Gaandal Dam
The Gaandal Dam (Vyvlander: Daam Gaandals, pronounced /daːm gaːndalz/) was a large arch dam straddling the Gaandal Valley. It lay between the villages of Julsel and Lysepaas in southern Vyvland, around fifteen kilometres to the south of Jesel. It is famous for its sudden collapse in 1953, just nine months after its construction. Death tolls from the collapse and ensuing flood are estimated at roughly 2500 people, although figures vary due to the government of the former South Vyvland covering up the incident for many years. The dam's collapse is one of the largest civil catastrophes in Vyvlander history.
Construction
Construction on the Gaandal Dam started in early 1952, with the dam having reached its full height of 112 metres by November. It was officially opened by Jeusev Jueves, the Master-President, in January 1953. He proclaimed it to be "another example of the engineering prowess which stretches across our land". During the months when the Gaandal Dam was active, it supplied electricity and drinking water to Jesel via a twenty-kilometre long aqueduct underground.
Collapse
The collapse was due to fissures in the gneiss rock below the dam wall, in which water collected under high pressure after the first heavy rains felt by the dam. Construction had been very hasty, without many safety checks, and as a result, cracks had reportedly begun to appear in the dam wall within the first month of operation. However, little action was taken to restore these issues, which were thought to be superficial in contemporary official reports.
After relatively heavy rains in November, which had caused the dam to fill to its operational capacity for the first time, a small high-pressure stream of water emerged from under the right flank of the dam. This was unanticipated, but was explained at the time as a natural feature caused by the full capacity of the dam. However, this stream was just a small sign of significant build-ups of water in the rock below. Early on the 21st November, another two fissures opened up streams in the rock face above the first. These were noted, and concrete was ordered to be poured into one of the holes. While the pouring team were working, a much larger fissure appeared directly under the dam wall, which proved unstoppable. Shortly before 22:30, this fissure widened so much that the entire left flank of the dam collapsed, sending a twenty-metre-high wall of water down the valley at 50kph.
The first village hit was Masfrop, two kilometres downstream, in which all but three of the 88 people in the village at the time perished. The flood lessened by the end of the Gaandal valley, but still passed into the neighbouring Lysedal valley with enough force to wipe out the town centre of Medeldal. Due to poor emergency warning systems, many of those living at least ten kilometres downstream from the collapse also failed to escape. Inaction was heightened due to the collapse of the dam occurring at night.
Aftermath
The government of South Vyvland attempted to keep the disaster as quiet as possible domestically and internationally, refusing foreign aid donations in the collapse's aftermath. However, Jueves was still unable to remain free from guilt over the dam's collapse; it became the beginning of a period of instability which would lead to his overthrow in a coup the next year. Reconstruction was initially slow, although it was prioritised by Jueves's successor, Erman Sanker. However, Sanker's government still remained very quiet about the causes of the dam or events after the collapse, which have mostly only been found out since reunification in 1983.
Today, the site of the dam is open to the public as a monument for those who died in the floods it caused. In 1977, a new dam was built two kilometres upstream, although this is on a much smaller scale than the previous dam.