How to stop overflowing water from other properties?

[Barbara35]

I have an existing colourbond fence as a boundary fence between my property and the adjoining property.

I continually have flooding when heavy rain pouring through from their  place. It is like a dam has burst and we have renewed all of our storm water and drains  at a cost of $9000.

Our drainage accommodates water on our property but not the extra from behind. When this happens it floods the top level which becomes like a swimming pool and over the garden and is like a waterfall coming down over the steps  to the patio. When the water gets to the patio we have to broom it to the side so that it doesn't enter the house. We have had to have SES provide sand bags.

We have spoken to the neighbor who says his yard floods as well but says it is nature and is not prepared to do anything .

We have spoken to the Council on a number of occasions and one again they are looking into it.

We are having quotes to build a wall across the back but this is very expensive. We thought we would get cement sheeting and put that across the back to prevent this flooding. We were thinking  of making it approx 3ft high. and to go across approx 405ft 

Not sure what product to use and really need help.

[Barbara35]

Mitchell,

Here are those photos.

These photos are after everything has drained and I have been able to take these photos. Hope these help.

No 1 shows the water still draining  down steps and on back patio.

No 2 shows water still draining and brooms we have use to broom water to the side of the patio so that it will run down the side and drains down the     side to take the surface water.

No 3 shows back yard  and lower garden with steps and the back boundary fence garden

No 4 shows under the boundary fence where the brick wall is . The brick wall does not come under the fence it is behind the colour bond fence.

[MitchellMc]

Many thanks for those photos, @Barbara35. They really help paint the whole picture.

I can see from your plan that a significant amount of subsurface drainage is installed all over your backyard. Even at the rear fence line, as I was encouraging earlier. Either the line from this drainage back to your stormwater is blocked, or the stormwater pipe itself is blocked, the grading of the line to make the water flow there isn't sufficient, or the line back to the stormwater is not of large enough capacity. I'd be keen to know where your stormwater line is and how this immense amount of agricultural pipe sends the water there.

I think this is a case of an amazingly well-thought-out drainage plan that hasn't had sufficient lines back to the stormwater installed. This drainage plan should cope with the water from your property and the next doors without issue. It is more than adequate to collect the water; it's just not capable of sending it anywhere. The standing water above the grate indicates that something isn't coping. I would take a guess and say that only one 100mm line is connected to all this drainage and is trying to delivery the collected water to the stormwater line. If this is the case, that's the point at which you need to run additional lines or increase the diameter of the pipe.

My only other thought would be, did you experience this issue before that very large dwelling was built in one of your images? Could this water potentially be coming from that property and not from the rear neighbours?

Mitchell

[Barbara35]

The pictures sent was after the flooding had stopped and this was the last to drain. In the video you can see how the water runs over the brick in the back and this is only after it has drained enough to be lower than the brick wall.

The ag pipe around the back fence down the side across the middle into the storm water which runs down the side of the house and out into the street is 100ml. Without the water coming from the property behind we do not have a problem. We know the ag line at the back works because if we over water then it runs out of the storm water into the street.

The reason that the water cannot get out is the volume of surface water coming through the back property it goes straight over the ag pipe over the garden and into the backyard. Floods the top level and rushes over the bottom garden and steps. We can not stop it we just have to broom it away to the side as fast as we can which is not easy.

The standing water above the grate is after water has drained and the flooding has stopped.

THE VOLUME OF WATER COMING FROM THE BACK PROPERTY IS LIKE A DAM OVERFLOWING NOTHING  CAN STOP IT AND OUR STORMWATER IS ALSO TRYING TO TAKE OUR WATER.

As far as the new buildings go we have always had this problem especially in the 15 years The owner of the property behind says he is getting water from these new building which add to his problem.

I have had council out and they are looking into these other properties and I have now have the General Manager/the Mayor/Director of City Services looking into this.

Waiting for them to contact me in the next few days and have another site visit.

I will wait until next week then I am going to put sand bags along the bottom of the fence to see if this will help also looking into sleepers as suggested.

Thank you for your interest

[Barbara35]

We have also asked Council to  put another  storm water drain in the gutter closer to our property to allow our storm water to expel into the gutters in the street as the water coming down the gutters flood almost into the middle of the street and above the kerb  so that it blocks our storm water outlet. If they did this then we could redirect our storm water directly into drain as this was done when town houses were built next door

[EricL]

Hello @Barbara35 

Thank you for posting those photos of your lovely backyard. The quick solution at the moment is to put up a rectangular wall of sandbags in your back patio area. This will prevent the water from accumulating in that spot when your lawn at the top starts to flood. You can at least relax a little bit as the water will not gather at the patio doors. 

I suspect that there is a slight slope in your property with the way the water is flooding after the steps. Another possible cause of the water from not draining away is that the street drain is actually flooded as well due to the amount of water running through it from the neighbourhood. Since you've already spoken to the local council, I suggest holding back in doing any major plumbing projects until you get a definite answer from them. 

Should another strong deluge occur, I suggest taking videos of the flood from its point of origin at your fence to the bottom area where the water is flowing to. I'm aware that you've spent a great deal on your drainage system, but I'm afraid that it is just not coping. I suggest speaking to a registered plumber and getting a quote on how much it would cost to modify the existing drain system to accommodate the large amount of extra water coming from your neighbours. 

Eric

[Barbara35]

Well it is 8:12pm and we have been brooming water away from the house once again for 2 hours. gutters full storm water couldn't get out had to put sand bags around  to allow our storm water to get out

SES came no sandbags will come back some time to leave some to block vents under the house and sand bag up near back door.

Rain has stopped. Maybe ok till next storm

Exhausted can't keep this up

[Barbara35]

Tried to take videos not really successful

[EricL]

Hi @Barbara35 

Sorry to hear your still battling the flood in your garden. If the SES are taking too long with the sandbags and you need them urgently, the store carries sandbags - Brutus 360 x 850mm Sandbag - 10 Pack. However, you'll need to order the sand from the special orders desk in order to make your own sandbags. 

Eric

[TedBear]

Hi again @Barbara35 .... very helpful to see the situation that the problem sits in.

Although this suggestion won't be easy to do in the short term....  your back garden layout reminds me of how ours was when I first bought the property.... although yours has a much worse water flow issue. At east I didn't have a neighbour' s overflow to contend with.

Our property slopes down from the back, had hard surfaces up in the back area and a pathway layout that invited all the water to the back door.

That's what your layout appears to be doing also.

My cure was to remove the garden bed on one side and replace it with a paved walkway which continues down beside the house to the front driveway and road. I also removed my steps that came directly down to the house and replaced that with a meandering earthen walkway.  That bit may not suit you, but perhaps you could consider adding another step at the top of your steps plus a raised "landing area" after that, which you would step (or could be sloped edges) up onto from the upper grassed area, before descending the steps. You seem to have enough room up there to incorporate a mound or landing without it looking out of place.  The idea is to avoid a tripping point at the top of the steps while also making it harder for the water to come down to your house that way.   If you were willing or able (if your property design allows it) to put a walkway in to act as an emergency river, the water could then be at least directed down hill, to the side of your house and out.

Just a thought, since this approach has worked for me - with the added bonus that I can now get a wheel barrow from the back to the front with ease, which I couldn't before.  Thanks for keeping us updated... it's quite a problem to tackle, but can't be ignored, of course.

[Barbara35]

What you are suggesting is an impossibility as well as the steps in the middle at the far side we do have a paved walkway from top to bottom this also has two drainage channel areas top  middle and bottom   and  the side passages have air conditioning and heat pump hot water system as well as 2x 2100 litres water tanks. These side areas also have drainage channels.

If we tried to block the stairs the water would only come over the gardens and still towards the house even though it could go down the side and flood the side of the house even more than it does now.. 

Financially  we cannot  do any more. 

As I have said no matter what is done the surface water is too great storm water not being able to get out into the gutter because the gutters are overflowing means that even our downpipes can not empty and they overflow.

This is a nightmare I have been in touch with Council again and they may come out to-day.

I think a hydraulic  engineer is needed  however I don't know whether we can afford one.