What do I need to do for stormwater drains?

When you develop a piece of land and put down hardstand surfaces (car parking, drainage etc.) and structures, you will change what happens to stormwater on site. The same amount of rain will fall as before but it will run off the property differently. If there is an existing stormwater system of pipes and drains you will have to calculate whether the pipe can handle increased rates and flows. If you need to build new drains the same applies. Sometimes the stormwater can be discharged into ground on your property into a properly designed treatment system. Or it can be discharged from your site by drains, sometimes into a Council reticulated system.