Groundwater, the Hidden Resource

Groundwater is the most abundant source of freshwater on earth, yet it remains a hidden resource in many ways. While groundwater abstraction increased explosively over the past decades, driven by population growth, economic development and the need for food, the available data on its availability, quantity and quality is very limited. Although 50% of the world population depends on groundwater, what the general public and most decision-makers know and understand about this precious resource is usually very little.

The water we drink every day from the tap or bottles is largely provided by groundwater, which supplies almost half of all drinking water in the world. Groundwater is also crucial to support food production. Recent studies reveal that climate change will reduce the replenishment of our sub-soil groundwater reservoirs, while the rate of groundwater pumping continues to increase each year. For example, key reservoirs supplying the Brazilian megacity of São Paulo are currently depleting, as the area suffers from its worst drought in 80 years. Many other countries and cities are facing the same situation today, and groundwater can serve as a buffer during periodic dry periods, to avoid water shortages. Until when?

During wet periods some of the water storage capacity will be recharged. But it is a sensitive balance, especially in a changing climate. Steady depletion of groundwater storage, accompanied by continuously declining groundwater levels, have an impact on water availability and quality.

It is impossible to manage an unmeasured resource. Without key data on the amount of water stored below ground and modeling of recharge capacities, it is impossible to find out how much water can be consumed sustainably before it is too late. More research is needed to ensure safe drinking water for the generations to come.

Because awareness is the first step towards change, the International Groundwater Resources Assessment Centre (IGRAC) is launching the #HiddenResource campaign today to explain why groundwater matters, with a new animated video ‘Groundwater, the hidden resource’. IGRAC is an initiative of UNESCO and the World Meteorological Organization (WMO) that facilitates and promotes world-wide exchange of groundwater knowledge to improve assessment, development and management of groundwater resources.

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