The Dam Of The Sayano-Shushenskaya GES

In the Netherlands, a low-lying country, dams were often applied to block rivers in order to regulate the water level and to prevent the sea from entering the marsh lands. Such dams often marked the beginning of a town or city because it was easy to cross the river at such a place, and often gave rise to the respective place's names in Dutch. For instance the Dutch capital Amsterdam (old name Amstelredam) started with a dam through the river Amstel in the late 12th century, and Rotterdam started with a dam through the river Rotte, a minor tributary of the Nieuwe Maas. The central square of Amsterdam, covering the original place of the 800 year old dam, still carries the name Dam Square or simply the Dam.
French engineer Benoît Fourneyron developed the first successful water turbine in 1832. The era of large dams was initiated after Hoover Dam was completed on the Colorado River near Las Vegas in 1936. By 1997, there were an estimated 800,000 dams worldwide, some 40,000 of them over 15 m (49 ft) high.