Drainage issues - don't know where to start

I have just moved into a new home in southern Qld. It is a flat block with sodic H1 soil. We purchased the land when it was dry and checked all the flood records etc to ensure there would be no problems with flooding.

There was a lot of rain during construction with water pooling around the slab. We paid a few thousand for the builder to backfill against the slab with 52 cubic metres of roadbase but this hasn't done anything to the problem areas, other than have a sinking path along the back and side of the waffle slab. It looks like he tried doing this on top of water that was already pooled. The yard was also churned up by machinery with water pooling in tyre tracks everywhere.

When we moved in on handover day the central courtyard was full of water so I dug a channel to drain that. Water was all around the block including a large deep pool along the back of the slab next to the path.

Stormwater is directed into a large tank with overflow directed to a gravel pit at the front of the block. However, this pit is full of water constantly and it is right across the front yard. When it rains the water pools back towards the house. The tank isn't even full yet.

We had to pay for services to be put on. We live on a street but council refers to it as an unformed road. We don't have a stormwater pipe to access and it has cost a couple of thousand dollars just to make our driveway accessible from the nearest paved street. Because the 'street' is higher than the front of our place water drains off into the front along the fence line and this causes water to build up in our front yard- where it sits and slowly evaporates. We are breeding zillions of tadpoles in our yard and the cane toads are moving in.

I don't know where to start. The soil is saturated and difficult to dig - it just sticks to the spade. Adding topsoil will just create a bathtub effect I've been told by neighbours. Even if I did dig some drains to get water away from the back and side of the slab, there is nowhere to direct it to and it will just cause flooding elsewhere.

The Geotec report did note a large depression and this corresponds with the area where the water is pooling the worst near the slab. The engineer only had the usual 'maintain drainage at all times during construction' clause with no mention of the depression.

Here are some photos taken about a week ago after it rained again. It has basically been like this for the four weeks I've been here. My concern now is that if I suddenly manage to drain water away from the slab it is going to cause excessive movement as the front of the slab is actually dry. The house is also a U shape around a central courtyard which is saturated too.

The following is the back corner. The path is constantly wet. I threw some dirt into the pool of water to try to stop my dogs getting so wet and wanting to play in it. Water is still there a week later - as it doesn't drain at all.

The wet side. The path is only an inch or so deep here so probably just covering more of the same. The access gate for the yard is at the top of the photo. Of course it has been inaccessible the whole time.

The street on the other side of the 'photo.' Yes. We have gum trees growing in the middle of our street. The Fraser coast council calls it an unformed road so won't do anything about the drainage or the face that the middle of our street is inaccessible. I can't access my next door neighbours house unless I go around the block and enter the street from the other end. The neighbours refer to this area as the 'swamp.' We are zoned low density residential and not rural.


The pile of dirt is from a hole dug for a stormwater detention drainage trench/pit. You can just see the grate for tank overflow below the junction of the fences top right of the photo. This is water before the tank has filled, so just drainage from the yard.

The other side of the fence from the above photo. This shows the 'street'


Water backing up from the stormwater pit - again before the pit has received overflow from the tank.


Water along the back of the house during construction.


Water in the courtyard during construction. It gets the same each time it rains and takes about a week to drain through my little drain I dug

The builder wanted another 3 or so thousand to bring in more road base to put in the courtyard and to dig 'ponds' in the back and front yards. I think these would be large water bodies with stagnant water - full of cane toads. Much of the yard is already almost ponds so can't see how this would work especially as there is no infiltration with sodic soil. We'll just end up with more and more water sitting in the yard.

I should explain that we were living 2000kms away while the house was being built. We had friends take photos of the build for us and the builder sent occasional pics, not showing the yard though.

I am aware that if I do anything like dig a spoon drain or drain water/not drain water and later there is slab heave, whatever I do or don't do will be used to put the blame on me. It is four weeks since moving in but it has been impossible to dig. I've tried but the clods stick to the tools and have to be knocked off. And I sink in the mud, get stuck or fall over, so venturing into the yard is something I've been reluctant to do.

I was told to contact the Qld building authority about this. He said he'd start a process and to ensure I keep evidence of interactions with the builder. However the builder won't respond to emails and wants phone calls only.

What I thought was strange was that a month after handover after I'd contacted the builder regarding this he turned up with a 'certifier.' It seemed like it was the final inspection which made me think it was odd as I thought this would be done before handover. The certifier took minutes to walk around the house and then the yard. When he saw it he said 'oh dear.' The builder told him about all the things he was going to do 'building ponds' etc and I noticed the certifier lifting his eyebrows and he just repeated 'ponds' and sounded dubious about the plan. I also said several times that we had no money left for building ponds but this was ignored. It really seemed like the builder was saying he hadn't finished the job but will later yet I am certain there is no intention too, especially if we have run out of money.

We wanted to be fairly self-sufficient for our retirement. That is why we got a tank and we selected the pump option which is $1000 extra. He turned up with the pump the day the certifier came because we'd asked him where it was. They'd also forgotten to install an extra exterior tap we ordered and paid for as it is a big yard to care for. He talked me out of the extra tap and said we could just use the pump as a tap as it is on the same end of the house and he promised a refund of the $190.
When he installed the pump himself (worth approx $200-250) he cross threaded a fitting and said he'd go and buy a new one. He came back a minute later from the car and put it back on. It looks as if it is still cross threaded. He also didn't install a y strainer so I've bought one as I've nearly given up on the builder actually rectifying anything. I haven't installed it yet. Apparently using the pump without one will void the warranty.I asked him about a cover for the pump and he said it doesn't need one as the eaves will protect it. They don't. It got wet the day after from rain. The pump manual says it must have a cover to protect it from rain and UV light.

When I was speaking to the pump manufacturer they asked me for a picture of the setup. They said it was highly unusual and recommended the tap and discharge pipe actually be attached to the wall of the house as is the usual setup. The pump should also be secured to the concrete but preferably in the cover. I've been reading the manual about ball valves on the inlet and check valves on the outlet but it doesn't make much sense to me as I've no experience with these things. I was suspicious that having a tap on top of the pump wasn't a good idea though.

A week after rain. This morning. The stormwater pit is in the dark at the top of the pic.
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the builder told me I can cut the plastic off but as it is obvious the ground level has to be changed I thought it better to leave it for now.

Have you looked at your certificate of title? Is there a drainage easement to the rear somewhere? When we built 10 years ago in a country town there was a stormwater connection point at the rear as the property was on the low side of the road.
You seem to have a lot of water and it must be ducted off the property somewhere bur not to a neighbour's property.
I understand council state you can't discharge to the unsealed road, but instead ask them about drainage plans for the subdivision that the developer must have had to provide. If no luck go higher to your states planning authority. I can't believe council would be allowed to approve development where the footing can't be protected from water.
If you want to engage someone to help a private certifier might be the person to start with.

I dug this to get rid of the pool that was in the courtyard. It is still muddy though.
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The other end of the drain I dug. Basically nowhere for the water to go.

The stormwater drainage pit is the corner of the fences. The tank hasn't overflowed yet. This is just from rain collecting on the block.

The tank is visible at the end of the house. This shows the water creeping back towards the house from the wet stormwater drain. When it rains the level just becomes higher.


The stormwater overflow from the water tank.

The back of the house today. The builder said the plastic lining the slab was cut off when the road base was put down.





This is the southern side of the house so no sun. This is how it looks every morning. Condensation.

No drainage easement. There is a spoon drain at the end of the street next to the road.
The story is that the developer did the other half of the street so it was fully serviced with a sealed road. Before he did our end of the street the council seized the land due to failure to pay rates and they sold the blocks on. They have wiped their hands of any responsibility for any of it. We had a problem just with the house number. First they said it was 7-9 of # street. We pointed out for months that there is already a 7 and 9 on the street so they added a north to our address. After I got my licence, rego etc and the ongoing confusion about people not being able to find our house they changed it to 21-23 # street and said to drop the north. After I redid everything again I was informed it is now 23 # street.
I complained about the difficult access as the road base sinks into the mud after rain. The council put some roadbase in a small patch next to the paved road at the end of the street and said it is an unformed road so that is all they can do.
I contacted them again last week and said the water from the street is ponding at the front of our yard and backing up into it. I am still waiting to be contacted back.
We contacted the local member a long time ago. We received a prompt response that he'd look into it, but nothing since.
I was after advice because I am thinking about perhaps engaging an engineer to give advice on drainage and also wondered if it was worth contacted the engineering firm who did the original drawings, although there are no drawings at all of drainage for the house at all. The pit is supposed to be designed and certified by an engineer but I've seen nothing about that. I've also read that sodic soils aren't suitable for such a pit as exfiltration won't happen.
The problem with the back of the house is that the rest of the yard is above it so I can't figure out how to slop the land down away from the house without just forming a big channel for more water to sit in.

Surface waterlogging and sodic soil is a real bad combination.

Do you know the height of your water table?

So sorry to hear about all these problems. It's he last thing you want in retirement.
You are required to "landscape" water away from the house, so don't fear being held liable for slab heave if you comply with this requirement; your problem is though it will accumulate away from the house and still flood.
You should find out the name of the certifier that visited with the builder and contact them. It seems like the builder may be unable to get a final certificate.
You can still keep records even if your builder won't respond to emails (which he fears legal problems). Keep a diary and your own written 'record of conversation' with detail of the time of call, who you spoke to, what you said and what they said. If this goes to court or arbitration I believe that diary is evidence.
If you've got non-competent ground you can improve it with a layer of geotextile fabric, then a layer of crushed rock, then a layer of roadbase for say a driveway. A layer of roadbase on top of the mud is just going to sink.
Check with all your neighbors how and where they drain stormwater. When you say swamp, is that just your block or the entire area?
The only other advice I can offer is don't let this go. You have a non-compliant building problem with no simple solution. Everyone is going to try to wash their hands of it. Be tenacious and push for action. The builder is only going to give a bandaid fix if pushed. Don't wait for people to get back to you (you mentioned above that you haven't had a response yet), chase them up.
Your problem is one of two things. One, the council is liable for approving a development with no drainage provision (most likely), or two, the builder did not grade and maintain drainage away from the building envelope (less likely as there seems nowhere to achieve this).