High water table near house.

Hi all,

I'm new to this forum, but it keeps popping up when I google water table and problems with soil.

I have recently moved into a new build property, the house is very well built, but I have now decided to landscape our garden.

I hired a gardener and he was digging holes to assess the soil quality and he found that there was very little top soil and lots of aggregate. So he kept digging 1/2 foot and he hit clay and then all of a sudden the hole starting filling with water.

He said it was unusual that the water table be that high and that if the builders have just finished the property then they should have known about the water table and constructed some form of drainage.

My question is, is it dangerous to have the table water so high near the property and if there is any build regulations that we can stick to the builders to sort the drainage problem.

I'm so stress about this as we only have 2 years worth of hiccups with a new build - any help would be appreciated as I'm a complete newbie when it comes to building/gardening side of things.

Cheers for reading 😊

To me this looks like the site was not properly prepared and that if possible you should contact the builder!  Provision for drainage should have been part of the site prep, and it seems like you shouldn't have to pay extra for it after the fact.  

Aye yi yi.

If this was me, I would call the builder immediately and get a response and document that response. Ask them to put their response into writing.  If they were reticent, I would call my county's building division and express concerns that my new property was not build to code and ask for guidance.  If that did not result in fruitful information and a plan, I would contact an attorney.  

Hi Letitia,
Welcome to Permies!  I see you are in Great Britain, and I have no idea what the laws there are.

If you are on a slope, a drain could be built, but I don't see that that should be your responsibility.  

Seems like contacting the builder is the first step, and as suggested, get the response in writing.  Probably make your notification in writing too, and keep proof of the date of notification and the builder's receipt of your notification.

It might be a good idea to proceed as if you are going to end up in court, and stay aware of that as you communicate with the builder only in writing.

Further, any resolution "should" include input/consultation from the appropriate engineering discipline, dunno, in this country it might be a civil engineer.

If this happened to me, here in this county we have building permits and building inspectors.   Therefore I would assume that this was done with the full knowledge of the inspectors, the permit was issued in the absence of a thorough investigation of site conditions.  Sometimes builders have "special" relationships with the building permit and inspector department.  So, if this was done with participation from the oversight agency that should have caught it rather than OKing it then you may need a lawyer as well.

Perhaps the participants here at permies with engineering expertise will give you a clear understanding of what you need to find out about your site to assess your situation

I hope I am wrong about needing lawyer and engineering professionals to take on both the builder and the local agency.  I have to watch that in myself, creating problems where there might have otherwise been cooperative partners in problem resolution.

It looks like a big mess, and I am so sorry for these unfortunate circumstances and challenge you will now face in finding resolution.

Good Luck with all of it!

Thekla

Letitia McLaughlin wrote:
I hired a gardener and he was digging holes to assess the soil quality and he found that there was very little top soil and lots of aggregate. So he kept digging 1/2 foot and he hit clay and then all of a sudden the hole starting filling with water.

Scary to suddenly have loads of water.

Just to double check, was it just the one hole that filled with water, or all of them, or some of them?  It 'suddenly' started filling with water - is it possible the digging might have nicked a water line?  

I don't know much about building, so it is probably as you say, a problem with the water table.  It's just when something this terrible happens, I like to double check it's not some lesser evil pretending to be a horrible thing.  

Letitia,

1) There is supposed to be a lot of aggregate so close to your foundation. It was put there on purpose and under your foundation to stabilize the slab that rests upon the gravel that rests upon the ground.  If you are going to contact your builder or the local building inspector you might ask them if they installed a water barrier (taped sheet plastic) under your slab foundation (maybe even foam insulation, considered a best practice) designed to keep moisture (and radon gas) from intruding into your home through hairline cracks that could develop in the cement slab.  The plastic sheeting water barrier is important under slabs to prevent mold in carpeting, etc., because concrete like brick can absorb and hold a lot of water that needs to go somewhere to vent itself off (either the ground below, out the sides, or indoors).  Whether there is a lot of gravel elsewhere on the lot would require digging and checking, and even then some of it may be where stuff was piled during construction for use in various places.
2) USA Home Inspectors would highly question the appropriateness of planting plants so close to the foundation as the root system can deteriorate cement over time, as well as hold moisture near cement and the side of your home, plus when you water it, you keep that area wetter than elsewhere on your lot.  It can cause rots on exterior walls, damage paint, and damage the concrete over time.
3) Some of your responses have already suggested that your problem may be a drainage issue and not at all a water table issue.   Since clay slows the drainage of water in the ground (and it is used at the base of man-made ponds for the same reason), it should be puddling somewhere, though you would certainly hope that it is not right up next to the house.  
4) Drainage seems to be the key and that may require someone familiar with your lot location, the various slopes around your yard, as well as clay issues above the aggravate under and adjacent to your foundation.  A knowledgeable neighbor (or a soils expert or building inspector) may suggest adding a lot of pebble gravel and sand around the house next to the exterior walls to improve drainage, depending upon how deep the clay is, as well as digging swales that direct rain water and snow melt to go somewhere else than toward your foundation.  Planting a large tree 20 feet minimum from the side of your house (to prevent root damage to any in ground piping and your foundation) will one day lessen the amount of rain that hits the side of your house.
4.A.) In Wisconsin, where I live, I installed "ground gutters" all around my house, partially to thwart snow melt on the north side of my house and wind-driven rain on the west and south sides of my house (e.g., to keep water out of my basement and to stop the white fuzzy-looking growth, called efflorescence, on my inside basement walls, which was salts leaching out of the cement block because of moisture moving through the walls (and evaporating once inside my basement...but that adds moisture to the basement that can easily grow mold).  The ground gutters ceased basement flooding, cement cracks, and the efflorescence (the fuzzy growth that people sometimes confuse with mold). These are sheets of plastic (I overlapped them by 9 inches minimum) buried under the dirt about 1 foot, and sloped away from the foundation. They carry and direct the rain that drops down from my exterior walls away from the house, and when it reaches about 12 inches depth in the soil.  It is a cheap improvement, costing me only about $20 for plastic and my time.  It took me 6 hours to dig out, install, and recover about 140 feet of ground gutters.  BTW, in WI these are legal, and are recommended in certain home jurisdictions for problematic water near foundations/basements.   Now depending upon how deep your frost level is during winter, what some people do is lay 2" - 4" closed cell foam boards at an angle sloped away from the house.  The reason why they do this is that these foam boards help insulate the ground from freezing; and as you may know (or guess) frozen ground "heaves"--that is it moves up and down (as it freezes and thaws, which can happen often during each winter) depending upon how deep the frost level is.  So if you have a side of your house that gets much colder in winter than other sides of your house, you might consider planting closed-cell foam boards (covered with plastic) because frozen ground is going to put a tremendous push (thousands of) pounds-per-square-inch onto your slab and may eventually crack it (and of course in the worst places...under and exterior wall).  I recommend you contact a highly experienced home builder (not your home's builder) to advise you on these ideas.  Four inch closed cell foam boards is much more costly than plastic (6 mil), but if you can get away with laying it in the ground around only part of your foundation that will decrease the overall cost plenty.  BTW, contrary to prevailing opinion in WI, during extremely cold winters (e.g., cold winters with no snow on the ground, which insulates ground from cold temps), the ground can freeze much deeper than the official reported "frost level" (our area about 36").  Frost heave pushes up porches, breaks up concrete slab (you should see my detached/unheated garage), sidewalks, breaks up driveways, and can lift and change the shape of decks.  It is much cheaper to insulate (in the ground) adjacent to ground structures (sidewalks, driveways, foundation, etc.) than to pay the price to install a new slab, new driveway, new sidewalks, etc.  Sorry to be so long with this info, but it is important info that many don't know about, and it may be valuable to consider when you think you will have to make an improvement to your lot.
5) Make sure (if you have roof gutters to catch rain water and direct it to the ground) that you have a gutter extension that goes out about 4 feet or more from your foundation.  If the gutter extension at the bottom of the downspout only goes out 4 - 6 inches you may never correct this problem having clay puddling the water in your soil next to your house.

Hi Letitia,

Welcome to Permies. My area is the sewage side of things... an obvious questions is "how is your septic tank functioning in such a poor site?" I realise that faced with potential structural damage to your house, sewage may not be such a priority - but if you or your neighbours have wells, then it's fairly important. I wrote a book on the subject and would be happy to answer any questions (Spoiler alert: there is a solution!) Anyway, I'll watch your replies with interest. I hope you find what you're looking for and then stay for some of the permaculture stuff.

 

One permacultury way of handling the problem is to take and plant a cutting of a weeping willow tree (away from the house).Weeping willows generally grow next to rivers.
This should
(A) absorb some of the water
(B) the leaves falling will help add more soil and
(C) (If that doesn't help) You can chew on a branch cause they make aspirin out of them.
Either way good luck

Tyler Ludens wrote:To me this looks like the site was not properly prepared and that if possible you should contact the builder!  Provision for drainage should have been part of the site prep, and it seems like you shouldn't have to pay extra for it after the fact.  

I don't think the internet is where you went to go on this one. Start with the building inspector, A builder other than the one who built the house and depending what you find out, maybe a lawyer too.

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I used to live in south Florida and when a house was build on a site like this you had to bring in truckloads of fill to raise the foundation up higher because constant submersion in water can affect your foundation. In that case we would always raise the house up on posts so the foundation stays above the water level.

Here in Alaska (hows that for a climate change) some homes are built on permafrost which is basically ground that is frozen all year around. If the house were on the ground it would melt the permafrost and the house would literally sink into the ground since much of the area in north Alaska is frozen swamp. In northern Alaska the house is literally set on top of the ground with special made adjustable blocks so you can continually adjust the house to keep it level.

I had intended to start my house in may but the good lord saw fit for me to start in November. The ground was frozen so i just set the house on 16x16 inch concrete pads and double concrete blocks rotating them 90 degrees each layer intending to put in posts this summer because the ground here is loose sand. A couple of months back we had a 7 earthquake and I didn't even have to level the house. Several houses around here were damaged.  Although I feared the house would fall, I wasn't to worried because the construction method makes the house very strong for earthquakes so I figured the worst would be that I would just have to jack up the house and re-block it. Luckily that didn't happen but it got me thinking that if this house survived a 7 earthquake, there must be something to this method. I think I am still going to put in posts but I am going to leave them an inch low. If the blocks do break it would only fall an inch. We have earthquakes here almost daily so I took special interest in worst case scenario which would be the house falling on the ground. One corner is 42 inches off the ground. At one point the whole house was supported on three corners while I had this high corner out one time to adjust the concrete pad to level it a little more. Just to see what would happen I slacked off the jack and the corner of the house only dropped about an inch.

Another house nearby built from half rotten scrap lumber just sitting on 4x4 posts with no x bracing also survived the earthquake with flying colors. I am afraid to go in it on a good day LOL. I don't know if there is any connection butI am going to look into it.

I don't recommend ANYTHING about this, I am not even qualified to build a house (although I did). It just caught my attention so I am going to leave it on the blocks for another year or so and see what happens.

Greg McCain wrote:One permacultury way of handling the problem is to take and plant a cutting of a weeping willow tree (away from the house).Weeping willows generally grow next to rivers.
This should
(A) absorb some of the water
(B) the leaves falling will help add more soil and
(C) (If that doesn't help) You can chew on a branch cause they make aspirin out of them.
Either way good luck

They are easy to root too. Just cut off the last 4 to 6 inches of a branch and remove all but the one or two smallest leaves. Stick them in wet peat moss for a week or two and they will sprout roots. You can use some Rootone (rooting compound) if you want but they root very easily and you don't have to buy or hunt and dig small trees. I started about 25 trees and all of them grew. They didn't survive the cow though. One night she wiped them all out.

Yep, building inspector first, then back to whoever was responsible for site prep to have them fix it. Cause if you get hard frost, you're gonna have trouble!

Jotham Bessey wrote:Yep, building inspector first, then back to whoever was responsible for site prep to have them fix it. Cause if you get hard frost, you're gonna have trouble!

original contractor to be responsible for the cost of remediation, but OTHER builders or professionals to assess the situation and assess the proposed plan of correction.  Left on "his" own, the original builder may do no better a job, demonstrate no better understanding of the non negotiable than the first time around

That's my non professional opinion, it only sounds like I know what I am talking about.  It's human nature I'm expressing my opinion about and getting an effective remedy the first time through, not legal nor building considerations.

This is standard with new construction: The construction company digs out non-fertile subsoil for the foundation/basement, then treats the site like a parking lot, driving their bulldozers, backhoes, lifts, trucks, etc. everywhere around the house. Sometimes even dumping a bunch of gravel to accommodate this in wet sites (it looks like you have a bunch of that kind of gravel in your hole). Then they just smooth a few inches of topsoil over it all to make it look good. The imported gravel has a bunch of fine particles which migrate with water down to the compacted subsoil, helping to seal what was already probably water-tight. Unfortunately, this is not easy to fix. A simple rototiller will not go deep enough. You need a back hoe to break up the compaction layer and incorporate organic matter (compost). Good luck!

-B

Two issues combine to create these troubles:
1.)It's business to get as much as you can for as little as you can.
2.) Specializing mean each worker knows only his task and not how that task fits with the whole. This results in lost of knowledge and changes be made to procedure that should never be made.

If you can't get the contractors to fix it, then here's a Fun solution:

Build water gardens everywhere. Your soil will pond splendidly. Scrape up what good muck you can and pile/berm/dike/heap/sculpt growing beds which control/soak the natural water flow across the site. Make broad shallow ponds (less moving heavy minerals, but still good capacity), cascading/pooling down the watershed. Build yourself an A-frame level, and go to town with a shovel on a rainy day. It's basically terracing, but have fun with it: wind channels around like wiggly little rivers and stuff. Definitely incorporate as much coarse woody debris (stumps + logs) as possible (the best natural slow-release sponge of water/nutrients). Hell, hugel it.  Attract some amphibians.  I'd share a pic or two of mine if I can figure out how to get my pictures off the computer and onto a URL...

-B

Firstly dont panic .
Secondly I assume you had a survey done when you bought the house ? Is this house covered under the ten year building federation guarantee ?
Thirdly is this really a problem ? are you on a slope ? Flood plain ?
Fourthly what do the council say ? Talk to the planning department .

David

And I am still wondering about R's question near the beginning of this thread, is there water in ALL the test holes, and is there a chance there is a leak in a water line.

Hiya to all,

Thanks for all the advice a replies - currently in talks with builder to sort as it is still under the 2 year building warranty.

Def haven't nicked a pipe (it was our first thought).

There's a higher water table/drainage issue nearer the house (as seen in photos), but the further we dig down the garden we are still seeing a high table - just not as high as near the house.

It's bizzare!

I have planted a apple tree in the left corner (approx 10ft from the house foundations and that is growing well. My grass has completely died now and the ground is constantly marsh like - it's depressing.

Any ideas if you guys think that the builders have tried to control the water table by installing a clay level - or why they would do that?

Again - TIA! 😊

Letitia

Not sure what a clay level is... but it doesn't sound like something that would help poorly draining soil.

The thing about water is that it always comes from somewhere, and it's always on its way to somewhere else.  Where is it coming from (uphill/roof); where is it ultimately going to (downhill)?  Once you have those two parameters identified, then your management options pretty much reveal themselves.  Whether your site is level or sloped, it boils down to shaping some simple redirection topography (and often it doesn't take more than a one-shovel swale/trench to make a significant difference!).  I find it to be really engaging landscape problem solving!

Good luck,
B

Has there been any housing or other development upslope?

If you got very heavy rains like I recently did the water table will naturally be high.

Do you have a wet basement?

Mold in the basement or elsewhere?

Installing a drain tile around your foundation could mitigate some of the water issues.

And yes, a water table that high will soften the soil and cause the house to settle in a way that could be problematic or dangerous.

Contact your local building department for advisement.

Take a trip down to citizens advice and ask them how to proceed.
I know from experience that gardening with that high a watertable is a real challenge and while I'm sure your house has a damp course (mine didn't it was too old) that amount of water isn't going to do anything any good.

Skandi Rogers wrote:Take a trip down to citizens advice and ask them how to proceed.
I know from experience that gardening with that high a watertable is a real challenge and while I'm sure your house has a damp course (mine didn't it was too old) that amount of water isn't going to do anything any good.

If their water table got any higher they would have a houseboat!

You can garden with a high water table. Just make raised bed garden or hugelgarden.

More initial work, but doable.

Some info:

http://blog.armchairbuilder.com/3816/house-foundation-excavation-high-water-tables/
https://www.gardendesignexposed.com/water_table.html

I’m in a similar boat in northern Michigan. The mobile home that was on the property when I bought the acreage seemed ok, (it was set in 2005 by former owner),  but with every winterfreeze and spring thaw the house began to twist on itself. Additionally, the mudroom they built attached to the front is detaching.

So the replies are spot on. The contractor who prepared the area foundation should’ve known this and is responsible for insuring home will be stable. While this can turn into a tragedy, unless the builder takes immediate responsibility, my experience in the legal system (paralegal) knows the wheels of justice move slow as hell and retaining a GOOD lawyer is a must should the builder decide to let it go to litigation.

There were quite a few good links, and some solid suggestions I’m going to use for my own issue.  But I would look at consulting your soil erosion department, the DNR and a professional landscaping engineer to see if there’s something you can do to mitigate the issue.

I am wondering if you have a good gutter system on the home? Try using rain barrels to catch the extra water and some good tubing to attach to barrels to carry water further from home. This might help keep things together while you go through the process with the builder?

Genine Hayden wrote:I’m in a similar boat in northern Michigan. The mobile home that was on the property when I bought the acreage seemed ok, (it was set in 2005 by former owner),  but with every winterfreeze and spring thaw the house began to twist on itself. Additionally, the mudroom they built attached to the front is detaching.

So the replies are spot on. The contractor who prepared the area foundation should’ve known this and is responsible for insuring home will be stable. While this can turn into a tragedy, unless the builder takes immediate responsibility, my experience in the legal system (paralegal) knows the wheels of justice move slow as hell and retaining a GOOD lawyer is a must should the builder decide to let it go to litigation.

There were quite a few good links, and some solid suggestions I’m going to use for my own issue.  But I would look at consulting your soil erosion department, the DNR and a professional landscaping engineer to see if there’s something you can do to mitigate the issue.

I am wondering if you have a good gutter system on the home? Try using rain barrels to catch the extra water and some good tubing to attach to barrels to carry water further from home. This might help keep things together while you go through the process with the builder?

We have that 100 year rain they talk about. Water table here is unusually high due to that problem.
And we just got more rain last night.

Yes gutter system is good. And we keep it cleaned out regularly. Yes, we do have a rain barrel (only one at the house).

Edit: we just got ANOTHER 1.75 inches of rain again last night. More tonight too - sigh....
I prefer to use common law myself instead of a lawyer. Cheaper too!
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