PATTIKONDA:24/07/2020.

A dam failure or dam burst is a catastrophic type of failure characterized by the sudden, rapid, and uncontrolled release of impounded water. Between the years 2000 and 2009 more than 200 notable dam failures happened worldwide. A dam is a barrier across flowing water that obstructs, that directs or slows down the flow, often creating a reservoir,lake or impoundments.

Dam failures are comparatively rare, but can cause immense damage and loss of life when they occur.Other cases include the Chinese bombing of multiple dams during typhoon NINA in 1975 in an attempt to drain them before their reservoirs overflowed.

• Sub-standard construction materials/techniques
• Spillway design error (near failure of 
• Lowering of dam crest height, which reduces spillway flow
• Geological instability caused by changes to water levels during filling or poor surveying
• Sliding of a mountain into the reservoir  – not exactly a dam failure, but caused nearly the entire volume of the reservoir to be displaced and overtop the dam)
• Poor maintenance, especially of outlet pipes
• Extreme inflows.
• Human, computer or design error or piping, especially in earthen dams
• Earthquakes.

The main causes of dam is overtopping: The crest dam is too high than capacity level.Foundation defects: error in constructions and failures of dam.Piping and seepage failures:These failures occur as a result of internal erosion caused by seepage and erosion.Conduit and valve failure: These failures occur as a result of problems with values and conduits.

Dam failures can be extremely harmful, especially because dams are considered “installations containing dangerous forces”.Many dam failures are also secondary results of other natural disasters such as earthquakes, land slides,heavy stroms, or heavy snow-melt. Other causes include equipment malfunction, structural damage, and sabotage.

In INDIA, The major failure is Machchhu dam failure or Morbi disaster was a dam-related flood disaster which occurred on 11 August 1979. The Machchu-2 dam, situated on the Machhu river, burst, sending a wall of water through the town of Morbi of Gujarat, India. The another dam failure is ratnagiri dam failure in 2019 in maharastra.