[[Image:InfiltrationPond.jpg|thumb|right|400px| An infiltration pond, size may vary.]]
Infiltration ponds are large open water ponds that are either excavated or in an area of land surrounded by a bank, and normally will not exceed 15,000 m3. They store rainwater but with the main aim of infiltrating the water to aquifers where it can be extracted using wells or from springs. They are constructed in areas where the base of the pond is permeable and where the aquifer to be recharged is at or near the surface. Examples include dune infiltration ponds in South Africa, Tajamar ponds in Paraguay, and infiltration basins in Niger. Large dams can also be used to artificially recharge aquifers – in Jordan, one dam was constructed to recharge a well field 8km from the dam site, and experience from the past 6 years shows that groundwater levels have increased by 25-40 metres. In Nepal, small ponds traditionally helped to recharge spring water.
==Suitable conditions==
Pond depth should be deep enough to prevent excessive algae and water plant growth, but not too deep so that anaerobic conditions are avoided – this means a depth of between 1-4 metres.
==Case studies==
Examples include dune infiltration ponds in South Africa, Tajamar ponds in Paraguay, and infiltration basins in Niger. Large dams can also be used to artificially recharge aquifers – in Jordan, one dam was constructed to recharge a well field 8km from the dam site, and experience from the past 6 years shows that groundwater levels have increased by 25-40 metres. In Nepal, small ponds traditionally helped to recharge spring water.
==References, videos, and links==
* [http://www.liv.ac.uk/surcase/themes_actions/sustainable_drainage.html Sustainable Drainage Systems (SUDS)]
