Oslo, Aug 10 : A dam at a Norwegian power plant partially collapsed after extensive flooding caused by storm Hans. The dam in Braskereidfoss, about 150 km northeast of the capital Oslo, spans Norway's longest river, the Glomma, reports Xinhua news agency. An unexpected deluge caused by a technical malfunction on Wednesday prevented the dam's floodgates from operating properly. Police evacuated 15 to 20 nearby households as the Glomma's water levels continued to rise. Aviation restrictions were also put in place around the Braskereidfoss power plant, specifically targeting non-essential flights. Akershus Energi, which operates three power stations downstream from Braskereidfoss, has emphasized its contingency measures for floods. These include the removal of river debris, such as large trees. Storm Hans has been battering Norway since Monday, resulting in over 4,000 reports of damages to properties. According to the Norwegian Nature Damage Pool and Finans Norge, the organisation for compensation for natural disasters in Norway, the destruction could cost an estimated 900 million kroner ($88 million). With 114 county roads and many national roads now inaccessible due to flooding and landslides, the Norwegian Public Roads Administration has deployed a national emergency response team to the most-affected areas, especially Innlandet. The storm has led to wide-scale evacuations, with 13 people evacuated in Lillestrom after a landslide, and over 2,000 residents moved in Viken due to flooding. Justice Minister Emilie Enger Mehl has announced that the government will deploy additional helicopter resources to assist with evacuations in storm-hit regions. /IANS