Leaky walls caused by neighboring building

[ChrisG]

i live in a brownstone-type house in Brooklyn (built 1899). Due to all the rain we've been having, a leak has been sending water cascading down my bedroom wall, bubbling off the paint, etc. The landlady sent a roofer over, assuming the leak originated there. Upon inspection, however, he said the leak is caused by the neighboring townhouse's drainpipe. The pipe is supposed to run from the roof gutter to a drain in the foundation, but the pipe is missing sections in the middle and where it should connect to the drain at the bottom. When it rains, water spews out of the middle and it's seeping into the building and coming out of my walls.

I'm hoping the landlady will know how to proceed, but in the mean time, what is the protocol for such a problem? the house next door is not occupied, it's bricked up and has been for as long as anyone can recall. The owner comes by occassionally to work on it, I guess (we can hear him banging around in there, but it really needs a gut renovation, not an old man with a hammer). What are the rules when the source of a problem with an apartment is on somebody else's property?

[Brooklyn Babe]

Talk things over w/ your LL, but:
1st everytime it happens take pictures with a newspaper.
2nd next time it rains call HPD to have an inspector check it out - let them know where it's coming from.
3rd get the roofer to document what the problem is, where it originates, and the estimated cost to fix it.
4th send a letter to next door neighbor (certified, then another w/ cert of mailing) w/ 30 days to fix.
If the problem is not remedied, your LL can sue your neighbor, you can also place pressure on HPD and DOB by calling constantly. They may send out their own contractors to fix it.