Rainwater Harvesting in Developed Countries – Setting High Quality Benchmarks

Developed countries have more advanced ways to manage their resources, to provide them to their citizens’ consumption. One of their success mantras is to save and preserve. Rainwater harvesting might be a greater need of developing countries, but it is also practiced in developed nations, to sustain their natural wealth and earning and to secure their position of being a developed country.

In one of our earlier blogs, we mentioned some instances about how rainwater harvesting is being done in the developing countries. There was so much to learn from their RWH techniques. Government and people of developed nations are engaged in rainwater harvesting methods too. To us, being a developing country, it may seem odd, because of the perception that the developed nations are well-versed, of almost everything. Then why are they practicing something which is believed to be a developing country’s thing? It is because of the following:

  • The population and demand for water are increasing in developed countries too. Before they find themselves in trouble, they are working on, to avoid the inevitable.
  • Developed countries find themselves more responsible for contributing towards the preservation of our planet’s climate and health. RWH is one of such initiatives.
  • And who doesn’t like freshness and quality of harvested rainwater?

This blog focuses on how the rainwater is harvested in developed countries. This will add more advanced methods to your database.


Singapore is a small country with a limited land area of 61,000 hectares (less than half of Delhi) but with 5.612 million population as of the year 2017. The country receives plenty of rainfall, with an average 167 days of the year. To meet the water demand of the ever-increasing population, almost every household practice the rooftop rainwater harvesting, for the use of potable water.

The Changi Airport provides a catchment area of 530 hectares. Two reservoirs are installed on the grounds

  • Water from one reservoir is pumped into a pre-treatment plant whose water is used for firefighting and toilet flushes.
  • Since the airport is close to the sea, the second reservoir collects water from the runoff from the tides and storm.

The annual savings in water usage is estimated to be $390,000.


Japan is more prone to earthquake and tsunami like emergencies. People have to keep themselves ready for such situations. Installing rainwater harvesting system is a part of that planning too. They install systems of varying sizes and styles, ranging from small storage capacity of 100 litres to a large capacity of 1,000 litres. They have also installed tanks as garden furniture, made up of terra cotta.

The subsidies offered by the municipalities have encouraged residents and owners of other buildings such as city hall, sports venue, etc. to have an RWH installed in their premises.

The Ryogoku Kokugikan Sumo Wrestling Arena has a storage tank with a capacity of 1,000 cubic meters which collects runoff from a catchment area of 8,400 square metre rooftop. The water is used for toilet flushing.

At a community level, the residents of the Mukojima district of Tokyo has set up, what is called “Rojison”. In this system, the runoff from every rooftop is collected in a steel rainwater tanks and is then used for tasks such as firefighting and gardening. After further purification, the water is used for cooking and drinking.


The promotion of rainwater harvesting in Germany is done in a unique way. The rainwater harvesting systems in German households have a different variant – they are designed in conjunction with seepage wells. Many German cities charge householders an annual rainwater drainage fee. If the rainwater runoff is retained (using RWH systems) or returned to the ground, this fee is waived off.

There are strict regulations regarding drinking water standards. Also, there is a serious problem of industrial air pollution. Hence, the household rainwater supplies are limited to non-potable uses, like toilet flushing, gardening, laundry.

The average annual rainfall in Germany varies from 563 mm to 855 mm.

The RWH system at Frankfurt Airport is the biggest system in Germany. It helps in saving approximately 1,00,000 cum (cubic meter) of water per year, collecting water from the roofs of a new terminal having an enormous area of 26,800 square meters. The six collection tanks have been installed in the basement of the airport with a storage capacity of 100 cum, handling the need of 13 million people per year. The water is mainly used for toilet flushing, watering plants and cleaning the air conditioning system.

Since 1993, a conjunction of rainwater harvesting and used water is being supplied to the Technical University of Darmstadt. The water is mainly used as a coolant in the laboratories, cleaning, and toilet flushing. Around 20% demand of drinking water is being covered since the time of installation of this system, saving up to 80,000 cum of drinking water per year.


Australia is the world’s second-driest continent with average annual rainfall below 600 millimetres, over 80% of the continent and below 300 millimetres over 50% of the continent. A National Rainwater and Greywater initiative called Under Water for the Future was launched by the Australian government to provide generous rebates on the installation of RWH systems. Australia has experienced a severe drought between the years 2003-2012. During this period, a serious need felt for conserving and recycling the water, with the help of rainwater harvesting technology.

The government provided up to $500 for households to install rainwater collection systems, and up to $10,000 for surf life clubs, for taking up large water saving project or installing a rainwater harvesting system. By now, 26% of Australian houses have a rainwater tank. In Sydney alone, the estimated savings from rainwater harvesting and water efficient appliances in 2016 was 90 billion litres annually.

Chaitanya’s Mission – To Make India Self Sufficient in Rainwater Harvesting

The population of any country is its strength. To promote and make rainwater harvesting a success, a nation needs its motivated people. The developed countries are setting a benchmark in practising rainwater harvesting techniques.

Chaitanya Rain Harvest Products & Systems is working to provide competitive and most modern solutions in RWH products and helping India to reach par with world’s most successful initiatives, taken for harvesting rainwater.


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