Relevance: cadastral activity in the Russian Federation undergoes regular changes in order to improve the efficiency of the implementation of cadastral processes. Therefore, the study of any specific cases in this direction makes sense. Considering that the article also deals with the interaction of such activities with the concept of water bodies, the condition and status of which are often of strategic importance, the work can be considered relevant in modern realities. The purpose of this work is to assess the situation in which a land plot that has passed the state cadastral registration procedure crosses the border of the water zone. Research methods: the work is based on the data obtained through the analysis of the relevant regulatory legal acts of the Russian Federation, the evaluation of satellite images, the study of the data of the Public Cadastral Map of the Russian Federation, the corresponding assessment and analysis of the data, the conclusion is given and conclusions are formulated. Results of the work and discussion: Based on the results of the studies presented in the work, it can be noted that when constructing a building in a water protection zone, special attention should be paid to compliance with the norms of distance from water and related more specific restrictions. At the same time, it is necessary to take into account the status of a specific land plot and the specifics of the objects located on it. As the case considered in the paper has shown, the legality and correctness of the operation of the site and facilities on it, at first glance presenting violations, may nevertheless have legal grounds and not actually violate the law for a number of particular reasons and assumptions.