Most freshwater is underground

The United Nations observed World Water Day this month to raise awareness about the two billion people who have no access to safe water. This year, the theme was ‘Groundwater: Making the invisible visible’. Here are some amazing facts about the invisible lifeline flowing under our feet:

Groundwater is the water found underground in the cracks and crannies of soil, sand and rocks called aquifers. About 90% of the Earth’s available freshwater is groundwater.

Groundwater feeds springs, rivers, lakes and wetlands, and seeps into oceans. As groundwater can be extracted by pumps and wells, it is the primary source of water for drinking, sanitation, farming, industry and ecosystems across the world, especially in arid regions. However, in many parts of the world, groundwater is extracted faster than it can recharge.

India is the world’s largest user of groundwater, and relies on it for irrigation and to quench its cities’ water needs. Over the last five decades, the number of borewells used to pump groundwater in the country has grown from one million to 20 million. Many parts of northern and eastern India are witnessing rapid depletion of groundwater.

Pollution threatens most of the world’s groundwater today. Naturally-occuring chemicals like arsenic and fluorine seep into groundwater making them unfit for human use. About 200 million people across the globe have access to groundwater whose arsenic concentration exceeds the WHO limits. India is one of the severely affected countries.

Agricultural pesticides, fertilisers, and sanitation waste also leach into the ground and mix with groundwater, leading to high levels of nitrates and microbes. In India, about 200,000 people die every year because of using filthy water, including groundwater.

Hence, actions towards sustainably using groundwater and rejuvenating it are necessary.

Spoorthy Raman