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.

[MitchellMc]

Hi @Stormwater2024,

I just thought I'd add that contacting your local council in situations like these is important. If you believe the recent development has created the issue, then they will likely investigate. Most councils have regulations surrounding natural watershed and do not allow residents to divert it purposefully or without regard to other blocks. Adequate drainage must be installed to help accommodate the flow and direct it to the mains stormwater. If you were to create a wall, the water would likely be directed to the next block, and if damages occur there, there could be liability issues.

Natural watershed, especially on sloped blocks, is a difficult issue to deal with. Depending on the properties' layout and if there is a significant amount of water entering your property, then the neighbour likely has it entering theirs as well. The issue gets compounded for the lower blocks as the higher ones drain into them. Building a wall or installing cement sheeting could be effective in preventing the flooding. Still, it's important to ensure that any solution you choose is effective and within your local council's regulations and guidelines. 

I suggest the first thing to do is call your local council.

Please let me know if you have any questions.

Mitchell

[Stormwater2024]

The drain was installed by the builder who did work next door when I showed him what his work had done to the landoverflow - redirected it to me.  He is denying this - of course!  The drain basically ends just past the tiled patio so the stormwater hits the deck on the side of the house.   Deck has consequently rotted and subsided.  The stormwater then flows under the deck on the side of my house.  Under the deck is a void and the stormwater flows through the void and this has caused significant erosion to the foundation.  Stormwater is entering along the fence line at the back right corner of my property.  The next door neighbour installed a pool with a step at the back of his property that acts like a quasi dam wall.  All the stormwater that dams finds its way under the adjoining fence and comes down like a river in my backyard.  I need a retaining wall of some sort to slow this water down so that it can be captured in a pit(s) and a commercial channel grate drainage system.  I will need 150mm pipe to take this water away down the right side of my property (under the void of the deck).  Cost for creating this new drainage all the way to the road is astronomical ( $70,000).  The other option is to plumb it into existing stormwater but I don't think this is a good idea (cost for this scenario is $35,000) incase of back up. Stormwater cascades down my backyard for hours on end so not sure if hooking up to existing stormwater plumbing will be adequate.  Are they any other solutions to this problem??  Happy to consider any other ideas sine I don't have $70,000 buried in my backyard!     

[MitchellMc]

Unless these are extreme rain events that happen only a few times a year, @Stormwater2024, this problem requires a well-thought-out solution. It sounds like you've had some quotes from professionals who have assessed the situation likely better than we could. You could enquire with other drainage experts for cheaper solutions, or the only other option I can think of would be to approach the council so they can determine whether you're now dealing with purely natural water shed or if the developments have exacerbated the issue by funnelling additional water into your property when it should have been captured on their side with adequate drainage.

If it's determined that they've contributed to your issue or, worse, created it, the council might mediate a solution. Given the costs you're facing, it's worth a phone call to get the process started.

Mitchell