Urban development in developing countries usually occurs with high population concentration in small areas, poor public transportation, lack of water facilities, polluted air and stormwater and floods impacts. Lack of integrated management of water supply, sewage, total solids, urban drainage and flood plain lies at origin of the problems.
The main types of floods which may impact urban areas are: Due to urbanisation: floods related to the increase of impermeable areas and man-made drainage facilities, such as conduits and channels; Due to flood plain occupation: when no reliable urban planning and regulation exists, population occupies the flood plain, usually after a sequence of low flood years. When a larger flood occurs, damage is very high and the municipality is requested to invest in flood protection for those areas.
Flood management is highly dependent on land use development. In many developing countries, the Urban Master Plan is mainly a compilation of tendencies of spontaneous occupation due to social and economics conditions. Understanding these aspects is fundamental to develop a sound flood management. These aspects are discussed, together with some Brazilian case studies.