How to fix an overflowing downpipe?

[ivanptr]

We suspect there's a blockage or damage in the underground stormwater drain, and we want to hire a plumber for a camera inspection to pinpoint the issue. If we can identify the blockage , then we can repair the drain ourselves buying materials from Bunnings.

However, we face complications:

1) It's challenging to hire a local plumber as they're fully booked. Considering the urgency before the upcoming cyclone, we're considering purchasing a camera for a self-inspection.

2) A plumber mentioned that the downpipes are part of a "Wet System," making them challenging for a camera inspection due to water-filled pipes. They suggested digging in wet areas to locate the leak.

Yet, if there's a blockage, wouldn't it be simpler to insert the camera from the stormwater outlets at the street kerb? we are more concerned about the blockage causing 2nd downpipe to overflow.

 

[EricL]

Hello @ivanptr 

I recall that there are companies that offer sewer camera inspection who are not plumbers. Perhaps you can locate one in your area, they don't need to be plumbers, but they do need to be able to tell if a sewer or drainpipe is blocked up.

However, I suggest conducting a simple test. Remove the drainpipe coming down the side of your house. the one that floods easily. Attach a Grunt 100um x 25m Temporary Polythene Downpipe and point it out to the front or a drain pit. You can use rubber band and duct tape to keep it attached to the dropper. If water does not overflow from your gutter, then it's safe to say that the drainpipe in the ground is blocked.

My best advice is to lay new pipe for the stormwater drain rather than trying to repair the old one.

Please remember that this type of plumbing requires a registered plumber. If in doubt, please consult your local building authority before you begin. 

If you need further assistance, please let us know.

Eric

[ivanptr]

Hi Eric,

We can't find words to express our gratitude for the brilliant idea of using a temporary downpipe to buy some time.

1. We've already purchased it tonight. Tomorrow, we're going to try using cable ties to attach it to the downpipe.

Considering the strong cyclone and gust, we hope the cable tie is sufficient. Or we should additionally wrap the downpipe with some sort of waterproof tape

2. "If water doesn't overflow from your gutter, then it's safe to say that the drainpipe in the ground is blocked."

So if the water still overflows, it might actually be water flowing back from the rainwater tank? 

[MitchellMc]

Hi @ivanptr,

You say there is a rainwater tank hooked up to these pipes? Is it at capacity? If so, it could likely be that its overflow is quite high, and you have water backing up this downpipe. Check the height of the rainwater tank overflow from the ground and then check the height of the downpipe. If the tank's overflow is, say, 2400mm from the ground and this downpipe is leaking 2400mm from the ground, then the tank being full could be the issue here rather than a blockage.

In a normal setup, when the tank reaches capacity the water should then divert to the stormwater line out to the street. So, there might still be a blockage there as you suspect.

Mitchell