No, no and ergh no. The sea does not flow into a river. The tide may go into an area usually occupied by fresh water but it is not flowing, it is controlled by the moon and is tidal.Well I agree, however, it's still sea level whether the tide's in or out and the difference between a high tide and a low tide can be the difference between rivers flowing into the sea or sea flowing into the river...or the height of a mountain at sea level would be lower at high tide and higher at low tide.