Modern rainwater harvesting techniques and DIY ideas– Steering towards a Green future

Modern rainwater harvesting techniques and DIY ideas

In the 21st century, we can no longer deny that water is becoming more and more scarce by the minute. Considering water is the key factor that enables all life to survive and thrive, conservation of water has become an important component for a greener tomorrow. The world requires a low-cost clean supply of water for years to come. And there is no better way to this than rainwater harvesting.

Why should one consider rainwater harvesting?

Modern rainwater harvesting techniques and DIY ideasAbout 71% of the area of our planet is covered with water, but still the UN estimates that about 18% of the world’s population lacks access to clean drinking water and fresh water. Of the total amount of water on the earth, about 97% is in the oceans, which is hence not fit for drinking or even gardening. The other 3% is what all animals, birds and humans depend on. This scarcity has made life miserable, especially in the developing and underdeveloped parts of the world. To tackle the situation, environmentalists all over the world encourage people to use less water and conserve more.

Benefits of rainwater harvesting

We are bound to look for alternative sources of water that can satisfy our rising water requirements. Rainwater is one of the best alternatives so far. If you have a plot of 2400 sq ft and your region receives an annual rainfall of about 1000 millimetre then you can collect about 230,000 litres of rainwater every year. It’s enough water to fully satisfy all the annual water needs of four people.

Rainwater is something that is in plentiful in most parts of the world and is a renewable source of freshwater, which can be made potable using basic purification systems. The nature has a ‘Water-Cycle’ to replenish the planet with water. Water from the oceans, seas, rivers and lakes evaporates and when the clouds become heavy, they pour down as rain. People can harvest this rainwater by storing the rainwater collected from the rooftops. At some places, people can store the rainwater first and use the excess water to recharge the ground water.

Easy ways to lower your water bills by harvesting rainwater

focus on the downpipeAre you tired of your escalating water bills? Why not harvest rainwater and use it wisely in order to reduce your water consumption and save your water bills? Rainwater harvesting isn’t something that requires a lot of capital. Your house receives rainwater every year and it releases it. Here is the way for you:

  1. First of all, you have to focus on the downpipe or the roof drain pipe of your house. The intention should be to extend it somewhat in order to manage the overflow and direct the surplus water into a container or stock tank. If it does not suit the position of your waterspout, simply cut it off so that a barrel can be placed or fitted right under it.
  2. Once you are ready to channelize the excess rainwater, shift your attention to the creation of soaker hoses that would flow water quickly. You might have a few old garden hoses left in your house. Make use of them in this purpose. Drill mid-sized holes in each of them and close their ends (not attached with the barrel) with screw-on caps. However, if you go for commercial garden hoses that are available in the market (you will basically be provided with porous soaker hoses), you might not get the desired results by adopting this procedure.
  3. Now it is time for purchasing the required materials, tools and equipment. You can go to any hardware store nearby your area. It would be even better if you can take a pencil sketch of the entire setup that you want to procure. This way, you can easily make the storekeeper understand what you actually need for harvesting rainwater in your house. Usually, you will need a bulkhead fitting and quite a few outlets. The diameter of the bulkhead fitting must be at least 3” so that the water can easily flow out of the hole present in the barrel or the fittings. The manifold outlets should be used for connecting the fast-flowing soaked hoses to the bulkhead fitting.
  4. Next, come to the barrel or the container. You can either buy a readymade one with a small hole bored in it or make a pierce in your own barrel to suit your needs. Choose an area near the base of the barrel and create a hole. As soon as the hole is carved, mount the bulkhead fitting on it and attach it with the manifold outlets. Also, take some screws and connect the open ends of the soaker hoses with them.

It is always recommended that you set your garden or soaker hoses in such a place where the rainwater can be used the most during the next rainfall. This way, you can easily lower the water consumption as well as the water bills of your house to a great extent.

DIY ideas and rainwater harvesting techniques

This is one practice that can help store and save water for future consumption. Plus, individuals, group houses, or even corporate enterprises can efficiently use this method on a daily basis. The rainwater harvesting techniques have been in existence since decades now. The idea behind this is to collect rainwater from the surfaces it falls on and store it in rainwater harvesting tanks. Individuals or societies can either use this water directly or purify it later for drinking.

How to recycle rainwater and DIY ideas for rainwater harvesting systems

Getting drinking water is a persistent problem in the coastal areas. Most of the times, the ground water level is same as that of the sea water. There are a very few ground water pockets that remain uncontaminated by saline water. The rain water recycle with a syringe is a low cost solution for harvesting rainwater, recharging fresh water and meeting the budget and aspirations of the coastal inhabitants. This model can be replicated in any coastal area by using the existing housing plan without digging additional wells or ponds. Here are the instructions that will help you in recycling rain water.

Simple DIY Rainwater harvesting system of 500 liters for beginners

Complexity Level: Moderate

Rainwater harvesting systemResources Required:

  1. 3 PVC based syringe pipes
  2. a tank with a minimum capacity of 500 liters
  3. a storage reservoir
  4. motor
  5. 3 suction pipes
  6. foot valves


1. Detailed structural discussion

This unit consists of a tank with a minimum capacity of 500 liters and daily de-watering capacity of 400 liters. It uses three dedicated PVC based syringe pipes with the diameter of 2 inches to inject water from overhead sources down into a storage reservoir at 25 feet below the ground. It uses a 1.5 HP single phase and 230 V motor to pump up the stored water during de-watering. Individual foot valves are fitted to the three suction pipes of 1 inch diameter, which are connected to the network for de-watering. The foot valves help in priming the motor and filtering out the solid particulates, sand and contaminants from water, prior to being pumped up during de-watering.

2. Build the pit

Considering the months when the rainfall is recorded maximum, you can start working to install the rainwater recycling unit. Build a pit with dimensions 6 feet wide and 8 feet deep. Complete making the pit in summer before the rain comes and fills it up with sand, brought from the river.

3. Lining the pit above ground

Modern-rainwater-harvesting-techniquesLine the pit with a border wall, 3 feet high and 2 feet deep. This portion above the ground is to be used as tank, if made leak-proof.

4. Inserting pipes

Next, insert six pipes measuring 16 feet in length into the tank, going deep through the sand and soil below.

5. Release water

The rooftop rainwater is stored in a pressure tank. Release the water from the pressure tank to the PVC pipes. These PVC pipes are attached to the underground storage pit. Here, the PVC pipes act as syringes for injecting the rain water into the ground. The system is reliable enough to solve the problem of water crisis. The rainwater syringe zone is built to generate an exclusive fresh water level below the sea level at low tides. Unlike other rainwater systems, this arrangement does not need the construction of open wells. The arrangement of closely spaced vertical syringe pipes ensures a minimal footprint, unlike the larger areas taken up by horizontal feed systems.

6. Pumping out water

Whenever required, the water can be pumped out. Starting with a depth of 8 feet, the injected water can be used to recharge the ground water up to the depth of 230 feet. The average installation of the unit is less than Rs 20,000. This water is then pumped out by using a motor or hand pump.

Frequently Asked Questions:

Is the water safe for drinking?

The water that comes out is surprisingly crystal clear and fit for drinking. Remember, it is the natural water that you are filtering for use, when required.

Quick Tips:

Dig the pit during summers to avoid unnecessary mess.

Pump only the required amount of water. Do not forget that it is precious and has to be used wisely.

Things to Watch Out For:

Make sure that you have fitted each pipe properly before releasing water.

Modern rainwater harvesting techniques

Because of overpopulation many cities in both developing and underdeveloped countries are fast approaching a water crisis. The current water reservoirs cannot satisfy the complete water demands of all the people the world. A large portion of them are bound to suffer from water scarcity. According to statistics, around one third of the world’s population suffers from water scarcity at present. And that’s not all. Because of over consumption the water reservoirs are losing more water than they gain. So the situation will become even more difficult in the future.

Rainwater harvesting isn’t something that requires a lot of capital. Your house receives rainwater every year and it releases it. All you have to do is to devise a way to trap that water. Here are a few easy and effective methods that will help you in doing so:

Surface Water Connecting Channels

Surface Water Connecting ChannelThis is the first and the most basic requirement. Most of the modern houses have it. It consists of a rain gutter and a drainage pipe connected to it. It helps in collecting in one place all the rainwater that the roof of a house receives. If you don’t have it then your roof will scatter away the rainwater and it would become impossible to collect it.

Recharging Borewells and Tubewells

The borewells and tubewells generally get recharged by the underground water. But you can also use your collected water to recharge them. Just connect the rain drainage pipe to a filter that leads to the borewell.  It will not only help you it will also help the people around you. The water collected by the borewells seeps through perforations of its walls and it replenishes the ground water. And that ground water is ultimately used by everyone around you.

Rain Barrel

Rain Barrel provides you with the easiest way of collecting rain water. You just have to buy a Rain Barrel and connect it to the outlet of your rain drainage pipe and that’s all. A Rain Barrel doesn’t have many specifications. You can make one yourself by using any spare barrel that you have. But make sure that you cover the barrel properly so that it doesn’t become a breeding ground for mosquitoes or other insects.

A Rainwater Storage Tank in Basement

A Rainwater Storage Tank in BasementIf your house has a basement and if you want to take rainwater harvesting seriously then this product is for you. You can easily buy a rainwater storage tank that has an overall storage capacity of about 7000 litres. This tank will last for many years and it will serve as a major water source to you during the periods of dire necessity.


Earthwork is the easiest and the most cost effective way of collecting rain water. All you have to do is to choose a low lying ground which receives a lot of surface run off. After that you should dig trenches in that region and build earth walls to direct the flow of the water. The trenches will automatically collect the rain water and you’ll be able to use the water thus collected for the purpose of harvesting. You can even grow some plants around the trench and make a beautiful rain garden.

Ferrocement Tanks

Ferrocement TanksImage Source : Calvin.Edu

The Structural Engineering Research Centre or SERC in India does research on building low-cost structures for storing rainwater, irrigation and sanitation. The institute teaches people in rural India to build ferrocement tanks to harvest rainwater and store grains. A ferrocement tank is created using cement and a structure made of steel bars and iron mesh wires. The rainwater is collected through pipes coming from the rooftops, and stored in these tanks. This method of rainwater harvesting is also prevalent in countries like Thailand, Malaysia and some countries of the African continent.

A farm can actually benefit quite a lot from the multiple uses of a ferrocement tank. However, apart from this, other farming practices can also help in creating a greener future for all. Have a look at 7 sustainable ways to farm.

Rainwater harvesting for individual houses

Rainwater-harvesting-for-individual-housesImage Source :  Cmhc-Schl.Gc.Ca

The rainwater falling on the rooftops is channelized through pipes into a water tank. There is a need to ensure that the rainwater is not wasted by travelling to the drains. If there is a well in the vicinity, the rainwater from the rooftops can be diverted to the well. Any excess rainwater may be used to recharge the underground water.

Rainwater harvesting for group houses

Rainwater-harvesting-for-group-houses.Image Source : LastormWater.Org

Group housing complexes can construct a huge well collect the rainwater from the rooftops of all the houses.  They can also install a water purification filter in the complex to clean the rainwater. All the residents of the complex can utilize the rainwater collected and purified for drinking as well as other purposes.

Ground water dams

Ground water damsImage Source : RainWaterHarvesting.Org

Societies use this method of rainwater harvesting majorly in places where the underground water level varies. A dam is constructed underground to obstruct the flow of underground water and create a reservoir to store water. During the rains, the water percolates from the surface and reaches these underground reservoirs, increasing the water level by a considerable amount. The main advantage of these underground reservoirs is that the contaminants in the air do not pollute the water.  Also, the water stored underground does not reduce by way of evaporation.

However, pumping out water from groundwater sources for activities such as gardening can drain natural resources quickly. If you are an avid gardener, here are some ideas for an ecofriendly gardening.

In 2004, the government of Northern Sudan initiated a project to build a massive dam across the Nile river and alter the desert ecosystem of the nation. Scroll to the end of the article to know more about the merits, demerits, and challenges involved.

Ground water recharging

Ground water rechargingImage Source : Bp.Blogspot.Com

One can increase the level of the groundwater by artificial recharging methods. To do this, first create an artificial pit in the ground, and fill it with sand and pebbles. On top of the pit, make a chamber for collection of water, which will reach through the pipes form rooftops. Another way to do this is to build a well in the ground and covering it with concrete covers of appropriate thickness, so that people and vehicles could move without restriction on top. Channelize the rainwater through pipes into the well.

Rainpod – A rainwater harvesting barrel


The Rainpod, by designer David L’Hote of France, allows you to collect rainwater with its unique design and features. Working like a rain barrel, the conceptual Rainpod collects water in a large tank and, standing taller than a man, has the height and reach to cover a large area around it, sprinkling the area using nothing but gravity.

Rain Chain – Conventional Japanese design brought to modern reality

Rain ChainThis ancient Japanese links uses rain chains in lieu of traditional down spouts and have them divert rainwater into your rain barrel, or underground water tank. The rain chain allows you to give back to nature what you took from it.

RainDrops: Cheap rainwater harvesting system for developing countries:

RainDropsDeveloped by Evan Gant, the RainDrops system allows people to attach standard plastic bottles to an existing gutter system that has been installed to take the water from the roof to the drain. This way the water flowing through the gutter is stored in the bottles. Once the system is set up using a good number of bottles, it can give you water for gardening and even washing your hands. The system also makes sure that those old cola bottles are prevented from going in the landfills.

Watree – Upside-down umbrella to capture rainwater:

WatreeWatree is a rainwater harvesting system that looks just like an umbrella turned upside down. The system is designed to be placed in playgrounds and parks just as a rain shelter. While protecting people from rain, the system collects all the precious drops that fall on it and transfer it to tanks located in a different location. During summers when playground authorities are battling for water, the storage tanks can pump water back through a series of underground pipes.

Slow Water – An inverted parasol rainwater harvesting system:

Slow WaterSlow water is designed by Freddie Yauner. The design includes a chair that plays a dual role of storing the rain water as well as supporting your bottom. The inverted parasol allows rain falling upon it to be collected. This water can then be distributed through a hose pipe to storage points around the garden.

Filterbrella – A water capturing and purifying umbrella:

FilterbrellaThe Filterbrella has a very innovative activated carbon filter in its hollow rod. The hollow rod actually lets in rainwater, which gets purified by the activated carbon. This water flows into a bottle that is attached to the Filterbrella’s handle, thus making available pure, potable rain water on the go.

CISTA – A trendy rainwater harvesting system for the urban world

CISTACISTA can collect up to 100 gallons of rainwater at a time without taking much space. Built from stainless steel, the system is sturdy enough to do the job for decades. A climbing plant is planted at the base and naturally winds its way up to the top of the 8-foot-tall tower, giving it a green and environmentally-responsible look.

Lotus Flower – System to collect rainwater and keep it potable:

Lotus Flower –Inspired by the petals of a lotus flower, the system has been developed with the collaboration of Green Cross Italia. Just like a lotus flower, the system opens its copper petals during monsoons and keeps them closed during the other part of the year to preserve the purity of water. Tomas claims that the system can be built using local materials like concrete, copper and wood.

Merowe dam – one of the largest dams in Africa

Merowe damImage Source :

The Merowe dam, also known as Hamdab or Hamadab Dam, under construction on the Nile’s fourth cataract in Sudan, is one of the largest in Africa. The 1250 MW hydroelectric station in the project will triple Sudan’s electric power generation.

The huge dam will be 9 kilometers long and about 225 feet high. The reservoir lake will extend to more than 175 kilometers upstream and flood the fertile valley all along within months of completion. This dam will cover the farmlands of the tribesmen in the region. The vast reservoir has, however, led to the eviction of communities, creating tension between the government and the tribesmen inhabiting the areas.

What are the challenges of constructing the dam?

The Manasir tribe, angry at the loss of its ancient homeland which will almost entirely submerge, are driving out foreign archaeologists from the area, accusing them of helping the Sudanese government.

Experts have not yet calculated the ecological impact of the dam’s construction. However, the wide and long reservoir will separate and divide permanently the animal species of the delicate desert environment on its two sides.

As the construction of the dam nears completion, concerns about the submersion of important archaeological sites have also started emerging. The lake will swallow up countless artifacts and major fortresses of the Christian-era.

Archaeologists admit that they will lose an incalculable amount of information. They have excavated and studied only a tiny fraction of the vast area. This area has numerous unexplored pyramids. They are now in a hurry to salvage archaeological artifacts before the area submerges.

Sudan’s antiquities chief Salah Ahmed said ‘This area was completely unknown to archaeologists before, it was a missing chapter in Sudan’s history and nobody was planning to go there because it’s very hard from a logistical point of view.’ The beauty of the fourth cataract will also be lost forever, he said.

What does the project aim at?

The Chinese won the contract for the construction of the dam in 2002, the biggest international project the Chinese industry had ever participated in at that time. The work began in 2004 and experts expect that it will be over in 2008.

The US $1.8 billion project is almost entirely aims at  power generation and there are no definite plans for the development of agriculture, although the dam will prevent the annual flooding of farmlands downstream. The sites chosen for the resettlement of evicted farmers lie far away from the river in the more arid deserts. This is in contrast to the other major dam on the river, the Aswan, in Egypt where the waters of the reservoir has turned lands on both the banks of the Nile into centers of agricultural production.


Water is essential for living, humans, animals and plants all need water for survival. Unfortunately, it is the humans, who waste and pollute water. Ultimately, we are responsible for the increasing scarcity of clean water. It becomes the duty of the humans to come up with ways to reduce water pollution and wastage so that the entire ecology does not suffer. According to Dr Prem Jagyasi, all should practice Rainwater harvesting techniques; and, everyone should understand the necessity of water conservation for a greener future.Sooner or later we are doomed to face water crisis. And as recourse for survival we will be bound to use alternative water sources. So if we switch to them now then it’ll be a very wise decision on our side and it will save us from future sufferings.

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