Avalanche defences for Flateyri, Iceland. From hazard evaluation to construction of defences.

Abstract

The village of Flateyri was hit by two major avalanches in 1995, with the latter one killing 20 of the 45 people caught in it. These, together with the catastrophic avalanche in the nearby Súôavík in January the same year, initiated a complete review of all government actions and regulations regarding avalanche risk and avalanche defences in Iceland. The government set a long term goal for the acceptable risk to people living in avalanche prone areas and increased funding for the construction of avalanche defences. The avalanche situation in Flateyri is quite serious and the risk the inhabitants live with is very high. The town is threatened by avalanches from two gullies, Innra-Bæjargil in the north-west and Skollahvilft in the north-east, with several records of avalanches reaching well into the present residential area. To fulfil the safety requirements, an appraisal study was carried out and a proposal made for avalanche defences for the community, consisting of two earthfill deflecting dams and an earthfill catching dam. The proposal was accepted by the local authorities and the Icelandic government in the spring of 1996, design work was carried out in that summer and construction work started in September 1996. The construction of the dams is now close to completion, two years after the accident.