Water Conservation

The Mission:

Students will be able to explain need of water. Water is a useful natural resource. We humans are consuming water for different purposes at an alarming rate. If water usage is not regulated properly, then we might have to face water scarcity.

2. Concepts to understand:

2.1 Water distribution on the earth

Water is an important natural resource. 71% if the earth’s surface is covered by water. The water is distributed as follows among all the water resources.

• 97% of water available on the earth is found in oceans. Only 3% is water available as fresh water.
• Of total water resource, 2.1% of water available is frozen in ice caps and glaciers, and 0.9 % of water available is found in ground water.
• Only 0.009% water is available as fresh water in lakes, pond, river, etc.

The following pie chart, represent the water distribution on earth’s surface.

2.2 Water cycle

We all know that water evaporates on heating and forms water vapour. Similarly, water evaporates from the surface of water resources like pond, ocean surface, river, lake, swamp, etc. Water also escapes trees in form of water vapour. This process is known as transpiration. The water vapour rises in the atmosphere. The higher the vapour rise it cools down and condenses to form small water droplets. These small water droplets collectively form clouds. As the amount of water droplets in the cloud increases, these droplets combine to form bigger water drops. These drops fall on the ground in form of rain. In cold region the water droplets freeze to form icicles. Thus, cold regions experience snow fall or hailstorm.

The rainwater seeps in the ground and gets collected in form of ground water. Ground water can be extracted by means of borewells, or wells. Rain increases the water level in ponds, lakes, river, etc. Thus, replenishing the water in water resources.

We use fresh water from these resources and use it for various activities like household use, industrial and agricultural purposes. The following image represents the water cycle.

2.3 Need for water conservation.

We know that only 0.009% of the total water available on the earth is used by humans for various purposes as follow:

1. a) Household use: Fresh water is used for cooking, bathing, drinking washing utensils, washing clothes, cleaning purposes, etc. Fresh water is supplied to our home from municipal corporation. in some cities, households are provided with 24 hours supply. The amount of water used in such households is not regulated and it gets wasted frequently. Whereas in many villages and towns, fresh water is scarcely available, and they only get water for 15-20 minutes. In such places, people need to store waters for appropriate use and water wastage is near to zero or minimum.
2. b) Industrial use: Fresh water provided to factories is used to produce various goods or used for cleaning purpose. For example, water used for dying clothes is mixed with chemicals and is unfit for any other use. Such water is then discarded to drainage system or released into fresh water and may lead to contamination of freshwater resource.
3. c) Agricultural use: Water is used in farms for cultivation of crops. This water mixes with the chemical fertilisers used while farming and may seep into ground and mix with ground water, thus polluting ground water. Also, water used for cultivation of crops is lost due to evaporation. Thus, precious resource is wasted.

To avoid wastage of water, we need to conserve the water in many ways. Following are such ways to conserve water.

1. Rainwater harvesting: In areas receiving ample rainfall, the rainwater is collected at the rooftops of commercial or residential buildings, filtered and then collected in underground tanks. This water can be used for various purposes like cleaning utensils, washing clothes, watering plants, household cleaning, etc. It can also be used to wash cars, or for dying clothes in factories.
2. Modern methods of irrigation: Adopting to modern method of irrigation like drip irrigation reduces the over spillage of water in farms for crop cultivation and water is conserved.
3. Regulated water usage: In cities where water supply is provided for 24 hours should be regulated and population should be encouraged to store water and use it judiciously so that we can share this precious resource with others in need.
4. Groundwater recharge: The ground water being used for various purposes depletes the water table. If the ground water levels are not restored, then the ground water will soon deplete. To prevent ground water from exhausting, we can construct recharge wells where rainwater will get collected and gets filtered and then mixed with the ground water.
5. Repurposing water by filtering and boiling: Household water obtained from cleaning clothes or bathing can be collected in a vessel, and can be repurposed by filtering, cleaning and boiling. This water can be used for various other purposes like washing vehicles. Thus, by repurposing the water, we can reduce the use of fresh water for industrial use.
6. Desalination of seawater: Ocean water is salty, and we cannot use it directly for drinking or cooking purposes. It can also not be used for industrial as well as agricultural purposes. Thus, we need to remove the salt and the dissolved minerals from the oceanic water and filter it before using it. In desalination plants oceanic water and sea water is collected in a huge vessel and is boiled. The water vapour formed by evaporating water is then collected in other vessel and is condensed to form drinkable liquid water.