions & design limitations==
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.
{| border="1" cellpadding="5" cellspacing="0" align="none"
|-
! width="50%" style="background:#efefef;" | Advantages
! style="background:#ffdead;" | Disadvantages
|-
| valign="top" | - This technology requires minimal additional labor.<br>
- It offers flexibility of implementation; furrows can be constructed before or after planting.<br>
- Rainwater harvesting allows better utilization of rainwater for irrigation purposes, particularly in the case of inclined raised beds.<br>
- Rainwater harvesting is compatible with agricultural best management practices, including crop rotation.<br>
- It provides additional flexibility in soil utilization.<br>
- Permeable in situ rainwater harvesting areas can be used as a method of artificially recharging groundwater aquifers.<br>
| valign="top" | - In situ rainwater harvesting cannot be implemented where the slope of the land is greater than 5%.<br>
- It is difficult to implement in rocky soils.<br>
- Areas covered with stones and/or trees need to be cleared before implementation.<br>
- The additional costs incurred in implementing this technology could be a factor for some farmers.<br>
- It requires impermeable soils and low topographic relief in order to be effective.<br>
- The effectiveness of the storage area can be limited by evaporation that tends to occur between rains.<br>
|}
==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.
