I am trying to create a longterm solution for backyard drainage. The backyard is not done yet but I want to do the drainage right first. My plan was to create a french drain connected to a pit to catch the silt then have it connected to existing 90mm storwater pipe. Also planning to have an overflow pipe positioned higher and going towards the fence into an exisiting AG pipe drain to safe discharge point. However, my question is:
With the signifant amount of water collected in the yard, will it overload the existing 90mm downpipe towards the 100mm dwv stormwater pipe towards the kerb? I am worried since this whole area will be concreted later on and might cause any problems in the future. What is the best approach for this?
I asked a plumber as well and said that as long as the pipe you are connecting to is on slope and not holding water then it should be fine.
Looking forward to your advice.


