<p style="margin-left:19.85pt;">The assessment of water resources and the determination of the water balance is one of the main tasks of water management, and in view of climate change, water security is becoming of increasing concern. To support decision-making, this article presents an original model for assessing water resources and the respective water management process. The model is realized through a generalized net with four transitions and allows to determine the estimates of the individual characteristics by using fuzzy and intuitionist fuzzy values.</p>