Hey there @Ildemar_Pedro! I believe the way to normally influence the shadows interaction with the water would be increasing the amount of ambient light on it, however there’s some other methods that can modify the shadows in various ways. Here’s a couple threads with some resources, though some are more useful than others:
This is more focused on shadow resolution/shape/softness but can help mitigate harsher shadows:
This thread goes over some custom scripting to remove the shadow entirely on top of the water, but with it’s understanding could be modified to adjust how the shadow is handled: