proper drain for S13 hb sunroof??

[s13_newbie]

Hi, I have recently found out that my car leaks everywhere, so i stripped my carpet n drive around for few days to see where it leaks, it turn out that it is the rear washer nozzle that leaks n the water runs to the rear seatbelt cover, but anyway, i found a clear tube that looks like the drain for the sunroof, but I dun get y there is water in them, I know why it has water inside coz it is sitting at the bottom of the floor, and it needs to go back up for draining, but I am thinkin y nissan make it that way, or is that some cheap body shop's job???

if thats not the proper way, can some1 please tell me what is the proper, i wanna fix that, and then put my carpet back.......

Thanks in advance!