The collapse of the Lokso dam

Newspaper clipping 16 May 1944

MAJOR FLOOD DISASTER IN TUOVILANLAHTI

Water masses released by the broken dam on a path of destruction.

Damage likely to rise to 1–1.5 million marks.

Last Sunday at 2:15 p.m. a strange, mighty sound and crashing noise began to be heard in Tuovilanlahti. The reason soon became clear when a 4–5 metre high, fairly steep‑sided wave was seen approaching the village in the so‑called Korkeakoski River, which flows into Tuovilanlahti. It was a mixture of water and ice. The road bridge, which was at the “bottom” of the bay, about 300 metres from the pier on the road to Pielavesi, was swept away by the flood, even though it was solidly built and about 4 metres above the water level. Four smaller bridges further downstream, a couple of saunas and a considerable amount of various loose property along the riverbank were likewise carried off by the water. The entire cluster of houses in the valley along the riverbank was flooded. Some people had to escape from their homes through the windows. Many cows were led out of the cowsheds at the last moment, as in some cases they were standing almost up to their flanks in water. After about two hours the water began to recede slowly and is now roughly at its normal level.

The accident was caused by the breaking of the dam of the Lokso power plant, located about 2 km upstream from the river’s mouth. The dam is 7.5 metres high, made of stone, but it has no buttressing, just a straight stone wall. During the recent warm days, a considerable amount of floodwater had accumulated in the storage pond above the dam, which is 1.5 km long and up to 20 metres wide. The pond was solidly frozen, as the ice had formed in layers throughout the winter. When the ice then detached from the shores, the pressure against the dam became so great that its middle section broke and huge masses of water were released onto forbidden paths. The ice carried along by the flood in particular caused damage. It tore and broke trees and churned up the ground. The damage to bridges and buildings must also be attributed to the ice. A few residential buildings and cowsheds will still have to be demolished, as the flood washed away the ground beneath them to the point that they are on the verge of collapse. In many cellars the water ruined property, and there will be cleaning work in the village for a long time to come.

The Lokso power plant was built about twenty years ago by farmer Taavi Savolainen. Tuovilanlahti Engineering Works Ltd. then raised the dam and operated the power plant as the electricity supplier for the Savon Wheat Mill owned by Mikko Lankinen. The entire village of Tuovilanlahti also received its lighting from there.

About a kilometre further upstream on the same river is Finland’s highest waterfall, Korkeakoski.

The extent of the damage is for the time being difficult to estimate. In addition to what has already been mentioned, the flood carried away the machinery of the power plant. According to a rough estimate, the damage amounts to 1–1.5 million marks.

Road traffic naturally came to a halt, but on Sunday evening already, work began on building a temporary bridge on the initiative of district police chief Patala and under the direction of roadmaster Partanen. However, it will take a few days before motor traffic can resume. Pielavesi, Keitele and Kiuruvesi

Mother’s Day 1944 has remained very vividly in the memory of every older resident of Tuovilanlahti. The day of the event is remembered as May Day, which is understandable, as more than 70 years have already passed since this great flood.

That year the arrival of summer was somewhat later than usual. Before Mother’s Day there had already been a few warm days. It was warm on this May 14 as well. The first thunderstorm of the summer was suspected to be the cause of the sounds that began to be heard on Sunday afternoon. A humming, clattering, rumbling, banging and crashing is what those recalling the event say they heard.

It was not a thunderstorm, however, but what some villagers say they had suspected might happen; the Lokso dam had broken, causing considerable material damage. There were no human casualties, although there were a few “near miss” incidents. The first to notice the dam break was, of course, the dam watchman Otto Jääskeläinen. Otto’s wife Anna escaped at the last moment from the cottage that had been built next to the dam. Otto Jääskeläinen immediately set off to bring the news to the village, as the telephone line from the dam had been cut. Taavetti Virtala says he had been looking over his fields, wondering whether he would soon be able to start fieldwork. He too says he was puzzled by the strange sounds and suspected a thunderstorm was causing them. But strange things seemed to be happening in the river valley; the tops of the spruces were swaying violently and then disappeared from sight. Soon Otto Jääskeläinen had rushed past Kalapuro at a speed that the usually calm Otto was not known to use. At that moment Taavetti says he guessed that the Lokso dam had broken. He hurried indoors to inform his family and the guests who happened to be present.

Antti Mykkänen, who lived at the school, also noticed the strange disappearance of trees in the riverbed. He hurried to the telephone to call the village and warn of the impending danger. This is how Antti’s words of warning are said to have sounded: “Be on your guard there in the village, the Lokso dam has broken now and there may soon be a lot of water coming.”