As the water remains on the Earth due to gravity......and gravity requires huge amounts of mass (the mass of the earth) to exert any reasonably sized force......how "on Earth" do you imagine a model might replicate that.
What is the obsession with models? .....I think you mean simulate.....modelling is used to try and explain......simulation is used to confirm the strength or otherwise of a theory.
Black holes, neutron stars, supernovas.......do you imagine these are all modelled/simulated here on Earth?