This paper presents a comprehensive method of GIS-modeling and mapping the sustainability of electrical networks to climatic affects (including wind and sleet loads) on the example of the southwestern part of the Krasnodar region. We have proposed a number of improvements in the part of climate modeling (the use of morphometric indicators, spatially weighted regression) on the example of maximum sleet loads during 25 years period. We have also suggested an original approach to the assessment of structural sustainability of power grids. It provides the stability of energy supply to the end user due to the availability of alternative options for connecting to the power centers. Structural stability assessment is carried out on the basis of network modeling and acts as an indicator of the network parts which are the most vulnerable to natural disasters. The combined use of climate and network model allows justifying the strategy of the energy systemdevelopment by increasing the reliability of energy supply to the end user.