How to connect stormwater pit or drain to pvc tee

[JonnyB]

I was about to finish adding a manifold and some solenoid valves to run some irrigation off an existing 32mm irrigation pipe, then it rained hard and the area around the irrigation pipe offtake flooded and I realised I have to sort out the drainage first.

Fortunately there's a downpipe with a PVC tee and cap right next to it.

You can see in the pics that the PVC goes into a clay pipe soon after in goes underground.

I want to install a 25.7mm rainwater pit case from Bunnings and attach it to the PVC pipe, but I'm open to other ideas.

After install I'm planning on paving in between the storm water box and a valve box from around one of the offtakes in the Ag pipe.

I'm limited a little by height and depth - ideally to top lip of the pit case is below the height of the pavers so that the solenoids don't flood but the opening of the PVC tee is above that.

No doubt I will have to get a qualified contractor to help with this project but please could I seek some community advice on this?

Thanks in advance.

[EricL]

Hello @JonnyB 

Welcome to the Bunnings Workshop community. It's sensational to have you join us, and thanks for sharing your question about connecting a storm water pit to your drain.

Just a friendly reminder that any plumbing work must be carried out by a licensed plumber for safety and compliance.

From a theoretical point of view for example, you could install a PVC "Y" junction right at the outlet of the terracotta pipe. This will allow you to install a pit closer to the center where the water might accumulate. This also has the advantage of not having to extensively modify your existing storm water pipes. The lip of the pit however can't be lower than the level of the terracotta pipe. The last thing you want to happen is to have back flow issues should there be a blockage or overflow at end of the drain.

In regards to the pipe manifold and solenoids, I suggest adding a few more elbows along with blue line pipe and elevating the solenoid parts off the ground if possible. This is just in case the drain pit fails; This will keep your solenoids dry and prevent them from shorting out. I also suggest putting them in a plastic electrical box for extra weather protection. 

Once everything is set into place you can then pave the area. My best advice would be to put a fall in the paving assembly away from your house. In this manner any accumulating water will first flow away before it gathers in the pit.

Let me call on our experienced members @Dave-1 and @Nailbag for their recommendations.

If you need further assistance, please let us know.

Eric

[JonnyB]

Oh wow Eric thanks so much for your reply.  I follow your comments on this forum and you are always very helpful.  Welcome Dave and Nailbag views also.

I'll take another look at whether its viable to install a Y junction closer to the terracotta.  I've seen other advice on this forum about how to connect the box to the Y junction.

If I got the whole manifold assembly higher it would make the pit easier to install and I could back fill in to cover the ag pipe. I can probably install a 90 degree poly bend on one of the irrigation pipe offtakes to further elevate it above the pipe.  I think they sell 32mm right poly right angles at my local Bunnings in Tuggeranong. 

I really have to get this job finished some day soon and will of course seek further advice from a licenced plumber.  Will post results here for future generations.