Storm Water Protection And River-basin Wide Water Management By Realising Decentralised Measures Of Rainwater Management In The Catchment Area Of A Watercourse

Abstract

This contribution gives an insight into the results of the research project “Decentralised measures of flood protection at the river Lausitzer Neisse” carried out for the German Federal Foundation for Environmental Protection. It focusses on the description of modes of action and the effectiveness of decentralised measures to a preventive flood protection, Besides technical flood protection and the protection and enlargement of floodplains, decentralised measures in the entire catchment area of a river are introduced as an important component of flood protection. The project concentrates on urban water management and on the improvement of the storage capacity of agricultural land. The water retention potential of these two approaches is examined and simulated. Finally, a method to develop a flood-protection concept with decentralised measures in the river basin is worked out. 1 The field of problem Since the 1990s, the matter of flood protection became a new subject of public and scientific discussion in Germany and other European countries. Heavy and extensive floods e.g. in the Rhine (1993, 1995) and Oder basin (1997, 2001) threatened cities and whole landscapes and had adverse effects on public and private values and the environment. These heavy flood events led to controversial discussions about different strategies of rainwater management. In the previous scientific discussion, besides technical flood protection systems and the pro© 2002 WIT Press, Ashurst Lodge, Southampton, SO40 7AA, UK. All rights reserved. Web: www.witpress.com Email witpress@witpress.com Paper from: Hydraulic Information Management, CA Brebbia and WR Blain (Editors). ISBN 1-85312-912-7 56 Hydraulic [nfimmtion itianogenzent tection and enlargement of floodplains, decentralised measures to improve the retention capacity in the catchment area are mentioned as one strategy of flood protection [3]. However, their contribution to the mitigation of high-water is yet hardly examined and seems to be undervalued. Hence, a research project – sponsored by the German Federal Foundation for Environmental Protection – was conducted to focus on the contribution of decentralised measures to a preventive flood protection. 2 The research project: Decentralised measures of flood protection at the river Lausitzer-Neisse The Neisse-research project aims at analysing the effects of decentralised measures on the retention of precipitation water in the catchment area. The main research object is the river Neisse, a transboundary river between Germany, Poland and the Czech Republic, that was affected by a huge flood event in 1997. To take into account the range of different aspects, the research partners belong to the fields of hydrology, soil science, agriculture and spatial planning working together in an inter-disciplinary manner. The project started in 1999 and will conclude in the beginning of 2002,