__NOTOC__
[[Image:controlled flooding icon.png|right|80px]][[Image:ControlledFlooding.jpg|thumb|right|300px200px|Groundwater recharge in spreading basins. Arizona, USA. Photo: CAP (2002)]]
This is a floodwater harvesting technique where the water diverted from a river, with the help of diversion structures and canals, is spread evenly over a large surface area where it is used for recharging groundwater, irrigation, filling ponds, and watering grazing land. The concept is that a thin sheet of water flows over the land but at minimum velocity in order to avoid disturbing the soil cover. This includes [[Irrigation_-_Spate_irrigation|spate irrigation]], but also standard channel irrigation which takes river water via channels to fields.
==Field experiences==
[[Image:FloodwaterSpreading.jpg|thumb|right|300px200px|Plan of how floodwaters will spread. Click image to zoom. <br> Drawing: [http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0CDgQFjAB&url=http%3A%2F%2Funesdoc.unesco.org%2Fimages%2F0014%2F001438%2F143819e.pdf&ei=uqt8T9_sL6ibiQKTqdzFDQ&usg=AFQjCNFjJrN8OJHYuNSZrDZIrDtZxc_LRg&sig2=J7p3YnDub8Ixn2n4DU-uBw ''Strategies for Managed Aquifer Recharge (MAR) in semi-arid areas.''] UNESCO.]]
====Iran====
Overexploitation of groundwater has caused significant drawdown of the water table (1.5m/year) and deterioration of groundwater quality in the Dorz Sayban Plain, which is located 115 km to the southeast of Larestan, Iran. 3500 hectares of land are irrigated using groundwater in this plain. To decrease the rate of the drawdown of the water table, five floodwater spreading systems for recharge of groundwater were designed and constructed in the region 1983 and 2001.
==Manuals, operations and maintenance==
* [http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=9&ved=0CGIQFjAI&url=http%3A%2F%2Fwww.iaea.org%2Ftechnicalcooperation%2Fdocuments%2FBrochures%2Fsust/technicalcooperation/documents/Brochures/sust-groundwater.pdf&ei=KeB8T8WnN6PiiAKS_4W7DQ&usg=AFQjCNH3fWzPOyaJjopuEoluwIh-veyHVw&sig2=q9gJHSqAZNGoIrVbuHa_qw Sustainable Development of Groundwater Resources in Southern and Eastern Africa]. International Atomic Energy Agency.
==Acknowledgements==
* CARE Nederland, Desk Study: [[Resilient WASH systems in drought-prone areas]]. October 2010.
* Gale, Ian, [http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0CDgQFjAB&url=http%3A%2F%2Funesdocunesdoc.unesco.org%2Fimages%2F0014%2F001438%2F143819e/images/0014/001438/143819e.pdf&ei=uqt8T9_sL6ibiQKTqdzFDQ&usg=AFQjCNFjJrN8OJHYuNSZrDZIrDtZxc_LRg&sig2=J7p3YnDub8Ixn2n4DU-uBw Strategies for Managed Aquifer Recharge (MAR) in semi-arid areas.] UNESCO's International Hydrological Programme (IHP), 2005.
* [http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CDMQFjAA&url=http%3A%2F%2Fwww.colusarcd.org%2Fnodes%2Fprojects%2Fdocuments%2FGoals_Objectives_Actions_Climate.doc&ei=jVGQT9yCH8SoiAKYyJCjAw&usg=AFQjCNFPToFx9KEpNSM7gTbs2dn_Dz8zqQ&sig2=eNOQzbhrGc7kySDzZdno-w Address unknown future effects of climate change.] Colusa County Resource Conservation District, USA.