How to deal with a clogged foundation drain?

May 21, 2012 10:44 AM

How to deal with a clogged foundation drain that's flooding my alley?

I live in a rowhouse; it has a walk-in basement that leads out to a below-grade alley.

I diagrammed my drainage situation.

Whenever it rains, the alley fills up with water. There's a drain in the middle of the alley, under which is a shallow pit. I've never seen into it as it's always at least a little bit full of water. (The drain filter is clean.)

In my basement, there's a trap door leading to an excavated part of the foundation, at the bottom of which is a valve. I assume that in my diagram there's a pipe running right to left that eventually reaches the sewer.

How do I fix this stuck drain? I assume the valve in my basement is for cleaning it out, but can I just snake it from the alley? (As an added annoyance, the valve does not want to come open, and the pit it sits in is very narrow and hard to fit a wrench into.)

posted by zvs to home & garden (9 answers total)

The valve in your basement is actually a clean out and it is almost certainly for your sewer service and (hopefully) not connected to your alley drain. You should call the local public works department and let them know about your alley problem. They will let you know if they clean them out or if it is your responsibility. If it is yours you can (maybe) remove the grate on the drain and use some kind of tool/shovel/heavy rubber gloves to reach in and clean it out. I don't know about where you live but needles (as in used hypodermic drug needles) are really common in the stormdrain catchbasins around here so be very, very careful. There are companies that do this kind of work also (usually under enviromental services in the yellow pages/goolge) that can do it for a surprisingly low amount of money-usually 200-300 hundred or less sometimes. But i bet your public works department can help you the most.
posted by bartonlong at 10:52 AM on May 21, 2012

To clarify: The alley is entirely on my property, not a city storm drain or anything. I'm in NYC so the storm sewer and the sewer are the same system (I think).

I have reached in with a shovel to clean it out but didn't come up with anything.
posted by zvs at 10:56 AM on May 21, 2012

Oh, and the grate cover is easily removed -- it's only held on with gravity.
posted by zvs at 10:56 AM on May 21, 2012

you could try using a rented pressure washer to clean out the drain. It will be super messy, but it works.
posted by Bohemia Mountain at 11:31 AM on May 21, 2012

Can you dig up around the alley drain and put in a 3x5x5 French drain?
Also, would it work to rent a large size socket and extension to get the valve open? Being able to snake it certainly wouldn't hurt.
posted by BlueHorse at 1:57 PM on May 21, 2012

Ok, I really should have checked your profile before answering. I don't know if queens is on a combined or separate storm drain/sanitary sewer system. At this point the answer is probably hiring a plumber to come out and scope if you have tried to reach in and find a clog with no success. This involves sending a camera on the end of a cable down the hole and try to find the blockage. Or You get it snaked ( you can do this yourself with rented equipment and instructions from either google or a DIY plumbing book) and see what comes up on the end of the snake-hopeflly some leaves and trash is all. If it comes up with dirt you have a collapsed line and bigger problems.

The last thing that can happen is has the alley settled so that the drain inlet is higher than the surrounding pavment? if so the answer is to get new pavement in to raise up the area so it drains again (however, from your description, I don't think this is the case). I think you have a clog in your drain line but the cause of the clog is unknown and how to fix it really depends on the type of the clog.
posted by bartonlong at 3:15 PM on May 21, 2012

Some followups:

I confirmed that I'm in a combined sewer-storm area on the city's map. And yeah, the pavement seems properly graded -- the drain is definitely at the bottom of the pooled area.

I think I'm at the "call a plumber" point. I snaked it out myself with a manual auger. The snake made it about 18' (well under the house) but won't go further.

(On the plus side, none of the fixtures are backed up, so I guess it's just in the line that runs to the storm drain... wherever it joins the sewer.)
posted by zvs at 4:50 PM on May 21, 2012

I'll second the pressure washer suggestion. I picked up a cheap Karcher electric unit from Costco for this and other small jobs. But you could start by using a hose with a pressure nozzle.

Did it for a stairwell drain behind our house and it totally solved the problem. The issue was accumulated debris was blocking the water from getting down to the gravel drainage pit below it. BLASTING into the muck dislodged it and floated enough of it to the surface to allow me to clean it up.
posted by wkearney99 at 7:18 AM on May 22, 2012

Huh. Well! I went out and bought a drain bladder attachment for my garden hose, and resolved to go deal with it as soon as the rain subsided.

Got up this morning -- the drain had cleared on its own. There's a telltale spiral of debris on the pavement, and no puddle. The neighbor's equally clogged drain has not cleared. Guess the snaking was enough to dislodge the clog a bit? This is a new experience.
posted by zvs at 7:35 AM on May 25, 2012