The Sobradinho Lake and Dam, Brazil
The lake is about 320 km long, with a surface of 4,214 square kilometers and a storage capacity of 34.1 cubic kilometers at its nominal elevation of 392.50 meters, making it the 12th-largest artificial lake in the world. It encloses the waters of the São Francisco River, one of the largest and most important rivers in Brazil.
The reservoir, which represents 60.4% of the hydroenergetic resources of the Northeast of Brazil, has conditions to guarantee the power supply for the region for two years but its water level is very undependable. In some years the drought can be so critical that the energy supply is in doubt.
In the current image, the water level appears to be high. The lake and river are both filled with sediments, suggesting recent rainfall. An algal bloom is visible at the northern portion of the lake.
The Sobradinho dam has a maximum height of 41 meters and a total length of 12.5 km; its power plant has 6 generating units with Kaplan turbines with a unitary power of 175,050 kW, totalling 1,050,300 kW.
The dam has a loch, whose chamber is 120 meters long and 17 meters wide allowing boats to surpass the barrier of the 32.5 meters created by the dam, and guaranteeing the continuation of the navigation between Pirapora, Minas Gerais and Juazeiro, Bahia – Petrolina, Pernambuco.
There is a city with the name of Sobradinho located near the dam. The population is 38,000 and the area of the municipality is 1.324 km². It grew with the construction of the dam, because upon the creation of the huge lake, the flooding forced the inhabitants of four cities and 30 villages had to leave their homes.
In all, 11,853 families (more than 70 thousand people) abandoned the old towns before the end of 1977. Of this total, 5,806 families remained in rural lots around the lake and 3,851 families moved to the new towns, including Sobradinho.