The thesis aims to create an undesired event, which will be included in the risk catalog project WaterRisk, compared with the project Techneau. The other part will be focused on the implementation locality of risk analyze by using application WaterRisk.cz, which has been developed under the research project 2B06039 - WaterRisk. It will be tested on two water tanks- Čebín and Holé Hory, the implementation will involve only the water tank Holé Hory. Testing will be proceeded in close cooperation with the operator. The output of the work will rate risk of tested location and compare it with Vírský oblastní vodovod as two most important sources of water for the Brno city.