Abstract: Computer-implemented methods and non-transitory computer readable storage media facilitate calculating outflow of water from a selected catchment. A computer-implemented method calculates an outflow of water from a selected catchment is calculated. An identification of a selected catchment from a plurality of catchments within a geographical area is received from a user workstation. A database of multilayered data is accessed, where the data includes hydrological data, geophysical data, and meteorological data for each of the plurality of catchments within the geographical area. From the multilayered data, one or more additional catchments are automatically identified within the plurality of catchments, to identify a group of navigated catchments that drain into the selected catchment. For a given time period, a model is generated determining an outflow of water from the selected catchment and the group of navigated catchments.