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Managed Aquifer Recharge (MAR)

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Construction, operations and maintenance
* [[Wells, shafts, and boreholes]] recharge – in which infrastructure are developed to pump water to an aquifer to recharge it and then either withdraw it at the same or a nearby location (e.g. aquifer storage and recovery, ASR);
* Induced bank infiltration – in which groundwater is withdrawn at one location to create or enhance a hydraulic gradient that will lead to increased recharge (e.g. bank filtration, dune filtration)
* [[Rainwater harvesting - general|Rainwater harvesting]] – in which rainfall onto hard surfaces (e.g. building roofs, paved car parks) is captured in above or below ground tanks and then allowed to slowly infiltrate into soil.
There are several common operational issues experienced by MAR schemes. These include: clogging of wells, stability of infrastructure under operating conditions, protection of groundwater quality, operation and management of the scheme, ownership of the stored water, monitoring, loss of infiltrated/injected water, policy and cultural acceptability and related stakeholder communications. Successful operation requires appropriate training for operators, access to successful demonstrations of the technologies being deployed and sound and integrated management of water resources.
==Costs==The diverse range of managed aquifer recharge (MAR) schemes illustrates how the economics of different adaptation options can vary considerably. Low technology schemes such as [[Controlled_flooding_/_Spreading_basins|controlled flooding / spreading basins]] and [[sand dam]]s are less expensive (about US$10 to US$50 per ML, ignoring pipeline costs) than, for example, borehole injection methods (in the order of US$100 to US$1,000 per ML). Consequently [[Wells,_shafts,_and_boreholes|borehole injection methods]] are often less viable, particularly for agricultural purposes, although in some areas may be suitable for urban and domestic water use. This provides an example where the economic feasibility is driven not only by cost, but also other considerations such as the scale of the scheme and the end-user of the water resource. ==Field experienceexperiences==
'''MAR example: sand dams in Kenya'''<br>
Sand dams are not appropriate for all locations. They require unweathered and relatively impermeable bedrock at shallow depth; the dominant rock formation in the area should weather to coarse, sandy sediments; sufficient overflow is required for fine sediments to be washed away; and risk of buildup of soil and groundwater salinity needs to be low. Cooperative effort, ownership and ongoing maintenance
by the local community are also necessary for the success of these schemes.
 
==Acknowledgements==
* [http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&ved=0CE0QFjAB&url=http%3A%2F%2Fwww-wds.worldbank.org%2Fexternal%2Fdefault%2FWDSContentServer%2FWDSP%2FIB%2F2010%2F06%2F15%2F000333038_20100615010832%2FRendered%2FPDF%2F550270NWP0Box01Groundwater01PUBLIC1.pdf&ei=8UT7T57aHoe62gWlwaXMBg&usg=AFQjCNFXzDm1OJhSeiQxrla-MT8JsgidfQ&sig2=GxLsfzDpXl8K4K6otHxX0A Water and Climate Change: Impacts on groundwater resources and adaptation options.] Water Working Notes, Note No. 25, June 2010. World Bank, Water Partnership Program.
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