An embankment dam is a large artificial dam . It is typically created by the placement and compaction of a complex semi- plastic mound of various compositions of soil or rock. It has a semi-pervious waterproof natural covering for its surface and a dense, impervious core. This makes the dam impervious to surface or seepage erosion . Such a dam is composed of fragmented independent material particles. The friction and interaction of particles binds the particles together into a stable mass rather than by the use of a cementing substance.
31-455: Kingsley Dam is located on the east side of Lake McConaughy in central Keith County, Nebraska , and was the second largest hydraulic fill dam in the world at the time of its completion. It was built as part of the New Deal project. The dam is 162 feet (49 m) tall, 3.1 miles (5.0 km) long, and 1,100 feet (340 m) wide at its base. On the east side of the dam is Lake Ogallala and on
62-407: A grain merchant and mayor of Holdrege, Nebraska , one of the leading promoters of the project. Although he did not live to see the completion of the project, his leadership and perseverance eventually culminated in a public power and irrigation project that helped Nebraska become one of the nation's leading agricultural states. The lake , formed by Kingsley Dam , is a man-made body of water that
93-495: A State Recreation Area at the lake. NGPC's offices are at the Lake McConaughy Visitors Center just south of the dam. The Visitor Center contains a water interpretive center, gift shop, theater, and information office. Kingsley Dam is located at the east end of Lake McConaughy and was the second largest hydraulically filled earthen dam in the world (behind Fort Peck Dam ) on the time of its completion. The dam
124-418: A dam and the filling of the reservoir behind it places a new weight on the floor and sides of a valley. The stress of the water increases linearly with its depth. Water also pushes against the upstream face of the dam, a nonrigid structure that under stress behaves semiplastically, and causes greater need for adjustment (flexibility) near the base of the dam than at shallower water levels. Thus the stress level of
155-537: A dam or floodgate in the United States is a stub . You can help Misplaced Pages by expanding it . Lake McConaughy Lake McConaughy (known locally and affectionately as Lake Mac ) is a reservoir on the North Platte River . It is located 9 miles (14 km) north of Ogallala , Nebraska , United States , near U.S. Highway 26 and Nebraska Highway 61 . The reservoir was named for Charles W. McConaughy,
186-434: A simple embankment of well-compacted earth. A homogeneous rolled-earth dam is entirely constructed of one type of material but may contain a drain layer to collect seep water. A zoned-earth dam has distinct parts or zones of dissimilar material, typically a shell of locally plentiful material with a watertight clay core. Modern zoned-earth embankments employ filter and drain zones to collect and remove seep water and preserve
217-404: A small sustained overtopping flow can remove thousands of tons of overburden soil from the mass of the dam within hours. The removal of this mass unbalances the forces that stabilize the dam against its reservoir as the mass of water still impounded behind the dam presses against the lightened mass of the embankment, made lighter by surface erosion. As the mass of the dam erodes, the force exerted by
248-686: A thick suspension of earth, rocks and water. Therefore, safety requirements for the spillway are high, and require it to be capable of containing a maximum flood stage. It is common for its specifications to be written such that it can contain at least a one-hundred-year flood. A number of embankment dam overtopping protection systems were developed in the early 21st century. These techniques include concrete overtopping protection systems, timber cribs , sheet-piles , riprap and gabions , Reinforced Earth , minimum energy loss weirs , embankment overflow stepped spillways , and precast concrete block protection systems. All dams are prone to seepage underneath
279-501: Is 22 miles (35 km) long, 4 miles (6.4 km) wide at its largest point, and 142 feet (43 m) deep near the dam (at full capacity) – it was constructed between 1936 and 1941 and is fed by the North Platte River . When full, the reservoir has a capacity of 1,740,000 acre-feet (2.15 km ), covers 35,700 acres (144 km ) and has 76 miles (122 km) of shoreline, making it the largest reservoir in Nebraska. Lake McConaughy
310-631: Is Lake Ogallala, commonly called the 'Little Lake'. Water flows out of Lake McConaughy through the Morning Glory tower, and out the other side of the dam through the hydroelectric plant into Lake Ogallala where the water continues flowing down the North Platte River. This smaller lake has rocky shores, but is well known for great camping and fishing. Lake McConaughy is also a popular location for fishing, boating, water sports, camping and hunting. The Nebraska Game and Parks Commission (NGPC) operates
341-619: Is a large dam on the Indus River in Pakistan , about 50 km (31 mi) northwest of Islamabad . Its height of 485 ft (148 m) above the river bed and 95 sq mi (250 km ) reservoir make it the largest earth-filled dam in the world. The principal element of the project is an embankment 9,000 feet (2,700 m) long with a maximum height of 465 feet (142 m). The dam used approximately 200 million cubic yards (152.8 million cu. meters) of fill, which makes it one of
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#1732852296637372-411: Is situated below the south end of the dam. Embankment dam Embankment dams come in two types: the earth-filled dam (also called an earthen dam or terrain dam ) made of compacted earth, and the rock-filled dam . A cross-section of an embankment dam shows a shape like a bank, or hill. Most have a central section or core composed of an impermeable material to stop water from seeping through
403-616: The asphalt make such dams especially suited to earthquake regions. For the Moglicë Hydro Power Plant in Albania the Norwegian power company Statkraft built an asphalt-core rock-fill dam. Upon completion in 2018 the 320 m long, 150 m high and 460 m wide dam is anticipated to be the world's highest of its kind. A concrete-face rock-fill dam (CFRD) is a rock-fill dam with concrete slabs on its upstream face. This design provides
434-536: The concrete slab as an impervious wall to prevent leakage and also a structure without concern for uplift pressure. In addition, the CFRD design is flexible for topography, faster to construct and less costly than earth-fill dams. The CFRD concept originated during the California Gold Rush in the 1860s when miners constructed rock-fill timber-face dams for sluice operations . The timber was later replaced by concrete as
465-406: The core is separated using a filter. Filters are specifically graded soil designed to prevent the migration of fine grain soil particles. When suitable building material is at hand, transport is minimized, leading to cost savings during construction. Rock-fill dams are resistant to damage from earthquakes . However, inadequate quality control during construction can lead to poor compaction and sand in
496-406: The dam must be calculated in advance of building to ensure that its break level threshold is not exceeded. Overtopping or overflow of an embankment dam beyond its spillway capacity will cause its eventual failure . The erosion of the dam's material by overtopping runoff will remove masses of material whose weight holds the dam in place and against the hydraulic forces acting to move the dam. Even
527-486: The dam, but embankment dams are prone to seepage through the dam as well; for example, the Usoi landslide dam leaks 35-80 cubic meters per second. Sufficiently fast seepage can dislodge a dam's component particles, which results in faster seepage, which turns into a runaway feedback loop that can destroy the dam in a piping-type failure. Seepage monitoring is therefore an essential safety consideration. gn and Construction in
558-515: The dam. U.S. Bureau of Reclamation reservoirs on the North Platte River in Wyoming capture precipitation and snowmelt from the mountains and utilize the water for irrigation and hydroelectric production within the North Platte Projects. Return flows from these projects to the North Platte River make up a significant portion of the inflows to Lake McConaughy. On the east side of Kingsley Dam
589-491: The dam. The core can be of clay, concrete, or asphalt concrete . This type of dam is a good choice for sites with wide valleys. They can be built on hard rock or softer soils. For a rock-fill dam, rock-fill is blasted using explosives to break the rock. Additionally, the rock pieces may need to be crushed into smaller grades to get the right range of size for use in an embankment dam. Earth-fill dams, also called earthen dams, rolled-earth dams or earth dams, are constructed as
620-452: The design was applied to irrigation and power schemes. As CFRD designs grew in height during the 1960s, the fill was compacted and the slab's horizontal and vertical joints were replaced with improved vertical joints. In the last few decades, design has become popular. The tallest CFRD in the world is the 233 m-tall (764 ft) Shuibuya Dam in China , completed in 2008. The building of
651-566: The embankment which can lead to liquefaction of the rock-fill during an earthquake. Liquefaction potential can be reduced by keeping susceptible material from being saturated, and by providing adequate compaction during construction. An example of a rock-fill dam is New Melones Dam in California or the Fierza Dam in Albania . A core that is growing in popularity is asphalt concrete . The majority of such dams are built with rock and/or gravel as
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#1732852296637682-437: The impervious Brule clay formation that lies beneath the dam. The dam's face is protected by more than a million tons of rock in several layers and more than 180,000 "jackstones," (rebar-reinforced concrete tetrahedrons), each weighing 800 lb (360 kg). The dam is 162 feet (49 m) tall, 3.1 miles (5.0 km) long, and 1,100 feet (340 m) wide at its base. The Kingsley Hydroplant, which went on-line in 1984,
713-453: 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 frozen-core dam is a temporary earth dam occasionally used in high latitudes by circulating a coolant through pipes inside the dam to maintain a watertight region of permafrost within it. Tarbela Dam
744-449: The largest man-made structures in the world. Because earthen dams can be constructed from local materials, they can be cost-effective in regions where the cost of producing or bringing in concrete would be prohibitive. Rock -fill dams are embankments of compacted free-draining granular earth with an impervious zone. The earth used often contains a high percentage of large particles, hence the term "rock-fill". The impervious zone may be on
775-424: The primary fill. Almost 100 dams of this design have now been built worldwide since the first such dam was completed in 1962. All asphalt-concrete core dams built so far have an excellent performance record. The type of asphalt used is a viscoelastic - plastic material that can adjust to the movements and deformations imposed on the embankment as a whole, and to settlement of the foundation. The flexible properties of
806-501: The refinanced portion of the debt was paid off in 1995). The Depression-era construction project provided jobs to more than 1,500 people. CNPPID, a political subdivision of the State of Nebraska, owns and operates the dam and reservoir and an associated hydroplant below the dam. The source of water for Lake McConaughy is primarily the North Platte River. Water flows into the lake from a 32,500-square-mile (84,000 km ) drainage area west of
837-501: The reservoir begins to move the entire structure. The embankment, having almost no elastic strength, would begin to break into separate pieces, allowing the impounded reservoir water to flow between them, eroding and removing even more material as it passes through. In the final stages of failure, the remaining pieces of the embankment would offer almost no resistance to the flow of the water and continue to fracture into smaller and smaller sections of earth or rock until they disintegrate into
868-690: The south side is the Kingsley Hydroelectricity Plant. The Nebraska Game and Parks Commission and Central Nebraska Public Power and Irrigation District are also located in this area. Kingsley Dam, the Kingsley Hydroelectricity Plant, the Morning Glory Spillway, and the Outlet Tower – a large structure near the dam used to release water from the lake – are main visual icons of Lake McConaughy. This article about
899-404: The upstream face and made of masonry , concrete , plastic membrane, steel sheet piles, timber or other material. The impervious zone may also be inside the embankment, in which case it is referred to as a "core". In the instances where clay is used as the impervious material, the dam is referred to as a "composite" dam. To prevent internal erosion of clay into the rock fill due to seepage forces,
930-465: Was constructed to store water for irrigation for The Tri-County, later renamed Central Nebraska Public Power and Irrigation District (CNPPID) hydro-irrigation project. A hydro-electric plant was later added and went online in 1984. The total cost of the Project was $ 43 million, paid by a $ 19 million PWA grant and a $ 24 million federal loan (the federal debt was paid off when the loan was refinanced in 1972;
961-453: Was named for George P. Kingsley, a Minden, Nebraska banker, who worked with C. W. McConaughy to promote the project. The dam was built by pumping sand and gravel from the river bed to form its sides, while pumping a mixture of loess soil and water into the center of the structure to form its watertight core. Seepage of water under the dam is prevented by a wall of interlocked sheet piling driven 30 to 160 ft (49 m) deep and tied into