ABSTRACT
Water is the basic requirement for living as well as it may be a threat to lives. This natural change in condition has been aggravated by urbanization. Although the disadvantages of urbanization for the ecosystem and human well-being are recognized, people continue to migrate from rural to urban areas. Concepts for flood control in urbanized areas should counterweight the effects of urbanization. For the impervious part of urbanized catchments effective rainfall is calculated by subtracting an initial loss from the original rainfall. The potential of structural and nonstructural measures taken within an urbanized catchment were investigated for their effect on flood peaks. For planning and design of major and minor drainage systems it is impossible to derive the required design data directly from measurements of the past because the surface structures, due to urban development, continuously change. Consequently, urban drainage in cities like Bangkok or Houston becomes most difficult.
