500,000 WISY filters installed worldwide could supply BERLIN with rainwater

What could we do with 42 million m³ of rainwater ?

More than 500,000 rainwater filters from WISY are in use worldwide. They save precious drinking water or provide clean water, where is none at all. Together they are filtering 42 million m³ of rainwater annually. That‘s more than all residents of Berlin use in the same time to flush their toilets and equals 1,332 litres per second!


  • WISY rainwater filters worldwide: more than 500,000 pieces
  • Realistic combined capacity for rainwater, taking the connectable roof area for each filter into account: more than 42 million m³ of rainwater per year
  • Inhabitants of Berlin (2012): 3,36 million
  • Average need of toilet flush water per inhabitant in Germany: 34 litres/day or 12.4 m³/year