Facts About Global Groundwater Usage
- Groundwater is the world’s most extracted raw material with withdrawal rates
currently in the estimated range of 982 km3
- About 70% of groundwater withdrawn worldwide is used for agriculture. 
- Groundwater provides almost half of all drinking water worldwide. 
- Globally, about 38% of irrigated lands are equipped for irrigation with
- The total volume of groundwater in the upper 2 km of the Earth’s continental
crust (not inclusive of high-latitude North America or Asia) is approximately
22.6 million km3
, of which 0.1 million km3
to 5.0 million km3
is less than 50
years old (judged as “modern” or recently recharged). 
- The volume of modern groundwater is equivalent to a body of water with a
depth of about 3 m spread over the continents. 
The 15 nations with the largest estimated annual groundwater extractions (2010)  are:
The 15 nations with groundwater having the largest share in total annual freshwater
withdrawals, ranked by all water use sectors 
- Margat, J., and J. van der Gun. 2013. Groundwater around the World. CRC Press/Balkema.
- Smith, M., K. Cross, M. Paden, and P. Laban. 2016. Spring — Managing groundwater sustainability. IUCN, Gland, Switzerland.
- Siebert, S., et al. 2010. Groundwater use for irrigation — a global inventory. Hydrology and Earth Systems Science 14, no. 10: 1863–1880.
- Gleeson, T., K.M. Befus, S. Jasechko, E. Luijendijk, and M.B. Cardendas. 2016. The global volume and distribution of modern groundwater.
Nature Geoscience 9, no. 2: 161-167.
- Margat, J., and J. van der Gun. 2013. Groundwater around the World. CRC Press/Balkema