The construction of small dams and hillside reservoirs is a common practice for dealing with erratic and unevenly distributed rainfalls in arid and semi arid areas. Moreover, these small hydraulics structures are recommended as a solution to adapt to climate change in rural areas. They are fundamental for the sustainability of the water resources. However, these dams are potential sinks for upstream sediment. Therefore, it would be useful to monitor and measure the amount of sediments in small dams because it is necessary to understand siltation and better functioning of these vital structures. This control and these measurements require the application of the bathymetry or topography surveys which is too expensive for the responsible of these small dams. In this context, this paper proposes a simple and low cost method called: Triangulation of the estimated silted level. This method is based on direct measurement of the accessible silted level in dam. This new method is compared with another method based on the initial Elevation-Capacity curve of dam, usually used when the bathymetry is not attainable. The results of both of them have been verified with those of the bathymetry and electrical tomography methods and validated the proposal method as the most approximate. Therefore, this method is recommended as a new direct and simple technique to evaluate the amount of silting in small dams and hillside reservoirs.