Another “Fix my shonky drainage problem” threadÂ…

[roverrescue]

So I have been fighting this battle a year now
Pool installed and filled for Christmas 2020.

When it rain it pours is a pretty safe assessment of our rainfallÂ… we average good volumes in summer and they generally fall in a few hours!!!!

Result is the retaining wall gets well charged with water and what little drainage was installed behind the wall is clearly overwhelmed and murky ****e is deposited onto the tiles and flows into the pool.

Obviously in hindsight I would have done things differently - like maybe not pitch all the flat areas around the pool - towards the pool which you spend half your life trying to keep clean.

Looking for ideas. I have a few but will keep quiet and not taint the witness your honors’.

Wall is stacked granite with sand cement mortar sitting on a concrete footing
Tiles are travertine layed onto a 100mm concrete slab

Dirty Water seeps from two places the back corner of the pergola along the pergola slab and drops onto pool deck (left circle and arrow) and also through the wall in the corner and along pool deck (right circle and arrow) as can be seen in photoÂ…

Thoughts on how to keep seepage out of pool appreciated

S

[LRJim]

So I have been fighting this battle a year now
Pool installed and filled for Christmas 2020.

When it rain it pours is a pretty safe assessment of our rainfallÂ… we average good volumes in summer and they generally fall in a few hours!!!!

Result is the retaining wall gets well charged with water and what little drainage was installed behind the wall is clearly overwhelmed and murky ****e is deposited onto the tiles and flows into the pool.

Obviously in hindsight I would have done things differently - like maybe not pitch all the flat areas around the pool - towards the pool which you spend half your life trying to keep clean.

Looking for ideas. I have a few but will keep quiet and not taint the witness your honors’.

Wall is stacked granite with sand cement mortar sitting on a concrete footing
Tiles are travertine layed onto a 100mm concrete slab

Dirty Water seeps from two places the back corner of the pergola along the pergola slab and drops onto pool deck (left circle and arrow) and also through the wall in the corner and along pool deck (right circle and arrow) as can be seen in photoÂ…

Thoughts on how to keep seepage out of pool appreciated

SBuilt plenty of retaining walls over the years, mostly are Besser blocks but this would still work for you.
You would have to dig a trench at least 400mm wide and a bit deeper than the pool level along the back of the wall. Lay some aggi pipe (the ones that are covered in the mesh work great) and connect the end to a storm water outlet or run it out to a garden etc.
Back fill the trench with 40mm scoria up to 200mm of the top of the wall then top soil over that to the top of the wall.
What we do with most retaining walls is waterproof the back with bitumen paint and lay some core flute up against the wall before backfilling. Since you have a stack stone wall it may be hard to bitumen paint it but the core flute will definitely help alot alone.
Laying some geomesh between the scoria and dirt will help stop excess soil and weeds from getting into the scoria also.
What I've stated is what most engineers or building surveyors would ask for these days.
It's a bit of a job considering you have a finished garden but it would be the only real way to fix the issue.
You could try and seal the whole front but wouldn't be a guarantee to fix it.

Best of luck mate
Cheers

[roverrescue]

Thanks LR Jim
Unfortunately apart from sealing the back of the wall all that was done at build
100mm socked Aggie , back fill gravel wrapped in geotec and just the top soil coverage

I agree - in retro spect the Aggie could have been routed to drain more efficiently
But I’m guessing this flow through the wall is essentially overwhelming the drainage behind the wall
It only happens after bigger dumps of rain

If we get 10-20mm rain drop it will
Be okay

60mm over night and we get a brown pool for breakfast !

S

[discorevy]

https://media.prod.bunnings.com.au/api/public/content/d8893eeb715e4f09b436ef60241ab464?v=858b0242&t=w500dpr1probably something like this along the bottom of the wall would be easiest