In the video footage filmed by construction workers, the snake’s head was shown to measure 1 meter in diameter. According to the Guinness book of world records, the world’s largest snake alive is in captivity is Medusa in Kansas City USA. Medusa measures 25 ft 2 inches in length.
Incidentally the Belo Monte Hydroelectric Dam in Brazil on completion will be the world’s fourth largest dam after the Three Gorges Dam in China. Watch the video of the episode.