In this graduation thesis the problem of assuring the optimal geometry of terrestrial positional geodetic networks, established for periodical deformation surveys of geotechnical objects, is discussed. In particular, four geodetic networks, established for monitoring the dams of hydroelectric plants Moste, Mavčiče, Vrhovo and Boštanj on Sava river are analysed. To find the optimal geometry of discussed networks the "trial and error" method of network optimization was used. This method is based on computer simulations of measurements. For every discussed geodetic network we defined additional reference points, which were selected on the basis of the results of previous measurements in these networks. For every variant of each discussed geodetic network simulated measurements were adjusted using the extended method of least squares. Results show that most of the discussed geodetic networks already have optimal geometry and don't necessarily need improvements.