How to improve drainage?

So I have been wanting to fix a drainage problem on my friends property but I wasn't sure but today the wet weather has confirmed my suspicion.

The property is a sloping block

Slopping Block

The water runs down from the highest point on the block and is surface water that turns into 3 main streams. The heaviest of the 3 runs down the south side of the block fence line and the garden alongside the fence has been washed out many times.

The first and second water flow runs into a entertainment area making lots of mess and fortunately there is a drain that was blocked today by the abundance of garden matter, luckily we were home to unblock the drain or we may have had a flood through the house itself.

I created a little dam to stop most of the water going into the entertainment area but look at the amount of water on the path and the garden behind the Besser block wall is submerged.

So what I want to do is run a drainage from north to south or across the property backyard before it runs through the living area. I though a spoon drain would suffice but that's a lot of water and what about garden foliage blocking?

I looked at the building plans and found that the drain from the entertainment area runs underground along the south side fence line and I want to run the spoon drain into this piping system to the roadway.

Drainage pipe.png

The drain is the dash line from the space open private down along the south side fence to a detention basin before running onto the roadway.

This would in my opinion take the surface water from the backyard to the roadway drainage.

Watching the drain in the entertainment area was unsettling as the garden foliage block the drain and I would like to get some opinions on which type of drainage would be better and yes I will be doing this myself and will pave the clothes line area, regain the southside fence garden by replacing all the washed away soil.

https://www.youtube.com/watch?v=nod1fCw5tJM

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Comments

Jewelleryrescue

Hi @Kvic

I being tring to visualise you storm water situations. I have some answers

For the drain getting blocked by leaves etc there are several after market Drain Leaf strainers. Think traffic cone with holes in it pointing up more over a strainer.

Look at it goes into a pit. But turn it upside down you have a raised leaf blocker if this suits it can be engineer to fit upside down maybe use 2 1 in the pit one over it.

Everhard EasyDRAIN Leaf Basket To Suit Rainwater Pit I/N: 4770227 $9.84

https://www.bunnings.com.au/everhard-easydrain-leaf-basket-to-suit-rainwater-pit_p4770227

Down the side garden besser wall you need a series of Geotextile dams /baffles to capture the heavier dirt and allowing the water to pass through or over the top in peak rain event. Geotextile lasts a long time is why I suggest this. Dig the ground 40mm deep x 50cm wide laying the leading edge Under ground and lay loose bricks as a dam wall down 50 cm away with the geotextile going over the brick.

Another way would to be cover the garden ground in Geotextile material locking the dirt under the mat cut X holes in it for plants to go through

I still might add bricks as mini soil Dams.

Old fashion sand bags made of geotextile like material would work. You want it to last 2o years plus as a min

Up The top Open space private area where you wanted the dish drain maybe for the full yard width. Choose a deeper drain and add the plastic House gutter roll of mesh as a cover filter to stop leaves from entering the storm pipes. At least you can connect to an under ground pipe there.

Bunnings has many options from ag pipe to full plastic and metal drains.

With periodic rain events it is super hard to design a system to stop all wayward water. But it is do able at need.

I just finished replacing dish drain for a deeper 100mm plastic drain and grate I had to cut concrete and steel reo with a large angle grinder and blade with a follow up chisel point hammer drill

EricL

Hi @Kvic

Thank you for sharing your question about improving your drainage. It's great that you've received excellent advice from @Jewelleryrescue. My grandfather's house had a traditional spoon drain installed in their driveway and I've never seen it blocked up. I suppose I lean more towards traditional drain systems. One of the drawbacks of an open drain system is that you'll need to keep cleaning it after every deluge.

However, modern drain systems such as the Everhard EasyDRAIN systems come as a complete set with leaf blockers, drain pits and heel-friendly grates. It will be necessary to cut into the concrete to install the drain systems, but once it's in you will have an effective drain strain system that should prevent flooding.

I suggest having a good look at the way the water is flowing down the side of your house and planning an effective drain system that will carry away any excess rainwater. In this manner, even if you're not home the water has a way of getting out.

Let me call on our experienced members @Adam_W and @homeinmelbourne for their recommendations.

If you need further assistance, please let us know.

Eric

Kvic

https://www.workshop.bunnings.com.au/discussion/comment/25482#Comment_25482

I understand that it is hard to visualise my confronting flooding problem so I have another video of the upper backyard area which starts at the backyard fence and comes down to the beginning of the living area, this area is not used and natural vegetation is allowed to grow so that no lawnmowing is done and what I like about this property, there is only the pathway at the front of the property to take care of, unlike all the neighbors, ha ha.

I would like to put the spoon drain above the clothes line to prevent the surface water running across the clothes line area and down to the beginning of the entertainment area. This will reduced flooding of the entertainment area which it should handle with the drainage already there.

I then want to extend the detention tank pipe from the building plan up to the vegetation backyard to the spoon drain couple with the Everhard drain system?

The foliage of the backyard is from the entertainment area and not so much the upper backyard that is where most of the flooding water comes from. The spoon drain running north to south or across the upper backyard will capture the flow of water shown clearly in the video.

The yard is higher around the clothes line and I feel I will need to build a retaining wall to run along the spoon drain as the lower end of the slope is the south side this works to my advantage to capture the water runoff to the Everhard type system which is then connected to the detention system that runs underground to the street bypasses the washed out garden beds that can be reclaimed for vegetation and I would also then pave the clothes line area with pavers and a pathway to the entertainment area.

MitchellMc

https://www.workshop.bunnings.com.au/discussion/comment/75427#Comment_75427

Hi @Kvic,

It sounds like you should choose three locations on the property at the top, middle and lower sections and run 100mm socked slotted draincoil across the property. Those three lines can be connected to unslotted draincoil and it used to connect to your stormwater pipe.

It appears that a fair amount of this water is trapped behind retaining walls, which indicates that it's likely a combination of surface water accumulating behind them and groundwater emerging from the sloped block. Spoon drains can be effective at capturing surface water but don't assist with any water travelling under the surface of the soil. Burying draincoil below the surface would be the most efficient way to capture surface water that falls through the gravel into it and the sub-surface water. Have a look at this handy step-by-step guide: How to install garden drainage. The deeper you can bury the draincoil the more sub-surface water you can capture.

Let me mention a couple of our members, @hollyelphinston and @doberon, that are currently completing some drainage work to see if they have any input.

Please let us know if you have any questions that we can assist with.

Mitchell

Kvic

https://www.workshop.bunnings.com.au/discussion/comment/101459#Comment_101459

Thanks again Mitchell, this piping is flexible and will conform to the backyard environment.

Checking the Wollongong council requirements I will need to consider a Detention tank and the underground piping already on this property must be 100mm. Most of the water that now flows into the entertainment area would be taken away with the drain coil system and as I have never seen a backlog of water from the drain in the entertainment area the piping would be ok but half of the backyard water doesn't flow into the detention system.

The flow from the backyard in the video shows 3 main streams, the worst is the southside fence line that does not flow into the entertainment area and I suppose should flow directly into the detention system with 2 other tanks placed along the flexible piping system?

The other consideration are the water flows that comes from the adjacent property on the south fence line that pours into the garden area from the neighborhood, this causes damage to the garden which contains serval trees.

While there are some places I can place the drain the roots of the trees get in the way and I wouldn't like to rip the out?

I could also place a separate drain coil along the pathway outside the garden area and maybe some drain holes in the Besser blocks that could also feed into the detention system but with added water flow.

MitchellMc

https://www.workshop.bunnings.com.au/discussion/comment/117673#Comment_117673

@Kvic,

For the south-side fence line, you could consider installing a drainage pit to capture this water. The drainage pit can be connected to your retention pit with draincoil.

Tree roots will be an issue when installing your draincoil. It would be worth severing minor roots, but if there are major roots in the area, you might like to revert to the idea of a surface drain.

Can I ask if the videos are taken directly after torrential rain or a normal rain event? I know we saw a downpour in Sydney yesterday that no matter what drainage was in place it would have overflowed. I was driving at the time, and even the roads were like rivers.

Mitchell

Kvic

https://www.workshop.bunnings.com.au/discussion/comment/127109#Comment_127109

Those video's are from yesterday and I am in the Wollongong region which was what I needed to understand about how to tackle this drainage problem which has been on the board for a few months till I understood the property needs which came about yesterday and thank you for your post that has provided the best solution.

I have had another look at the fence line and root problem and I think I will go with the drain coil in the garden bed between the fence and the trees as they are plant away from the fence around 300mm and the soil to the bottom of the fence is 300mm so I should be able to made a pit.

This should work well as the water will be taken away as it comes from the neighbors property and not take the soil from the garden.

I want to build a Besser block wall between the north and south fences and run the pit along that wall on the high side so I can build a brick paving path around the clothes line to the stairs on the south line fence to cleanup this area. Do you think that would work ok.

MitchellMc

https://www.workshop.bunnings.com.au/discussion/comment/133353#Comment_133353

That sounds like it would work @Kvic.

Once you've created your Besser Block wall, place the draincoil behind it at the bottom and fill above it with drainage gravel. The water that runs down and hits the back of the wall will drop down into the draincoil and be carried to where you'd like it to go.

Mitchell

Kvic

https://www.workshop.bunnings.com.au/discussion/comment/137184#Comment_137184

So I have decided to make a start on the drainage problems and I feel as I have never done this before that the starting place will be to measure the width of the backyard with 2 stakes and a string line and use a level to make sure the string is level on a block that isn't.

I would then measure the distance from the string to the ground surface in several places.

From this I should be able to find the concrete base and where I will need to step for a new level of Besser block, how many block and half blocks, caps and how much mortar I may need.

I also made this drawing to try better understand my needs and the design of what I need to do.

Am I going in the right direction and is there something I need to improve on?

I made a mistake and will correct the fence should be north and south.

Anne Back Yard.jpg

MitchellMc

https://www.workshop.bunnings.com.au/discussion/comment/139837#Comment_139837

Hi @Kvic,

In order to determine the number of blocks and amount of mortar you'll need for the wall, could you please let us know the length of the wall that you'll be creating?

It sounds like you are on the right track. Your sloped string line is throwing me a bit, though. Is that a separate one from the one you've described that is level and for establishing the level block base?

I see you have road base under the drain coil. The drain coil needs to sit on the soil, or the water will run through one wall and out the other side instead of being carried away. Also, there should be road base directly above the drain coil so the water can drop through it and into the coil. You seem to have a layer of soil above. You'll see what I mean in this helpful step-by-step guide: How to install garden drainage.

Please let me know if you have any questions.

Mitchell

Kvic

https://www.workshop.bunnings.com.au/discussion/comment/141667#Comment_141667

I was going to work out the number of materials I needed, myself, once the rain has gone and just working out my approach for this job.

Yes, you are right the string line should be straight across for a measurement to the ground.

The drain coil is in front of the wall with the limited draw ability in google draw.

Should the concrete base of the block wall be lower than the drain coil sitting on the ground?

I will make the changes you have pointed out and show soil under the drain coil, the measurements of the string line, and approximately the materials needed, soon.

EricL

https://www.workshop.bunnings.com.au/discussion/comment/143051#Comment_143051

Hello @Kvic

The drain coil is supposed to be lower than the concrete base. The water in theory will flow to the lowest point of the floor and from there flow into the drain coil and get carried away. In regard to your clothesline area have you considered placing a series of drain coils to divert all that water out of the area?

Here is a handy step-by-step guide on how to install Vinidex Draincoil:

If you need further assistance, please let us know.

Eric

Kvic

https://www.workshop.bunnings.com.au/discussion/comment/144016#Comment_144016

The clothes line is at the highest point of the yard on the north fence and as this property is a duplex the water will be funneled from the north fence across to the south fence side and then continued down the property southside fence to the existing rain water underground pipe, half way down as shown on the property plan when the property was built 20 years ago.

As this existing pipe is 100mm then I will install the 100mm sock drain pipe system.

The drain pipe across the yard from the north and south fence should capture most of the water down from the backyard and any water that comes across from the neighbors property along the south fence line will be captured before it connects into the existing water pipe system.

I feel I have most of the water flow problem sorted with this solution.

The only concern I have is where and how to lay the drain pipe along the Besser block fence.

If I have the soil removed lower than the block base then water could wash out soil below the block wall, if I extend the concrete base of the block then that could help or should the drain pipe be moved away from the wall?

EricL

https://www.workshop.bunnings.com.au/discussion/comment/144757#Comment_144757

Hi @Kvic

Have you thought about building it like a French drain? You can remove the soil and use GRUNT 1 x 10m Non-Woven Geotextile Membrane Drain Mat Fabric so that you get full soil filtration and then place gravel on top instead of soil. I've placed an image below to give you an idea of the possible layout.

If you need further assistance, please let us know.

Eric

Kvic

https://www.workshop.bunnings.com.au/discussion/comment/144757#Comment_144757

I have measure up the yard.

I will lay a wall across the yard, 6.6m, and then at a right angle extend the wall for another 3.5m along the neighbors fence line to the existing wall.

Across the Yard

Across Wall.png

The boundary fence joins a step existing Besser block wall 3.5m

Fence Line Wall.png

The drain line runs across the yard and down th3 boundary fence to the underlining storm water pipe.

EricL

https://www.workshop.bunnings.com.au/discussion/comment/145311#Comment_145311

Hi @Kvic

Thank you very much for the update on your plans. My only recommendation for this project is to add two extra full blocks just in case you have accidental damage while installing the blocks.

Please keep us updated with your progress, we look forward to seeing the start of your drainage project.

If you need further assistance, please let us know.

Eric

MitchellMc

https://www.workshop.bunnings.com.au/discussion/comment/145311#Comment_145311

Hi @Kvic,

Will these walls retain soil? If so, they'd likely need engineering, especially the first 1200mm high one.

Here's a helpful step-by-step guide on How to our a concrete slab. You'll also find these calculators handy for calculating how many bags of concrete you'll need for the slab and how much mortar you need for the blocks.

Mitchell

Kvic

https://www.workshop.bunnings.com.au/discussion/comment/145744#Comment_145744

Most of these walls will be mostly uncovered but I could included rebar and filled with cement where the block height is over 3 blocks or more but I don't feel it will and may find that I could remove a couple of rows from the top, on all walls, when laying.

The north fence is the highest at 460mm which is less than 3 blocks high and then it drops away so most of the wall will be 1 or 2 blocks.

The neighbor's fence line drops very quickly from the 1.2m and most of that wall is not supporting the ground and is why it is stepped to run along the property ground level as does the old block that it will be attached to.

The same goes with the other shorter block wall that goes from the north fence to the steps.

North Side Fence

Neighbor Fence Line and the yellow post is the 1.2m

Kvic

https://www.workshop.bunnings.com.au/discussion/comment/146074#Comment_146074

So I checked out the weather for this weekend and saw the rain was coming next week so l started to dig out my across the yard drain pipe channel, pick and shovel style, very heavy going with rocks and roots but I did make a good mess of it and then the rain came.

Channel ChannelOther end

So the channel filled up with water and I hadn't open it up to the south side of the fence. I open up the south side channel to flow down the property.

South side fence line.

The water from the channel runs down in between the Besser blocks and fence. Currently or the reason for putting in a drain was to divert the water coming out from under this stairway and flooding the lower court yard with water and mud.

I decided to add a blue food dye to the water at the channel while it was raining to see where the water flows?

South side fence lineUnder stair case

So the water flooding in the channel is seen here coming out from or still coming out from under the stairs and interestingly along the south line fence.

So I hope that when the weather dries up tomorrow to cart 2 ton of blue metal up from the front driveway by hand or bucket attached to a step climbing trolley to start laying the drain pipe system from the north fence across to the south side fence and then down along the fence line to the underground down water pipe system.

While there is still some flooding in the entertainment area there seems to be a lot less and most of it is running down the south side fence and is a lot cleaner without the mud.

I assume once the pipe is in place the water will be carried off quickly and further reduce the flow into the entertainment area.

EricL

https://www.workshop.bunnings.com.au/discussion/comment/146366#Comment_146366

Hello @Kvic

Thank you very much for the update on your drainage project. It's good to hear that you've managed to dig up a diversion channel for the water coming into your backyard. Just remember to get the Vinidex 100mm x 20m Socked Slotted Draincoil along with a Vinidex 100mm Draincoil End Cap to prevent soil from entering the top of the draincoil.

We look forward to seeing your next update.

Eric

Kvic

https://www.workshop.bunnings.com.au/discussion/comment/146592#Comment_146592

I have the socked 100mm Drain-coil and connectors already.

I have decided that I do not agree with the gravel being placed on the bottom or placing the pipe on top of 50mm gravel.

Gravel under pipe

The pit or diversion channel has show the water sits on top of the soil-rock-clay surface and is what is draining into the entertainment area shown by the food dye and by placing that gravel under the pipe will cause a level of water to always drain into the entertainment area. I want to place the pipe directly on top the mud with gravel to support the sides of the pipe. The water should then drain from the ground surface into the pipe and not sit below the pipe.

Maybe a 10mm furrow for the pipe to sit in so the water drains completely into the pipe.

The side gravel is then very important to support and clear the ground from the pipe from dirt and I may widen this pit to have 100mm of gravel on each side of the pipe and 100mm above the pipe.

Today the sun is out for a few days for me to continue the digging and laying of the pipe.

EricL

https://www.workshop.bunnings.com.au/discussion/comment/146782#Comment_146782

Hi @Kvic

Thank you very much for the update on your drainage project. The purpose of the 50mm gravel is to prevent the drain coil from settling into the soil. However, if you've surmised that the soil is hard enough, I recommend putting in some GRUNT 1 x 10m Non Woven Geotextile Membrane Drain Mat Fabric under and over the drain coil to prevent fine sand and silt from entering.

Eric

Kvic

https://www.workshop.bunnings.com.au/discussion/comment/146366#Comment_146366

North to southSouth side fence line

Hole dug, pipe laid, gravel filled.

send it down huey

EricL

https://www.workshop.bunnings.com.au/discussion/comment/146593#Comment_146593

Hi @Kvic

Thank you very much for the update, your drain layout is looking very good. My only suggestions are to move the excess soil near the drainage away from the gravel channel. I also recommend levelling and flattening the gravel near the steps going down so that the water does not form gulley's.

Eric

Kvic

https://www.workshop.bunnings.com.au/discussion/comment/75427#Comment_75427

I am trying to overcome waterflow issues on the property and while there are straightforward solutions the permissions are a bit more challenging. My partner doesn't like most of the first idea's and that has challenged me to come up with other solutions which I have to agree has worked out better.

I have a slopping block with reduced water issues after laying a drainage system across the yard.

There is still water flowing into the entertainment area which has been greatly reduced from mud and water to mostly clean water.

The water flows from under the stairs from the backyard with is on the east side fence and then because the concrete entertainment area has been laid for the water to flow to the centre of the entertainment area where there is a storm water drain.

The concrete is covered in water

The first solution was to cut the concrete with a channel to fit drainage from the steps to the stormwater drain but the aesthetic would look ugly.

So I did lay some bricks on the surface to direct the water further along the concrete where I can direct the water into the stormwater drain.

Water and mulch re-directed

So this got me to thinking that I could go up instead of going down or somehow cutting or griding a spoon waterway into the concrete that is only 100mm thick and going up which is a tripping problem.

So I thought I would ask here for some idea's.

Dave-1

@Kvic

A lot of work! And I mean a LOT. I know what you are talking about re the rain in Wollongong. (live in the area as well) and have the same type of issue as you. Tho not as much surface water from my neighbours maybe. Would love to see what your solution is like after the next rain. 🙂 I run outside everytime and take photos of my solution as it is 🙂 I like mucking around with drainage and digging tho get stressed when the solution is costed out. Im hopping mine holds up over the coming years.

Just posted a couple of projects on stormwater rectification. And the landscaping and water retention will follow soon. The gravel around the pipes really seems to help subsurface water travel.

Dave

Kvic

https://www.workshop.bunnings.com.au/discussion/comment/27078#Comment_27078

A lot of work when you are 66 and carry 2 ton of blue metal from the front driveway up 20 or so steps with a large bucket on a tri wheel trolley. Digging 18 meter's of earth but the outcome is that since the job is now partly finished and we have had some rain the water has mostly disappeared down the drain and I find I can now get up out of the lounge without lounge arm support.

MitchellMc

https://www.workshop.bunnings.com.au/discussion/comment/101976#Comment_101976

Hi @Kvic,

It appears that this area is capturing water. If adding a drainage channel is not an option for you, the next best would be installing a drainage pit. This drainage pit will capture water in the lower area and hopefully redirect it to your stormwater before it has a chance to build up. Also, a drainage channel could be incorporated into the system under the stairs to capture water exiting the wall.

Please let me know if you have any questions.

Mitchell

Kvic

https://www.workshop.bunnings.com.au/discussion/comment/117973#Comment_117973

So there have been advances in the drainage but I am quickly learning that when I want to do a job around the house it is never that simple for me.

Our front door is around the side of the house which leads into the backyard area and I want to clean the mould of the rendered wall of the front door area and then paint it. The mould extends not just to the rendered wall but most of the backyard so the rendered wall is actually the last thing that I need to do as I don't want to pressure clean the wall and then the pathway afterword's which would go blow rubbish all over the newly painted wall.

The pathway extends from the front of the house to the backyard and beyond so I started with the backyard.

Pressure washer the difference

So I will stain and oil these stairs but how do I clean from under those stairs.

While it looked difficult the truth is it came out fairly easy with a broom.

Mud and plants

Afterwards

This mud comes from the backyard which was there before the drainage was put in, further up the backyard, so how has that drainage made a change, not yet as I have more to tell first.

So I pressure cleaned from the backyard steps, all the entertainment area down along the pathway to the front yard.

Well worth the effort but his uncovered further problems,

Gaps between blocks and concreteCracks in walls

I was able to put the long wood saw down between these gaps and remover the old concrete expansion joint material and replace it.

The cracks in the wall were hairline and not any loose concrete so I decided to paint the wall several times till all the cracks disappear and were well cover with the sealing and anti mold paint.

So what started out as I wanted to paint this wall turn out to be much more and I considered it the right way to do this job.

So the rain came finally and I can see the results of all this hard work.

After RainingWith the mudToday clean water

So have I come to and end, not by a long shot, there is mor to come.

MitchellMc

https://www.workshop.bunnings.com.au/discussion/comment/127343#Comment_127343

Amazing work @Kvic! You've really put in the hard effort to achieve some wonderful results.

I'm sure there is more to come, but you should feel very accomplished with what you have achieved so far.

Well done.

Mitchell

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