WTF happened, blocked soakaway

[rfsteel]

I have a soakaway at back of my bungalow, in front of my garage, for the past 3 years the soakaway has been slow draining, but still functioning in heavy rain.



After friday nights downpours, I changed my downpipe guards from the golf ball type to the light bulb type, clearing the guttering at the same time.




This morning, I awoke to find my soakaway completely silted and blocked.






Seems very strange after the all day of rain on Sunday, only for it to block overnight on the Tuesday, surely changing my drain guards hasn't caused it ?

[boyse7en]

I had to clear my downpipes guards after Sunday's heavy rain as they had silted up. I think the long dry spell have caused a build-up of lichen/dust on the roof and the rain has washed it all off at once.

[xx99xx]

Could be more than just the surface blocked with silt, the soakaway itself could be full of silt further down and no longer has the capacity to hold or drain water. Jetting the soakaway may help if the problem persists

[rfsteel]

Thanks, just had it jetted, and ended up down the side of the garage, sort of explains the hidden footpath, looks like this is the top of the soakaway.




Think I'll be busy this weekend finding the end of the pipe, as I didn't have to dig very deep to find rubble and the start of a chamber/void.

[shtu]

Weeks of dry weather, then heavy rain = loads of dust and dirt washed into the system in one go.

If you're digging things up anyway, you might want to look at,

- Building a small catch pit before the entry to the soakaway. Literally a small chamber with a pipe in, pipe out, and space for silt, leaves, etc to settle.

- If you still have trouble, changing the soakaway to the plastic cells. Far more capacity in the same amount of space.

[Toltec]

One of our downpipes had stopped draining so I got a drain cleaning, backwash pipe for my jet washer and sucked the silty water out using a wetvac. Eventually after about four metres the backwash pipe would not go any further and water started draining through the pipe. It was still a bit slow, but good enough for all but the worst downpour and a lot easier than digging the drive up.

[rfsteel]

Fortunately I didn't have to dig too far to find the inlet pipe to the soakaway




Have got a mini digger and driver booked for next week to help clear the rumble mounds, so will also get him started on a 50m trench to the rear of the garden so that I can install a french drain later on this year.

[rfsteel]

After digging the existing soakaway out further, I felt it was up to its intended purpose, so have removed most if the clay and silt around the outlet pipe, tipped a bag of 20mm shingle and couple of broken paving slabs to give me a level base to install a gully, that will hopefully work as a mini catch pit and future maintaince point.



Once installed, out with the karcher and the pipe jetting hose to backwash the soakaway pipe, then out with the wet vac to remove the silt from the system.



Plan now is to let this gully outlet directly into the soakaway, and will backfill with the removed hardcore and add further shingle.

[DrDeAtH]

Might be worth replacing the soakaway whilst you're digging up the garden.
They don't last forever..

[rfsteel]

DrDeAtH said:

Might be worth replacing the soakaway whilst you're digging up the garden.
They don't last forever..

Unfortunately funds are tight, and whilst digging the trench can be done in a day, building and laying a french drain soon adds up, especially for a 50m run.




I've got the dumper for the week to clear the hardcore thats been there over 2 years, so think I'll concentrate getting trench in my rear bank, so that I can build an outfall to address this historic flooding location.



Hell I might even dig another soakaway as a way of hiding all the hardcore instead of skipping it

[rfsteel]

All done, having tested the downpipes at the front of the house, nothing made it through to the soakaway, so either these pipes are blocked, or there are other soakaways at the front, so another reason not to attempt the french drain just yet, as this soakaway is just serving the driveway and the flatroof.


seeing as this is on a budget, I re-used the old drain guards as a final catch filter for the outlet into the soakaway



Backfilled the hole with the hardcore originally removed

Leveled off with shingle

Weed control membrane and some more shingle

followed by some topsoil and a hose test, all is good, just have to wait for the next downpour to see if it has helped.

Edited by rfsteel on Monday 6th August 13:15