Science Articles

Rainwater Harvesting – A Crucial Step Towards Saving Water

Rainwater Harvesting

Do you enjoy playing in the rain or watching the rainfall?

Have you ever imagined where this huge amount of water disappears?
Yes, the water seeps into the soil but most of this fresh rainwater flows into the gutter.

Water is a precious resource and only through water can life sustain on earth. The scarcity of water is currently a serious global issue. Hence, it is important for all of us to do our bit to save water. One of the best techniques to manage and conserve water is Rainwater Harvesting.

Rainwater harvesting system

Rainwater harvesting is a method used for collecting and storing rainwater into natural reservoirs or artificial tanks. The systems used for this process depend on the area and can range from easy installation systems to automated systems that require advanced setup. These systems are usually fitted with components such as pre-filters, drains, and storage containers. Advanced pressurized systems are fitted with pumps and treatment devices such as UV lights, chlorination devices, and post-filtration equipment.

Importance of rainwater harvesting

97% of the water on Earth is salt-water. That leaves 3% as fresh water, out of which only 0.5% is available for drinking. The remaining 2.5% of fresh water is sealed in ice caps, glaciers, soil, the atmosphere or under the earth’s surface, or is toxic for consumption. Therefore, rainwater harvesting should be practiced to encourage conservation of water and sustainable living.

Types of rainwater harvesting

Rainwater harvesting is one of the traditional ways of saving water during the rainy season. The primary types of harvesting rainwater are surface runoff harvesting and rooftop rainwater harvesting.

1.Surface runoff harvesting method

Surface runoff is the flow of excess rainwater that occurs on the ground surface which does not penetrate the soil. This can take place when the soil is saturated by water, or when the rainfalls more swiftly before the soil can absorb the excess water. The surface runoff harvesting method is collecting the excess flowing water into a tank below the surface of the ground for irrigation and other purposes. Man-made surfaces such as roads, gardens, and playgrounds can also be used as catchment areas.

2.Rooftop rainwater harvesting method

Rooftop rainwater harvesting is an economical and efficient way to harvest rainwater. Rainwater is captured from the roof catchments of domestic houses or commercial buildings and stored in the tanks. The roof is equipped with pipes that channel water to a pit or tank, avoiding wastage of water from falling off. Harvested rainwater can be used for household or commercial needs.

Safety measures for rooftop water harvesting to prevent water contamination:

• The roof has to be kept clean. Restrict pet animals from strolling on the roof. Clean the roof once before the first rains.

• Whitewash for Reinforced Cement Concrete (RCC) rooms.

• Construct two separate storage tanks for rainwater and municipal supply respectively.

• Do not let the light enter the sump to avoid the growth of algae.

• Use a small motor or hand pump to lift the stored water, as dipping the pot regularly will pollute the water.

Advantages of rainwater harvesting


• The most important advantage of rainwater saving is that it helps to preserve our environment.

• Prevents soil erosion and also improves the moisture level of the soil, enhancing the flora and fauna of that region.

• Being free of chemicals like fluoride and chloramines makes it a good source of water for irrigation.

• It reduces the use of fuel resources, power supply, and pollution caused during the process and delivery of water to homes, businesses, farms, and communities.

• Saving water for future use will resolve water shortage problems and droughts associated with climatic change.


• Rainwater after the filtration process can be used for drinking, watering lawns and gardens, for daily chores like washing clothes or utensils, etc.

• Water can be stored for community use at hospitals, fire and gas stations, health clubs, and restaurants that require large amounts of water to provide services.


• It can be used as emergency storage or as an alternative to municipal sources thereby curbing issues like rising water supply and service costs.

• Systems used for rainwater harvesting are inexpensive and easy to maintain.

The Central Ground Water Board (CGWB) has also organized various awareness programs in the Country to promote rainwater harvesting and artificial recharge to groundwater. The Ministry of Water Resources had also encouraged school children to participate in large numbers for a National Level Painting Competition on “Water Conservation” to raise awareness.

“When the wells dry, we know the worth of water” – Benjamin Franklin
Let’s not wait for the wells to run dry, to understand the worth of water. Save Water, Save Life.


As the rainy season has already arrived, let’s do a fun learning activity on rainwater harvesting.
Make sure to perform the complete activity in succession to avoid breeding of mosquitoes.
Perform the following steps along with a parent or guardian.

Collect: Keep a bucket outside your home or on the terrace when it starts raining to collect the rainwater.

Filter: Once the water is collected you might notice sedimentation of dust particles. Therefore, it is necessary to carry out the process of filtration. Transfer the collected water into another bucket by passing it through a clean muslin cloth.

Utilize: Once you have completed the collection and filtration process you can use this water for household purposes like watering plants, washing cars, flushing toilets, etc.

Get Unique Education Updates and Notification