The spillway is the structure of the hydroelectric power plant destined to extravasate the exceptional floods in order to protect the dam against overtopping. The layout and type of spillway depend on the general arrangement of the works of a hydroelectric power plant, which in turn depends on the topographical and geological characteristics of the site. In general, the spillway has five distinct elements: approach channel, control structure, chute channel, energy dissipator and exit channel. Jansen–USBR, in the book titled Dams and Public Safety presented several cases of dam rupture. The main causes are foundation problems, seepage, erosion, embankment movement, liquefaction, concrete deterioration, spillways, outlets, demolition, sliding and induced earthquakes. Every spillway must be operated according to the plan of operation of the gates, which contemplates the whole range of flows to be discharged throughout its useful life, in normal and emergency situations.