Groundwater forms the invisible part and plays a key role in the hydrologic cycle. Although groundwater is invisible, its impact is visible everywhere. Humanity’s demand for water is growing. Pressure on water resources is increasing due to overuse, pollution and climate change. Droughts and heatwaves are becoming more intense and frequent. Sea-level rise is driving salt-water intrusion into coastal aquifers and groundwater aquifers are depleting.
Stored in rocks and soil, groundwater is our biggest source of liquid freshwater. It sustains drinking water supplies, sanitation systems, farming, industry and ecosystems. It is also critically important to the healthy functioning of ecosystems, such as wetlands and rivers.
Yet, some 20 per cent of the world’s aquifers are being overexploited, leading to land instability and subsidence, and, in coastal regions, seawater intrusion under the land. As climate change gets worse, the need for groundwater will become more and more critical.
Groundwater may be out of sight, but it must not be out of mind.