Water in Diesel scare

[piglet14]

Good mate of mine had a 9K bill on his 3.0 Diesel BMW 635(?).
Water in fuel wrecked pump & injectors and BMW kindly replaced the tank & fuel lines while they were at it.
There were several cars damaged that week, Audi included.
Cause was given to be local Shell garage, not a supermarket.
My question is, I thought the filter housing is a water trap and if it isn't how can we protect against this sort of thing?
Water must collect in the tank over time due to condensation & poor fuel, where does it go?

 

[jay1601]

No the filter doesn’t have a water sepetstor just contains a paper filter.

If your worried just fit a water separator before the filter in the engine bay.

 

[stevegrass777]

The water is supposed to sink to the bottom of the filter, and that is why most diesel filters have a plastic thing in the bottom so you can drain it out every now and then.
But if you get a gallon of water it won't cope with that