Resumen
The aim of this paper is to use a methodology to introduce uncertainty of hydrological and operational input data into mathematical models needed for the design and operation of reservoirs. The application of uncertainty to input data is calculated, with the reservoir volume being affected by these uncertainties. The values of outflows from the reservoir and hydrological reliability are equally affected. The simulation model of the reservoir behavior was used, which allows to evaluate the results of solutions and helps to reduce, for example, the cost of dam construction, the risk of poor design of reservoir volumes, future operational risk of failures and reduce water shortages during the operation of water reservoirs. The practical application is carried out on the water management analysis of a reservoir in the Czech Republic. It was found that uncertainty of storage volume with 100% reliability achieved ±4% to ±6% values and the subsequent reliability uncertainty is in the value interval of ±0.2% to ±0.3%.