The invention discloses a method of predicting the fluid level at a predetermined location in a fluid flow network (10) having at least one regulator (16, 18) to control the flow of fluid along fluid flow network (10). The method includes the steps of collecting data based on timed measurements of fluid levels upstream (24, 28) of at least one regulator (16, 18), fluid levels downstream (26, 29) of at least one regulator (16, 18) and the opening position (30, 32) of at least one regulator (16, 18), and using data analysis (40) to provide a model based on the data whereby the model will provide prediction of fluid level at the predetermined location based on timed measurements of fluid levels upstream (24, 28) of at least one regulator (16, 18) and the opening position (30, 32) of at least one regulator (16, 18).