How do I build a proper flood simulation model in gis?

I'm having issues cause when I play the animation the water polygon layer is too far below the floated raster landscape or DEM to simulate the flooding. In the tutorials I used the polygon water layer was already just below the DEM, when played the layer rises according to the input values but mine is just too... show more I'm having issues cause when I play the animation the water polygon layer is too far below the floated raster landscape or DEM to simulate the flooding. In the tutorials I used the polygon water layer was already just below the DEM, when played the layer rises according to the input values but mine is just too far off probably requiring input values of around 8000m just to get close to a DEM or landscape i'm floating