Links to hard information about countries with high rates of greywater recycling would be very helpful in influencing areas that have unfavorable laws.

  • I created a meta question About environmental questions versus sustainability questions here.
    – user141
    Commented Feb 11, 2013 at 15:40
  • 1
    I'm considering questions that deal with the legal structures that allow for sustainable practices to be on topic.
    – Laizer
    Commented Feb 11, 2013 at 19:41
  • While this intersects with sustainability it is more of an environmentalism question at this scale. And maybe these questions are on topic which is why I asked the meta.
    – user141
    Commented Feb 11, 2013 at 19:54
  • I voted to close because this type of question lends itself to answers that quickly become out of date.
    – bstpierre
    Commented Feb 16, 2013 at 12:19

1 Answer 1


It's very difficult to find any hard numbers. Countries that currently have the highest greywater usage are most likely countries with very poor water-supply systems (think Congo, Liberia, Palestine). These are also the countries that do not have the resources to keep track of things like this.

Alternatively, to get some indication of interest in greywater reuse you can look at Google Trends. It shows that most searches on grey water/gray water/greywater/graywater/grauwasser/eaux grises are currently done in:

Australia     79.19
USA           40.20
South Africa  26.01
Canada        25.80
New Zealand   18.36
UK            16.83
India          7.07
Ireland        6.12
Germany        1.51
France         1.00

Note that the numbers don't mean anything. They are just a particular amount of interest relative to each other. I've calculated them by looking at the average and regional interest for each keyword. Also, this data is very much biased towards English, German and French speaking countries where many people have internet.

BTW, if you're interested in a document that describes the policies of certain countries, then you may find this PDF interesting.

  • The German term is "Grauwasser". google.com/trends/…
    – Stockfisch
    Commented Apr 17, 2013 at 15:41
  • @boo2060 Thank you for the translation! I've included the German term 'grauwasser' and French 'eaux grises' in the calculations.
    – THelper
    Commented Apr 19, 2013 at 7:25

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