Indicators for urban drainage system : assessment of climate change impacts

Changes of the climatic conditions will affect urban drainage systems, as they are closely related to the weather phenomenon and are built as to cope with the weather occurring. The aim of this paper is to investigate indicators that can be used to describe and compare impacts and adaptation measures in existing urban drainage systems. Problems in the system due to climate change can be summarised as problems with flooding of surfaces and basements, increased amount of combined sewer overflows (CSO), increase of the inflow to waste water treatment plants (WWTP) and increase in pollutants spreading from urban areas to the environment. The impacts needs to be described with indicators taking into account the system behaviour both before, during and after an event (e.g. urban flooding) has occurred, and can be divided into (A) description of the system performance, (B) capacity exceeding in the system, and (C) description of consequences as a result of capacity exceeding. The consequences can be divided into sustainable aspects as: technical, economical, socio-cultural, environmental, and health. The research is performed within a project which will also include model simulations of urban drainage systems in four Swedish municipalities as to assess impacts and evaluate the use of indicators.Godkänd; 2008; 20080909 (karober