How to Harvest Rainwater and Greywater

You don’t know the value of water until the well is running dry…

Water is a wonderful renewable resource, the value of which we often tend to ignore because of our unlimited access to it. But the picture is certainly not fair everywhere. The adequate amount of water supply is still a dream in many areas of the world where drought and other weather perils are a common trend. When one wastes it because s/he doesn’t know how to store the excess amount, someone else is looking for a lifesaving drop. Much (if not all) water deficiency problems can be addressed by harvesting rainwater. In the ancient times, societies around the world used to have rain barrels to hold the water for future purpose, but the practice had been paused mainly because of our lack of awareness. Fortunately, the growing concerns helped us reconsider the harvesting concept.

Benefits of rainwater harvesting are many. It reduces ground water decline, conserves surface water wastes during the monsoon times, reduces the level of soil erosion, and develops a culture of resource conversation. Besides these, the water can be used for a range of purposes, including watering the plants in your garden. It saves you money and helps you realise a number of benefits. So literally when it rains, it means opportunities are falling from the sky. Learn how to harvest them below:

Where to harvest: The water can be harvested from different areas, depending on the amount of rain and pattern. The options could be as diverse as rooftops, paved/unpaved areas, stormwater drains, water bodies etc.

How to harvest rainwater for gardening: The whole concept of rain water harvesting revolves around three elements:

1. Collection Space 
2. Transportation system 
3. Storage facility

Analyse your collection space. If it is a roof which can rightly channelize the water, try to determine how much water you are required to collect for the gardening. On an average, 25/40 foot roof can shed more than hundreds of gallons of water hourly. The collection of water also depends on the number of barrels, which can be purchased from the garden supply stores. 


The transportation system is based on the roof drain pipe and gutters you install. The pipes should be strong and large enough to transport the water. Use fitters to keep debris, misquotes and other problems away.


The storage facility is the barrels you purchase. You can even build your own (watch our next articles). Consider placing them properly and that they can store sufficient amount of water. To counter the overflowing, you can fix a pipe with them and distribute it to the garden area, where the water would not stay idle.

Greywater is the usual household wastewater that is still unscathed from toilet waste. The sources of greywater could be shower, bathroom wash basins, washing machines etc. This water is different from the toilet wastewater, which is also called black water.

Benefits: It can be used for different purposes. The most common is to water the plants. It improves plant growth, encourages soil fertility, reduces fresh water usage etc.

How to reuse greywater: The simplest form of collecting and reusing greywater is to allocate a bucket in which the water can be preserved for a few hours and then supplied in the garden. Alternatively, a good number of alternative methods are available through which the greywater can be distributed directly to the garden area, but for that you have to follow certain guidelines. Greywater is not benefical for the plants if handled improperly. The water can also be used for other purposes including cleaning.

Greywater irrigation could be unhealthy if you have little space and unsuitable soils. We’ll cover a comprehensive article detailing everything about greywater recycling in an upcoming article. Don’t forget to read the post.