The significance of groundwater…. Syed Mohammad Ali
Human beings cannot survive without freshwater. Besides rain, and glacial charged surface water sources such as lakes and rivers, groundwater provides another vital source of freshwater. Yet, groundwater reservoirs are being depleted and polluted at an alarming rate an issue that merits much closer attention.
A recent UN report Groundwater: Making the invisible visible highlights issues of relevance to this vital natural resource. For eg, it points out how nearly 30% of all freshwater on Earth is stored underground. Groundwater provides nearly half the water used for domestic purposes, and it is an especially important resource for rural populations not connected to public or private water-supply systems.
Groundwater is not just important for humans. Water holes in dry areas are usually fed by groundwater, which helps maintain complex ecosystems. Wetlands, and other water bodies, are often also dependent on groundwater as one source of replenishment.
Despite the importance of groundwater, underground aquifers which have taken millennia to form are being rapidly depleted, at rates which far exceed their capacity to recharge. While it is difficult to quantify the overall amount of groundwater stored in underground aquifers, NASA calculations back in 2015 had indicated that more than half of our planets 37 largest aquifers were under immense stress.
Besides excessive extraction, groundwater pollution is another major problem. Industries use groundwater for manufacturing, mining, construction and oil and gas extraction. The apparel, food and beverage sectors are also heavily dependent on groundwater for their production processes. Such industries not only use up a lot of water, but also pollute groundwater sources via discharge of untreated or partly treated industrial effluents.
Agricultural production is another culprit regarding groundwater extraction and pollution. The rampant use of chemicals in agriculture contaminates groundwater making it unfit for drinking. Moreover, immense amount of groundwater is used up for irrigation as well as livestock farming and its associated activities, such as food processing.
Groundwater aquifers are significantly stressed within populous South Asia. India now uses more groundwater than China or the US. Pakistan itself is heavily dependent on groundwater, accounting for 9% of all groundwater extracted around the world. Most of the groundwater extracted by Pakistan is used to irrigate water-thirsty cash crops such as rice and sugarcane, instead of trying to address the unmet needs of marginalised households.
It is highly problematic for groundwater to be considered a private resource linked to land ownership. For decades, farmers around the world have used electricity and diesel pumps to extract groundwater with reckless abandon. Now use of solar-powered pumps is set to become common. While use of solar power is sustainable from the perspective of global warming, it can pose a risk of worsening water extraction of groundwater, which is a dilemma policymakers need to pay closer attention to.
Effective regulation is desperately needed for more sagacious use and protection of groundwater sources and recharge zones. The UN has now sensibly begun highlighting the need for better groundwater governance processes at regional and transboundary levels.
Climate change is impacting groundwater too. While lack of rain lessens recharge and dries up surface water, leading to increased demand for groundwater usage; heavy downpours in areas lacking adequate sanitation flush fecal pathogens and other chemicals through shallow soils into underground aquifers. Global sea level rises have also led to seawater intrusion into aquifers, including in Pakistan, where salinity of freshwater in coastal areas is creating all sorts of health problems. One wonders what has become of the Recharge Pakistan programme launched by the previous government.
Groundwater remains a vital source for addressing the growing water demand of burgeoning populations. Yet, for groundwater to provide a solution to the problem of growing water insecurity, it must be used more judiciously and be adequately conserved for our future generations.
Courtesy The Express Tribune, March 24th, 2023.