Abstract: The structures with large bloc are exposed to self and external factors affecting on interdependence the parts of the structure between them and its interdependence with surrounded on the other hand. Leading to limited movement in a block structure relative to the surrounding or the parts movement relative to each other. Monitor this movement and measured it in time periods give a clear perception of the administrators on the work of those facilities. In this research was selected one of barrages on the Al-Forat River as a case study. The barrage under study (which is a three parts, the most important part is (barrage) that his job water reserve for the purpose of raising the water level and the other remaining parts are a (head regulators) for the purpose of organizing access water to the city through the two side channels). Epoch monitoring used to find the relative positions of the points at certain period of time and compare this position with the absolute coordinates of these points and the monitoring process is repeated every thirty day for a whole year. The final result shows that the body of the barrage under study fixed and that the movement and crawling limited to embankment on both sides and the process of merge between traditional monitoring and GPS provides an accurate and economical control system for the barrage and should be linked monitoring results for the barrage with time (the dimension of time).