Can you make a list of activities for which you need water at home? To get you started, let’s suggest bathing, washing clothes, drinking, washing dishes, etc. Measure the amount of water used for each activity with a bucket or a mug. Now, divide it by the number of your family members, and you will see how much water is used by each person every day.

An individual uses 600 to 700 litres of water in a day on average.

Many people get water in their homes from taps, while others draw water out of wells or hand pumps. Either way, have you ever wondered where this water comes from? Water in the taps is drawn from a river, lake, well or any other water body. It is then supplied to our homes via a network of pipes. On the other hand, water in the wells is groundwater (water present beneath the earth’s surface), which is drawn up with the help of a bucket or a hand pump.

Do you know that almost two-thirds of the earth’s surface is covered with water? Out of this, about 2-3 per cent is suitable for human use, and it is found in rivers, lakes, ponds and groundwater. The rest of the water, found in ice caps, oceans, atmosphere, sea, etc., is unsafe for drinking as it has excess salt, toxins, and other impurities.

We have already learnt that water in our homes comes from rivers and other water bodies. Have you wondered where the water in rivers comes from? Water is continuously moving. It never stops. It keeps on circulating between oceans, ponds, rivers, seas, lakes and land. This process is called the water cycle or hydrologic cycle or the hydrological cycle.

The process of the water cycle has three main parts:

1. Evaporation
2. Condensation
3. Precipitation

Evaporation

You must have seen that wet clothes dry out faster on a sunny day, while on a rainy or humid day, they tend to stay wet. Or the floor dries out faster when you switch on the fan. This happens because liquid water in the clothes or on the floor evaporates to form water vapour, leaving the surface dry.

The process through which liquid water changes to vapour or its gaseous form is called evaporation.

Condensation

You must have observed water droplets gathering on the surface of a bottle of cold water on a hot day. This happens as a result of condensation. The process of converting water vapour into liquid water is called condensation.

Precipitation

Have you ever wondered why it rains? This is because when water vapour gets condensed in the atmosphere, it forms clouds. This results in precipitation in the form of rain, hail, or snow.

There are four stages of the water cycle:

Stage 1: Evaporation: Due to the heat of sunlight falling on oceans, seas, lakes, rivers, and other water bodies, the temperature of water rises. This causes evaporation of water from the surface of water bodies. This vapour goes up in the sky with the rising air currents. Similarly, leaves of plants and trees lose water which goes into the atmosphere as vapour. This process is called transpiration.

Stage 2: Condensation: The vapour in the sky starts to cool with increasing altitude and becomes liquid or moisture. This moisture is carried around with winds and air currents and leads to the formation of clouds.

Stage 3: Precipitation: As the clouds become heavier with moisture, they fall onto the earth’s surface in the form of rain, snow, sleet, or hail. This depends on temperature conditions.

Stage 4: Runoff and Infiltration: The falling rain runs off into rivers, oceans, groundwater or is absorbed by the soil or ground, adding to the groundwater.

After runoff and infiltration, water is again ready to start evaporating and follow the same cycle.

You must have heard of rivers or ponds drying up. Have you ever heard of oceans drying up? The level of oceans is under almost all other land surfaces. The water that falls on the land as snow or rain eventually goes into the oceans. Snowy mountaintops often melt to form rivers and streams, which cover long distances to fall into oceans or seas. The water falling on land also fills up these rivers and streams that ultimately flow into oceans.

As we have read in the previous section, only a small percentage of water is available for human, animal and plant use, about 2-3 per cent. The water in the oceans and seas is too salty and cannot be used. Groundwater is usable, but when used excessively, it leads to depletion.

The amount of water on earth remains the same, but the percentage of usable water decreases by the day. Thus, there is an imminent need to conserve water, especially as the population continues to grow.

There are several ways by which we can conserve water:

1. Use water wisely: Turn off the taps while brushing your teeth or washing your hands. Ensure that the collected water is used for household chores like washing, gardening, etc. Use buckets of water instead of a hosepipe to wash your vehicles.
2. Avoid leakages: If there are any leakages in your taps and pipes, get them fixed to avoid wasting water.
3. Avoid long showers: Try to cut down on long showers as it leads to water wastage.

One of the best ways of saving water is to collect rainwater and store it for use. This process is called rainwater harvesting. One of the common ways of rainwater harvesting is through the rooftop.

Rooftop rainwater harvesting: This process begins with rainwater collected from rooftops and directed into a storage tank via pipes. The collected may have many impurities like dirt, gravel, etc., and thus, needs to be purified before use. For this purpose, the collected water is allowed to flow into a pit in the ground, where it seeps into the soil to recharge the groundwater.

What Happens When It Does Not Rain For A Long Period?

We have learnt that water is a precious natural resource. When it does not rain for a long period in a particular region, there are possibilities of natural calamities like drought.

Without rain, the soil continues to lose water by transpiration and evaporation and becomes dry. The level of groundwater decreases and ponds and wells dry up. In such conditions of drought, it becomes challenging to get food as vegetation starts to die.

Have you seen in the news areas of India and Africa that are severely affected by drought? Can you imagine how people living in those conditions cope up? Thus, it becomes essential for us to use water carefully and conserve it.

Water is an essential natural resource that sustains all forms of life. While the total amount of water on earth remains constant, the percentage of usable water is very less, almost 2-3 per cent of the total. Thus, there is a growing need to conserve water by using it judiciously and employing methods that can lead to recharging of drinkable water.

1. What does H20 stand for? 

H20 is the molecular formula for water. It consists of two hydrogen atoms (H) and one oxygen atom (O).

2. What is the importance of water?

Water is an essential requirement for any living being. From animals and plants to human beings, nobody can live without water. 

3. How much water should I be drinking? 

One should drink almost 10-12 cups of water every day.

4. What are the 15 uses of water? 

• It is used for drinking.
• It is used in agriculture activities.
• It is used to wash clothes.
• It is used to do dishes.
• It is used to clean vehicles.
• It is used to bathe.
• It is used in industrial activities like cooling, processing, etc., of a product.
• It is used in cooking.
• It is used to brush teeth.
• It is used in activities related to gardening and fisheries.
• It is used to generate hydroelectric power.
• It is used in transportation.
• It is used in recreational activities like water sports, swimming, etc.
• It is used for environmental activities like creating wildlife habitat.
• It is used to flush the toilet.