History Channel: Modern Marvels - Dams

They block the force of a river, produce enough electricity to power cities, move water over hundreds of miles and irrigate fertile valleys.

Dams prevent floods and produce "green" energy. Visit a hydroelectric dam, the most technologically advanced type of dam, and a dam in Brazil that is five times the size of the Hoover Dam. At the Utah State University Water Research Laboratory Hydraulics Lab in Logan, Utah, watch a model of a dam crumble beneath tons of water and discuss how future dam failures can be averted. Learn how dams adversely affect river systems and as a result, there are many proponents of dam removal.

The task was monumental: build the world's largest dam in the middle of the desert, tame the river that carved the Grand Canyon...and do it all within seven years! When the 726-foot-hight Hoover Dam was completed in 1935, it was the largest dam in the world. The ambitious government-sponsored project promised to change a barren southwestern desert into a bountiful agricultural community by focusing its goals on flood control, irrigation, drink water, and the procurement of electricity. In this in-depth program, Modern Marvels presents the dramatic and controversial history behind the building of the dam. Through archival footage, discover the immensity of the task at hand for the thousands of workers involved, and reveal the innovative construction techniques that were required to finish the job on time. From the impossible expectations to successful superstructure, this is the comprehensive story behind the Hoover Dam.