Meteorological history | |
---|---|
Date | 1979 |
Overall effects | |
Fatalities | 1,800–25,000 (estimated) [1] |
Damage | Estimated ₹100 crore (equivalent to ₹26 billionorUS$310 million in 2023) [2] |
Areas affected | Morbi and villages of Rajkot district,Gujarat,India |
The Machchhu dam failure or Morbi disaster is a dam-related flood disaster which occurred on 11 August 1979. The Machchu-2 dam,situated on the Machchhu River,failed,sending a wall of water through the town of Morbi (now in the Morbi district) of Gujarat,India. [2] Estimates of the number of people killed vary greatly ranging from 1,800 to 25,000 people. [1] [3] [4]
The first dam on the Machchhu river,named Machchhu I,was built in 1959,having a catchment area of 730 square kilometres (280 sq mi). The Machchhu II dam was constructed downstream of Machchhu I in 1972,and has a catchment area of 1,929 square kilometres (745 sq mi). [5]
It was an earthfill dam. The dam was meant to serve an irrigation scheme. Considering the long history of drought in Saurashtra region,the primary consideration at the time of design was water supply,not flood control. It consisted of a masonry spillway of 206 metres (676 ft) consisting 18 sluice gates across the river section and long earthen embankments on both sides. The spillway capacity provided for 5,663 cubic metres per second (200,000 cu ft/s). [6] The embankments were of 2,345 metres (7,694 ft) and 1,399 metres (4,590 ft) of length on left and right side respectively. [7] The embankments had a 6.1 m top width,with upstream and downstream slopes 1:3 (V:H) and 1:2 respectively;and a clay core extending through alluvium to bedrock. The upstream face consisted of 61 cm small gravel and a 61 cm hand packed rip-rap. The dam stood 22.6 metres (74 ft) above the river bed and its overflow section was 164.5 metres (540 ft) long. The reservoir had a storage capacity of 101,020 cubic decametres (81,900 acre-feet). [8]
The failure was caused by excessive rain and massive flooding leading to the disintegration of the earthen walls of the four kilometre long Machchhu-2 dam. The actual observed flow following the intense rainfall reached 16,307 m3/s,thrice what the dam was designed for,resulting in its collapse. 762 metres (2,500 ft) of the left and 365 metres (1,198 ft) of the right embankment of the dam collapsed. [7] Within 20 minutes the floods of 12 to 30 ft (3.7 to 9.1 m) height inundated the low-lying areas of Morbi industrial town located 5 km below the dam. [6]
Around 3.30 pm the tremendous swirling flow of water struck Morbi. Water level rose to 30 feet (9.1 m) within the next 15 minutes and some low lying areas of city were under 20 feet (6.1 m) of water for the next 6 hours. [2]
The Morbi dam failure was listed as the worst dam burst in the Guinness Book of Records [9] (before the death toll of the 1975 Banqiao Dam failure was declassified in 2005). [10] The book No One Had A Tongue To Speak by Tom Wooten and Utpal Sandesara debunks the official claims that the dam failure was an act of God and points to structural and communication failures that led to and exacerbated the disaster. [11] There was great economic loss. The flood damaged farmland,leading to a decrease in productivity of crops.
The book by Wooten and Sandesara gives vivid first person accounts of many survivors. It narrates how people scrambled for rooftops,hilltops,and other safe grounds in order to save themselves. Over a hundred people took shelter in Vajepar Ram Mandir but later the deluge submerged them with the temple. Women were compelled to drop their babies into the furious surge in order to save themselves and people lost their loved ones in a flash. [12]
During reconstruction of the dam the capacity of the spillway was increased by four times and fixed at about 21,000 m3/s. [6]
The Gujarati disaster film Machchhu is based on the Machchhu dam failure. [13]
Dartmouth Dam is a large rock-fill embankment dam with an uncontrolled chute spillway across the Mitta Mitta,Gibbo and Dart rivers,the Morass Creek and a number of small tributaries. The dam is located near Mount Bogong in the north-east of the Australian state of Victoria. The dam's purpose includes irrigation,the generation of hydro-electric power,water supply and conservation. The impounded reservoir is called Dartmouth Reservoir,sometimes called Lake Dartmouth. The Dartmouth Power Station,a hydro-electric power station that generates power to the national grid,is located near the dam wall.
Kelly Barnes Dam was an earthen embankment dam on Toccoa Creek in Stephens County,Georgia,United States,just outside the city of Toccoa. Heavy rainfall caused it to collapse on November 6,1977,and the resulting flood killed 39 people and caused $2.8 million in damage. The dam was never rebuilt.
Oroville Dam is an earthfill embankment dam on the Feather River east of the city of Oroville,California,in the Sierra Nevada foothills east of the Sacramento Valley. At 770 feet (235 m) high,it is the tallest dam in the U.S. and serves mainly for water supply,hydroelectricity generation,and flood control. The dam impounds Lake Oroville,the second-largest reservoir in California,capable of storing more than 3.5 million acre-feet (1.1×10 12 US gal;4.3×109 m3).
The Saluda Dam or Saluda River Dam,officially the Dreher Shoals Dam,commonly referred to as the Lake Murray Dam,is an earthen embankment dam located approximately 10 miles (15 km) west of Columbia,South Carolina on the Saluda River. Construction on the dam began in 1927 and was completed in 1930. The purpose of the dam is flood control,hydroelectricity,recreation and water supply. At the time of its completion,the Saluda Dam was the world's largest earthen dam,creating the world's largest man-made lake,Lake Murray. In 2005,construction on a 213 ft (65 m). tall roller-compacted concrete (RCC) dam was completed at the toe of the original dam in order to mitigate an earthquake-caused dam failure.
Copeton Dam is a major clay core and rock fill embankment dam with nine radial gates and a gated concrete chute spillway across the Gwydir River upstream of Bingara in the New England region of New South Wales,Australia. The dam's purpose includes environmental flows,hydro-electric power generation,irrigation,and water supply. The impounded reservoir is called Lake Copeton.
Googong Dam is a minor ungated earth and rock fill with clay core embankment dam with concrete chute spillway plus a nearby 13 metres (43 ft) high earthfill saddle embankment across the Queanbeyan River upstream of Queanbeyan in the Capital Country region of New South Wales,Australia. The dam's purpose includes water supply for Canberra and Queanbeyan. The impounded reservoir is called Googong Reservoir.
Tooma Dam is a major ungated earthen embankment dam across the Tooma River in the Snowy Mountains of New South Wales,Australia. The dam's main purpose is for the generation of hydro-power and is one of the sixteen major dams that comprise the Snowy Mountains Scheme,a vast hydroelectricity and irrigation complex constructed in south-east Australia between 1949 and 1974 and now run by Snowy Hydro.
The Ross River Dam is a rock and earthfill-filled embankment dam across the Ross River,located between Kelso and Mount Stuart in the City of Townsville in northern Queensland,Australia. Built initially for flood control,Lake Ross,the impoundment created by the dam,serves as one of the major potable water supplies for the region.
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.
The Nillahcootie Dam,a rock and earth-fill embankment dam with a unique Gothic arch-shaped crest spillway across the Broken River that is located near Mansfield,in the Alpine region of Victoria,Australia. The dam's purpose is for the supply of potable water and for irrigation. The impounded reservoir is called Lake Nillahcootie.
The Cotter Dam is a concrete gravity and rockfill embankment dam across the Cotter River,located in the Australian Capital Territory,Australia. Both the dam and river are named after early settler in the area Garrett Cotter. The impounded Cotter Reservoir is a supply source of potable water for the city of Canberra and its environs.
Al Wahda Dam,formerly known as M'Jaara Dam,is an embankment dam on the Ouergha River near M´Jaara in Ouezzane Province,Morocco. It was constructed for flood control,irrigation,water supply and hydroelectric power production. It is the second largest dam in Africa and the largest in Morocco. It was described by Land Ocean Interactions in the Coastal Zone (LOICZ) as "the second most important dam in Africa after the High Aswan dam."
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.
Machchhu River is a river in Gujarat,India,with its origin in the Madla hills. Its basin has a maximum length of 130 km (81 mi). The total catchment area of the basin is 2,515 km2 (971 sq mi). The river is also occasionally transliterated as Machhu River.
The Dikgatlhong Dam is a dam near the village of Robelela on the Shashe River in Botswana,completed in December 2011. When full it will hold 400,000,000 cubic metres (1.4×1010 cu ft). The next largest dam in Botswana,the Gaborone Dam,has capacity of 141,000,000 cubic metres (5.0×109 cu ft).
This is a list of notable recorded floods that have occurred in India. Floods are the most common natural disaster in India. The heaviest southwest,the Brahmaputra,and other rivers to distend their banks,often flooding surrounding areas.
In February 2017,heavy rainfall damaged Oroville Dam's main and emergency spillways,prompting the evacuation of more than 180,000 people living downstream along the Feather River and the relocation of a fish hatchery.
Meenkara Dam is an embankment or earthen dam built on the banks of the river Gayatripuzha,a tributary of the river Bharathapuzha,at Muthalamada in the Muthalamada Grama Panchayat near Kollengode in the Palakkad district of Kerala with masonry spillway sections. It is part of the Gayatri Irrigation Project. The project was started in 1956 and partially commissioned in 1960. The project was fully completed in 1964. The irrigation scheme has been prepared for agriculture and drinking water in Palakkad district. Farms in Chittoor,Nemmara,Alathur in Palakkad district and Vadakkancherry in Thrissur district will benefit from this irrigation scheme.
On October 30,2022,a pedestrian suspension bridge over the Machchhu River in the city of Morbi in Gujarat,India,collapsed,causing the deaths of at least 141 people and injuries to more than 180 others.