The earth referred to as the “blue planet”, has more water than land, 70% and 30% respectively. Freshwater resources are essential for all forms of life; they support ecosystems and contribute to civilization.
Despite its importance, fresh water is an extremely limited resource. It makes up only 2.5% of the earth’s surface water, with saltwater constituting the other nearly 96.5%. Of this 2.5%, less than one-third – coming from lakes, rivers and swamps – is available for human use; the rest is locked in the form of ice, glaciers and polar caps.
Another vital source of fresh water is groundwater aquifers. They account for 99% of all liquid fresh water on earth and a quarter of all the water used by humans. Groundwater provides 50% of global urban domestic water- the other half comes from rivers and lakes- and around 25% of agricultural irrigation water.
When water comes out of a tap, there is no telling of its source and the processes undergone to reach its destination. For most urban dwellers, to get clean water out of the taps means raw water has undergone processes of storage, abstraction, and treatment, before distribution, at an immense financial cost and energy, and complex infrastructure is used.
Globally, the agricultural sector uses 70% of the freshwater, with 25% coming from underground aquifers. Agricultural activities are crucial to feeding the earth’s 8 billion inhabitants, employing over a billion people and generating over US$ 2.4 trillion per year.
As populations grow, the demand for food increases and more irrigation is needed. Half of the world’s wetlands have been converted into cultivated land, reducing natural habitats for animals and plants. The Indian Green Revolution of the 1960s was important in lifting the country out of poverty and food insecurity, owing much to crop irrigation, which relies mostly on underground water resources.
Unfortunately, decades of overexploitation on irrigation have led to low levels of underground water, particularly in some regions in Pakistan, India and California in the USA. While irrigation consumes the largest share of freshwater locally and globally; it also wastes approximately 60% of it through leaky systems, inefficient application methods and cultivation of thirsty crops.
The unsustainable water abstraction levels from rivers and lakes have contributed to the drying up of freshwater bodies; with current examples being the Aral Sea in central Asia and Lake Chad in West Africa. The Aral Sea, once the 4th largest freshwater lake, is now a very small and salty water body.
According to the United Nations, approximately 2.1 billion people in the world lack access to clean drinking water; one billion of them in Sub-Saharan Africa, or about 70% of its population. Seventy-four per cent of the global population have adequate access to safe drinking water, the majority being in Europe, Australia, and the Americas.
Approximately 4 billion people worldwide live in areas experiencing water scarcity, with experienced shortages at least one month per year. Global warming, accelerated by human activities, affects rainfall patterns. Floods and droughts are now more frequent throughout the world. In polar regions, glaciers and icepacks are disappearing, with a devastating impact on freshwater supplies in the downstream regions which traditionally relied on them.
UNESCO reports that one-third of the glaciers in the world, including the Swiss Alps and Yosemite National Park in the USA, will melt away in the next decades due to climate change. The glaciers that cap Mount Kilimanjaro will vanish by 2050. In the last five years, South Africa has experienced droughts, fires and floods, costing human lives and causing huge destruction to infrastructure. Climate experts predict much wetter rainy seasons and drier winters, causing floods and droughts. Therefore, the nation must put in place strategies to mitigate climate impacts and improve its management of freshwater resources.
In order to meet the need for freshwater, both for people and ecosystems, water conservation is crucial; consciously limiting consumption, avoiding waste and recycling or re-using water as much as possible. This is all based on lifestyle changes.
Every individual can conserve water following simple domestic habits; such as turning off the tap while brushing teeth or shaving, running full loads of clothes when doing laundry, positioning sprinklers correctly in the lawn and garden, planting native shrubs and groundcovers less demanding in water compared to other exotic plants, allowing the lawn to rest for a few months, making compost out of food waste and applying it to the garden for better water retention, repairing leaking taps and pipes, upgrading to more water-efficient appliances, harvesting rainwater from rooves and re-using it to water gardens and rinsing vegetables in a dish of water instead of under a running tap.
World population growth is putting a huge strain on limited resources increasing competition for water. In transboundary rivers, lakes, and other bodies, higher water demands by an upstream riparian nation often leads to heightened insecurities for downstream countries which sometimes degenerate into conflicts. One of the examples is the dispute between Egypt and Ethiopia concerning the use of the Nile River water.
With the myriad of issues and threats to our freshwater resources, there is a need to educate, protect and conserve our water. The agricultural sector could address the water crisis with worldwide reforms. Mines require innovations to use less water and to be regulated to avoid surface and groundwater pollution. We all need to act now!
(Leevonia Ussi and Rudo Sanyanga Hungwe)