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Embankment (earthworks), a raised bank to carry a road, railway, or canal across a low-lying or wet area; Embankment dam, a dam made of mounded earth and rock; Land reclamation along river banks, usually marked by roads and walkways running along it, parallel to the river, as in:
The side of a levee in Sacramento, California. A levee (/ ˈ l ɛ v i / or / ˈ l ɛ v eɪ /), [a] [1] dike (American English), dyke (British English; see spelling differences), embankment, floodbank, or stop bank is an elevated ridge, natural or artificial, alongside the banks of a river, often intended to protect against flooding of the area adjoining the river.
Most flood embankments are between 1 metre and 3 metres high. A 5-metre-high (16 ft) flood embankment is rare. [1] Modern improvements to this design include constructing an internal central core made from impermeable substance like clay or concrete, some even use metal pilings. [2] Some authorities call man-made structures levees.
By placing these embankments somewhat back from the margin of the river-bed, a wide flood-channel is provided for the discharge of the river as soon as it overflows its banks, while leaving the natural channel unaltered for the ordinary flow. Low embankments may be sufficient where only exceptional summer floods have to be excluded from meadows.
Cattle grazing below high water, Isle of Dogs, 1792 (Robert Dodd, detail: National Maritime Museum) The Embanking of the tidal Thames is the historical process by which the lower River Thames, at one time a shallow waterway, perhaps five times broader than today, winding through malarious marshlands, has been transformed by human intervention into a deep, narrow tidal canal flowing between ...
The natural slope of the flood plains is often very small, and little fall (or head loss) is permissible in the culverts. Researchers developed and patented the design procedure of minimum energy loss culverts which yield small afflux. [21] [22] [23] A minimum energy loss culvert or waterway is a structure designed with the concept of minimum ...
Modern zoned-earth embankments employ filter and drain zones to collect and remove seep water and preserve the integrity of the downstream shell zone. An outdated method of zoned earth dam construction used a hydraulic fill to produce a watertight core. Rolled-earth dams may also employ a watertight facing or core in the manner of a rock-fill dam.
The next step was to move the dikes ever-more seawards. Every cycle of high and low tide left a small layer of sediment. Over the years these layers had built up to such a height that they were rarely flooded. It was then considered safe to build a new dike around this area. The old dike was often kept as a secondary defense, called a sleeper dike.