Hydrogeological assumptions for stormwater management in Tallinn

Most cities in temperate climate zones, including Tallinn, face the threat of torrential rains and resultant floods, which cause extensive damage to city economies. The main causes of floods are climatic; however, unreasonable building activity and insufficiently developed and maintained drainage systems also contribute to this problem. The percentage of impervious pavement has increased with the consolidation of buildings and road networks. Rainwater drainage is an important issue in a number of different areas of human activity ranging from town planning and environmental protection to building, maintenance and operation of rainwater drainage systems. Hence, to deal with the rainwater drainage issue, it is necessary to develop an integrated and scientifically justified strategy. The present study represents a constituent part of the relevant strategy development process. The authors pay special attention to options for increasing rainwater percolation in different environmental conditions, including geological setting, topography and different soil filtration properties.