Diversion dam

Last updated
The Faraday Diversion Dam, Clackamas River. This dam slows a normally fast and shallow river for partial diversion to a hydroelectric dam. The diversion tunnel opening can be seen in the upper left. Floodgate drum.JPG
The Faraday Diversion Dam, Clackamas River. This dam slows a normally fast and shallow river for partial diversion to a hydroelectric dam. The diversion tunnel opening can be seen in the upper left.
The Imperial Dam diverting the Colorado River in the southwestern United States. Imperial Dam.jpg
The Imperial Dam diverting the Colorado River in the southwestern United States.

A diversion dam is a dam that diverts all or a portion of the flow of a river from its natural course. Diversion dams do not generally impound water in a reservoir; instead, the water is diverted into an artificial water course or canal, which may be used for irrigation or return to the river after passing through hydroelectric generators, flow into a different river or be itself dammed forming an onground or groundwater reservoir or a storm drain.


An early diversion dam is the Ancient Egyptian Sadd el-Kafara Dam at Wadi Al-Garawi, which was located about twenty five kilometres south of Cairo. Built around 2600 BC for flood control, the structure was 102 metres long at its base and 87 metres wide. It was destroyed by a flood while it was still under construction. [1] [2]


Diversion dams are one of three classifications of dams which include: storage dams, detention dams, and diversion dams. Storage dams are used to store water for extended lengths of time. The stored water then can be used for irrigation, livestock, municipal water supply, recreation, and hydroelectric power generation. Detention dams are built to catch surface runoff to prevent floods and trap sediment by regulating the flow rate of the runoff into channels downstream. Diversion dams are used to raise the water level in order to redirect the water to the designated location. The diverted water can be used for supplying irrigation systems or reservoirs. [3]


Diversion dams are installed to raise the water level of a body of water to allow the water to be redirected. The redirected water can be used to supply irrigation systems, reservoirs, or hydroelectric power generation facilities. The water diverted by the diversion dam to the reservoirs can be used for industrial applications or for municipal water supply. [3]


The design a diversion dam will fall into one of four basic types: embankment style dams, buttress style dams, arch style dams, and gravity style dams. [3]

Embankment style diversion dam

Embankment style diversion dams are constructed to counteract the force of the water pushing on the dam by building a dam with enough weight to withstand the force. Embankment dams are commonly made from materials in the surrounding area where the dam is being built. The materials generally include: sand, gravel, and rocks. The combination of these building materials with either clay or an impervious membrane gives the embankment dam its integrity. As a result, the combination of its simple construction and locally available building materials the cost of building an embankment dam is lower than the other types of dams. [3]

Buttress style diversion dam

Buttress style diversion dams are designed using angle supports on the downstream side of the dam. The supports are fixed to the wall of the dam in order to help counteract the force of the water on the dam. Buttress style dams are built across wide valleys that do not have a solid bedrock foundation. [3] Bedrock is solid rock that makes up the upper part of the earth’s crust. Bedrock can be made from sedimentary, igneous, and metaphoric rock origins. [4] Buttress dams require extensive steel framework and labor. As a result, buttress style dams are expensive to construct and are seldom built today. [3]

Arch style diversion dam

Arch style diversion dams are designed using an arch shape with the top of the arch facing upstream. The arch shape provides extra strength to counteract the force of the water. Arch style dams are generally constructed in narrow canyons. Arch style dams are commonly made from concrete. To ensure the dam’s integrity, a solid contact between the bedrock foundation and the dam’s concrete base is required. The dome style dam is a type of arch dam. The dome style dam curves in both the horizontal plane and vertical plane. The arch style dam only curves in the horizontal. [3]

Gravity style diversion dam

Gravity style diversion dams are built to non counteract the force of the water pushing on the dam by building a dam with enough weight to withstand the force. Gravity dams are commonly constructed using masonry or cement. The foundations of the gravity dams are generally constructed on top of a solid bedrock foundation. However, gravity dams can be built over unconsolidated ground as long as proper measures are put in place to stop the flow of water under the dam. If water were to get under the dam, the dam could fail. [3]

See also

Related Research Articles

Dam Barrier that stops or restricts the flow of surface or underground streams

A dam is a barrier that stops or restricts the flow of surface water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use, aquaculture, and navigability. Hydropower is often used in conjunction with dams to generate electricity. A dam can also be used to collect or store water which can be evenly distributed between locations. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees are used to manage or prevent water flow into specific land regions. The earliest known dam is the Jawa Dam in Jordan, dating to 3,000 BC.

Gardiner Dam Dam in Saskatchewan

The Gardiner Dam on the South Saskatchewan River in Saskatchewan is the third largest embankment dam in Canada and one of the largest embankment dams in the world. Construction on Gardiner Dam and the smaller Qu'Appelle River Dam was started in 1959 and completed in 1967, creating Lake Diefenbaker upstream and diverting a considerable portion of the South Saskatchewan's flow into the Qu'Appelle River. The dam rises 64 metres (209 feet) in height, is almost 5 km (3.1 mi) long and has a width of 1.5 km (0.93 mi) at its base with a volume of 65,000,000 cubic meters. The dam is owned and operated by the Saskatchewan Water Security Agency.

New Melones Dam Dam in California

New Melones Dam is an earth and rock filled embankment dam on the Stanislaus River, about 5 miles (8.0 km) west of Jamestown, California, United States, on the border of Calaveras County and Tuolumne County. The water impounded by the 625-foot (191 m)-tall dam forms New Melones Lake, California's fourth largest reservoir, in the foothills of the Sierra Nevada east of the San Joaquin Valley. The dam serves mainly for irrigation water supply, and also provides hydropower generation, flood control, and recreation benefits.

New Bullards Bar Dam Dam in California

New Bullards Bar Dam is a variable radius concrete arch dam constructed in the early 1960s in California on the North Yuba River. Located near the town of Dobbins in Yuba County, the dam forms the New Bullards Bar Reservoir, which can hold about 969,600 acre⋅ft (1,196,000 dam3) of water. The dam serves for irrigation, drinking water and hydroelectric power generation.

Pine Flat Dam Dam in Fresno County, California

Pine Flat Dam is a concrete gravity dam on the Kings River in the Central Valley of Fresno County, California United States. Situated about 28 miles (45 km) east of Fresno, the dam is 440 feet (130 m) high and impounds Pine Flat Lake, one of the largest reservoirs in California, in the foothills of the Sierra Nevada just outside the boundary of Kings Canyon National Park. The dam's primary purpose is flood control, with irrigation, hydroelectric power generation and recreation secondary in importance.

Nagarjuna Sagar Dam Dam in Telangana and Palnadu district, Andhra Pradesh

Nagarjuna Sagar Dam is a masonry dam across the Krishna River at Nagarjuna Sagar which straddles the border between Nalgonda district in Telangana and Palnadu district in Andhra Pradesh. The dam provides irrigation water to the Nalgonda, Suryapet, Krishna, Khammam, West Godavari, Guntur, and Prakasam districts along with electricity generation.

New Waddell Dam Dam in Maricopa County, Arizona

The New Waddell Dam is an embankment dam on the Agua Fria River in Maricopa County, Arizona, 35 miles (56 km) northwest of Phoenix. It serves as part of the Central Arizona Project (CAP) while also providing water for the Maricopa Water District. The dam creates Lake Pleasant with water from the Agua Fria and also the CAP aqueduct. In addition, it affords flood protection, hydroelectric power production and recreational opportunities. Construction on the dam began in 1985 and ended in 1994. Its reservoir submerged the Old Waddell Dam which was completed in 1927 after decades of planning.

Navajo Dam Dam in San Juan and Rio Arriba Counties, New Mexico

Navajo Dam is a dam on the San Juan River, a tributary of the Colorado River, in northwestern New Mexico in the United States. The 402-foot (123 m) high earthen dam is situated in the foothills of the San Juan Mountains about 44 miles (71 km) upstream and east of Farmington, New Mexico. It was built by the U.S. Bureau of Reclamation (Reclamation) in the 1960s to provide flood control, irrigation, domestic and industrial water supply, and storage for droughts. A small hydroelectric power plant was added in the 1980s.

Rio Grande Project

The Rio Grande Project is a United States Bureau of Reclamation irrigation, hydroelectricity, flood control, and interbasin water transfer project serving the upper Rio Grande basin in the southwestern United States. The project irrigates 193,000 acres (780 km2) along the river in the states of New Mexico and Texas. Approximately 60 percent of this land is in New Mexico. Some water is also allotted to Mexico to irrigate some 25,000 acres (100 km2) on the south side of the river. The project was authorized in 1905, but its final features were not implemented until the early 1950s.

New Exchequer Dam Dam in Mariposa County, California

New Exchequer Dam is a concrete–faced, rock-fill dam on the Merced River in central California in the United States. It forms Lake McClure, which impounds the river for irrigation and hydroelectric power production and has a capacity of more than 1,000,000 acre-feet (1.2 km3). The Merced Irrigation District (MID) operates the dam and was also responsible for its construction.

Daniel-Johnson dam Dam in Quebec, Canada

The Daniel-Johnson dam, formerly known as Manic-5, is a multiple-arch buttress dam on the Manicouagan River that creates the annular Manicouagan Reservoir. The dam is composed of 14 buttresses and 13 arches and is 214 km (133 mi) north of Baie-Comeau in Quebec, Canada. The dam was constructed between 1959 and 1970 for the purpose of hydroelectric power production and supplies water to the Manic-5 and Manic-5-PA power houses with a combined capacity of 2,660 MW. The dam is 214 m (702 ft) tall, 1,314 m (4,311 ft) long and contains 2,200,000 m3 of concrete, making it the largest dam of its type in the world.

Caliraya Dam Dam in the Philippines

Caliraya Dam is an embankment dam located in the town of Lumban province of Laguna, in the Sierra Madre Mountain Range of the Philippines. The reservoir created by the dam, Lake Caliraya, initially supplied one of the oldest hydroelectric plants in the Philippines, and later became a popular recreational area for numerous water sports and fishing. The dam's construction was started in 1939 under the supervision of the architecture firm of Pedro Siochi and Company and a small hydroelectric plant was operated in 1942.

New Don Pedro Dam Dam in California

New Don Pedro Dam, often known simply as Don Pedro Dam, is an earthen embankment dam across the Tuolumne River, about 2 miles (3.2 km) northeast of La Grange, in Tuolumne County, California. The dam was completed in 1971, after four years of construction, to replace the 1924 concrete-arch Don Pedro Dam.

Idamalayar Dam Dam in Ernakulam District, Kerala

Idamalayar Dam is a multipurpose concrete gravity dam located at Ennakkal between Ayyampuzha and Bhoothathankettu in Ernakulam district of Kerala on the Idamalayar, a tributary of the Periyar River in Kerala, South India. The dam however extends east as far as Malakkappara. Completed in 1985, with a length of 373 metres (1,224 ft) and a height of 102.8 metres (337 ft), the dam created a multipurpose reservoir covering 28.3 km2 (10.9 sq mi) in the scenic hills of the Anamalais.

Zengwen Dam Dam in Dapu, Chiyai County, Taiwan

Zengwen Dam, also spelled Tsengwen Dam, is a major earthen dam in Dapu Township, Chiayi County, Taiwan on the Zengwen River. It is the third tallest dam in Taiwan, and forms Zengwen Reservoir (曾文水庫), the biggest reservoir in Taiwan by volume. The dam stores water for irrigation of the Chianan Plain, Taiwan's most productive agricultural region, and provides flood control along the Zengwen River which flows through Tainan City. The dam supports a 50 megawatt hydroelectric power station.

Gleno Dam Dam

The Gleno Dam was a multiple arch buttress dam on the Gleno Creek in the Valle di Scalve, northern Province of Bergamo, Italy. The dam was built between 1916 and 1923 with the purpose of producing hydroelectric power. The middle section of the dam collapsed on 1 December 1923, forty days after the reservoir was filled, causing widespread flooding that killed at least 356 people.

Middle Rio Grande Project

The Middle Rio Grande Project manages water in the Albuquerque Basin of New Mexico, United States. It includes major upgrades and extensions to the irrigation facilities built by the Middle Rio Grande Conservancy District and modifications to the channel of the Rio Grande to control sedimentation and flooding. The bulk of the work was done by the United States Bureau of Reclamation and the United States Army Corps of Engineers in the 1950s, but construction continued into the 1970s and maintenance is ongoing. The project is complementary to the San Juan-Chama Project, which transfers water from the San Juan River in the Colorado River Basin to the Rio Grande. Although distribution of water from the two projects is handled through separate allotments and contracts, there is some sharing of facilities including the river itself. The ecological impact on the river and the riparian zone was the subject of extended litigation after a group of environmentalists filed Rio Grande Silvery Minnow v. Bureau of Reclamation in 1999.

A detention dam is a dam built to catch surface runoff and stream water flow to regulate the water flow in areas below the dam. Detention dams are commonly used to reduce the damage caused by flooding or to manage the flow rate through a channel. Detention dams can also be constructed to replenish groundwater and trap sediment. Detention dams are one of three classifications of dams: storage dams, diversion dams, and detention dams. Storage dams store water for extended times for irrigation, livestock, municipal water supply, recreation, and hydroelectric power generation. Diversion dams raise the water level to redirect the water to a designated location. The diverted water typically supplies irrigation systems or reservoirs.

Potter Valley Project

The Potter Valley Project is an hydroelectric project in Northern California in the United States, delivering water from the Eel River basin to turbines in the headwaters of the Russian River. The project is owned and operated by Pacific Gas and Electric Company (PG&E). The main facilities are two dams on the Eel River, a diversion tunnel and hydroelectric plant. Average annual throughput is 159,000 acre⋅ft (196,000,000 m3), although this figure varies significantly with both the amount of precipitation in the Eel River basin and the demand on the Russian River.

Yuba–Bear Hydroelectric Project

The Yuba–Bear Hydroelectric Project is a complex hydroelectric scheme in the northern Sierra Nevada in California, tapping the upper Yuba River and Bear River drainage basins. The project area encompasses approximately 400 square miles (1,000 km2) in Nevada, Placer, and Sierra Counties. Owned by the Nevada Irrigation District, it consists of 16 storage dams plus numerous diversion and regulating dams, and four generating stations producing 425 million kilowatt hours of electricity each year. The Yuba–Bear Hydroelectric Project consists of the Bowman development, Dutch Flat No. 2 development, Chicago Park development, and Rollins development.


  1. Günther Garbrecht: "Wasserspeicher (Talsperren) in der Antike", Antike Welt, 2nd special edition: Antiker Wasserbau (1986), pp.51-64 (52f.)
  2. Mohamed Bazza (28–30 October 2006). "Overview of the History of Water Resources and Irrigation Management in the Near East Region" (PDF). Food and Agriculture Organization of the United Nations. Archived from the original (PDF) on 2007-08-08. Retrieved 2007-08-01.
  3. 1 2 3 4 5 6 7 8 Goings, David B. (2004). K. Lee Lerner and Brenda Wilmoth Lerner (ed.). The Gale Encyclopedia of Science (Web). Detroit: Gale. pp. 1149–1152. Retrieved 22 February 2013.
  4. K. Lee Lerner and Brenda Wilmoth Lerner, ed. (2004). The Gale Encyclopedia of Science (Web) (3rd ed.). Detroit: Gale. pp. 468–469. Retrieved 22 February 2013.