Hydrogeological report

Abstract

NGI is engaged by Norwegian water resources and energy directorate (NVE) to carry out stability analysis of the Åknes rock slide. This report is presenting and analysing the most important investigations and monitoring, such as packer tests and piezometer measurements in both open boreholes and boreholes with packers dividing the borehole in sections. A hydrogeological model is presented. The main conclusions are: - Water head on the sliding plane are small, only small peaks up to 3-4 meter over short periods of time are monitored. For most of the boreholes the water table is several meters below the main sliding plane. - The hydraulic communication in the slope is high. It seems like the hydraulic system is fed from a bigger area, not only the backscarp.