Question: How many years after the German hydroelectric power station failures did the station built above the Niagara Gorge fail ?

text: List of hydroelectric power station failures
List of failures

This is a list of major hydroelectric power station failures due to damage to a hydroelectric power station or its connections. Every generating station trips from time to time due to minor defects and can usually be restarted when the defect has been remedied. Various protections are built into the stations to cause shutdown before major damage is caused. Some hydroelectric power station failures may go beyond the immediate loss of generation capacity, including destruction of the turbine itself, reservoir breach and significant destruction of national grid infrastructure downstream. These can take years to remedy in some cases. Where a generating station is large compared to the connected grid capacity, any failure can cause extensive disruption with in the network. A serious failure in a proportionally large hydroelectric generating station or its associated transmission line will remove a large block of power from the grid that may lead to widespread disturbances.
Plant Location Country Description Year
Möhne Reservoir Ruhr Germany Destroyed during WWII by RAF Lancaster bombers during Operation Chastise . 5.1 MW capacity lost for about six weeks 1943
Edersee Dam Waldeck-Frankenberg Germany Destroyed during WWII by RAF Lancaster bombers during Operation Chastise . 16 MWe of generation lost 1943
Schoellkopf Power Station Niagara Falls , New York United States Destruction of the plant as it fell from the Niagara Gorge wall and collapsed into the Niagara River , caused by water seeping into the back wall of the power station . One worker was killed and damage was estimated at US $ 100 million ( or $ 940 million today , adjusted for inflation ) 1956
Vajont Dam Pordenone Italy Overtopping due to landslide caused by instability of the rock around , with the evidence of the instability suppressed by the Government . 1,917 deaths 1963
Mangla Dam Kashmir Pakistan The power house was damaged due to an Indian Air Force raid during the Indo-Pakistani War of 1971 . The 1000 MW hydro project was temporarily out of service 1971
Banqiao Dam Henan China 26,000 dead from flooding , 145,000 dead from subsequent famine and epidemics , 11 million homeless . Caused loss of generation , dam failed by overtopping in a 1-in-2,000 year flood 1975
Teton Dam Idaho United States The dam foundations washed away and a wave swept aside everything in its path , including two towns , killing at least eleven people , and thousands of cattle 1976
Machchhu Dam Machchhu India The Machhu Dam-II collapsed , leading to the deluge of the city of Morbi and the surrounding rural areas . 1800-25,000 people were killed 1979
Lawn Lake Dam Colorado United States Failed in fair weather due to a combination of poor construction , age , and neglect . Caused downstream failure of the Cascade Dam . Destroyed historical Stanley hydro power station and a fish hatchery . Flooded a campground and the town of Estes Park impacting 75% of business activity . $ 31 million in damages and three lives lost . Three similar dams in the region were subsequently demolished 1982
Dartmouth Dam Victoria Australia The 180MW Francis turbine-generator running at full speed was instantaneously stopped by a foreign body left in the penstock following maintenance . [ 7 ] The installation shifted about 2m within the base of the 180m high earth and rock fill gravity dam wall of the 3,906GL reservoir . After initial consternation regarding the integrity of the wall ( declared safe after lengthy assessment ) , the hydro installation was repaired/replaced but was off-line for several years . A breach of the wall would have obliterated only a couple of small towns and a sparsely settled agricultural area in the relatively narrow 120 km Mitta Mitta valley below the dam , but more significantly , would have resulted in the over-topping and probable failure of the earthen walls of the 40m high 3,038GL Lake Hume , 200 km downstream on the Murray River . This is immediately upstream of the regional cities of Albury and Wodonga and a much more intensively settled irrigation area , and consequences would have been disastrous 1990
Srisailam Dam Andhra Pradesh India Due to poor reservoir operation , flood water overflowed into the semi underground power house ( 770 MW ) from the point where a protection wall was to be constructed before power house commissioning in 1987 . Flood water deluge caused the complete submergence of power house , massive debris accumulation , electrical equipment replacement and loss of power generation for a year 1998
Bieudron Hydroelectric Power Station Valais Switzerland 1269 MW loss , penstock rupture , three fatalities , flooding and loss of generating capacity 2000
Taum Sauk Hydroelectric Power Station Missouri United States Due to its being designed without a spillway and continuing to operate when management knew the gauging system was faulty , the upper reservoir was overtopped when water continued to be pumped from the lower reservoir after the upper was already full . A large section of the upper reservoir failed , draining over a billion gallons of water ( 4 million m³ ) in less than half an hour . There were no fatalities , but five people were injured . The failure resulted in permanent damage to the surrounding landscape and power generation did not resume until 2010 2005
Itaipu Dam Paraná ( BR ) Alto Paraná ( PY ) Brazil Paraguay 18 GW power generation loss due to storm damage of transmission lines 2009
Sayano-Shushenskaya Dam Khakassia Russia 2009 Sayano-Shushenskaya hydro accident , 6 GW power generation loss , 75 fatalities , due to turbine failure 2009
Srisailam Dam Andhra Pradesh India On 2 October 2009 , an earth dam burst above the Srisailam reservoir creating a record inflow which threatened the dam 2009
Vishnuprayag hydro electric station ( 400 MW ) Uttarakhand India Flash floods resulted in accumulation of huge quantity of muck and debris in the dam reservoir 2013
Dhauliganga hydro electric station ( 280 MW ) Uttarakhand India Unprecedented flash floods in June , 2013 in the State of Uttarakhand causing the complete submergence of power house . Massive debris accumulation , electrical equipment replacement and loss of total generation capacity for more than six months 2013
Uri-II Power Station ( 240 MW ) Jammu and Kashmir India A large fire incident happened in one of the transformers of the power station 2014
Oroville Dam California United States Damaged spillway caused evacuation of 180,000 2017