Hydrotechnical structures, even if they are small compared to the large water dams, are sometimes underestimated in geotechnical evaluation of stability. Stability analysis of hydrotechnical structures can be carried out by various methods of calculation. The differences are mainly due to consideration and taking into account some effects on the stability. Using a given example of designed and constructed firewater reservoir in the mountain area, the role of detailed stability evaluations can be demonstrated, which takes into account all kinds of negative factors influencing the stability. In this case of designed earth structure, we tried several alternatives of computational methods for the assessment of stability - from the limit equilibrium analysis methods to the finite element method (FEM), as well as a new method for calculating the stability by meshless (meshfree) method (MFM), methods which are not primarily intended for stability analysis. Stability analysis of hydrotechnical structures can be carried out by various methods of calculation. The differences are mainly due to consideration and taking into account some effects on the stability. The results of procedures were compared and evaluated in order to highlight the advantages and disadvantages of a new numerical analysis of slope stability calculations.