Lessons learnt from the monitoring of a 185 metre high arch dam in Lesotho

ABSTRACT: The authors are intimately involved with the dam safety surveillance of the 185 m high Katse Dam. They share their experience that stretches from the initial design and installation of the instrumentation system to the evaluation of the information. During this course they have learned from the many errors and mistakes they made (and witnessed). These are discussed briefly before concluding with a few remarks on a balanced approach to monitoring a dam of that size.