Upper Tietê Floodplain Conservation Plan

The portion of Upper Tiete basin located upstream Penha Dam covers an area of 1,836 km², its longer and shorter axes measuring 87.9 and 33.6 km respectively. The river thalweg is approximately 118 km long; along this reach, the river preserves its original characteristics, including its meanders, for almost the whole length. Upper Tiete floodplain is surrounded by districts of Sao Paulo City and many other nearby cities, presenting urbanization rates up to 80%; the floodplain is characterized by a fast and unplanned land occupation process. The type of occupation is characterized, mostly, by low income families. One of the most important roles of this floodplain is to retain and attenuate the flood waves. This effect causes a benefic lag between flood peaks coming from upstream reach of the basin (Upper Tiete floodplains reach) and downstream reach, the latter comprising important parcel of Sao Paulo City and other important surrounding cities, such as Guarulhos and the so called ABC cities (Santo Andre, Sao Bernardo, Sao Caetano, Diadema etc).