In Australia, there are separate systems for sewage and for excess rainwater and stormwater. Allowing stormwater to drain into the sewer system can cause problems with flooding and may be illegal. Sewers that overflow with stormwater can overflow onto roads and onto neighbouring land, causing danger to motorists and damage to property. Stormwater can also cause the land to be soaked if it is discharged directly onto the ground rather than into a sewer. This water can also travel downhill and cause flooding on properties on lower ground. For this reason, it is always best to discharge rainwater from your land into the stormwater system wherever possible, where it can be discharged safely away from human habitation. Here is how to make sure your stormwater drainage is not causing problems with the sewer system.
Check you have a stormwater connection
Not all properties have a stormwater connection. However, it is always best to connect to the stormwater system if this is available. If you are in any doubt, your water authority will be able to help.
Check your pipes
On a dry day, use your hosepipe to check where your water is discharging. Hose water into your downpipes one at a time and also into any ground-level drainage points. You will easily be able to see where the water is discharging and will be able to check that the water is draining into the stormwater system.
Check where rainwater is flowing
When it is raining, check that the rainwater is being collected and not just gathering on the ground. It should flow into a rainwater tank, a stormwater pit or onto a roadside kerb so that it can enter the stormwater system once it has been collected.
Check your rainwater tank
If you have a rainwater tank, you should check that the overflow is draining into the stormwater system rather than the sewer system.
Check your swimming pool
If you have a swimming pool, check that the overflow is discharging into the stormwater system — only filter backwash should enter the sewer system. You can also help prevent flooding by ensuring that you do not discharge any pooled water into the sewer system immediately after a rain event.
Ensuring you are connected to the stormwater system helps keep your neighbours safe from flooding. If you are in any doubt, get in touch with your water authority or a licensed plumber.