Table 1. Structure of dam surveillance system in Switzerland Level Responsibility Activities Reports 1 Owner (dam safety engineer, technical staff) Regular inspection of condition (by visual observations) and behaviour (by measurements). Tests of spillway and bottom outlet gates. Monitoring records and test protocols 2 Experienced engineer (civil engineer) Analysis of the measured data and observations. Annual inspection of the dam. Yearly report on condition and on measured behaviour. 3 Experts (civil engineer and geologist) Inspection and appraisal of the dam safety every five years. Report on condition and long-term behaviour. Analysis of special safety related questions. 4 Dam Safety Authority On-site inspection. Review of the annual reports and the expert’s appraisal. Verification of the implementation of the necessary measures. Interventions if measures have to be implemented.