Four general aspects of spillways are worth noting.
Spillways constructed to one side of earthen dams are featured in the design of Oroville Dam and of Mangla Dam in Pakistan.
Spillways are particularly important safety features for earth dams, protecting the dam and its foundation from erosion.
In principle, the Mississippi's floods are either constricted by levees, hastened out of danger zones by floodways and improved channels, dissipated down spillways and into reservoirs, or starved by the impounding of tributary floods.
In the event that the main levees are threatened, the excess floodwater drains away down spillways (e.g., from north of New Orleans it is diverted past the city by spillways leading through Lake Pontchartrain to the Gulf of Mexico) or bursts "fuse plugs," the specially weakened sections of levee leading to harmless floodways or reservoirs.
Lawrence lowlands is composed primarily of glacial landforms: glacial lake bottoms and shorelines, till plains, moraines, drumlins, eskers, and giant spillways carved by glacial streams.
From streamflow data, determinations can be made of the minimum, maximum, average daily, and average monthly flows; the size of dams, spillways, and downstream channel; and the seasonal and carry-over storage needed.
Floodgate, gate for shutting out or releasing the flow of water over spillways, in connection with the operation of a dam.
Spillways, controls, and embankments designed to permit discharge measurements are simply different kinds of broad-crested weirs.
The Selinda spillway fills with floodwaters from the Angolan hills once every 20 or 30 years, bringing tilapia, hippos, pelicans, snub-nosed ducks and rafts of water lily which locals eat as a delicacy.
On May 14th the Army Corps of Engineers created that wall of water when it opened up the Morganza Spillway, sending 600,000 cubic feet of water per second into the Atchafalaya River basin but keeping the floods from reaching Louisiana's two big downriver cities and keeping the river itself from changing course.The Mississippi drainage basin is exceeded only by the Amazon's and the Congo's.
