URBAN STORMWATER INFILTRATION PERSPECTIVES

In urban areas there are many problems with water management: combined sewer overflows, peak flows, man-induced droughts, consolidation of t he soil, damage from frost penetration, etc. It is preferable to look at all these problems In relation to each other, according the concept of integrated water management. This paper focuses on the possibiliti es for urban stormwater infiltration. The results of three studies are presented. The first study concerns the flooding of the Shirako River in Tokyo. It is shown that with the help of stormwater infiltration t he floods can be reduced remarkably. The second study concerns combine d sewer overflows and the discharge from treatment plants for catchmen ts in Denmark and the Netherlands. When looking at the total yearly di scharge from the combined sewer and the treatment plant. it is shown t hat infiltration is more effective than detention. The third study sho ws the impact of urban stormwater infiltration on the groundwater flux in an area in the south of the Netherlands. To relate the different r esults from the three studies an analogy is introduced with the human body. The combination of problems results in a so-called urban hang-ov er. It is shown that the positive effects of urban stormwater infiltra tion within an integrated approach are more significant than looking a t all the effects separately.