rainwater harvesting

The concept of capturing rainwater and storing it for later use is well documented from pre-Roman times and on all the major continents, although in industrialised countries, until recently, the practice had largely died away with the introduction of reliable mains-supplied water. With the ever-growing demand for water (and subsequent increases in cost), and the known adverse impacts this can have on local environments, the UK market demand for rainwater recycling systems is on the increase - mirroring what has already taken place in other industrialised countries.

Besides the advantage that rainwater is free of charge, it neither has to be purified nor transported over long distances. The two most important arguments to support the use of rainwater are as follows.

a) Substitution of drinking water
With the benefit of saving precious potable water

b) Coping with storm water run-off at source
With the benefit of preventing flooding

Water use in the office

Thanks to its characteristics the use of rainwater also has positive side effects:

  • ideal for plant growth
  • better washing efficiency - 50% detergent can be saved in areas of hard water
  • no calcification of the washing machine
  • The combination of rainwater harvesting and soak away is an excellent ecological concept (SUDS).

Systems

Due to different buildings and various possibilities of using rainwater, there are different systems for the requirements and applications. Generally we divide them into domestic and commercial systems.

Normally domestic systems are to supply the toilet, washing machine, garden irrigation and provide cleaning water for car washing etc.

Commercial & industrial systems supply domestic applications as well as others, such as e.g. cooling water systems, industrial cleaning, vehicular washing, fire fighting.

In a lot of cases synergies with other technologies bring more benefits and reduce cost e.g. grey water recycling, fire fighting, attenuation, vehicular washing.

Up to 46% of water within the home can be utilised with rainwater