Imagine a scorching summer day when you turn on the tap and no water comes out. There would be no water to drink, wash, bathe and cook. It sounds scary, right?

Now imagine a whole city or country running out of water. The people in the country would be frightened. The available water bodies would dry up, crops would fail and people would go thirsty. Unfortunately, this isn’t just a science fiction story or movie, because many countries around the world are already bearing the brunt of such a situation. Yes, they are actually going through this. Water isn’t just something we use, it is life and it is who we are. We all have learnt in our science books that our body is made up of 70 percent water. It is present in every tear we shed and every leaf we touch. Our heart, brain, blood and enzymes need an aqueous medium to keep us alive. To be more specific, humans are literally walking containers of water.

Many unfortunate kids in different parts of the world have to travel extra miles to fetch water. In the Middle East, for example, the governments have installed very expensive desalination plants to convert salty sea water into drinkable water. People in Tharparkar, Sindh, and major cities of

Balochistan province, such as Turbat, Gwadar, Chaghi and Quetta, face severe water shortages around the year. Sometimes these desperate people need to wait for days to get water from tankers or to stand in long queues to get a pint of water.

Water is so priceless that many countries would often fight for, have debates on and, on top of that, wage war for it. Recently, we have witnessed the escalating tension between India and Pakistan over the Indus River basin water. Given that it is one of the biggest rivers of South Asia, it waters fields and plants, fills taps and supports life for millions of people in Pakistan and India.

In 1960, a treaty was signed between Pakistan and India to distribute the river water properly. As per the treaty, India got the right to the eastern rivers, — Ravi, Sutlej and Beas, and Pakistan got the western ones, Indus, Chenab and Jhelum.

However, as climate change intensifies, with glaciers melting and changing rainfall patterns, people on either side of the Subcontinent confront the problem of water shortage. Tensions escalate when these rivers run low.

Despite governments fighting and climate change playing out its wrath on the people, there are many great things we can do as kids to save and reuse water.

But before exploring the ways on how to reuse water, let’s differentiate between black water and grey water.

Understanding black and grey water

Black water is the water coming from the toilets and sewage system. It typically contains human waste and pathogens like bacteria and viruses. Black water is highly contaminated and needs extensive treatment before it can be used.

Grey water, however, is less toxic and makes it a perfect fit for household applications. Grey water is generated every day from washing our hands to bathing, and from doing our dishes to washing our clothes. This water can be reused to flush toilets, for cleaning purposes and watering plants. Reusing grey water doesn’t only help us save water for generations to come, but it is cost-effective and also reduces the load on our sewerage systems.

Reusing air conditioning water

Most of us have air conditioners in our homes, so you must have noticed the water dripping from air conditioning units. This water, often called condensate, typically forms when the air conditioning units absorb the humidity of our rooms and convert it into water droplets. This condensate, which is often wasted, can be collected and repurposed for non-drinkable uses.

According to the recent study of the Pakistan Council of Research in Water Resources (PCRWR), a single AC unit can produce five to 20 litres of water each day, depending upon the humidity level and the capacity of the air conditioning unit.

The water from the air conditioning units can be collected by placing a bucket under the drainage pipe. As this collected water is free from pollutants and pathogens, it can be used to water plants (since it is chlorine free), flush toilets, wash cars and kitchen utensils, and for cooling purposes on industrial settings. However, this water isn’t safe to drink unless treated well.

Don’t waste RO water

Reverse Osmosis (RO) systems are widely used to purify water in Pakistan, especially in government offices, homes and schools. This system ejects two to three litres of wastewater to purify one litre of water. This water isn’t harmful, but contains a significant amount of salts, dissolved solids and minerals, so it isn’t fit either for drinking or taking a bath. It can be used to wash clothes, especially for initial soaking, flushing toilets, car washing and construction use. And it can also be used to water salt-tolerant plants such as aloe vera, hibiscus, lemongrass and certain shrubs which like mild saline water.

Washing machine water isn’t trash water

According to estimates, a single washing machine can use 60 to 120 litres of water per load. Isn’t this a lot of water? This type of grey water has dirt, soap and fabric residues produced during washing and rinse cycles. While being non-contaminated, this can be used for non-drinkable purposes like using it for flushing the toilets and cleaning the outdoors.

Don’t water plants with this water when you have used bleach, boron and strong detergents with high sodium levels, as it could harm the plants and soil health. Furthermore, one of the common uses of this type of grey water is to wash courtyards, stairs and driveways.

From sink to soap

Again, the water from the shower and bath tub is very reusable too. Instead of wasting it away, reuse it to flush toilets and wash cars. Simply collect the bathroom water by placing a bucket or installing a grey water collection system under the drainage outlet. This way you are not only reusing the water, but also saving the clean water.

Moreover, water from the sink and hand-washing, which ideally contains soap and toothpaste, can be collected in containers and later be reused to clean outdoor surfaces. In places like hospitals, mosques and schools where hand-washing stations are installed, water could be collected on a large scale for non-potable purposes.

Rainwater harvesting

Rainwater harvesting is one of the oldest methods to use rainwater in future, rather than allowing it to run off into drains and fields. It is often collected on rooftops, natural ponds, lakes, artificial reservoirs and tanks. This method not only reduces the chances of flooding, but also prevents soil erosion. Interestingly, many environmentalists are using this method on their rooftops and this has been widely applied for a long time in rural areas where there is scarcity of water, such as Tharparkar, Mithi in Sindh and various parts of Balochistan and KP.

Can we help in rainwater harvesting?

Yes, of course! We can use buckets, tubs and bottles to harvest water during rain at home. At homes and schools, kids can work with their parents and teachers to set up a barrel under a roof or an inclined surface to collect water during rainy days. Decorate the barrels and label it “Rainwater” and also remind other kids to not mix soap or dirty water in it. As monsoon is approaching, do this right away.

Though reusing grey water is important, we must be careful while using it. Don’t store it for more than a couple of days as it could attract insects, develop a stink and pathogens like bacteria and viruses could grow on it.

You don’t have to wait to grow up to be powerful leaders to work on water treaties; you could start with a bucket and the willingness to help. Do you know that a report says that if every family in the country reuses 10 litres of water daily, we could save 20 billion litres of water every year? This water could be sufficient for over 80 days of usage for the whole population of water-stressed Quetta and 12 to 13 days for a much bigger city like Karachi.

Together we can save every drop today and make a big difference tomorrow.

Published in Dawn, Young World, June 21st, 2025