Did you know that groundwater makes up 99 percent of all usable fresh water on the planet? 

Groundwater, often known as Subterranean water, refers to all water found beneath the earth’s surface. 

Table of Contents

Importance of Groundwater

Groundwater is the primary natural water source for agriculture, the food sector, and the overall economy. 

Groundwater is critical to the ecology because it maintains the water level and flows into rivers, lakes, and wetlands

Rivers, marshes, lakes, and subterranean ecosystems within karst or alluvial aquifers rely on groundwater.

Groundwater is comparatively less expensive, more convenient, and less pollutable than surface water. 

The groundwater quality does not vary significantly throughout the year, which is beneficial to the industry. 

Groundwater is usually of very high quality, and it requires far less treatment than river water to make it safe to drink. Pollutants are removed by the soil and rocks through which groundwater travels.

Many sections of Africa and the developing world rely on groundwater. It is commonly located near villages and does not require the high expenses of gathering, purifying, and piping surface water. 

Because groundwater is sluggish to respond to fluctuations in rainfall, it remains accessible during the summer and during droughts when rivers and streams have dried up.

How is groundwater formed?

groundwater occurrence - groundwater facts
Groundwater occurrence under the rocks| Illustration by Water Science School

Groundwater exists in saturated and unsaturated states in strata and soils, and its movement is slow. Precipitation, such as rain and snow, is the source of groundwater. 

A drop of rain that soaks into the soils finds its way to the water table, the underground reservoir’s water level. Underground streams, lakes, and veins do not generally contain groundwater. 

Groundwater is found in porous soils and sands that store water, similar to how a sponge holds water. Groundwater is discharged through springs, lakes, rivers, streams, or constructed wells. 

Some facts about groundwater 

  1. Groundwater is estimated to be 2.8 million trillion gallons. 
  1. Groundwater accounts for one-third of the freshwater used by people in most parts of the world; however, in some territories of the world, this percentage can reach 100%.
  1. According to NASA satellite data, 13 of the world’s 37 major aquifers are deemed severely depleted.
  1. An estimated 20% of the world’s population relies on groundwater-irrigated crops.
  1. Every day, 53.5 billion gallons of groundwater are used to irrigate crops.
  1. Nearly half of the inhabitants in the United States and many other developed countries rely on groundwater for their drinking water. However, irrigation is its primary application.
  1. Groundwater is a natural resource on the verge of being replenished.
  1. Groundwater is the liquid that seeps through cracks and other gaps in rock and sand beds.
  1. Groundwater is used to help us grow our food. With 64 percent of groundwater, irrigation is used to cultivate crops.
  1. Groundwater supplies 99 percent of the world’s usable freshwater.
  1. Around 38% of irrigated fields worldwide are set up for groundwater irrigation.
  1. More than half of the groundwater withdrawn in many countries is for domestic water supplies, and it provides 25 to 40% of the world’s drinking water.
  1. Groundwater is the most exploited raw material on the planet, with extraction rates currently estimated to be in the range of 982 km3 per year.
  1. The volume of contemporary groundwater is similar to a 3m deep body of water scattered throughout the continents. 

Issues Faced by Groundwater 

1. Overdraft

sac valley groundwater pumping - groundwater facts
Sac valley groundwater pumping| Photo by Maven

Overuse, over-abstraction, or overdraft of groundwater can pose significant difficulties for humans and the environment. 

The most obvious issue is a drop in the water table that puts existing wells out of reach. 

Due to excessive pumping, the water table has plummeted hundreds of feet in some regions, such as India and California. 

Even freshwater biologists and ecologists overlook the importance of groundwater to ecosystems. 

Excessive pumping might deplete the “bank account” of groundwater. The amount of water held on the earth is comparable to the amount of money in a bank account. 

If you withdraw money quicker than you deposit new money, you’ll soon run out of money in your account. 

Groundwater pumping is the primary cause of groundwater depletion. The following are some of the negative consequences of groundwater depletion:

  1. Wells drying up
  2. water levels in streams and lakes dropping
  3. water quality is deteriorating, and pumping expenses rising
  4. The sinking of the land

2. Pollution

On-land rubbish dumping is the most common source of groundwater pollution. 

Industrial and domestic chemicals, landfills, industrial waste lagoons, tailings, and process wastewater from mines are also significant contributors.

A contamination plume within an aquifer can be created by contaminants emitted to the ground to make their way down into groundwater. 

Landfills, naturally occurring arsenic, on-site sanitation systems, and other point sources, such as gas stations with leaking underground storage tanks or leaking sewers, can pollute the environment.

3. Seawater intrusion

sea intrusion - groundwater facts
Groundwater flow pattern and sea intrusion| Illustration by USGS

The flow or presence of seawater into coastal aquifers is known as seawater intrusion, and it is a type of saltwater intrusion. 

Although artificial influences can exacerbate it, it is natural, such as sea-level rise due to climate change.


Groundwater supplies a generally uniform supply of water in some environmentally sensitive locations to sustain plant and animal species is an essential source of supply for agriculture and many businesses. 

For billions of people, it is a source of drinking water. Having a more excellent grasp of groundwater’s role and helping to safeguard the little groundwater left. 

Improving our understanding of groundwater is critical for preserving the groundwater as two billion people do not have easy access to clean drinking water.

(Last Updated on January 31, 2022 by Sadrish Dabadi)

Rishu Shakya, a bachelor’s degree graduate in Business Information Management, holds an extraordinary empathy towards mother nature and her ecosystem. She has always been captivated by green Earth and its charm. She regards spreading awareness about clean energy and sustainable development as her passion as well as responsibility. She believes her compassion about the Earth and human relationships will undoubtedly assist our planet to be a better place.