For safety control and economic improvement, the surveillance of the dams and their structural behavior requires observation and monitoring with high accuracy. As well, the stability of concrete vault dam depends on its overall geometry, and the analysis results strongly rely on the accuracy in which this geometry can be measured in practice. And, with the progress of modern technology using the Terrestrial Laser Scanners (TLS) in deformation measurement, the accuracy is much improved. Currently, this technology (TLS) is used in large and complex engineering structures such as dams to better understand their behavior due to its accuracy and speed in obtaining a cloud points 3D in different time intervals. In fact, for the first time in Morocco, the concrete vault dam named Asfalou, located in city of Taounate, is used for case study in order to verify the efficiency of the TLS results. This paper describes the main steps of this approach and the assessment of its effectiveness compared to the conventional method.