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Advice on drainage project needed

Posted by astphard 9a (My Page) on
Fri, Sep 21, 12 at 23:11

We need to have some drainage work done at our house, and we've started having contractors out to give us estimates (though actually receiving the estimates is harder than I thought it would be). But from the things they've said, we have a bit of confusion about the right direction to go in.

During heavy rains there will be a lake created in our backyard, and also by the back side of the house (where water then enters the basement). During especially heavy rains, there is another area along the back of the house that will take in water.

We also know that we're going to need the yard regraded, as it slopes toward the house. There is also a driveway that goes all the way to an old garage/shed in the backyard. Half of that driveway is really poorly graded, aiming straight toward the house. (The back half of the driveway.) The front half of the driveway also slopes toward the house, but there's a sort of concrete bumper that seems to keep water out of the front half of the basement. But in an ideal world, that should probably go as well.

This is where some of the questions come in. The contractors agree that there should be some kind of drain put in the backyard where the lake is, and route that toward the driveway area where additional drainage will be put in.

1) Should the drainage along the driveway be right next to the house, or on the far end of the driveway? Currently there is a drainage pipe along the side of the house. The back half doesn't seem to work, but the front half does.

2) Should the flexible corrugated piping be used or rigid PVC piping?

3) For the drainage area in the backyard, we hope to add on a raised deck to the back of the house. Would it be okay to have the backyard drain be under the deck, or is that going to cause problems?

4) Should we just start off with the removal of the back half of the driveway, and hope that fixes the problem, or go on ahead and pay the bigger bucks and have the front half of the driveway redone and properly graded?

I'm attaching some drawings to try and illustrate what I'm talking about.


Follow-Up Postings:

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RE: Advice on drainage project needed

Most of the contractors who have come have talked about putting the drainage pipes right next to the house, like this picture shows.


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RE: Advice on drainage project needed

But then there was somebody else who recommended putting the drainage pipes further away, as seen in this picture. The gutters downspouts were recently extended to empty out on the far end of the driveway (though if we were having drainage put next to the house I'm sure we could have them empty directly into those as well).


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RE: Advice on drainage project needed

Do you need the driveway to the shed? If not, remove before other grading is done.

If you could get the person in your town or county who is in charge of waste water mgmt. to look at this, I'd recommend that. The Planning Dept. probably best place to start.

Previous owners of my home installed perforated 6" french drain pipe. It wasn't wrapped and now deep grass roots have invaded. Arrgghh.

AND if you could post pictures of the house and grounds showing the problems it might help responders.

Rosie


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RE: Advice on drainage project needed

It wouldn't be possible to get bids that could be compared unless contractors bid on a specific drainage plan. You need to prepare a drainage plan (it might be simple, or not) or hire someone--a landscape architect or a drainage engineer--to prepare it for you. With the information you've provided so far, it's not possible to know the extent of the problem, and therefore, what the solution might be. If you can provide more detailed and accurate information, the drainage issue might be able to be assessed here. But drainage issues can be tricky and sometimes it's difficult to convey the necessary information. It's important to know the path that the water takes from where it comes on to the property to where it leaves. I'd start by uploading photos that illustrate this path. The photos should not be close-ups, but ones that show the surroundings and link to each other in such a way that one could get a "feel" for the site. Photos should also be taken from viewpoints that illustrate slope where it's pertinent.

Don't use corrugated pipe that snaps together in segments. Roots can infiltrate at the joints and clog the pipe. PVC with glued joints would be better if it's acceptable by local code. A continuous, unbroken run of black corrugated would be acceptable but it's important to make sure it's laid with no "bumps". PVC holds up better under pressure; black corrugated sometimes becomes crushed.

I would not place a drain inlet below a deck. It's okay to have a drainage pipe route pass below a deck, but it's better to avoid it, if possible.

As a general rule, it's preferable to have drainage solutions be at the grade surface than it is to have drain inlets and buried pipe. The latter requires maintenance and sometimes has a way of "acting up" at the worst possible time ... in the middle of a heavy, extended downpour.

The picture is of roots pulled out of segmented corrugated pipe. Each is several feet long.


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RE: Advice on drainage project needed

Thanks for the advice so far. We've had landscape architects come out to look at the issue and then give estimates about the work. So we've been trusting that they know what they're talking about when proposing their plans. But perhaps the water management of our town would be able to help, I hadn't thought of that. Granted, I'm not sure we have one, but I'll investigate.

The back half of the driveway is definitely coming out (it's all ripped up anyway, at least in part due to the live oak). Also, we plan on pulling out the fountain as well.

Ok, pictures. I'm going to post a collage of pictures, and see how that goes. If you would prefer for me to post these individually so that they're bigger, let me know.

1) Back of the yard looking toward the house. I'm not sure how well you can see the slope toward the house.

2) Part of the backyard with the dip where the pond is created during heavy rains.

3) From the back of the house looking toward the back of the yard. I think you can see the slope in this one.

4) Looking from the shed down the driveway toward the front of the house.

5) About the halfway point of the driveway looking towards the shed. The back corner of the house (where you can also see another doorway) is where the worst part of the drainage issue is, at least in terms of coming into the house. All of this broken up section of driveway is definitely coming out.

6) From the front corner of the house looking down the driveway toward the shed. You can see the slight slope toward the house, but this part hasn't given us issues with drainage so far (to our knowledge...but we had tenants down there who weren't always great about letting us know when issues arose).


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RE: Advice on drainage project needed

The area that does not show up well in you photos is behind the house. To show slope, you need to photograph transverse to the slope, not in line with it, while holding the camera level. It would be good to show views behind the house that are transverse to the lot length (from one side line to the other.) It would also be good to get a straight-on view of the back of entire house, but at a closer distance than the one's you've already posted. Show the entire house, including 10'-15' ground apron in front of the structure (back of house.) Don't include more than a foot or two at each side of the house. Post full size pictures.

Gut reaction so far is that you would be best off removing the entire drive, regrading and keeping the drainage at the surface. Installing drain inlets and buried pipe seems like a band-aid to me. A band-aid that will eventually keep falling off. The better portion (front part) of the driveway is built flat across it's width. It needs to be constructed as a modified swale that funnels water away from the building and to the center of the drive. As it is, being flat, water has a good chance of infiltrating the structure during heavy rain. I had a similar driveway situation once and my solution was a paver driveway that was built slightly dished at the center. It was a great relief to see ALL water move away from the building.

The difficult part of this problem seems to be at the back of the house. You would need to work out a plan before any work begins because it's possible that you could need a retaining wall in order to create space that drains the area at the back of the structure. If a retaining wall is needed, the driveway that's being removed could actually supply the material of which to construct it. (Done properly, broken concrete can make a nice retaining wall. It would require organized, not random demolition. But it's one way to kill two birds with one stone.) The tree, its roots and the garage present notable complications to grading at the back of the house.

Are you sure you had a landscape architect come to speak with you and not a landscaper? There is a big difference between these job categories. LA's would not normally be giving estimates for drainage/grading construction work. They would provide design work on which contractors would bid. I don't think your city could be counted on to provide actual help. They'll be happy to tell you that as the property owner, it's your obligation to fix.


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RE: Advice on drainage project needed

A problem like yours, you ask five contractors how they'd approach it and you'll get five different answers. Sure, there'll be some overlap, but you won't be comparing apples to apples when looking at the numbers (and having read your post in the other forum where you were asking about negotiating contractors down on price, I know the value you place on the numbers).

So the way to compare apples to apples is to hire a designer or landscape architect or engineer to create a plan for how to deal with the drainage, and have everyone bid to those specs.

Or, you do some research and find the contractor in your area who is a whiz when it comes to drainage solutions, and hire him to do whatever he proposes. Water's tricky. It can end up in places you don't expect unless you know what to look for. While I stand firmly behind my design skills, when I'm presented with a challenging issue like yours I call my go-to drainage contractor Chuck. I'm pretty sure that on full moon nights he turns into a water droplet and goes down and convinces the other water droplets to go elsewhere. Dude's magical.

Local soils and the way in which houses are built in your local area are two huge variables that determine how water is going to behave and the ramifications for your dwelling. There are some things where the opinions of random strangers on the interwebs are harmless, but I think you're asking for trouble if you don't get advice from someone with boots on the ground. Someone who doesn't know local soils and hasn't shot grades to see how water is *actually* moving on your property can cost you a chunk of change if they guess wrong based off a photo.


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RE: Advice on drainage project needed

atsfard, Marcinde is so right in her advice.....highly recommend you pay attention to these suggestions.

Rosie
p.s. I think I'm right with the 'her' designation. Doesn't matter though, just my reading experience speaking.


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RE: Advice on drainage project needed

"p.s. I think I'm right with the 'her' designation. Doesn't matter though, just my reading experience speaking."

HEY! Oh well, you had a 50-50 shot :)


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RE: Advice on drainage project needed

"Someone who doesn't know local soils and hasn't shot grades to see how water is *actually* moving on your property can cost you a chunk of change if they guess wrong based off a photo."

Marcinde, I hope you (and the OP) are not interpreting my comments along these lines. The purpose of the thread is not to circumvent the design process. It's essential and must occur. But the OP should develop a basic understanding of what the problem is and how it can best be solved. Otherwise, he may be at the mercy of an incompetent designer. The thread can bring to light and explain what "5 different answers from 5 different contractors" might be missing. At least, the general theory of how the property should drain--what proper grades SHOULD be--can be explained in simple terms.


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RE: Advice on drainage project needed

Marcinde's articulately stated answer should be the go to cut and paste master answer to just about every drainage question that you see on these forums.

Drainage challenges must be explored on site.
Drainage challenges can rarely be solved by simply looking at a photo.
There are too many variables that require throrough investigation that a simple photograph cannot provide.

There's no harm in educating ones self to the type of questions that should be asked of a professional once they are on site but never misconstrue the advice from the internet as the solution to the problem.


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RE: Advice on drainage project needed

I'm astounded that people seem to be misconstruing the purpose of the thread. It's NOT TO SOLVE the drainage issue. It's to help GUIDE the OP on HOW HE CAN SOLVE IT, or at least, how he can grasp awareness of the situation. Most people can understand the basic concepts of grading and drainage.


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RE: Advice on drainage project needed

Yard, I see where you're going with it. I just feel like when it comes to drainage or site-specific structural issues, the best and most appropriate answer is "get a local answer." If someone has already spoken to multiple contractors and they are STILL coming here for advice, maybe they're not asking the right contractors.

I'm a designer, not an installer. But the first half of my career was spent actually building stuff and the second half has been spent designing it, then hopping in the trench and making sure I know exactly what's going on. The vast majority of what we do is based on rudimentary science and mathematics. If I can't explain what I'm proposing, why I'm proposing it, and why it's the best solution, then maybe the job should go to someone who can.

The OP has one of the most challenging landscape problems: how do we move water from where we don't want it to where we do want it, efficiently, without dumping it in our house or on the neighbors' property? The best we can do here is what you were doing, laying out the basic parameters for the OP. But that begs the question - why hasn't the person proposing the work performed this education?


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RE: Advice on drainage project needed

For once I'm going to side with Yard. Often contractors propose that which is profitable and easy to sell to the client. What they need is often something different. A more educated client is not so apt to be a victim.
As to solutions for drainage, no you can not design from photos or less than a full knowledge of the the site particulars. Early in my career I spent years gathering data on sites for the purpose of civil design which was reduced to a plan drawing. Every relevant fact of a terrain can be shown on paper. For many projects, the design was completed without the engineer ever visiting the site. There is no reason drainage can't be remotely designed were all relevant facts are known. A comprehensive set of photos can serve to indicate what data is needed and prevent needed facts going unnoticed. Whether a homeowner can be successfully guided to provide the data depends on the homeowner and the complexity of the job.


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RE: Advice on drainage project needed

I didn't mean to cause any controversy, but thank you for the advice given. I agree with those who are talking about the importance of local expert advice. That's one of the reasons why we're hiring someone to do this, and not trying to DIY it even though I've seen many other threads in these forums about people trying to do that.

After reviewing my notes and the individuals' qualifications, two of them are both landscape architects & landscape contractors, and two are landscape contractors (who are also listed separately as drainage contractors in the phone book). One person is just a general contractor/handyman who has done work for us in the past who talked about his previous drainage/regrading work.

The reason I asked my question is to give us some insight as to what more knowledgeable people think is going to work as we try and select someeone to do this project. As Marcinde said, we do value the money, but money is not the most important factor. We want the job done correctly and to last. We'd rather pay more to get it done properly than try and skimp, and then later have to pay more money instead of just doing it right the first time. But if a less expensive option will fix it right the first time, then we're not opposed to that either.

1) Everyone who has come out has talked about adding a drain to the backyard. (The only issue has been where to place it.)

2) Everyone who has come out has talked about adding drainage piping leading to the front. (Some have talked about using rigid pipes while others have recommended the flexible piping.)

3) 2 of the people think we definitely need to take out the whole driveway, and put half back in properly graded. A 3rd thinks that would be the best option, but thinks that we could get away with taking out the back half only. People 4 & 5 think we only need to do the back half.

4) Everyone agrees the yard should be regraded.

So perhaps I should have started this thread with this post instead. Should the flexible piping be a tip-off to eliminate those who suggested it? If someone has recommended doing half the driveway only and not urged us to do the whole thing, is that another red flag?

Would you still like me to post the additional pictures? Or are they not necessary for these questions?


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RE: Advice on drainage project needed

"If someone has recommended doing half the driveway only and not urged us to do the whole thing, is that another red flag?"

In my mind, it's a red flag. Look at the flat cross-section profile of the front portion of the drive. Imagine the heaviest rainstorm you can--one that goes on for hours with a heavy downpour. As flow piles up, it's impossible that water will not infiltrate the building ... unless the entire cross-section slopes away from the building. But it doesn't. Pls8xx makes the point that contractors often propose that which is the easiest/most profitable. Unless their work is very well known to the client, that places their recommendations into question. I'm not saying that the recommendations are automatically not good ... just that they must be looked at with a suspicious eye. The recommendations of a landscape architect WHO IS ALSO A CONTRACTOR must be looked at in the same regard. And JUST because a person is an LA does not mean they are well qualified in all aspects of that work. (I was trained to design a highway, but I couldn't design one to save my life!) ... or that they don't have a profit motive ... or even a lazy streak.

Astphard, as I mentioned your property is similar to one I once owned. So similar in fact that it's eery ... not just the narrow drive at the left, but even the paint and trim colors! We had a garage that was too small to be a real garage in the same position. We had a slope (a MUCH more substantial one!) coming straight at the back of the house. There was an existing concrete patio at the back of the house and fortunately, it was swaled and sloped to carry water toward the drive. I swaled the drive to allow the flow to continue.

That everyone who has come out to look at the situation has advised installing a drain and piping makes me the lone dissenter. In spite of that fact, I cannot stress enough how much more trouble-free drainage at the surface of the ground is compared to that which is buried. Though I haven't seen a close-enough view of the back of the house yet to render an opinion, my gut reaction remains the same as it was earlier: this can probably be handled with surface grading and drainage for a much more trouble-free, long term solution. Especially, if you're going to be re-grading anyway.

Marcinde, you'll see that nowhere am I advising the OP NOT to get a local solution. I'm only advising him on what he should be looking out for while doing it. As well, I agree with pls8xx ... if the proper information could be gathered, there's no reason a drainage/grading solution couldn't be done from afar. But no one here has offered to do one. What's happening here is helping someone to look out for their self.


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RE: Advice on drainage project needed

Since I mentioned making use of the material of the old drive I thought I'd post a photo showing broken concrete used as a wall. Such walls can be built with mortar for a more refined appearance, or dry-stack for a more rustic appearance (that's do-able for most people on a DIY basis.) A wall that's dry-stack would require concrete chunks of a larger dimension and more batter (step back at each course) to the wall. At a distance, or to the common eye, broken concrete as a wall is virtually indistinguishable from stone, especially as it weathers and ages.

I'm not saying a wall is needed here. Just that if one is, here's an option. It's probably not a cost-saving option unless it's a DIY project as it requires grid-like demolition of existing concrete. Of course, a person would need to explore to see if there's wire mesh built into the concrete as that could cramp the possibilities. But many old drives were built without it.


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RE: similar example

One condition that must be met regardless of the circumstances is that at all faces of the house, water must drain away from the house. It might be a puzzle to figure out how to do it, but it can and must be done. Water cannot travel adjacent to and in line with a wall of the house ... which is what's occurring with the existing driveway configuration, both front and back portions.a

I thought I would show how I solved my own drainage problem in a similar situation. (My original drive had a flat cross-section like yours.) It requires no subsurface drainage apparatus: no inlets or pipes to clog or clean out. Everything was out in the open and obvious. Here's the basic scheme (... hope it helps):

[As a side note... I wasn't ready at the time to cough up big $ to replace my driveway. The event that forced it was a complete and total halt to the sewer system. It suddenly, without warning, became impossible to flush the toilet or dump a cup of water down the kitchen sink drain. Completely impossible! The water wasn't even moving slowly. After many calls to professionals and the city, not a single person could determine or explain the cause. The septic guys said we had to be on sewer and the sewer guys said we had to be on septic. After eventually finding where the sewer line exited the house--directly under the driveway (which looked much like the one is this thread... halfway good and the other part, a crumble of rubble.) With the unbelievable estimates we were getting from plumbers to remove half the drive and fix the line and tie into the city sewer, it was impossible to accept any. For about $300 I rented a back hoe and did the demolition myself. (I used the concrete for a retaining wall, but didn't have the experience at that time to know to demolish it so it was more easily usable.) As it turned out, we had a power pole at the end of the drive where it met the street. When they installed it years earlier, they unknowingly partially crushed the sewer pipe (which was clay). Gradually, the partially collapsed pipe eventually clogged completely. When a plumber tried to snake it, he only ran into a point he could not pass. So we had a general idea of how many feet away the clog occurred. But we didn't know much beyond that. We ran into the damaged portion purely by accident as we dug toward the city sewer to install the new line.)


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