Abstract
The Brazilian metropolises are undergoing great transformations. The peripheries have become critical situations, where different public policies, settlements of precarious housing units and disaggregated environmental systems conflict. River floodplains, such as that of the Tietê river in eastern São Paulo, are paradigmatic of a condition of non-equilibrium, requiring a new perspective on the extreme phenomena that affect the urban landscape: torrential rains, floods. It is necessary to develop social strategies and technical tools to deal with climatic instabilities and to re-evaluate the relations between the river and the city, integrating flood containment devices and the environment into other conceptual and operational foundations.
KEYWORDS:; Critical situations; Non-equilibrium; River; City; Floods