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Community and Q&A

Basement water

Andrew207 | Posted in General Questions on

After the last very heavy rain storm my basement flooded as the floor drain could not keep up. The floor drain is connected directly to the public sewer. The floor drain has a 4″ compression one way valve, which seemed to not work well during this surge.

I’m thinking of installing a backup pump (it would probably only activate a few times a year). The problem with a sump pump is that I’d have to dig out a hole, which would be lower than the current drain. I’d rather use the passive drain most of the time so it would not use as much electricity. 

I’ve thought of using an automatic utility pump, but those don’t seems as durable as sump pumps and as such carry shorter warranties. 

The other option was to dig a sump pump pit, but at a depth that the pump would not activate unless the drain failed.

I’d appreciate feedback and alternative ideas.

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  1. walta100 | | #1

    Do you have any point on your property lower than your basement floor you could drain the water to?

    Where is the water coming from and can you divert it elsewhere?

    Is the drain that is backing up a combined storm a sanitary drain?

    Are your gutters connected to the drain that is backing up?

    Do you really need a floor drain in your basement?

    If the city drain is backing up what does the city say about fixing the problem?

    If you pump into the same drain you are likely to overflow the next lowest fixture basement tub or toilet.


  2. Andrew207 | | #2

    There are no gutters on the house. I'm sure installation of gutter would help the problem, but the area is naturally wet and a stone wall foundation that always has a background flow of groundwater entering regardless of rain and we probably won't dig up the foundation to do exterior water proofing.

    It is connected to the sanitary drain. Once the storm surge slowed down the drain emptied out the basement overnight.

    Have not contacted the city yet.

    At this point, I still want a pump as a backup since I was only an inch short of getting the boiler wet. The pipe would be connected to a pipe going outside, not into the drain.

  3. walta100 | | #3

    Long ago most places allowed storm water to be drained in the sanitary systems. Today the EPA fines them when the treatment plant gets overwhelmed so now they will fine you for introducing storm water into the sanitary system. Since your drains back up when it rains it is clear some of your neighbors are discharging into the sanitary system.

    Living over a pit full of your neighbors raw sewage in the time of a pandemic is the most unappealing thought I have had all year.

    Do you have any point on your property lower than your basement floor you could drain the water to?

    Do you really need a floor drain in your basement?


  4. Andrew207 | | #4

    There are French drains made of concrete around the perimeter. I'd have to pound up the slab to make a sump pit. Perhaps that is the best bet. I do have a one way valve on the drain to prevent it from backing up onto the floor.

  5. Andrew207 | | #5

    The property is fairly flat so no options to run a passive pipe to day light.

  6. walta100 | | #6

    I would be tempted to put an inflatable rubber plug in the floor drain if the water in the basement only gets a few inches deep. This will force the water to find the next higher exit from the pipe likely to be a tub or shower in the basement.

    If you or your neighbors are putting storm water in the drain try to get them to stop.


  7. 1869farmhouse | | #7

    A lot of sump pumps have a primary and a secondary switch. I’d get one of those, disable the primary switch, install as one normally would, and install the secondary above the gravity drain.

  8. Expert Member
    BILL WICHERS | | #8

    Many older areas have combined storm and sanitary sewers. This used to be common. I lived in such an area many years ago and occasionally heavy rains would cause the sewer to backup into the basement. In such areas, there isn’t much you can do since it’s not so much yours and your neighbors water runoff causing the problem, it’s water from the streets going down storm drains along the curb.

    A sump pump would probably be your best option here. Set your gutters up to drain with a gravity system to a low spot on your property, don’t drain them into the sump pump. Use the sump pump only for water that gets through the basement wall. The sump pump can then pump into the same drain system that carries the gutter water away, although if you use a separate pipe you get a bit of redundancy just in case.


  9. Expert Member
    Akos | | #9

    Take a look at pg5 for the proper setup:

    What you want is a backflow preventer on the basement drains only (this assumes that flood level never reaches main floor height) and separate sump pump with interior perimeter drains to outside. Sump pumps use very little power, there is no reason to not use it for all your groundwater issues. Sometimes storms are followed by power outages, so make sure there is battery backup for it or get one of the water driven pumps as backup (these use large amounts of city water but don't need power to run).

    Backflow preventers can fail, important to check them periodically.

    You would have to avoid using any basement fixtures during a big rainstorm as these will have nowhere to drain once the backflow preventer trips.

  10. Andrew207 | | #10

    Thanks for link. We've decided to install a sump pump pit so this won't happen again.

    The article mentions that the pit needs a 18 inch distance from a footing, but within 24 inches of a wall. I'm not sure how that could work assuming the footing would be under the wall.

    1. Expert Member
      Akos | | #11

      Not sure what they are referring to for 24". You don't want the pit too close to the foundation as it might undermine the footings.

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