Brazil: Flood Management in Curitiba Metropolitan Area

This text presents the lessons learned from the Flood Management in Iguaçu River. The usual
approach would be to increase the Iguaçu river capacity to cope with the 50 or 100 year flood.
Under these conditions the population would occupy the floodplain because of the flood
frequency decrease just after the works. After a few years the development of the upstream
basin will change the hydrograph and increase the flood frequency and peak of the floods. In
this future scenario there will not be more space for the increase of the section width, since the
flood plain would be occupied. In this scenario the flood control could be done only by dikes
(with pump station and internal drainage) or deepening the river by a reach of at least 50 km,
which represents high cost. This is the scenario occurred in the Metropolitan Region of São
Paulo and the cost of deepening the channel was evaluated in more than a billion dollars in
1986!