India receives over 1,284 millimetres of rainfall every year and this presents itself as a significant rainwater harvesting potential. The water if filtered properly can be used for portable consumption - including drinking. Rainwater is actually considered to be the purest form of water.

With growing water scarcity and awareness in urban cities, many families are opening up to rainwater harvesting practices. The low set-up cost and maintenance make rainwater harvesting appealing.

With several ways to harvest rainwater, you can get started easily. Before we explain how to harvest rainwater at home, let’s try to understand why harvesting rainwater is important.

Why Harvest Rainwater? 

Access to clean and potable water is a major problem in India. As per Niti Aayog, around 600 million people or close to half of the country’s population suffer from extreme water stress. On top of that, 75% of households don’t have access to drinking water at their premises. This is despite the fact that over 400 rivers are flowing across the country.

What’s more alarming is that the problem seems to be widespread in both rural and urban areas. Several urban cities in India are already facing acute water shortages. The list includes Delhi, Bengaluru, Chennai, and many more are predicted to join. While state and central governments have formulated several policies and laws to address the problem, the efforts have not reaped concrete results.

This is where DIY (Do It Yourself) rainwater harvesting can help bring in the transformation. With around 4 months of monsoon in India, there is a gigantic potential for India to harvest rainwater. Homes can meet a significant portion of their water needs by simply harvesting rainwater at their homes because harvested rainwater has multiple uses.

Rainwater Harvesting Advantages 

• By installing a basic filtration system that removes debris and garbage from the rainwater, the filtered water can fit for potable use. You can use the water wash vehicles, utensils, water plants or mop the floor. The utility of rainwater is the same as for tap water, if not better. In fact, rainwater can promote plant growth because it is not chlorinated.
• Rainwater can become your primary or backup source of water. Households can reduce their dependence on municipal water, thereby reducing their utility bills and consequently the demand for water resources.
• Tools needed for rainwater harvesting are cheap and make installation inexpensive. Once set up there is negligible maintenance cost involved.
• Harvesting rainwater has the potential to reduce water runoff, waterlogging and water stress in cities. By harvesting rainwater you get to play your part in becoming an environmentally responsible citizen. 

Different Methods to Harvest Rainwater at Your Home

1. Rain Saucer

The easiest method to harvest rainwater is by constructing a rain saucer. Things you need:

• A container or barrel to store the rainwater
• Nylon or silk fabric used for making umbrellas
• Small PVC pipes 

To make the rain saucer, attach the nylon or silk material to a circular ring. This will help in making an inverted saucer or umbrella. Attach the saucer to a pipe and place it on top of the barrel. This will help the rainwater to get collected in the barrel. 

The rain saucer can be placed at any convenient location to harvest rainwater. You can also attach two saucers to a single barrel. It will increase the surface area for the collection of water. Ensure that the barrel is tightly closed to prevent mosquitoes from contaminating the water. 

2. Rain Barrel

Another easy way to harvest rainwater is by creating a simple rain barrel. All you need is a container and a lid. Place the container or barrel under a downspout through which rainwater flows. Secure the top of the barrel with a lid and screen the ends of the downspout. Doing this will protect your collected water from mosquitos. Alternatively, add a spoon of vegetable oil to the barrel. Vegetable oil coats the surface of water keeping larvae and mosquitos away. 

3. DIY Rain Chain

If you want to try a fun and exciting way of harvesting rainwater, then consider making a rain chain. They are beautiful and can add a flair to your garden or verandah. Rain chains can be created using small plastic boxes, aluminium utensils, toy boxes or similar objects at your home. 

To create a rain chain, take the plastic boxes or utensils and make holes at the bottom. This will create a water outlet. Then use a link chain and attach the plastic boxes or utensils at a distance of 5-6 inches from each other on the chain. If you don’t have a link chain, use a rope to hang the boxes. Once they are ready, hang them outside in your verandah or garden. Every time it rains, watch how your rain chain mimics the look of a fountain.

Creating a rain chain can also become an art and craft task for your children. They will be thrilled to make one and watch the rainwater flowing through it.

4.Setup Rainwater Harvesting at Residential Associations

Residential associations can come together to install a holistic rainwater harvesting system at their buildings. The rainwater that falls on the terrace can run through pipes into a large storage container. A filtration system can be installed to clean this water and make it fit for portable consumption. The cost of setting up this rainwater harvesting system will depend on the size of the property, however, it’s not very high.

Once the water has been filtered, it can be used to wash cars, perform cleaning or watering plants. The water can also be filtered through a sump. This will reduce the dependence on groundwater.

Local authorities in Kolkata like NKDA (Newtown Kolkata Development Authority) are even issuing notifications to make it mandatory for high-rise buildings to install rooftop harvesting systems. The aim of this exercise is to develop a sustainable environment in the township. This should further encourage housing societies and complexes to take up rainwater harvesting.

5. Naturally Recharge Wells or Borewells

If your building has the infrastructure installed to collect rainwater from the rooftop, the collected water can be used to recharge groundwater. The water is led through pipes to an open dug well that recharges groundwater. 

The same method can be used for borewells by creating a recharge pit. A pit has a one-metre diameter and is six metres deep. The water then percolates through the recharge pit into the ground, increasing the groundwater level.