This is the 5775th most frequent Russian word.
протекает
"Протекает" means "flows" or "leaks."
Here, 'протекает' indicates the physical movement or flow of the river through the forest.
Река протекает через лес.
The river flows through the forest.
In this context, 'протекает' means that the roof is leaking and water is seeping through.
На потолке протекает крыша.
There's a roof leak on the ceiling.
In this usage, 'протекает' describes the progression or unfolding of a process in a figurative sense.