Döda fallet
Döda fallet (English: dead fall) is a former whitewater rapid in of the river Indalsälven in Ragunda Municipality in the eastern part of the province of Jämtland in Sweden.
Glacial debris had blocked the course of the Indalsälven at Döda fallet for thousands of years, creating a reservoir of glacial meltwater 25 km (16 mi) long known as Ragundasjön (English: Ragunda lake),[1] which overflowed over a natural spillway that bypassed this dam of debris, in a long high steep rapid known as Gedungsen or Storforsen (English: great whitewater rapid).
In one place its course before the Ice Age went southwest of a high rock spur with Qvarnodden hill on its end sticking out of the valley's northeast side.
The whitewater rapid Storforsen however was a major obstacle as it damaged or destroyed much of the timber, forcing use of land transportation (portaging) past the waterfall.
A new method was tried: a nearby stream was led into a temporary reservoir, which was released when full, washing much sand away, and this was repeated, steadily further upstream, until it reached Ragundasjön.
The porous ground beneath the canal could not withstand the force of the water, which at 9 p.m. on 6 June started to quickly erode deep into the esker and the sediment below it.
In only four hours in the night of 6/7 June 1796, Ragundasjön drained completely, triggering a 25-metre-high (82 ft) flood wave moving down the river towards forests, islands, sawmills, residential buildings, boat houses, utility buildings, barns, fields and meadows, causing much destruction and establishing the much deepened and scoured-out course of the canal and the Lokängen valley as part of the river's new course, and carrying a huge load of debris, probably thus restoring its prehistoric course as before the Ice Age.
Although it was one of Sweden's largest environmental disasters, no one is believed to have been killed by the event, because it was night and their houses were on high ground,[7] but much property and cultivated land were destroyed, and dead salmon lay all around on the meadows and hung in the trees.
The washed-away soil and sediments redeposited at the Indalsälven's delta in the Baltic Sea north of Sundsvall, creating new land which Sundsvall–Timrå Airport was later built on.
[8] An article in the Swedish Family Journal [sv] (Svenska Familj-Journalen) from 1864 describes how the Wild Huss in a boastful state wanted the whole of Sweden to know that the Indalsälven was navigable from above Ragunda, and to demonstrate it, he decided to travel along the river in a small boat out to the Baltic Sea and further down to Stockholm.
At a rock barrier in the bottom of the former Ragundasjön a new waterfall was formed, Hammarfallet or Hammarforsen in Hammarstrand, now turned into a hydroelectric power station.
