In the year of 2000 some parts of Sweden were subjected to extreme floods that threatened individuals and important functions in society. The main problerns concerned buildings and infrastructure as well as environmental and health risks. The situation called for co-ordination and co-operation between authorities at regional/local level and many other actors. For many reasons, among them the fact that the floods lasted for different periods of time in different parts of the country, the authorities handled the situation in different ways. The co-ordination system is very formalised in some parts of the country. The co-ordination required by extraordinary situations, such as severe floods, must be based on the watersystem and not on administrative borders. Co-operation based on common interests makes information and command and control easier when more than one authority at regional/local level are subjected to floods. The authorities also need clear information as well as adequate förecasts. Furthermore, when there are floods, it is important that regulations and responsibilities are explicit and adapted to an effective management for the society as a whole. As an example of co-operation it can be mentioned that the Armed Forces participated to a considerable extent in the rescue operations. Furtherinore, volunteer organisations gave information and social support to the inhabitants in the areas subjected to the floods. When it comes to information handling"it can be coneluded that a co-ordinated. and common source of information based on the watersystem as a whole, makes the handling for and between different actors as well as towards media and inhabitants easier. Furthermore, personal information and support to inhabitants create calm and confidence in the society.