Author(s): Newton De Oliveira Carvalho; Carlos Frederico Castro Alves; Antonio Manoel Dos Santos Oliveira; Aloisio Celeri; Robson Tanaka; Antonio Soares Ferreira
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Keywords: Porto Primavera reservoir; Sedimentological studies; Parana river basin; Brazil
Abstract: Porto Primavera Dam is located on the ParanaRiver, on the borders of the states of Sao Paulo and Mato Grosso do Sul in Brazil, downstream of JupiaDam and upstream of Itaipu Dam. Its basin has a drainage area of 574,000 km 2. The reservoir surface area and capacity are 2,040 km 2 and 15.7×10 9 m 3, respectively, in its normal maximum level of operation. Because of the existence of upstream dams, the sediment load carried to Porto Primavera reservoir comes mainly from six tributaries with significant catchment area. Low dam height and high intake flow resulted in very low intake crest elevation, which reduces dam lifetime by sediment deposition at dam upstream toe. Due to the lack of previous sedimentological observations, sediment load measurements were carried out in four tributaries with significant sediment yield in order to reevaluate the present reservoir capacity and the remaining power generation lifetime. The survey has evidenced that the basin is suffering a gradual increase in sediment yield over time due to population growth, changes in land use and climatic variability, which yields higher precipitation levels and river flows, although quite slowly. The studies came to the conclusion that the sediment deposit in the upstream dam toe will not reach intake crest during project economic lifetime. However, it has been clear that an effective ground conservation plan should be fulfilled in the near future. It was also concluded that there must be a permanent sediment load monitoring in conjunction with periodical water depth surveying in order to evaluate sediment deposition evolution.
Year: 2004