Waterharmonica: natural constructed wetlands to convert tretaed wastewater into a usable water

Natural purification systems have already been used for years in The Netherlands to improve the quality of waste water before discharge or reuse. The first basic ideas design for the ‘Waterharmonica’ as the link between the Water Chain and the Water System were rewarded by the Foundation for Applied Water Research (STOWA) on its 25th anniversary in 1996. Since then Waterharmonicas have been constructed in various places in The Netherlands firstly on a small scale but now also on a large scale. Extensive research has been carried out into the working and effectiveness of these systems during over 15 years and they are still being studied. Moreover the Waterharmonica became rooted in Dutch water policy. Experience with Waterharmonicas illustrate that much is now known about how useful Waterharmonicas are. Rules of thumb are available for designing them; choices can be made in terms of the performance required such as the buffering of water and disinfection. It is known that at lower loads the systems are effective at capturing and converting nutrients but also in enlarging the biodiversity so that the natural values increase. This can easily be linked to recreation and perception. It might also be the case that their greatest value lies in the cooperation of people from totally different backgrounds and interests in an attractive part of the water cycle: an STP manager now sees why he treats the water â€" and it is not only to meet the standards. At sites where the Waterharmonica is combined with an ecological connecting corridor it can function as a stepping stone or habitat (e.g. the Kristalbad). The Waterharmonica is very well suited to play a role in urban water management see for plans in several cities like Apeldoorn Arnhem and Amstelveen (Veluwe 2005 Arcadis 2004 and Leloup Voort et al 2012). A consequence of the Waterharmonica approach is the creation and restoration of wetlands and the conversion of costs of water purification into economic and natural revenues for citizens but also for water authority. This applies to an even greater extent to the ‘developing world’ (Mels Martijn et al 2005). The sensible use of water and nutrients helps fight poverty and simultaneously conserves and enhances important ecosystems. It is not only the solution to a waste water problem; it is especially an area and ecosystem-oriented approach.