Rainwater tank issues

Eastlink makes me reasonably close to you and I can travel for work during this COVID-19 lock down.

Apart from that, I can't recommend anyone, it's rare to see a rainwater harvesting system that isn't substandard.

Send me a PM if interested.

We built a house with burbank in Melbourne. Initially it was connected incorrectly with the overflowing from the tank connected to the inlet pipe. We eventually got a plumber to fix that issue but this week with the heavy rains two of our downpipes are overflowing from the top of the downpipe.

Just when you think you have heard of everything.....

Unfortunately, plumbers have no formal training in rainwater harvesting and numerous bad installation practices are endemic.


I assume the overflowing downpipes are the furthest from the tank. How many downpipes supply the sub surface carrier pipe?

Are the downpipes fitted with leaf diverters?

Can you post a photo (not too close up) that shows the top of the infeed vertical riser at the top of the tank?

Do you have any way to flush out the sub surface carrier pipe?

One of the downpipes is nearest to the tank and the other one that overflows is on opposite side of the house.

Thanks for the photos.

Your first two photos show a 'dry' system pipe that discharges into the meshed basket at the top of the tank. This downpipe should not be overflowing.

You have said that two downpipes overflow from the top of the downpipes but the downpipes sit underneath leaf diverters. Do they overflow from the top of the downpipe under each leaf diverter or from the leaf diverters?

The leaf diverter shown will often have a large aperture outer mesh that lets a lot of debris pass through that then clogs the finer mosquito proof inner mesh. Do your leaf diverters have the large aperture outer mesh and if so, have you been able to check the inner mesh for clogging? If the outer mesh is mosquito proof (less than 1mm apertures), you should still check to see whether there is also an inner fine mesh.

The tank is badly sited. It should have been positioned with the leaf diverter at the end of the tank and a very short pipe plumbed directly from the leaf diverter to the meshed basket inlet at the left end. This would have allowed easy access to the leaf diverter for maintenance.

Which direction does the house wall at the tank face? I know it isn't south!

Waiting.....

Information asked for is required before a full answer can be given. There are also other design issues that the owner is most probably not aware of.