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FLOODED Crawlspace

FLOODED Crawlspace

FLOODED Crawlspace

I have an interesting issue. My crawlspace is about 3 ft deep, 15 ft long and about 6 ft wide.
It fills with water and won't go away, of course. I've pumped it out and it just seeps back in.
It has 3 walls that are concrete blocks, and one that is just hard packed clay, red clay.
What should I fill it with to fix it? The previous home owner dug it out (why I don't know)

I don't want to put a sump pump and drain in it, in my opinion that would just encourage more water to show up.

You know, kind of like using a well so the water keeps coming to it... theory.

Any ideas are welcome.


RE: FLOODED Crawlspace

This is generally not a one-size-fits-all solution. Depends on a lot of factors, that have been discussed in numerous previous threads. Did you try doing a search?

The idea that a sump pump will encourage more water is generally not true. If anything it will lower the hydrostatic pressure, which should be one of the first things you try to address.

RE: FLOODED Crawlspace

I did try a search, my search foo is weak.

I will try again, but not much came up under my search words.

RE: FLOODED Crawlspace

If you can establish gravity flow with the end above the local high water table at the outlet, the drain should not let water into the crawl. The slope can be flat if neefed. It will still drain, just more slowly.

I would be concerned wit allowing vermen access to the crawl though through the pipe.

I trust you have adequate venting in the crawlspace?

If you cannot establish gravity flow, then a sump pump is your only option short of filling the crawl with concrete.

Mike McCann, PE, SE (WA)

RE: FLOODED Crawlspace

basement and crawl space were my two main searches, I read everything.

nothing appears to be similar to my situation nor can I glean anything from them.

Lowering the water table is the only 'suggestion' I could see that may help but I am not sure how to do that.

ok my "theroy" about pumping it out and letting more flow in is 'bogus' I can buy that. I don't know anything and am just taking a guess and looking for suggestions.

The only 'solution' I could come up with (after talking to several local people on the phone, yea old fashion, am I) would be to get some subsoil (fill dirt) and pack it in there.

then dig a temp hole to put in a sump pump to drain it, so it can 'dry out' the drying out of the soil will harden it to make it more 'resistant' to filling up and it would then be 'natural" ground water.

heck, I'm grasping at straws, and still trying to search and find some info.

any links would be appreciated.

RE: FLOODED Crawlspace

yes i have adequate ventilation, thanks for the reminder.bigsmile

I can put a drain from the crawl space to the 'ditch' below the house, it's about 100 ft or so away.

the issue is that the 'bottom' of the crawl is about 4 ft below the surface, if the crawl is filled with dirt, so it's level with the ground, would I have to have the drain at the bottom of the crawl? or is 2-3 ft below the surface for draining acceptable?

what kind of pipe should I use for this? the 4" half holed? (don't know the correct name) or what?
this 'drain pipe' would likely be 2-3 feet under ground.

RE: FLOODED Crawlspace

Depends on the soil type and the source of the water... if free draining and near a lake, you could 'pump the lake dry' <G>. A sump and pumping should depress the watertable a tad.

You might consider installing a 'French drain' outside the crawlspace area. This would also require pumping, or drainage to a ditch or whatever.

Have to be careful with dampness... this is a 'breeding ground' for mold and fungus which can cause health issues as well as structure deterioration.


RE: FLOODED Crawlspace

No lake or pond anywhere close, not even 5 miles close

RE: FLOODED Crawlspace


The first thing I would want to establish is the source of the water.

Are you on the downgrade of a slope? In this case your water intrusion may be from saturated up-slope soils. The preferable thing in this case is to intercept and divert the flow around your structure.

If this is actual groundwater, you are strictly back to solutions outlined previously. (I suppose we can't absolutely rule out a broken water line nearby either without more information).

RE: FLOODED Crawlspace

there is no slope near, actually it's on a fairly flat piece of land and the surrounding land is flat too, Flat, meaning there is no hill anywhere around, the property is on a very gentle slope. I'd say no more than 5 ft rise over 300 feet.

no broken water lines, only one line from the city hook up, it's turned off.

RE: FLOODED Crawlspace

I am not sure I get the gist of your question. But it seems you have a structure, like a building or garage with a crawlspace underneath. first, what is the source of water that fills your crawlspace?
If it is rainwater just flowing into the crawlspace, then you have a problem with drainage. You need to look at how to keep surface water from getting into the crawlspace. Consider the surrounding area, likely the crawlspace is at a sump location, or low-spot. Water should be flowing away from the perimeter of the crawlspace. If you have downspouts, extend them away from the foundation so that rooftop runoff does not discharge near the foundation.
If just groundwater seeping out and fills up the hole in the crawlspace, then you need to consider filling with dirt and gravel/stone to stabilize it. I would install sump pump as a last resort.

RE: FLOODED Crawlspace

Stop the water from getting in there in the first place.


there is no slope near, actually it's on a fairly flat piece of land and the surrounding land is flat too, Flat, meaning there is no hill anywhere around, the property is on a very gentle slope. I'd say no more than 5 ft rise over 300 feet.

no broken water lines, only one line from the city hook up, it's turned off.

How high is your groundwater? Dig a test pit beside your house and see if it fills up with water over time to the same elevation as your crawlspace. Report back your findings.

Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East - http://www.campbellcivil.com

RE: FLOODED Crawlspace

I don't know the source of my water. That's half or a majority of my problem.

I have all drainage away from the house all ditches lead away, no broken water lines.

the only thing I can hazard a guess is that in times of heavy rain, when the ground is soaked that is 'seeps' in from below.

I'll dig a test hole and report back.

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