When discussing water issues, it’s important to discuss what you can’t always see. It’s easy to tell that there’s less rainfall, or when lakes and rivers are drying up. However, there’s a large source of water that we don’t always account for. Groundwater, which accounts for approximately half of the global domestic water supply, is facing depletion due to excessive usage.
What is Groundwater?
Groundwater is, as the name suggests, water found underground. It can be found in the cracks between soil, sand, and rock. Groundwater is stored in formations of those sediments known as aquifers.
The issue:
To better understand how groundwater is used and what leads to depletion, Bangladesh is a perfect example. At first glance, Bangladesh doesn’t seem like a place with Groundwater issues, because of the heavy rainfall they receive. According to the World Bank Group, Bangladesh receives around 87 inches of rainfall annually. However, this water isn’t reliable year-round, and a majority of the surface water they do have isn’t usable. Bangladeshi Surface water is heavily contaminated with human waste and arsenic, meaning it’s unsafe for drinking or irrigation.
To solve this problem, Bangladeshis began to rely more and more on groundwater, the trend starting when they became independent in 1971. As of 2013, they ranked 6th in how much groundwater they extracted.
Let’s zoom in a little bit on one Bangladeshi city. The capital, Dhaka. It’s one of the world’s megacities and is the country’s center for agriculture and the textile industry, as well as the most populated city in the country. The rapid growth and urbanization of the city mean that the need for water only increases.
The Dupi Tila formation is where Bangladesh’s capital city gets the majority of its groundwater. More than 82% of Dhaka’s total water supply comes from here, and the rate of extraction is only growing. In 2013, the city extracted about 2.4 billion liters of water per day.
This kind of continued use isn’t sustainable. It’s a struggle of supply versus demand. As more and more water is extracted, the less and less the aquifer can recharge at the same rate.
This highlights the pressing need to address groundwater depletion not just in Bangladesh, but on a global scale.
The effects:
Groundwater depletion leads to a lot of things in addition to there just not being enough water.
It means that water will become more and more inaccessible to impoverished communities because the cost of getting water will increase
Ground Subsidence. This is when the ground starts to sink due to the rapid depletion of groundwater. According to Dhaka University, the city is sinking by over half an inch a year. This problem isn’t confined to Dhaka alone. Places around the world with groundwater depletion face similar sinking of the ground.
Surface water in rivers and lakes also decreases. Groundwater is often naturally released into riverbeds, resulting in rising surface water levels. When groundwater depletes, it also affects river water levels.
Dried-up wells lead to the need to dig a higher quantity of deeper wells.
The Solutions:
Groundwater depletion is not a hopeless problem, but it is a pressing issue that requires proactive change and a drive to find solutions. This can mean a variety of things, including initiatives that bring in modern solutions. To take a look at Bangladesh, the managed aquifer recharge (MAR) initiative shows promising results. The plan is to intentionally recharge the aquifers using sources such as stormwater, reclaimed water, desalinated water, and potable water. While there aren’t exact numbers to back this up, studies suggest optimistic outcomes.
However, these attempts are futile if we don’t scale back on the use of groundwater itself. We need to learn how to better manage groundwater usage. For example, textile factories in Bangladesh use three times the recommended amount to make just one pound of fabric. If the water could be better managed, then the amount of water used would go down.
By using a combination of new techniques and better policy, we can tackle groundwater depletion on a global scale.