In the past, my basement was flooded twice. Both of which where lower than 8".

I'm wondering if the following works to prevent future flooding of my basement or stop water from spreading to the entire basement. Since water seeks level, water level of outside of the house and inside should be very close. If I build walls (lets say 18" - 24") surrounding the sump pump, will that stop the water from spreading to the rest of the basement?

On top of the walls surrounding the sump pump, if I build other walls surrounding the water heater, furnace, A/C. Will that at least stop water from reaching the water heater, furnace, A/C? Those units are very expensive to replace.

I also need to put washer and dryer on a raised platform, maybe 12" height.

Please advise if that works or please provide any suggestions.


  • First question is where does the water come in. Walls around the sump pump will most likely prevent water from getting to sump pump. If due to sump pump failure/power loss, then a secondary battery sump pump is required. Raised platforms are a good idea, walls may help or hinder, they prevent water from going there, but also prevent water from leaving.
    – crip659
    Commented Sep 6, 2021 at 14:44
  • If not mistaking, water coming in from the sump pump basin. Water is not from the basement walls.
    – mchlkwn
    Commented Sep 6, 2021 at 14:58
  • If not mistaking, water coming in from the sump pump basin, and not from the walls. I can open an opening surrounding the sump pump so the water in the rest of the area can go back to the sump pump. Am wondering if the walls surrounding the sump pump works if the water coming in from the basin. Since water seeks level, if the past highest level was 8", 18" wall should stop all future failure (sump pump outgoing rate was lower then the incoming rate.
    – mchlkwn
    Commented Sep 6, 2021 at 14:59
  • The only thing walls will do is make the water raise more before flooding basement over the walls. Best idea is get a bigger sump pump or add another sump pump, a bit higher than the first, second kicks in when first is over whelm.
    – crip659
    Commented Sep 6, 2021 at 15:13
  • If your sump is keeping up with the inflow rate, then there shouldn't be any flooding. Containing the water in, effectively, a deeper sump pit will work temporarily. Until it doesn't. Consider a second pump or bigger pump to increase the output rate. I had issues with the control board of my furnace shorting out due to flooding. Added a 2nd pump, about 2" higher than the first. Haven't had a single issue since.
    – FreeMan
    Commented Sep 6, 2021 at 15:42

2 Answers 2


Forget the walls...

Water should be stopped at its point of entry. Because you suggest building "walls around the sump pump", then I assume that water is entering your basement at that point. It is the sump pump's job to remove water from the basement.

If the sump pump is able to remove water faster than it comes in, then it will keep the basement from flooding. I would focus my attention on that point.

Look all around, inside and out, and ask yourself: How can I slow the water entering my home? Can I build a ramp made of clay dirt against the outside of my house? Can I dig a shallow ditch which will allow water to move away from my house? Can I move the sump pump discharge farther from my home? Can I increase the size of the sump pump discharge line? Can I install a larger sump pump? Can I install a second sump pump which will turn on if the first pump cannot keep up? In summary: Can I slow the entry of water? Can I increase the exit of water?

If the water cannot be kept out, then reinstall your appliances on platforms. Do not build walls around them. Wall are as good at keeping water in as they are at keeping water out. Life is full of surprises, so I would not build walls around the appliances. Water can come from your furnace. Water can come from your A/C. Etc, etc.

I question walls around the sump pump too, because it is your drain in the event water does get into the basement -- no matter where it comes from. Your water heater, your washing machine, etc. are just as capable of flooding your basement. Same situation: Walls are as good at keeping water out as they are at keeping water in.

Platforms are good. Putting your furnace on a platform might the difficult, but platforms are good.


The traditional solution for water coming out of a sump basin is larger or more pumps. In Fox Valley area IL, a neighbor had 4 pumps in his basin, in wet weather 3 pumps would run. I had two pumps, one was a 12V back-up, but it occasionally ran when the other pump was running. On the other hand, also putting something like a plastic barrel with no bottom over the basin would not hurt; although it may be tricky to seal to the basin.

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