__NOTOC__ <small{{Language-title box|english_link=Water Portal />Rainwater Harvesting / In situ rainwater harvesting | french_link=La collecte des eaux de pluie in situ | spanish_link=Captación de agua de lluvia in situ | hindi_link=वाटर पोर्टल / वर्षाजल संचयन / यथास्थान वर्षाजल संचयन | malayalam_link=Coming soon|tamil_link=Coming soon | korean_link=원위치 빗물 집수 | chinese_link=原地集雨 | indonesian_link=Panen Air Hujan / Panen Air Hujan Langsung in Situ | japanese_link=In situ雨水貯留}} [[Image:in situ2In situ - rainwater harvesting.jpg|thumb|right|200px|In situ rainwater harvesting in Jodhpur, Rajasthan. Photo: [http://www.greenfieldeco.com/photogallery.php Greenfield Eco Solutions Pvt. Ltd]]]In arid and semi-arid regions, where precipitation is low or infrequent during the dry season, it is necessary to store the maximum amount of rainwater during the wet season for use at a later time, especially for agricultural and domestic water supply. One of the methods frequently used in rainwater harvesting is the storage of rainwater '''in situ'''. Topographically low areas are ideal sites for in situ harvesting of rainfall. This technique has been used in the arid and semi-arid regions of northeastern Brazil, Argentina, and Paraguay, primarily for irrigation purposes. The in situ technology consists of making storage available in areas where the water is going to be utilized.
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.
====Use of Furrows as Rainwater Storage Areas====
[[Image:furrowRainwater Furrow.jpg|thumb|right|250px|Half-moon furrows around newly planted Acacia seedlings catch and retain rainwater. Photo: [http://www.fao.org/docrep/009/a0100e/a0100e07.htm FAO] - T.F. SHAXSON]]
Furrows may be used as an in situ means of storing harvested rainwater. They are built prior to or after planting to store water for future use by the plants. A variation on the use of topographic depressions to store rainfall, this method uses flattened trenches between the rows of crops to store water. Furrows may have mud dams or barriers every 2 m to 3 m along the row in order to retain water for longer periods of time and avoid excessive surface runoff and erosion. Raised beds may also be used to trap the water in the furrows, or uncultivated areas may be left between rows, spaced at 1 m apart, to assist in capturing rainwater falling on the land surface between furrows.
* '''Aderaldo de Souza Silva''', Empresa Brasileira de Pesquisa Agropecuaria (EMBRAPA), Centro Nacional de Pesquisa de Monitoramento e Avaliacao de Impacto Ambientalt (NPMA), Rodovia SP-340 km 127.5, Bairro Tanquinho Velho, Caixa Postal 69, 13820-000 Jaguariuna, São Paulo, Brasil. Tel.(55-4198)67-5633. Fax (55-4198)67-5225.
* Large wiki on water use for agriculture: [http://web.archive.org/web/20151025174729/http://agropedia.iitk.ac.in:80/ Agropedia]
===Acknowledgements===
[http://www.oas.org/dsd/publications/Unit/oea59e/begin.htm#Contents Source Book of Alternative Technologies for Freshwater Augmentation in Latin America and the Caribbean]. 1.2 Rainwater harvesting in situ. UNEP - International Environmental Technology Centre United Nations Environment Programme. Unit of Sustainable Development and Environment General Secretariat, Organization of American States, Washington, D.C., 1997.
