Monday, August 08, 2011

More Action After the Flood

So what are your choices when you want to try and combat a chronic flooding problem?  Last year, we chose to try and live with the inevitability of flooding.  Unfortunately, we did not plan on this becoming a yearly occurrence.   It can't possibly happen three years in a row, right?  Well, I'm not willing to take that chance so I've started to look into various mitigation procedures.

Option A: A Sump
A sump is a pit that is dug into the basement of your home, at a low point, where a pump is installed.  When the pit fills with water during a flood, the pump turns on and the water is pumped into the yard or back into the stormwater system.  Option A is not good for us because, as you can see by the diagram, the only aim of a sump is to resolve storm runoff and groundwater issues, not sewer backup. 

Our flooding is caused by sewer backup, not by stormwater from our downspouts and draintile outside.  Sewer backup is when the sewer system becomes over-taxed as stormwater is combined into the system during storms.  The system can't flush to the proper location (in our case south to a major sewer line) and it backs up into the low points of the system.  In our case, it's the basements of our homes in the Northeast corner of the OP.  All a sump will do is put water back into the system, then back into our house.  Also, in order for the backup to reach a sump, it would have to flow from our drains, across the basement floor to a low point where the sump is located, creating a mess along the way.  It is also very unlikely that any pump can keep up with the kind of overflow that these storms have produced.
Option B: A Backflow Preventer or Check Valve
This is a device that is put onto your sewer line that allows waste to leave the home but in the case of a sewer backup, it does not allow waste to flow back into the home.  This is a slightly more expensive option as it requires a valve to be put on your sewer line.  In our case, this would also incur a cost of connecting all of the sewer lines at one place as they leave the home.  This would also be a problem at our home because we have exterior storm drains (from the roof) that drain into sub-grade tile that enter our sewer system.  These too would have to be somehow tied in as they are another point of sewer entry.  Finally, this valve should be checked and cleaned periodically to insure that it "seats" correctly, sealing the home in case of a backflow event.  This is yet one more additional cost.  This might be an option for us but if I am going to dig everything up anyway, perhaps there is something better.

Option C: Overhead Plumbing
In our home, there is a basement bathroom and laundry tub.  Also, two floor drains, one interior and one exterior, connect at the basement level.  The rest of our plumbing, from the kitchen and bathrooms, connects upstairs.  If all of the plumbing were located at the upper level, above the height of the sewer backflow, then we wouldn't have this problem.   There are a number of ways to accomplish this.  At our home, we would likely have to collect everything to a pump pit at the basement level.  This includes floor drains, exterior drains, basement fixtures and upstairs fixtures so that's a lot of excavating and work.  From there, a pipe would run up, to the height of our ceiling of the basement and back down to the height of the sewer line.  A pump would be installed at the pit to allow for the waste from the home to be ejected out.  This "loop" up to the ceiling line is what is critical.  As long as the exterior flood line stays below the top of that loop, there will be no backup in the basement.  This prevents sewage from running back into the house.  See the diagram below if you still don't understand:
"Option C" is currently the option we are looking at.  It is a "Cadillac" of systems and the most expensive but it also seems to be the most reliable.  I just wonder if we can afford it.  I am an architect practicing during one of the worst economic downturns the country has known.  I am hardly at the top of the economic food chain so this could be tricky.  I knew my straits were dire so I even looked to public sources for help.  Many local municipalities allow for grants for mitigation practices so what about the OP?  I wrote to Ron Davis, our State Hazard Mitigation officer and, unfortunately, this is the response I got:

The short answer is that we won’t be able to provide funds for your work. The primary reason is that we have determined that the methods you described are successful in keeping water out of that basement; it moves the water down line to the next basement that lacks backup prevention methods. We did not feel that this was a good use for taxpayer dollars, but it is a good mitigation measure.

There are a couple of other issues with providing funds to Oak Park: they don’t belong to the National Flood Insurance Program and they don’t have a mitigation plan. They will be working with Cook County to develop a plan, but that will probably take a year to complete. Both are prerequisites to funding.

I’m sorry we are not able to provide assistance.

I didn't really expect a very different answer because I understood the issues at stake here.  This was not a national disaster and Cook County and Oak Park do not have emergency plans in place.  There are currently a group of folks in my community that are working on this issue and hopefully I will be able to assist in some way with those efforts but for the foreseeable future, we are S.O.L.   I guess the only part of the letter I find a bit annoying is the subtext.  First, it seems to recognize the fact that Oak Park and Cook County see my basement as part of a stormwater retention system and it is fine to keep it that way.  Second, it insinuates (much like a neighbor did while we were at a community meeting last week) that I am a "bad neighbor" if I take such steps to protect my home from damage because it affects those that will not or cannot do the same.    

In the meantime, we had a plumber that is a business associate of my wife's out last week to look at the house. We are holding our collective breath for the estimate because whether or not my neighbors think I am being neighborly by installing the overhead plumbing, I am not sure I care.  I'd take anything over the need to clean someone elses shit out of my basement once more.   

On another note, we got some serious rains yesterday.  No flooding but the rainbow was beautiful.
Note: Above is a less than scientific analysis of all of the issues that involve residential plumbing and flooding so these situations and systems may not pertain to your home.  I'd love to hear any comments or corrections but if you are having similar problems, I strongly suggest you discuss the issue with a couple plumbers.

1 comment:

Andy said...

My neighbor got water on July 23 as well...I did not. Last year, I had my sewer line power-rodded and scoped, which discovered that the drain tile under the street had shifted laterally, constricting the flow of water from my house to the sewer (which is why last year I got clear, "clean" rainwater backing up out of my floor drains. My next move is to replace my backyard and gangway sidewalk, restoring it to the correct height and pitch, and grading the backyard accordingly, since my yard is about 8 inches lower than the alley (and the yards around me). My thought is, they don't care if my yard collects their rainwater -- I have to take care of myself first. And that involves repairing the grade so that I can take the permanent sandbags away from my back basement stairs.