What Has Got into the Ground Water Tables?

Groundwater is the water that is present under the Earth’s surface. It is an accumulation of freshwater that has been collected from rain, snow or melting ice. It is present in the cracks and hollow spaces between rocks and soil in the Earth. Almost 30% of all freshwater that is readily available to us and not stored in the form of ice, is in the form of groundwater. Plants utilize groundwater and the water we procure from borewells is also groundwater. Groundwater also maintains water levels of inland water bodies like lakes and ponds. When there is a large enough rock underground that holds a substantial amount of water that can be extracted by a well, we call it an aquifer. We are very heavily dependent on groundwater for our daily water needs. In a study conducted by the World Bank, it was estimated that almost 60% of the water used for agricultural irrigation and 85% of the drinking water utilized in India is groundwater.

Water table is the upper level of the groundwater, the boundary between soil and water. It determines the levels of groundwater. Over the past few decades we have seen water tables decrease and aquifers disappear at alarming levels. Groundwater is fast drying up and there is not enough rainfall to replenish it. Furthermore groundwater is essential not just for consumption but for the maintenance of entire ecosystems. If groundwater depleted below a critical level in an area, the land would turn into a desert. No plant or animal would be able to survive there, it is an extreme ecological disaster.

There are many reasons we are seeing such acute groundwater depletion. Overconsumption of underground aquifers for flood farming and other activities that require an excessive amount of water. Overpumping of water leads to us extracting water faster than it takes to replenish, leading to barren lands. In an attempt to ease the Indian farmer’s burden, the Government of India provided subsidies for the electricity used to pump water for agricultural purposes. This led to rampant over pumping of water as flood farming is a very common agricultural practice in India. Eventually, the underground water depleted to such an extent that the Government had to remove these subsidies to discourage farmers from pumping water at these rates.

Another common reason for the depletion of groundwater is overexploitation in urban and industrial contexts. There is an increasing need for freshwater everyday with the growing population and the growing economy. Coupled with this global warming has made rain infrequent and insufficient in many areas, causing aquifers to not get enough rainfall to replenish and hence depleting. The depletion of freshwater also causes saltwater contamination in these aquifers. Since all large bodies of water are connected, when freshwater depletes, saltwater from the seas and oceans start filling up these underground spaces making the water unfit for use.

Sources:

https://www.worldbank.org/en/news/feature/2012/03/06/india-groundwater-critical-diminishing#:~:text=in%20the%20world.-,It%20uses%20an%20estimated%20230%20cubic%20kilometers%20of%20groundwater%20per,supplies%20are%20dependent%20on%20groundwater.

https://www.conserve-energy-future.com/causes-effects-solutions-of-groundwater-depletion.ph