I'm still looking at options for my south Brisbane site and whether it will be split or just a knockdown rebuild, based on costings and practicalities of getting stormwater uphill to the street. As the neighbours did not give permission to run a pipe through their yards, I'm now getting a survey done and quotes for trenching to the existing services. If I just do a knockdown rebuild instead of a 2 lot subdivision, do I still have to address the stormwater runoff for the single property based on the current requirements for stormwater discharge? Or can I retain the primitive stormwater runoff based on the old property? The existing house is a post war home with no stormwater pipe running from it.