This paper is devoted to the space-time conservation (STC) method and its application to a water hammer in steel pipelines. The STC method, due to its numerical properties, in particular its high accuracy, can be an interesting alternative to traditional numerical methods, especially when dealing with problems where the numerical errors have the potential to significantly influence the solution, making interpretation very difficult. As the problem of water hammer is one of such problems, an analysis of the application of the STC method to this case can be very interesting.