The Truth About Running Water
This well known myth has been in the recesses of peoples' minds for centuries. There are people that believe in it (some vampires themselves) most who have no idea about the history behind it, and some do not believe at all because they simply do not believe in the being called The Vampire.
According to one psi-vampire, their kind do not like crossing water, but they can if they want. The reason for their dislike is that it drains their power and 'shorts them out' like electrical appliances do when put in water. Running water just makes these people nervous and uncomfortable. They do, however, use water to focus their energies, especially those of them that practice Wicca.
The following is some of the origins of the myth.
Many vampires believe that their soul will be trapped if they die in running water - but that doesn't mean they can't cross it!
It was thought in ancient times that the only sure-fire way to kill vampires is to submerge them in running water. People believed that spirits could not cross running water, which therefore, would temporarily separate the vampire from the bonded souls of their victims, which they must release first. This therefore leaves the vampire vulnerable to many variations of death (such as drowning).
Another variation of the myth was that they could only cross water at the ebb and flow of the tide. The vampire could then be carried over (in their coffin or ship) but in Bram Stoker's 'Dracula' even as a bat the vampire could not cross water so had to stay in the ship. And there are precedents in folkloric beliefs for this. The vampire may change shape and fly, or jump over.
If the vampire is immersed in running water, he is thought to be helpless and will be destroyed. The reason stems from the analogy of water to the mirror. This myth comes from the Church (in earlier times) trying to feel protected because it was believed that nothing evil could cross running water.
On some of the Greek islands, there was occasionally found the practice of re-burying the corpse of an alleged vampire on a desert island in the belief that the vampire could not cross the water to another shore.
Cases of vampires unable to follow their victim after that person crossed running water have been found in Greece (as mentioned above), Eastern and Western Europe, and China, although they apply more to other supernatural creatures. For example, in Katherine Briggs' book 'An Encyclopedia of Fairies'(Pantheon Books, 1976), p 336: "If chased by evil fairies (again going back to the mention of just 'evil'), one could generally escape by leaping to safety across running water, particularly a southward flowing stream".
There has been much evidence in many folkloric beliefs and well known books about the belief that vampires cannot cross water.
I guess the only way to really find out for sure is by yourself - with the help of a vampire of course!