10.4122/1.1000001704 Geldof, G. D. Interactive implementation DTU Library, Technical University of Denmark (DTU) 2005 Complexity existing urban areas implementation integrated planning stormwater source control uncertainties Water and Environmental Planning en Conference full text 10.4122/1.1000001703 application/pdf 1 In the last decades it has become clear that improving the quality of the urban environment asks for an integrated approach and stormwater source control. However, practice shows stubborn behaviour. Water managers did start to produce integrated water plans, but only a few measures in these plans are really implemented. This paper uses complexity science building bricks to handle above mentioned problem. Instead of the traditional serial approach a parallel approach is introduced. This is called Interactive Implementation. Interactive Implementation shows the characteristics of a learning process, where people act parallel and learn from each other\342\200\231s mistakes. Practice and science are interwoven. Parts of the vision are constructed, even when the financing of the whole vision is not fully organised. Most of the public and political support reveals itself as an emergent property. Spatial integration takes place on a large scale (the vision) and integration of water, traffic, recreation, education and culture takes place in small-scale practical projects. In new urban areas to be developed, the traditional serial approach most of the time suffices. However, in existing urban areas the process of Interactive Implementation has to be applied. The paper illustrates how Interactive Implementation can be put into practice.