A Global Groundwater Disaster?

"Groundwater, the unseen source of life for two billion people, is diminishing almost everywhere in the world, according to a study published today by the UN Environment Programme (Unep). So much water has been pumped from beneath Mexico City that buildings have in some places sunk two metres. The water table under the high plains in the American Midwest has fallen on average by three metres a decade and up to 30 metres in some places. So much has been extracted from southern Florida that the aquifers are at risk of flooding by sea water."