A couple of weeks ago reader asked the depth to which a car could wade a ford. You mentioned water in the engine but even worse is when the water is too deep. Cars float, even 4x4s, which is why Land Rover, Jeep, etc. recommend no deeper than 50cm or the top of the wheels. Small cars will float on shallower water but any floating you loose traction and you end up downstream in deeper water; sink and you drown. It happened recently to a lady driver in a Freelander. If in doubt, do not enter a deeply flooded ford.