Stormwater and sewage are two completely separate water systems, and yet they are confused with each other by property owners, and sometimes accidentally cross-connected, more often than you might expect. The consequences of confusion range from minor (incorrectly routing roof water) to serious (raw sewage entering stormwater drains and discharging to the Hastings River or coastal beaches).
Understanding what each system does, how properties in Port Macquarie connect to each, and where septic systems fit into the picture is practical knowledge for any property owner or buyer in the region.
What Is Stormwater?
Stormwater is surface runoff from rain, rainwater that falls on roofs, roads, paving, and land and runs off rather than soaking into the ground. Stormwater is collected by:
- Roof gutters and downpipes from buildings
- Street stormwater pits and pipes
- Kerb and gutter in urban streets
- Drainage channels in rural areas
In Port Macquarie’s urban area, stormwater is collected in a network of pipes that discharge to local waterways, primarily the Hastings River, Oxley River, Koala Beach, and coastal catchments. Stormwater receives no treatment before discharge. Whatever goes into the stormwater system goes directly to the waterway.
What Is the Sewage System?
The sewage system (also called the sewer or wastewater system) collects wastewater from inside buildings, toilet waste, shower water, kitchen sink water, laundry water. This is contaminated water that requires treatment before it can be safely released to the environment.
In Port Macquarie’s sewered areas, the sewerage network is operated by Port Macquarie Hastings Council’s Water & Sewer division. Wastewater flows from properties through the reticulated sewer network to a wastewater treatment plant, where it is treated to a standard safe for release.
Why They Must Never Mix
Stormwater and sewage must be kept completely separate because:
- Stormwater goes directly to waterways without treatment. Sewage entering the stormwater system means raw sewage discharged to the Hastings River, Camden Haven, or beach areas, a public health and environmental hazard.
- Stormwater entering the sewer system (called inflow) overloads the sewer network and treatment plant, can cause sewage overflow from manholes, and increases treatment costs.
- Cross-connections are illegal under the Plumbing and Drainage Act 2011 and NSW Code of Practice for Plumbing and Drainage.
In older properties, particularly pre-1960s buildings in the Port Macquarie urban area, cross-connections sometimes exist, either as original design errors or as plumbing “improvements” made by unqualified people over the years. Licensed plumbers are trained to identify and correct cross-connections.
Properties Connected to Both Systems
Properties in the Port Macquarie urban centre are typically connected to both:
- Stormwater: Roof downpipes and on-site drainage connect to the stormwater network in the street. Surface water from driveways, paved areas, and gardens also drains to stormwater.
- Sewer: All internal plumbing (toilets, showers, sinks, laundry) connects to the sewer system.
These connections happen at the property boundary, the sewer connection point and the stormwater connection point are separate physical locations.
Properties Not Connected to Sewer: Where Septic Comes In
Not all properties in the Port Macquarie Hastings LGA are connected to the reticulated sewer. Properties outside the sewer service area manage their wastewater on-site using a septic system (conventional, AWTS, or other approved onsite sewage management system).
These properties still connect to stormwater, roof and surface runoff still goes to a stormwater system (either the street drainage network where it exists, or on-site to the ground or a natural watercourse).
For these properties, the on-site sewage management system handles all wastewater from inside the house. The absolute rule is the same: stormwater must not enter the septic system, and septic effluent must not enter the stormwater system.
Common Areas of Confusion
”Is my property on sewer?”
For properties in Port Macquarie’s urban areas and larger townships like Wauchope, you can check whether a sewer connection point exists at your property boundary. Contact PMHC’s Water & Sewer division with your address. If you see a “sewer” line item on your council rates notice, you are likely sewered.
For properties in rural areas, outer suburbs like Sancrox, Fernbank Creek, and semi-rural areas around Thrumster, connection to town sewer is less certain. Some streets within these areas are sewered; others are not. See our guide on which Lake Cathie and Bonny Hills properties are on septic vs sewer for a coastal example of this mixed situation.
Roof Water Connecting to Septic
This happens more often than you’d expect on rural properties. Roof downpipes should never connect to the septic system. Roof water entering the septic tank:
- Dilutes the tank contents, reducing biological treatment effectiveness
- Massively overloads the land application area during rain events, causing flooding and backup
- Accelerates sludge carry-over to the absorption area, reducing its lifespan
If you suspect your roof water is going into your septic (symptom: system backs up during heavy rain when you haven’t been home), have a licensed plumber check the downpipe connections.
Subsoil Drainage Entering Septic
On properties with subsoil drains installed for drainage management, these drains must discharge to stormwater or an appropriate drainage outlet, not to the septic system. Again, routing groundwater into the septic tank massively overloads it.
Septic Effluent Entering Stormwater Drain
If a failing septic system overflows to the surface and that surface drainage connects to the street stormwater, untreated sewage enters the stormwater system. This is an environmental offence and a public health risk. Council can issue penalty notices for this outcome even if it results from a system failure rather than deliberate connection.
What to Check on Your Property
| Check | What to Look For |
|---|---|
| Roof downpipes | Should discharge to stormwater drain, on-site soakage or water tank. Not to septic. |
| Subsoil drains | Should discharge to stormwater drain or appropriate outlet. Not to septic. |
| Kitchen sink | Should go to septic (or sewer). Never to stormwater. |
| Toilet | Always to sewer or septic. |
| Laundry | To sewer, septic, or approved greywater system. Never to stormwater. |
| Shower/bath | To sewer, septic, or approved greywater system. Never to stormwater. |
Development and Renovation Implications
If you are renovating or adding to a property in Port Macquarie, all new plumbing must be connected correctly to the appropriate system. Any new connection that changes the wastewater load (adding a bathroom, bedroom, or granny flat) may trigger a requirement to upgrade the septic system if you’re not on sewer, or to pay additional sewer connection charges if you are.
For properties not connected to sewer where town sewer is now available, Council may require connection as part of approving a development.
FAQ
How do I know which stormwater pit in the street is mine to connect to? Your property’s drainage connections are documented in the plumbing approval from when the house was built. If those records are not available, a licensed plumber can trace the existing connections. Council’s engineering team can also advise on the stormwater network near your property.
My neighbour is running something into the stormwater drain that looks like sewage, what should I do? Report it to Port Macquarie Hastings Council’s environmental health team or to the NSW EPA Pollution Line (131 555). Sewage entering stormwater is an environmental offence.
My property is on septic, is the stormwater from my roof going to the same system? It should not be. Roof downpipes on a septic property should drain to a soakage pit, rainwater tank, or overland flow path, not to the septic tank. If you are unsure, a plumber can trace your downpipe connections.
Can I connect my rainwater tank overflow to the septic system? No. Tank overflow should go to a stormwater or soakage outlet. Connecting it to the septic would overload the system every time the tank spills.
What’s the fine for sewage entering the stormwater system in NSW? Under the Protection of the Environment Operations Act 1997, pollution offences (including sewage to stormwater) can attract significant fines, up to $1 million for corporations and $250,000 for individuals for serious offences. Even for accidental pollution from a failing system, the financial and legal exposure is significant.
Not sure whether your property is on sewer or septic, or concerned about how your drainage is connected? Send an enquiry: an inspection can confirm your system configuration and identify any connection issues.