Hydraulic and Legal Conditions for Buildings in Floodplains-Case Study of Kalisz City (Poland)

Abstract

The 2000 Water Framework Directive (WFD) and the 2007 Floods Directive (FD) have forced the member states of EU to introduce specific regulations and rules related to the development of flood plains. An important assumption of the introduced regulations is the gradual postponement of buildings from areas endangered by flooding. This is a rational approach from the point of view of minimizing the risks associated with flooding. However, many cities are located on rivers. The growth of these cities is not possible or would be very limited without the possibility of developing areas very close to the river. Therefore, a conflict of interest arises between local self-government authorities, entrepreneurs, private persons and institutions responsible for flood protection and water management. The first group see urban areas in the vicinity of the river as economically attractive and the latter as the potential increase in the risk of flooding. The main purpose of the work is to present the scope of hydraulic analyses supporting the decision-making process on the development of flood plains. In the conducted research, a case study was used for the city of Kalisz located in central Poland on the Prosna River. It is being planned to build a housing estate in Kalisz within areas threatened by flooding. Although, inevitably, Kalisz has its residential, administrative and industrial buildings located very close to the Prosna River, the city's system of flood protection is unsatisfactory, mainly due to the lack of funds. The local water management board is very reluctant to refer to projects related to the development of areas in the vicinity of watercourses, which, in its opinion, will further increase the risk of flooding. The paper shows that carrying out detailed hydraulic, design and construction analyses significantly supports the legal process of issuing permits for the development of areas threatened by floods.