Garden Drainage

Dan_B

Hi,
The drainage in my garden is very bad.
I want to install a drain connected to the mains sewage at the bottom of my garden where the water runs off my shed and path.

The closest mains sewage is at the top of my garden and the garden slopes very slightly towards the back.

I assume I just cut into the mains, stick a connector on and run my pipe down to the bottom?

Any one done this before that can offer any tips?

Thanks

delly

I'm nearing the end of my drainage project which i'll be doing a full right up on when finished. I had a quote from a guy to do the job for around €3,500, so i decided to give it a bash.

I'm not planning to break into the general drainage supply, but I was told by the guy who quoted me that you can't go near the sewage supply, and that it has to be where your rainwater goes from your gully.

What i have done is dug a hole about 1.3m deep, .75m wide and 1.20 long and filled it with rubble. I then have perferated(sp) pipes covered with gravel running into this hole. I'm now in the process of getting the new grass down.

The hole works well as while empty over Winter it filled up with very heavy rain, but had emptied out fully within the week.

Dan_B

Hi Delly,
I tried the route you went down with a sump hole and a perferated pipe but it just has not worked for me.

When I said I was connecting into the mains sewage I meat where the gully from the side of my house draings, I can see how I have confused that now.

Thanks

delly

Well in that case, you should be grand. Again the guy who quoted me said that he would cut into the concrete and simply join up the pipe. He also said that you could install a pump thats triggered when the water reaches a certain level, but this would probably add to the cost.

Dan_B

Thanks,
Must look into the pump,might sort the slope issue.

AlanD

I'm just about to start a similar project in my garden. The drainage is absolutely non-existent at the moment. After some heavy rain, half the garden is under several inches of water. After reall heavy rain, the water would come up over my ankles.

So in the bad spots a year ago, I dug some soak pits. One worked really well and you could see the water flow in to it, but it was overwhelmed really, so I sunk another one which didn't work so well because that was even more so overwhelmed. I filled them in with rocks and covered them with earth. The drainage is still very bad, so I now need to put in a network of drainage pipes.

We tried bringing the builders to court over leaving land not suitable for it's intended use, but the whole thing was looking to cost us far more than we wished to spend, so we dropped the case and decided to do it ourselves. I wouldn't even consider a pro outfit cos I know they'll charge a figure close to what was quoted above.

I'd be interested in hearing how you get on and reading the report of the completed project.

Question: What's the problem with sending rain water down the sewerage pipes? I think I can easily break in to the rain water pipes, but I'm just wondering.

AlanD

delly wrote:

Well in that case, you should be grand. Again the guy who quoted me said that he would cut into the concrete and simply join up the pipe. He also said that you could install a pump thats triggered when the water reaches a certain level, but this would probably add to the cost.

any idea how the pump works and where it's situated?

GreeBo

AlanD wrote:

I'm just about to start a similar project in my garden. The drainage is absolutely non-existent at the moment. After some heavy rain, half the garden is under several inches of water. After reall heavy rain, the water would come up over my ankles.

Hmm yikes.
Sounds to me like your garden is way too compacted.
Rather than just add drainage it might be worth it long term to dig up the entire Garden to a depth of 2 feet and at least see whats down there.
Having to dig drainage for every puddle is not ideal to say the least.
In the case that you actually need drainage you should just be able to use a HerringBone design to drain the entire garden.
This will only work if the water is able to drain through the soil until it reaches the pipework, which it sounds like it cant do in your garden.

Good luck.

delly

AlanD wrote:

any idea how the pump works and where it's situated?

Not 100% sure, but the picture in this link may help

redman

http://www.boards.ie/vbulletin/showthread.php?t=241395&highlight=pump+drainage

AlanD

GreeBo wrote:

Hmm yikes.
Sounds to me like your garden is way too compacted.
Rather than just add drainage it might be worth it long term to dig up the entire Garden to a depth of 2 feet and at least see whats down there.
Having to dig drainage for every puddle is not ideal to say the least.
In the case that you actually need drainage you should just be able to use a HerringBone design to drain the entire garden.
This will only work if the water is able to drain through the soil until it reaches the pipework, which it sounds like it cant do in your garden.

Good luck.

Yikes is right! :eek:

Yes the ground is very compacted about 2 foot down. When we bought the house I dug up the whole garden (not knowing there was a problem at the time) to clean it out and level it and seed it. I rotivated it down to about 1 foot or a bit more.

When I dug the soak pits, there was a layer of 2 inch stones (after construction) and then about 1 foot of thick sticky dauby clay, almost like plasticine. This is the problem obviously, so the water builds on top of this and needs to evaporate to go away because it isn't soaking. Although the soak pit now helps, it's just not enough.

My plan is to put in a herringbone design and drain the water away to the rain water shores. However, I've been thinking about an alternate solution....

Would it work if I could get some way of drilling holes in the ground, about 6 inches wide and about 10 foot deep and then filling it with sand or pebbles. If I drilled enough of them, the water should always find a way of soaking away. How would I drill them? Is it a viable solution?

GreeBo

Well that "should" work, it depends on how deep you need to go...
For example, on a golf course we use pole forking to achieve the same idea.
Hundreds of cores are taken out to a depth of about 4-6 inches and then filled over with sand.
This will eventually change the properties of the soil.
You have, as you say, wet sticky clay.
You need to change that by adding more dry materials like peat (dont add peat!) and sand.
Topsoil instead of peat, I guess, save the bogs and all that.
When you rotivated, did you add in any other materials to the soil?

ScottishDanny

Have you considered a 'French Drain'? Its basically a trench 6" wide by 12" deep running down a slope in the garden. Cover the bottom with permeable weed suppressing membrane, run 4" diameter pipe down the trench with holes drilled in the bottom. Cover with loose gravel and roll a layer of turf over the top.www.houstonlandscape.com/ Drainage.htm

AlanD

when I dug up the garden initially, I added a couple of hundred worms. I dug them up from my home place and brought them down. They've certainly flourished as I constantly seem them now. My hope was that they would make the soil a whole lot better over time since I had noticed some compaction and figured these guys would help sort it out. Hasn't worked so far.

I didn't add any other material to the ground. Could I still do this? Would I need to drill holes, like on a golf course. How long does it take to change the ground composition?

If drilling holes, I really would want to get below 4/5 feet to ensure there were drainage paths to deeper ground. The compacted soil goes down that far.

AlanD

ScottishDanny wrote:

Have you considered a 'French Drain'? Its basically a trench 6" wide by 12" deep running down a slope in the garden. Cover the bottom with permeable weed suppressing membrane, run 4" diameter pipe down the trench with holes drilled in the bottom. Cover with loose gravel and roll a layer of turf over the top.www.houstonlandscape.com/ Drainage.htm

I've been thinking a bit more about drainage because of this topic and I think adding in herring bone or even french drainage could be self defeating. There is a slope down towards the back and one corner of the garden. This is where all the water accumulates. My plan was to start pipes here and work back up the garden, obviously with the right gradient to bring water back. Is it possible to counter act the natural fall of the garden?

GreeBo

If its that deep you might be better off just digging up the whole thing and then adding 20% sand 20% quality topsoil. and starting again...
You are gonna need to get a fair whack of materials to add in (depending on the garden of course) but you will also have 40% to dispose of...
Might be a good idea to hire one of those mini-diggers...

I dont envy you the task.
While doing all this it worthwhile analysing where the water is coming from, do you have a lot of runoff areas (roofs without gutters, patio areas?) You will need to fix these or else install a drainage system before you are back at square 1.

Even with uncompacted soil, lots of water will leach away all the goodness and give you an impermeable layer before too long.

GreeBo

AlanD wrote:

Is it possible to counter act the natural fall of the garden?

Only by going deeper as you get to the drain, or by installing a pump of course.

smashey

AlanD wrote:

Question: What's the problem with sending rain water down the sewerage pipes? I think I can easily break in to the rain water pipes, but I'm just wondering.

You would need permission from your local Council to do this. Also, any problem with the sewage could back up through your garden.

AlanD

oh dear.....I'm not liking the sound of this. Didn't really think it was that serious. Although water up over my ankles is serious enough I guess.

Where the water comes from? Rain only, although I have added a small enough patio but this definitely has not made the problem worse as it was there before hand to the same extent.

Given that a particular corner of the garden is the worst offender, a pump would probably work well at getting rid of the majority of water. The rest of the garden tends to be full of muck too after a lot of rain but adding a pump in this garden might help the rest of the garden drain quicker.

What could be happening is the layer of 2 inch stones put down for heavy machinery during construction of the estate could be acting as a "road" for the water to fall down to the back of the garden.

Hhmmm....maybe I have a case to take up with the builders after all. Would hate to take them to court for the disaster of a garden they left us with and lose. It'd cost far too much then.

GreeBo

AlanD wrote:

Hhmmm....maybe I have a case to take up with the builders after all. Would hate to take them to court for the disaster of a garden they left us with and lose. It'd cost far too much then.

Get a landscaper to survey the problem, he should be able to tell if its natural or man made.
Then talk to your builder, then talk to your solicitor.

AlanD

GreeBo wrote:

Get a landscaper to survey the problem, he should be able to tell if its natural or man made.
Then talk to your builder, then talk to your solicitor.

Good idea. We've already had the solicitor involved who sent the builders a letter who then replied saying that they did give us a garden fit for it's intended purpose. The part of the contract that could be challenged is so ambiguous on vague that we'd have a tough time proving it, but then if the garden is unuseable for the majority of the year, what's the point. So I think we'll go back down the solicitor's route.

This is what the garden looks like after 2/3 days of rain and then lasts for at least a week or more afterwards. In dry weather this will take about a month to dry up totally:

Flooded Garden

GreeBo

AlanD wrote:

This is what the garden looks like after 2/3 days of rain

I refer you to my previous "Yikes"
Ok, thats really, really bad.
You are probably going to start to lose at least part of that wall as the foundations start to sink.

How old is the house/garden?
Take more of those pictures as evidence.

ScottishDanny

Thats serious flooding alright!

I reckon try the following

* Ask you neighbours if they have/had similar problems. If they did and fixed it, ask how.

* 'Spike' the ground with a fork, add sand

* Dig a French Drain

* Plant a very thirsty tree at the bottom corner, I'm no gardener but a bit of googling or a visit to a garden centre might get a result - could work well with the drain.

If none of that works, plant some rice!

beldin

Quick comment. You say the garden slopes down away from the house, how much of a slope is it. How deep is your manhole you are going to connect to. Once the bottom of the manhole is deeper than the bottom of your garden then you can run a drainage pipe.
I had a similar problem with the garden sloping away from the house, the point I connected to the drains was however about 2 feet down so I could connect to it and then have a slight slope to drain the water away. You don't need much of a fall , as long as there is some bit.
I dug down to the side of the manhole then ran my pipe for there , covering it with pebbles and then some soil.

AlanD

yeah it's pretty bad alright. I've loads more pictures, including a few with our dog wading through it to show how deep it actually is.

That's interesting that the wall could start having trouble. Is it possible for a landscaper or engineer to determine if it's a natural problem or a man made problem while the ground is relatively dry, which it is now?

I've been looking through the yellow pages to find people who deal with land drainage and I'm not having much luck. I've also done a fair bit of googling to see what I could find. Not a whole lot of info there either, well nothing like the info I need for such a serious problem.

Yes, my neighbour has a problem too with drainage. Not to the same extent, but it's still pretty soppy all the same.

AlanD

beldin wrote:

Quick comment. You say the garden slopes down away from the house, how much of a slope is it. How deep is your manhole you are going to connect to. Once the bottom of the manhole is deeper than the bottom of your garden then you can run a drainage pipe.
I had a similar problem with the garden sloping away from the house, the point I connected to the drains was however about 2 feet down so I could connect to it and then have a slight slope to drain the water away. You don't need much of a fall , as long as there is some bit.
I dug down to the side of the manhole then ran my pipe for there , covering it with pebbles and then some soil.

Oh the slope isn't that much, perhaps half a foot to a foot from house side to back of garden. The rain water pipe would be below this for sure. Although, if i was to start a drain from the middle of that "pond", I'd want to be starting it sufficiently under the surface to drain away not just water that could accumulate over the surface, but water under the surface too.

I should contact the professionals really, but don't want to pay them the huge fees they charge either, hence trying to sort it out myself, but then I don't think I know enough to solve the problem myself. Maybe get the pro's in for a "quote" and see what they'd do, then go do it myself. Cheating, but it would work. Otherwise, sue the builders for giving me a sham of a garden.

Oh yeah, house is only 2.5 years old. Problem there from day 1.

delly

AlanD wrote:

Flooded Garden

Wow :eek:, and i thought i had problems. Thats a very serious looking amount of water, are you sure that your not hanging really wet clothes over that line .

Seriously tho', your garden looks well, so it would be a killer to rip it all up and start again. Perhaps the pump route might be the best option that would cause the least amount of trouble to your garden. That or go after the builders.

AlanD

delly wrote:

Wow :eek:, and i thought i had problems. Thats a very serious looking amount of water, are you sure that your not hanging really wet clothes over that line .

Seriously tho', your garden looks well, so it would be a killer to rip it all up and start again. Perhaps the pump route might be the best option that would cause the least amount of trouble to your garden. That or go after the builders.

Well the clothes line is over that bit of the garden. But because the garden is a mess for 9/10 months of the year we can rarely use it.

I'm not keen on ripping up the whole garden, but if it's the only solution I'll do it. Perhaps that whole sub layer of stones and compacted clay needs to be removed. To do that would require me extracting a gate that's on the side of the house too....wouldn't be happy dismantling that cos we'd wreck it.

Although I did have an idea a few minutes ago which might work. I was reading an article about bad drainage causing problems in houses in Atlanta, GA. So they recommended putting in a dry creek of sorts to help take away water. So I thought, what if I put in a pump to pump water up on to the flower bed and in to a water "feature" or artificial river that would allow the water to flow down the back of the wall, along the bed and in to a sub-terrain pipe and off in to the rain water gutter......

AlanD

AlanD wrote:

what if I put in a pump to pump water up on to the flower bed and in to a water "feature" or artificial river that would allow the water to flow down the back of the wall, along the bed and in to a sub-terrain pipe and off in to the rain water gutter......

If I wanted to purchase such a pump and create an under ground resevoir so that water can seep in and the pump can then pump out the water when it reaches a certain level......where would I go to buy one or find out about one?

What type of shops deal with this sort of thing?

Is there a full system available that sits in the ground or would I have to make one myself and just buy a pump separately?

delly

AlanD wrote:

If I wanted to purchase such a pump and create an under ground resevoir so that water can seep in and the pump can then pump out the water when it reaches a certain level......where would I go to buy one or find out about one?

What type of shops deal with this sort of thing?

Is there a full system available that sits in the ground or would I have to make one myself and just buy a pump separately?

I don't know if you'll be able get the whole kit in one spot, but check this link from ebay for the type of pump you need.

Going from my own thinking, you'd still need the pipes throughout the garden to lead to a small concrete or brick pit where this pump would be, and then have a pipe leading to your drains.

AlanD

delly wrote:

Going from my own thinking, you'd still need the pipes throughout the garden to lead to a small concrete or brick pit where this pump would be, and then have a pipe leading to your drains.

You could be right. I'm thinking that I might try just the sump and pump first and see if the natural flow of ground water brings most water to the pump.

Are pumps pretty durable? So if the water was not very well filtered before it entered the sump, could it mess up the pump with small bits of grit or do pumps like the one on eBay handle little chunks of dirt?

I'm thinking of making the sump out of a 5 gallon drum and drilling loads of holes in it. Drop it in, surround it with stone chippings and cover up.

I'm also just wondering about my "water feature" part of the plan. I'm planning on putting in gutters along the back wall so the water can flow along and then under ground again and out to the rain pipe. Would a pump be strong enough to pump water about 20/30 feet directly to the rain away?

delly

AlanD wrote:

You could be right. I'm thinking that I might try just the sump and pump first and see if the natural flow of ground water brings most water to the pump.

Are pumps pretty durable? So if the water was not very well filtered before it entered the sump, could it mess up the pump with small bits of grit or do pumps like the one on eBay handle little chunks of dirt?

I'm thinking of making the sump out of a 5 gallon drum and drilling loads of holes in it. Drop it in, surround it with stone chippings and cover up.

I'm also just wondering about my "water feature" part of the plan. I'm planning on putting in gutters along the back wall so the water can flow along and then under ground again and out to the rain pipe. Would a pump be strong enough to pump water about 20/30 feet directly to the rain away?

I'm not too sure on most of these points, and can only give an opinion.

I reckon that most pumps won't last too long if they have to handle debris. If you check the diagram in my second post, there is a dirt catcher from the pipes, so i reckon that you'll have to use some form of filteration system. I would also design it so that you could gain access if needed.

In relation to the pump strength, i reckon that a distance of 30 feet shoudn't be too much trouble for a decent spec. If you think of the average central heating pump and the distance it has to work with, 30 feet isn't a great distance.

depadz

got drainage put in last year. was getting a shed built anyway so might have been a bit cheaper but got it done for 2K (garden is about 30m x 10m).
was a bit sceptical getting it done but it has worked out brilliant so far.

put in herring bone drains, draining into surface water waste which happened to be handy enough.

have two big dogs so garden was a mud bath for 6 months of the year previously. there wasn't a single puddle on it this year, no matter how wet it was.

someone told me that the drains will eventually block up but they put in a lot of stone (couple of different layers) so hopefully it will last the course..

AlanD

any idea how deep they went from deepest to shallow when laying the drainage pipes?

The pump is still the top of the list for me so far, but herring bone is still being considered.

Johnniep

Guys,

Just a couple of things that may be of help.

1. If you are doing any form of soak pit/french drain etc, ensure that you wrap/enclose it in a geotextile membrane or similar. This prevents fine soil particles entering and blocking the french drain and clogging it up over time.

2. As Delly has already mentioned, be careful in selecting your pump. A little water feature pump wount stand up to any abuse from dirt etc. Maybe consider installing a silt trap before the pump sump to prevent any dirt clogging the pump. Alternatively, select a fairly robust pump for the job. There are a number of pump companies out there (Consolidated Pumps, ABS Pumps) and they will be happy to help you select a suitable pump based on flow rates, static head.......etc.

It is very difficult to offer a generic solution that solves all problems, but it really does depend on the ground you are ultimately draining to. If it is a heavy clay, this will drain away very slowly and so soak pits may not be the best option. However if you have a gravelly or sandy soil, the percolation rate will be high and allow for rapid drainage rates.

One other point, all the councils DCC, Fingal..... are trying to reduce the volume of surface water (rain water) entering their sewers and "technically", if you want to connect to a public sewer you need to apply to the council directly and THEY will carry out the work (at your expence)

http://www.dublincity.ie/Images/drainage%20connection%20App%20form_tcm35-8496.pdf

Anyway, hope this is of some help

Regards,

John

tapest

AlanD wrote:

If I wanted to purchase such a pump and create an under ground resevoir so that water can seep in and the pump can then pump out the water when it reaches a certain level......where would I go to buy one or find out about one?

What type of shops deal with this sort of thing?

Is there a full system available that sits in the ground or would I have to make one myself and just buy a pump separately?

Hi
the price of that pump that DellY linked on Ebay...and it's "used". It's a submersible pump with a float switch on a lead. I have a lot of experience dealind with pumps from this size to ones you need a bicycle to get around (slight exageration), so before you go mad spending the hard earned on something thatbmay or may not work ( all depends if you can feed the pump quickly enough) Aldi or Lidl do a fairly good job for practically nothing...€20 ?? ..comres round every 6 months or so....pump delivery very good....Try this first
t

delly

AlanD wrote:

any idea how deep they went from deepest to shallow when laying the drainage pipes?

I didn't stick to exact depths all the way, maybe 8 to 12 inchs. This picture may give you an idea. When I have the grass down in about 2 weeks or so, i'll be posting up the whole thing from start to finish.