Digging a well to lower the water table affecting your basement -would this work?

[MiniMe4Eng]

This is what inspired me:

The well will be in the backyard and it will be used for both, the front yard and the backyard so the end result will be less water near the house in the back yard where let's say you have problems


The idea here is that you do not want to pay tens or thousands dollars to have your basement fixed when in reality you could dig that well outside of your house and fix the problem there in a constructive way Could there be any issues when after the water table lowers the soil settles ?

For a basement with minor infiltration what volume of what can I expect to have to evacuate to eliminate the problem
This is about a wet wall presenting efflorescence due to capillarity. This is near the corner of the house, it is localized on a stretch of around 12 feet and the other side of the corner has no problems.

 

[oldestguy]

OG again. In most communities you need a permit for this. They may depend on ground water for city water systems and these would interfere. Unless you know the soil stratigraphic, it can be a waste of money. Discharging the water is anther question. You may need a permit, since many surface water facilities are overtaxed and local infiltration m,ay be required (thus a vicious circle). Certainly it can't go into a sanitary sewer.

 

[Twinkie]

Do any other houses surrounding this house depend on a well? Are you forcing others to dig deeper?

If the water table is affecting the basement, someone didn't do their job during the engineering and construction phase of building this house. Trying to "lower the water table" is not a valid engineering solution. As OG said .... what are you going to do with all that water? Bottle it and sell at the local grocery store?

 

[MiniMe4Eng]

This is in a city, I am sure that nobody on a radius of 10 miles around me has a well in their backyard
This is not a well in a true sense and it would be designed to eliminate the water surplus that causes a wet wall as explained above. Before I tell you what I do with the water please tell me what volume of water can I expect to collect or should I collect in order to get rid of the wet wall problem


Note: This is in Toronto, I think the entire city gets its water from the lake, after is treated an purified

 

[oldestguy]

OG again. Your first, post in which you describe the saturated screenings at a patio, would indicate your problem is more likely caused by surface water, not ground water. Grasping at straws, to avoid getting an expert there appears to be the current situation now with three separate rooms in this forum. One more factor with a well or a French drain, in winter that discharge freezes in your location.

 

[MiniMe4Eng]

I assumed that drying out the lower soil might actually help with the surface water
Yes, I can not afford and expert. I recently bought the house and my pockets are empty...

 

[civilman72]

There are many reasons that wells are not used to solve wet basement issues. One of the major ones is you do run the risk of settling if you lower the groundwater too much. That is why it is important to place a foundation drain near the bottom of a footing, and not far below it. You would have to pay someone to do a lot of field investigation and design to make sure you control the groundwater levels properly and even an expert may struggle to give you the level of confidence you want. This is all assuming that your issue is with groundwater and not surface water as others have insinuated.

 

[oldestguy]

OG here again: It is possible to do that topographic survey, that members here recommend, by yourself with a helper, assuming you want to do that. Getting the field data can be done with a garden hose and with clear sections on each end, filled with water. If you wish to do that, I can describe more fully here. You apparently have good drafting program for creating your own "map".

 

[MiniMe4Eng]

Actually I too believe that it is a surface water problem
Nobody here could give me a straight answer about this:
I have a patio with limestone screening only as base. I recently properly regraded the slope and now the water is moving away from the house but it seems to me that despite of what I heard (that the limestone does not hold water -not too much) the limestone layer hardened and it actually trapped some water. My assumption is that the water is now sucked upward by the wall only in the lower area of the patio where it probably accumulated in time. (when I say accumulated I mean that the gravel in that area has more moisture in that area than in other areas of the patio).

One thing that got me thinking was what happened when I added more limestone to create the slope that I needed. That was completely dry (it came in bags) limestone. In like 30 minutes after we added that on top of the existing layer in some areas the new limestone screening turned wet. I left the area uncovered with bricks hoping to dry it out. For like two weeks it seemed to dry out but after I scratched the surface I noticed that there continues to be moisture under. Perhaps that is normal....

So coming back to my assumption I am asking you guys: is it possible that the wall keep absorbing (capilarity) water from the base of the patio? We have not had significant rain here in Toronto for more than a month, yet my wall is still wet. I was told by my brother in law who is architect and who coordinated the building of a good number of houses that the wall will take time to get dry and if I want to accelerate this I should dig some holes in the wall to accelerate the water evaporation.

My idea would be to rather disconnect the wall from the limestone layer by creating a small channel filled with gravel.

 

[cvg]

1) I can guarantee that there are numerous wells within a 10 mile radius. If you draw down the aquifer, you may affect them.
2) A well with sufficient capacity to lower the groundwater level would be very expensive
3) Electricity for the pump would be more expensive
4) A hydrogeologist and a driller could run tests and tell you how much to pump, you cant afford that either
5) Before you start drilling wells, perhaps you should do some basic research in how deep the water table is in your area. I think you will find out that unless you live in a swamp or on a spring, it is probably below your basement.
6) yes, lowering the groundwater can cause local subsidence. This is not a good thing.
7) waterproofing the basement walls may help, it would be cheaper than a well

 

[oldestguy]

Here is a shot of my old leveling device that hooks on ends of a garden hose. The clear plastic is 1/2" diam I think, readily available at hard ward store. In addition yard sticks, preferably calibrated in feet and hundredths, but any measurement system will work, to be converted to the ground elevations.

Capillary rise can do a lot of damage, but some sort of seal more likely will block it off, not gravity.

 

[MiniMe4Eng]

oldestguy, I was planning to use exactly the same method to measure the quotes in my yard.
I will post a link to a file that tells you a lot about the geology in my area, see my other thread here in this forum

 

[oldestguy]

Mini:

Sounds like you may be doing it right. I did a simple search for "surficial geology, Toronto, on" and got one very detailed report. I would assume there are other studies besides the Don River valley.

http://trca.on.ca/dotAsset/55381.pdf

As to experts in the area, our BigH came from that area.

 

[oldestguy]

Guess we both found it (as you post in the other room). Such is good information, but a topographic map of your lot and off the lot at least to center of streets, alleys and well into neighbors is needed to allow for a better understanding of your situation. Frequently I find some younger guys I deal with come with a question and assume that with a little information I can help. Sometimes that works, but not usually if there are complication issues. In your area, local surface drainage on and off site may be slow and not very rapid. Ground water may or may not be in the picture. History of the house construction, neighboring problems, etc. all help.

Also, even though it may not be useful, it is surprising how some very experienced contractors can look at something like this and recommend a fix that works. Costs sometimes are important, but doing half a job and not fixing it is not good either. As you know, my comments earlier on were with methods very few landscapers know anything about, so some training is needed for these.

At this time, with what I know, I would expect a lot of hand or light machine work is needed, at the least. A complete re-do of the patio would not be out of the question.

I'd like to come by as I travel to New York State via Canada, but that is not in any plan this year at least. I usually try to get through your town as quickly as possible.

 

[cr1973]

Minime:

Think of it this way: The limestone will not help at all with grading since it is porous. The clay layer BENEATH the limestone is what determines which way the water flows. If that clay layer slopes towards your house, water will flow towards your house. Even if the limestone grades away from your property at a full 2% slope, the clay beneath may not.

To properly grade your patio: You need to remove the bricks, scrape off the limestone base (put that aside for reuse), and get down to the clay layer. If that clay layer is flat, or backpitched towards the home, you'll need to haul in some clay and properly build your new slope away from the home. Make sure you grade the patio at least 10-15 feet to ensure that water will slope away from the home.

Once that's done, you can then rebuild the patio.

Also, make sure the area around the perimeter of the home is properly graded.

I had an issue where I had a wet basement wall at one corner. The landscape stones outside were very well graded away from the home... but guess what? The stone was about 8" deep near the home, but only a few inches deep 10 ft from the home. The clay layer beneath the stone was back-pitched. I did what I listed above, and that totally fixed my problem... that plus running my downspouts underground into a drain and out away from the home.