The revitalization of hydro-aggregates should be performed before the life-time expiry of most their parts. But, as in our practice aggregates have been under exploitation much longer then theoretical life-time advices (40, even 50 years), there is a need to estimate the equipment's condition through more sophisticated monitoring, providing the maximum level of safety and availability with minimum investment expenses, before the revitalization finally takes place. That estimation is based on appropriating calculations and measurements needed to take the competent decision. Results of that analysis can be also useful for estimation of the aggregate's power and parameters after the revitalization. In this paper the results of appropriate calculations and measurements for the Hydropower station HE Zvornik are given. .