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Why Rainwater Harvesting?
Summer-time is not a mild season in the Indian subcontinent. Its time to start rainwater harvesting system in your home or newly constructing project
It is a period of heat, humidity and in most cases water scarcity, as everyone uses more water in their frenzy to save themselves from the heat. In this situation, the most obvious method to conserve and collect water would be Rainwater Harvesting.
Rain water harvesting is an age-old practice and can be traced back to millions of years. It helps in replenishing the ground water table, and wells nearby, and it can further be filtered, purified and used for everything from irrigation to drinking.
In recent times, however, Tamil Nadu was the first to implement rainwater harvesting as a solution for their near-drought lack of water every summer season.
After the success and widespread acceptance in Tamil Nadu, the entire country began using rainwater harvesting to their benefit. Now, rainwater harvesting is a necessary provision in all buildings without which, approvals will not be sanctioned.
Methods and steps of rainwater harvesting:
Rain Water Harvesting depends upon its use, if its for drinking make sure its not contaminated.
1. Collection
The most common method of rainwater collection in India is by using the rooftops of buildings. The rain that falls on top of the roof is guided by pipes and channels into the tank and in addition the drain of the roof can be covered with mesh to avoid debris from entering the collected water.
With advancement of time and technology, the method of collection has also improved to involve less contamination. The surface of the roof can be cement, pavement, lawn, or metal sheets like galvanized iron.
2. Transport
The second step involves the transport of water to the collection tank by using pipes and gutters. Gutters can be GI, PVC, or even hollow plants like bamboo cut in half vertically.
The size of the gutters and pipes depends on the amount of water that is meant to flow through during maximum rainfall. Make sure that its fixed properly, so it doesn’t buckle or fall off due to the load of the water flowing through it.
To avoid contamination and leaks, make sure its regularly maintained and kept clean.
3. Filtering
Filtering the incoming water removes suspended particles and debris that made its way into the water from the gutters, pipes and catchment surface, i.e. the roof. Also use a First flush device to successfully remove the first rain water from the tank, since it has chemicals from atmosphere which can contaminate the water.
Smaller particles that makes its way into the water even with the mesh on the pipes is to be removed. Mostly used methods for rain water filtering are Sand and Charcoal based.
There are also more advanced filters available in the market these days, and depending on the ultimate use of the water collected, one can opt for a safer filter.
4. Storage
Storage tanks for rain water harvesting depends on the space available on site and water collected.
Its okay to keep it underground, partially submerged, or fully above-ground, as per the requirements.
PVC, Reinforced Cement Concrete, Ferro-Cement, masonry or metal sheets, are some types of tanks, depending on budget and client preference.
5. Recharge
If the aim of rainwater harvesting is to recharge the underground water table or wells nearby, the method of rainwater harvesting is different.
It does not need to be purified extensively or stored in tanks. The simplest method of recharging ground water is to provide pavements that will provide the percolation of water.
Another method is to provide recharge trenches, in which rainwater is collected and stored so that it can permeate into the ground and replenish the ground water.
The benefits of rainwater harvesting are immense. It helps maintain ecological balance for a resource we pretty much take for granted.
Rainwater harvesting systems are easy to use, understand and maintain and does not require any additional cost/ mechanisms/parts.
Other than the occasional de-silting and cleaning process, rainwater harvesting tanks are also very easy to use. The collected rainwater also helps keep the site and its surroundings clean and safe from flooding and excessive run-off.
The introduction of rainwater harvesting in your home can be a very eco-friendly and convenient solution to water scarcity in the summer months.
With rainwater harvesting, we can make sure that one of nature’s purest form of water is not going to waste.
Our future may be bleak with global warming and climate change. We may face more severe conditions in the near future. You can be the change you want to see in society. Go green today!
Have you done rainwater harvesting? Share your experience below.
I have seen recharge but not harvesting. Which one is better ?
In terms of cost – recharge is better as there is no tank
Efficiency- ?
Purity of water – ?
The efficiency would depend greatly on the amount of rainfall received annually. Harvesting the water to replace potable drinking water and such, will require purification systems to be set up to make it completely safe for human consumption. That will require both funds, and regular maintenance. I personally think that replenishing the ground water table is the easiest method to conserve rainwater, because it does not require as much filtration processes and care as harvesting rain for drinking purposes.