Partially blocked garden drain

[Richard Lindsay]

I have a drain underneath my patio that rises to the surface at two points. There are two square drain vents covering the 100mm pipe. One of the pipes has a 90 degree elbow at the bottom and connects to the other on its way to the sewer.

The pipe with the elbow is about a third full of water and doesn't drain fully. When I add water to this pipe it rises slightly and then drains back to the previous level. The other rising pipe has no standing water and I can see to the bottom.

I hoovered out the standing water with my shop vac and there were a few stones and a lot of dirt at the bottom. The pipe still wouldn't drain after doing this which leads me to think there must be more dirt further down the pipe.

I tried using a 25ft snake and managed to insert it fully but with no luck. I'm assuming this wont move the dirt. I also tried to use drain rods but cant get round the 90 degree elbow. I tried using the 4 inch plunger that came with the drain rods but its diameter is not large enough to create a seal on the pipe. I've also tried with a garden hose but that wont move it either.

Would getting a 6 inch plunger for my drain rod work or do you guys have any other suggestions?

Cheers for your time

 

[stem]

It could be the same arrangement that I have. The gully is designed to permanently have water in the bottom. It acts as a seal to stop the stench from the sewer escaping. The other connection to it, without any water, is a branch.

 

[Richard Lindsay]

Ah. That'll be it then. Cheers