Battles of the late Third Age

[Nilpaurion Felagund]

Sure, no one may fear a trickilng stream(except the ones full of parasites... ) but the Nazgul(except the Witch-King) fear water for its inhibiting property.

..but the river was a barrier to his sense of its movement...

(UT, Part Three, The Hunt for the Ring)

It's like an allergy. Would you drink milk if you knew you'd puff up as big as an oliphaunt?

But I agree on this part:

Even though the Nazgul had a fear of water, I think that they could ford a river if they absolutely had to.

Sauron's will rules supreme over their pet peeves(or allergies). And what
Sauron wanted is his Ring, found on a place called the Shire. If they had to cross a river for that, then, they'll have to.

Later days!
->Elenrod