Abstract
There are about 6000 dams in Norway, of which only 3500 are officially registered. About 10% of the dams are higher than 15 m, while the rest are lower, “small” dams. These structures are relatively old, most were built between 1950s and 80s, the so called “hydropower époque”. The procedure currently used in Norway to decide if a dam is safe or not consist of simple calculations prescribed in regulations [2], issued by the Norwegian Water Resources and Energy Directorate (NVE). The assumptions used are usually based on engineering experience and information obtained from drawings and visual site inspections.