Dam failure
A dam failure or dam burst is a catastrophic type of failure characterized by the sudden, rapid, and uncontrolled release of impounded water or the likelihood of such an uncontrolled release. 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. Most dams have a section called a spillway or weir over or through which water flows, either intermittently or continuously, and some have hydroelectric power generation systems installed.
Dams are considered "installations containing dangerous forces" under International humanitarian law due to the massive impact of a possible destruction on the civilian population and the environment. Dam failures are comparatively rare, but can cause immense damage and loss of life when they occur. In 1975 the failure of the Banqiao Reservoir Dam and other dams in Henan Province, China caused more casualties than any other dam failure in history. The disaster killed an estimated 171,000 people and 11 million people lost their homes.
Main causes of dam failures
Common causes of dam failure include:- Sub-standard construction materials/techniques
- Spillway design error
- 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
- Poor maintenance, especially of outlet pipes
- Extreme inflow
- Human, computer or design error
- Internal erosion or piping, especially in earthen dams
- Earthquakes
Deliberate breaching
Attacks on dams were restricted in Article 56 of the 1977 Protocol I amendment to the Geneva Conventions. Dams may not be lawfully attacked "if such attack may cause the release of dangerous forces from the works or installations and consequent severe losses among the civilian population", unless "it is used for other than its normal function and in regular, significant and direct support of military operations and if such attack is the only feasible way to terminate such support". Similar provisions apply to other sources of "dangerous forces", such as nuclear power plants.
Other cases include the Chinese bombing of multiple dams during Typhoon Nina in an attempt to drain them before their reservoirs overflowed. The typhoon produced what is now considered a 1-in-2000 years flood, which few if any of these dams were designed to survive.
List of major dam failures
| Dam/incident | Date | Location | Country | Fatalities | Details |
| Marib Dam | 575 | Sheba | Yemen | Unknown | Unknown causes, possibly neglect. The consequent failure of the irrigation system provoked the migration of up to 50,000 people from Yemen. |
| Döda fallet/1796 Ragunda lake burst disaster | 1796 | Jämtland | Sweden | 0 | Natural dam of glacial till had canal dug through it for purposes of navigation. As the till was hard to dig, water was used to erode the channel. The canal lead to the failure of the dam. |
| Puentes Dam | 1802 | Lorca | 608 | 1,800 houses and 40,000 trees destroyed. | |
| Hogs Back Dam | 1829-04-03 | Ottawa | ? | Inexperience with cold weather engineering allowed for a small leak in wall to form on March 28 and the dam to slump on April 2. The following day, on April 3, the dam failed and washed away down the Rideau River. A new dam of a different design was built atop the foundation of the original later that same year. | |
| Bilberry reservoir | 1852-02-05 | Holme Valley | 81 | Failed in a heavy rain. Inquest found construction was culpably negligent. | |
| Dale Dike Reservoir/Great Sheffield Flood | 1864-03-11 | South Yorkshire | 244 | Defective design and construction. Small leak in wall grew until new dam failed. More than 600 houses were damaged or destroyed. Lead to regulation. | |
| Iruka Lake Dam | 1868 | Inuyama, Aichi Prefecture | 941 | Under the influence of heavy rain from late April, this soil dam collapsed on May 13. Water accumulated in Lake Iruka overflowed downstream, causing severe damage to Inuyama, Iwakura, Kasugai, Tsushima Yatomi, and to Komaki. 807 houses were destroyed, with another 11709 flooded. | |
| Mill River Dam | 1874 | Williamsburg, Massachusetts | 139 | Lax regulations and cost cutting led to an insufficient design, which fell apart when the reservoir was full. 600 million gallons of water were released, wiping out 4 towns and making national headlines. This dam break led to increased regulation of dam construction. | |
| South Fork Dam/Johnstown flood | 1889-05-31 | Johnstown, Pennsylvania | 2 208 | Blamed on poor maintenance by owners, who lowered crest by a meter or more; court deemed it an "Act of God". Followed exceptionally heavy rainfall. 1,600 homes were destroyed. | |
| Walnut Grove Dam | 1890 | Wickenburg, Arizona | 100 | Heavy snow and rain following public calls by the dam's chief engineer to strengthen the earthen structure. | |
| Gohna Lake dam | 1894-08-25 | Garhwal | 1 | Failure of a landslide dam. Authorities had been able to evacuate the valley. | |
| Austin Dam | 1900-04-07 | Austin, Texas | 8 | In an extreme current, two 250-foot sections of the dam slid ~`about 20m downstream intact. The town was left without electrical power for months. | |
| Hauser Dam | 1908-04-14 | Helena, Montana | 0 | Heavy flooding coupled with poor foundation quality. Workers managed to warn people downstream. | |
| Broken Down Dam | 1908-09-24 | Fergus Falls, Minnesota | 0 | Design flaw; dam built on water springs. Four downstream dams and bridge destroyed; a fourth dam was opened and saved. Mills, homes and farms flooded. No fatalities. | |
| Austin Dam | 1911-09-11 | Austin, Pennsylvania | 78 | Poor design, use of dynamite to remedy structural problems. Destroyed paper mill and much of the town of Austin. Replacement failed in 1942. | |
| Desná Dam | 1916 | Desná | 62 | Construction flaws caused the dam failure. | |
| Lower Otay Dam | 1916 | San Diego County, California | 14 | Over-topped from flooding following heavy rains. Locally, blame was placed on Charles Hatfield who had been contracted by The City of San Diego for his efforts in rainmaking. Court cases following the dam's failure resulted in neither liabilities being passed to Mr. Hatfield nor the original payment, as both of the court's decisions ruled the event, 'an act of God'. | |
| Sweetwater Dam | 1916-01-27 | San Diego County, California | 0 | Over-topped from flooding; spillway inadequate, water rose over a meter higher than the dam and waterfalled over its surface. Dam had been raised after an similar earlier overtopping. Partial failure. | |
| Lake Toxaway Dam | 1916-08-13 | Transylvania County, North Carolina | 0 | Heavy rains and lack of water-level controls caused the dam to give way. Private lake destroyed, resort area failed. Dam was later rebuilt in the 1960s | |
| Tigra Dam | 1917-08-19 | Gwalior | 1 000 | Failed due to water infiltrating through sandstone foundation. Possibly more fatalities. | |
| Gleno Dam | 1923-12-01 | Province of Bergamo | 356 | Poor construction and design, inferior materials. Lasted 40 days. | |
| Llyn Eigiau dam and Coedty reservoir | 1925-11-02 | Dolgarrog | 17 | The outflow from Llyn Eigiau destroyed Coedty reservoir. Contractor blamed cost-cutting in construction. 25" of rain had fallen in preceding 5 days. | |
| St. Francis Dam | 1928-03-12 | Santa Clarita, California | 451+ | Geological instability of canyon wall. Designer inspected it hours before it failed. | |
| Castlewood Dam | 1933 | Franktown, Colorado | 2 | Bad design and maintenance, with proximate cause of heavy rain. Dam failed at 1 am on 3 August 1933, with dam waters just 15 miles from the City of Denver. Warnings to the city by 4 am allowed most people to move out of the way of the flood waters. | |
| Granadillar Dam | 1934 | Canary Islands | 8 | Bad design and foundation. | |
| Secondary Dam of Sella Zerbino | 1935 | Molare | 111 | Geological unstable base combined with flood. | |
| Horonai Dam | 1941 | Ōmu, Hokkaido | 60 | A torrential rain struck around Horonai River area. This is the dam collapse in the wake, and according to official confirmed, the lost houses reached to 32. | |
| Nant-y-Gro dam | 1942 | Elan Valley | 0 | Destroyed during preparation for Operation Chastise in World War II. | |
| Edersee Dam | 1943-05-17 | Hesse | 70 | Destroyed by bombing during Operation Chastise in World War II. Widespread destruction. | |
| Möhne Dam | 1943-05-17 | Ruhr | 1 579 | Destroyed by bombing during Operation Chastise in World War II. 11 factories were destroyed, 114 seriously damaged. | |
| Xuriguera Dam | 1944 | Barcelona | 8 | Heavy rain. | |
| Heiwa Lake Dam | 1951 | Kameoka, Kyoto Prefecture | 117 | In heavy rain, it swallowed the muddy stream of the village of the downstream portion and collapse the peace pond of irrigation ponds. 80 houses ware damaged in Kameoka and the surrounding area, a local official confirmed. | |
| Tangiwai disaster | 1953-12-24 | Whangaehu River | 151 | Failure of Mount Ruapehu's crater lake. Natural tephra dam failed. | |
| Taisho Lake Dam | 1951 | Ide, Kyoto Prefecture | 108 | Under the influence of heavy rain, outburst with a Ninotani Lake Dam. | |
| Vega de Tera | 1959-01-09 | Ribadelago | 144 | According to dam workers testimonies, the grounds had serious structural deficiencies due to poor construction. On the night of January 9, a 150 meters long portion of the containing wall collapsed letting out nearly 8 million cubic meters of stored water. | |
| Malpasset dam | 1959-12-02 | Côte d'Azur | 423 | Geological fault possibly enhanced by explosives work during construction; initial geo-study was not thorough. Two villages were destroyed. | |
| Kurenivka mudslide | 1961-03-13 | Kiev | 145 | Impoundment of the clay slurry reservoir failed after heavy rains, inundating the Kurenivka neighborhood with meters of mud. An unofficial modern report claims as high as 1,500 fatalities, while official reports state 145. | |
| Panshet Dam | 1961-07-12 | Pune | 1 000 | Dam wall burst due to pressure of accumulated rain water. Ti protect the earthen dam from the flow of water, concrete blocks were used instead of steel-reinforced concrete due to a steel shortage. | |
| Baldwin Hills Reservoir | 1963-12-14 | Los Angeles | 5 | Subsidence caused by over-exploitation of local oil field. 277 homes destroyed. | |
| Vajont Dam | 1963-10-09 | Monte Toc | 2 000 | Strictly not a dam failure, since the dam structure did not collapse and is still standing. Filling the reservoir caused geological failure in valley wall, leading to 110 km/h landslide into the lake; water escaped in a wave over the top of dam. Valley had been incorrectly assessed as stable. Several villages completely wiped out. | |
| Spaulding Pond Dam | 1963-03-06 | Norwich | 6 | More than $6 million estimated damages. | |
| Swift Dam | 1964-06-10 | Montana | 28 | Failed in heavy rains. Another nearby dam did likewise. | |
| Mina Plakalnitsa | 1966-05-01 | Vratsa | 107 | A tailings dam at Plakalnitsa copper mine near the city of Vratsa failed. A total 450,000 cu m of mud and water inundated Vratsa and the nearby village of Zgorigrad, which suffered widespread damage. The official death toll is 107, but the unofficial estimate is around 500 killed. | |
| Sempor Dam | 1967-11-29 | Central Java Province | 138 | Flash floods over-topped the dam during construction. | |
| Certej dam failure | 1971-10-30 | Certej Mine | 89 | A tailings dam built too tall collapsed, flooding Certeju de Sus with toxic tailings. | |
| Buffalo Creek Flood | 1972-02-26 | West Virginia | 125 | Unstable loose constructed dam created by local coal mining company, collapsed in heavy rain. 1,121 injured, 507 houses destroyed, over 4,000 left homeless. | |
| Canyon Lake Dam | 1972-06-09 | South Dakota | 238 | Flooding, dam outlets clogged with debris. 3,057 injuries, over 1,335 homes and 5,000 automobiles destroyed. | |
| Banqiao and Shimantan Dams | 1975-08-08 | Zhumadian | 171 000 | Extreme rainfall, beyond the planned design capability of the dam, dumped on China by Typhoon Nina. 11 million people lost their homes. Dam would later be rebuilt between 1986 and 1993. | |
| Teton Dam | 1976-06-05 | Idaho | 11 | Geological problems including unsuitable bedrock, seismic activity and caves. USGS, prior to completion: "Since such a flood could be anticipated, we might consider a series of strategically-placed motion-picture cameras to document the process". Water leakage eroded the earthen wall and lead to dam failure. 13,000 head of cattle died. | |
| Laurel Run Dam | 1977-07-19 | Johnstown | 40 | Heavy rainfall and flooding that over-topped the dam. Six other dams failed the same day, killing five people. | |
| Kelly Barnes Dam | 1977-11-06 | Georgia | 39 | Unknown, possibly design error as dam was raised several times by owners to improve power generation. | |
| Machchu-2 Dam | 1979-08-11 | Morbi | 5 000 | Heavy rain and flooding beyond spillway capacity. Old estimates were 1,800–25,000 but a 2011 book by Sandesara & Wooten refined the bracket to 5,000–10,000. | |
| Wadi Qattara Dam | 1979 | Benghazi | 0 | Flooding beyond discharge and storage capacity damaged the main dam and destroyed the secondary dam in the scheme. | |
| Lawn Lake Dam | 1982-07-15 | Rocky Mountain National Park | 3 | Outlet pipe erosion; dam under-maintained due to location. | |
| Tous Dam | 1982-10-20 | Valencia | 8 | Heavy flooding coupled with poor quality of the dam wall, lack of qualified staff and negligence of a warning of heavy rain in the area. On the next day, newspapers reported possibly 40 fatalities and 25 disappeared but in the coming days the count went down to 8 or 9. One year later, LaVanguardia spoke of 25. | |
| Val di Stava dam | 1985-07-19 | Tesero | 268 | Poor maintenance and low margin for error in design; outlet pipes failed leading to pressure on dam. | |
| Kantale Dam | 1986-04-20 | Kantale | 180 | Poor maintenance, leakage, and consequent failure. Destroyed over 1600 houses and 2000 acres of paddy fields. Dam was 1400 years old, and heavy modern vehicles were driven across it. | |
| Upriver Dam | 1986-05-20 | Spokane | 0 | Lightning struck power system, turbines shut down. Water rose behind dam while trying to restart. Backup power systems failed, could not raise spillway gates in time. Dam overtopped. | |
| Belci dam failiure | 1991-07-29 | Belci | 25 | The embankment dam, built between 1958 and 1962 for the Borzești Petrochemical Plant on the Tazlău river, collapsed after record rainfall firstly overtopped the structure, followed by its breach later onwards. As the event happened in the night, 250 houses were destroyed, killing 25 people in the process. | |
| Peruća Dam detonation | 1993-01-28 | Split-Dalmatia County | 0 | Not strictly a dam failure as there was a detonation of pre-positioned explosives by retreating Serb Forces. | |
| Merriespruit tailings dam | 1994-02-22 | Free State | 17 | Dam failed after a heavy thunderstorm. The dam was in an unacceptable condition prior to failure. Widespread devastation and environmental damage. | |
| Meadow Pond Dam | 1996-03-13 | New Hampshire | 1 | Design and construction deficiencies resulted in failure in heavy icing conditions. | |
| Saguenay Flood | 1996-07-19 | Quebec | 10 | Problems started after two weeks of constant rain, which severely engorged soils, rivers and reservoirs. Post-flood enquiries discovered that the network of dikes and dams protecting the city was poorly maintained. | |
| Opuha Dam | 1997-02-06 | Canterbury | 0 | Heavy rain during construction caused failure, dam was later completed. | |
| Virgen Dam | 1998 | Matagalpa | ? | In 1998 heavy rains and flooding from Hurricane Mitch severely damaged the Mancotal and El Dorado Dams, over-topping their spillways and nearly destroying the dams. The Virgen Dam was destroyed but later rebuilt. | |
| Doñana disaster | 1998-04-25 | Andalusia | 0 | Over-steepened dam failed by sliding on weak clay foundation, releasing 4–5 million cubic metres of acidic mine tailings into the River Agrio, a tributary of the River Guadiamar, which is the main water source for the Doñana National Park, a UNESCO World Heritage Site. | |
| Shihgang Dam | 1999-09-21 | Taichung | 0 | Caused by damage sustained during the 921 earthquake. | |
| Martin County coal slurry spill | 2000-10-11 | Martin County | 0 | Failure of a coal slurry impoundment. The water supply for over 27,000 residents was contaminated. The spill was 30 times larger than the Exxon Valdez oil spill and one of the worst environmental disasters ever in the southeastern United States | |
| Vodní nádrž Soběnov | 2002 | Soběnov | 0 | Extreme rainfall during the 2002 European floods. | |
| Zeyzoun Dam | 2002-06-04 | Zeyzoun | 22 | 2,000 individuals displaced and over 10,000 directly affected. | |
| Silver Lake Dam | 2003-05-14 | Michigan | 0 | Heavy rains caused earthen Fuse plug dam and bank to wash away. 1,800 people evacuated. Flood caused the failure of the downstream Tourist Park Dam. | |
| Hope Mills Dam | 2003-05-26 | North Carolina | 0 | In heavy rains, floodgate held shut bay water pressure. 1,600 people evacuated. | |
| 2003-08-23 | Wilnis | 0 | Strictly not a dam or dike failure. The original peat soil surrounding a polder was pushed away by the water in the canal. The peat became lighter than water during the 2003 drought. The real cause was new wooden piling along the canal. This new piling was water-tight and therefore the peat soil dried out. Around 1,500 residents had to be evacuated. | ||
| Big Bay Dam | 2004-03-12 | Mississippi | 0 | A small hole in the dam grew, spouted higher, and eventually led to failure. 104 buildings damaged or destroyed. | |
| Camará Dam | 2004-06-17 | Paraiba | 3 | Poor maintenance. 3000 people homeless. A second failure happened 11 days after. | |
| Shakidor Dam | 2005-02-10 | Pasni | 70 | Sudden and extreme flooding caused by abnormally severe rain. | |
| Taum Sauk reservoir | 2005-12-14 | Lesterville, Missouri | 0 | Computer/operator error; gauges intended to mark dam full were not respected; dam continued to fill. Minor leakages had also weakened the wall through piping. The dam of the lower reservoir withstood the onslaught of the flood. | |
| Ka Loko Dam | 2006-03-14 | Kauai, Hawaii | 7 | Heavy rain and flooding. Several possible specific factors to include poor maintenance, lack of inspection and illegal modifications. | |
| Campos Novos Dam | 2006-06-20 | Campos Novos | 0 | Tunnel collapse. | |
| Gusau Dam | 2006-09-30 | Gusau | 40 | Heavy flooding, lack of maintainence. Approximately 500 homes were destroyed, displacing 1,000 people. | |
| Lake Delton | 2008-06-09 | Lake Delton | 0 | Failure in June 2008 Midwest floods; nearby highway washed out, creating a new channel which drained the lake. | |
| Koshi Barrage | 2008-08-18 | Koshi Zone | 250 | Neglection of barrage and the building of barrage itself. The region however saw weak monsoon and multi-year drought preceding the barrage failuire. The flood affected over 2.3 million people in the northern part of Bihar. | |
| Kingston Fossil Plant coal fly ash slurry spill | 2008-12-22 | Roane County | 0 | Failure of a fly ash slurry pond. | |
| Algodões Dam | 2009-05-27 | Piaui | 7 | Heavy rain. 80 people injured, 2000 homeless. | |
| Situ Gintung Dam | 2009-03-27 | Tangerang | 98 | Poor maintenance and heavy monsoon rain. | |
| Sayano-Shushenskaya Dam | 2009-08-17 | Sayanogorsk | 75 | Not a dam failure, but rather the power station accident where the turbine 2 broke apart violently due to the metal fatigue caused by overlooked vibrations, flooding the turbine hall and causing the ceiling to collapse. The dam itself was unaffected, and the power station rebuilt within 5 years. | |
| Kyzyl-Agash Dam | 2010-03-11 | Qyzylaghash | 43 | Heavy rain and snowmelt. Causes, deathtoll disputed. 300 people were injured and over 1000 evacuated from the village. | |
| Hope Mills Dam | 2010-06-16 | North Carolina | 0 | Sinkhole caused dam failure. Second failure of the dam, will be replaced. | |
| Testalinda Dam | 2010-06-13 | Oliver | 0 | Heavy Rain, low maintenance. Destroyed at least 5 homes. Buried Highway 97. | |
| Delhi Dam | 2010-07-24 | Iowa | 0 | Heavy rain, flooding, malfunctioning spillwy and structural problems. Around 8,000 people had to be evacuated. Replacement uncertain due to lake-dredging debt. | |
| Niedow Dam | 2010-08-07 | Lower Silesian Voivodeship | 1 | Heavy rain, over-topped from flooding. | |
| Ajka alumina plant accident | 2010-10-04 | Ajka | 10 | Failure of concrete impound wall on alumina plant tailings dam. One million cubic meters of red mud contaminated a large area, within days the mud had reached the Danube. | |
| Kenmare Resources tailings dam | 2010-10-04 | Topuito | 1 | Failure of tailings dam at titanium mine. 300 homes had been rebuilt. | |
| Fujinuma Dam | 2011-03-11 | Sukagawa | 8 | Failed after 2011 Tōhoku earthquake. 7 dead and 1 unknown. Japanese authorities state that the dam failure was caused by the earthquake, making these the first earthquake-caused dam failure fatalities since 1930, worldwide. Nearby dams damaged by same earthquake. | |
| Campos dos Goytacazes dam | 2012-01-04 | Campos dos Goytacazes | 0 | Failed after a period of flooding. 4000 people displaced. | |
| Ivanovo Dam | 2012-02-06 | Biser | 8 | Failed after a period of heavy snowmelt. A crack in the dam went un-repaired for years. Eight people killed and several communities flooded. | |
| Köprü Dam | 2012-02-24 | Adana Province | 10 | A gate in the diversion tunnel broke after a period of heavy rain during the reservoir's first filing. The accident killed ten workers. | |
| Dakrong 3 Dam | 2012-10-07 | Quảng Trị Province | 0 | Poor design, Typhoon Gaemi flood surge. | |
| Tokwe Mukorsi Dam | 2014-02-04 | Masvingo Province | 0 | Downstream slope failure on a tall embankment dam, possibly as the reservoir was being filled. Residents evacuated upstream. | |
| Mount Polley tailings dam failure | 2014-08-04 | British Columbia | 0 | Tailings dam collapse due to negligent operation; reservoir was overfilled beyond design parameters despite repeated warnings of the danger combined with a minor dam breach a few months before and fundamental design flaws. | |
| Mariana dam disaster | 2015-11-05 | Mariana, Minas Gerais | 19 | Tailings dam collapsed. One village destroyed, 600 people evacuated. 60 million cubic meters of iron waste slurry polluted Doce River, and the sea near the river's mouth. | |
| Maple Lake | 2017-10-05 | Paw Paw, Michigan | 0 | A heavy rainstorm caused a section of a dam to crumble because of the weight of a pond above, which happened around 5 a.m. | |
| Patel Dam | 2018-05-10 | Solai | 47 | Failed after several days of heavy rain. Private dam, causes unclear. | |
| Panjshir Valley dam | 2018-07-11 | Panjshir Valley | 10 | Dilapidated dam crumbled under heavy summer rains, 13 missing, 300 houses destroyed. | |
| Xe-Pian Xe-Namnoy Dam | 2018-07-23 | Attapeu Province | 36 | Saddle dam under construction collapsed during rainstorms. 6600 people homeless, 98 missing. Company denied the dam had collapsed. | |
| Swar Chaung Dam | 2018-08-19 | Yedashe | 4 | Breach in the dam's spillway. 63,000 evacuated, 3 missing. 85 villages affected. | |
| Sanford Dam, Patricia Lake | 2018-09-15 | Boiling Spring Lakes, North Carolina | 0 | Overtopping after over 36" rainfall during landfall of Hurricane Florence. | |
| Brumadinho dam disaster | 2019-01-25 | Brumadinho, Minas Gerais | 270 | Tailings dam suffered a catastrophic failure releasing 12 million cubic meters of tailings slurry. 247 deaths. 23 people missing. | |
| Spencer Dam Failure | 2019-03-14 | Near Spencer, Nebraska | ? | ||
| Tiware Dam | 2019-07-02 | Ratnagiri District | 23 | Heavy rains overtopped and breached the dam. | |
| Edenville Dam | 2020-05-19 | Edenville, Michigan | None reported | Heavy rains overtopped and breached the dam. | |
| Sanford Dam | 2020-5-19 | Sanford, Michigan | None reported | The failure of the Edenville Dam immediately upstream caused a large inflow into Sanford Lake, which overtopped the dam, flowing "all over and around" its structure. |