At first sight one might think with rain and flood there will be water everywhere and since this water is full of electrolytes this could potentially lead to short circuit.
Then how do the trains run during heavy rain and floods so comfortably?
The answer lies in spotting the two terminals from which the train draws its electricity.
live terminal (positive) comes from the overhead conductors whereas the negative terminal comes from the steel tracks. The tracks are grounded so that you don’t get shocked when you touch them.
Now coming back to the question. Even if the tracks are flooded the positive and negative terminals are wide apart for any kind of possible short circuit to happen.