Flood control channels are large and empty basins which let water flow in and out (except during
flooding) or dry channels that run below the street levels of some larger
cities, so that if and when a flood occurs, the water will run into these channels, and eventually drain into a
river or other body of
water. Flood channels are sometimes built on the former courses of waterways as a way to reduce flooding.
Levees
Flood control channels are not to be confused with watercourses which are simply confined between
levee
A levee (), dike (American English), dyke (English in the Commonwealth of Nations, Commonwealth English), embankment, floodbank, or stop bank is a structure that is usually soil, earthen and that often runs parallel (geometry), parallel to ...
s. These structures may be made entirely of
concrete, with concrete sides and an exposed bottom, with
riprap sides and an exposed bottom, or completely unlined. They often contain grade control sills or
weirs to prevent
erosion and maintain a level streambed.
Distribution
By definition, flood control channels range from the size of a
street gutter
A street gutter is a depression that runs parallel to a road and is designed to collect rainwater that flows along the street diverting it into a storm drain. A gutter alleviates water buildup on a street, allows pedestrians to pass without walki ...
to a few hundred or even a few thousand feet wide in some rare cases. Flood control channels are found in most heavily developed areas in the world. One city with many of these channels is
Los Angeles, as they became mandatory with the passage of the
Flood Control Act of 1941 The Flood Control Act of 1941 was an Act of the United States Congress signed into law by US President Franklin Roosevelt that authorized civil engineering projects such as dams, levees, dikes, and other flood control measures through the United ...
passed in the wake of the
Los Angeles Flood of 1938.
See also
*
Drop structure
*
Urban runoff
*
Weir
*
Levee
A levee (), dike (American English), dyke (English in the Commonwealth of Nations, Commonwealth English), embankment, floodbank, or stop bank is a structure that is usually soil, earthen and that often runs parallel (geometry), parallel to ...
External links
LA River Flood Control Channel
Flood control
Environmental engineering
Rivers
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