Water Portal / Rainwater Harvesting / Groundwater recharge

Groundwater recharge is the enhancement of natural ground water supplies using man-made conveyances such as infiltration basins, trenches, dams, or injection wells. Aquifer storage and recovery (ASR) is a specific type of groundwater recharge practiced with the purpose of both augmenting ground water resources and recovering the water in the future for various uses.

Climate change considerations

• More storage capacity needed to overcome seasonal dry periods and to reduce floods.
  
• Higher rainfall intensities may exceed infiltration capacities. Create storage, enhanced infiltration or artificial recharge.
  
• Lower rainfall results in the need for transport and storage of water from other areas.
  
• Changes in vegetation will cause changes in evapotranspiration, surface runoff, erosion and sediment transport/deposition. This requires water and soil conservation measures, like terracing.

Infiltration ponds	Contour trenches	Contour ridges	Bunds	Permeable rock dams
Sand dam	Check dams (gully plugs)	Leaky dams	Gabions	Controlled flooding / Spreading basins
Tube recharge	Infiltration wells	Wells, shafts, and boreholes

Groundwater recharge links

• Sustainable Development of Groundwater Resources in Southern and Eastern Africa. International Atomic Energy Agency.
• Rainwater Harvesting and Utilisation. or (alternative link). Blue Drop Series: Book 2: Beneficiaries & Capacity Builders. UN-HABITAT.
• Managed Aquifer Recharge (MAR)

Acknowledgements

• Tuinhof, Albert and Heederik, Jan Piet. Management of Aquifer Recharge and Subsurface Storage or (alternative link). Netherlands National Committee for the IAH and Netherlands Hydrological Society. 2002.
• Aquifer Recharge (AR) and Aquifer Storage & Recovery (ASR). United States EPA.
• Management of Ground Water in Africa Including Transboundary Aquifers: Implications for Food Security, Livelihood and Climate Change Adaptation. United Nations Economic Commission for Africa, African Climate Policy Centre, 2011.
• CARE Nederland, Desk Study: Resilient WASH systems in drought-prone areas. October 2010.