As a result of the United Nations’ International Decade for Natural Disaster Reduction (1990-2000), and recent high profile disasters, disaster risk reduction has climbed high on the international political agenda. There has been a paradigm shift from reacting to disasters towards preparing for and mitigating effects of disasters. Among the measures that have been highlighted on the disaster risk reduction agenda are early warning systems. In a Swedish context, there are needs for early warnings for various flood risk types. Municipalities carry big responsibilities for managing flood risks, and early warnings have a potential to facilitate decision-making and ultimately reduce flood losses.

The aim of this thesis is to describe how a variety of flood warning signals are used in the risk management process of Swedish municipalities, how they can contribute to the flood risk reducing process, and which factors influence the success of this. The thesis is based on two papers.

Paper I is based on interviews with three respondents from Swedish municipalities that have invested in and established local early warning systems. The paper shows that the possible effects from a local early warning system are not only reduced flood losses but also potential spinoff, the occurrence of which is dependent on the well-being of the organisation and its risk management processes.

Paper II is based on interviews with 23 respondents at 18 Swedish municipalities, who have responsibilities related to flood risk management, and one respondent who works at SMHI with hydrological warning. The paper shows that municipalities can use a variety of complementary flood warning signals to facilitate decision-making for a proactive flood response. This is however not systematically the case, and is dependent on available resources.

The theoretical contribution of this thesis is a development of existing conceptual models of early warning systems with respect to risk management and system contexts, and the use of complementary warning signals.

Following the United Nations’ International Decade for Natural Disaster Reduction (1990-2000), and recent high profile disasters, disaster risk reduction has climbed high on the international political agenda. Among the measures that have been highlighted are early warning systems – for Swedish municipalities who are responsible for managing flood risks, early warnings have a potential to facilitate decision-making and ultimately reduce flood losses. This licentiate thesis, based on two articles, aims to describe how a variety of flood warning signals are used in the risk management process of Swedish municipalities, how they can contribute to the flood risk reducing process, and which factors influence the success of this. The articles show that the possible effects from a local early warning system are not only reduced flood losses but also potential spin-off benefits, the occurrence of which is dependent on factors such as organisational culture and the functioning of the wider risk management system, and that municipalities can use a variety of complementary flood warning signals to facilitate decision-making for a proactive flood response which, however, is not systematically the case as benefits are dependent on available resources.