Secret in Sewers: resevoir access (follow the leader room)

[Depili]

I have been trying to figure out how to reach the area marked by five ? marks on the map in the spoiler for ages and just can't seem to find a access point, would appreciate a subtle hint towards it.

SpoilerShow

The room is visible through some iron beam when looking from the platforms in the water room south of it.

[eduran]

Subtle hint:

SpoilerShow

There is a hidden switch in a dangerous area.

Exact location:

SpoilerShow

Move two tiles south, one tile west from where you are standing in your screenshot. The switch is on the wall to the north.

[Depili]

Thanks, had taken few passes in the suggested place but didn't notice it, well back to searching and dying

[Rlyeh]

nvm figured for myself