Household water

Household stormwater drainage systems

Property owners must maintain the stormwater system from their house, garage and other structures to the kerb and gutter or other approved discharge point. 

Maintenance of a property stormwater drainage system may include removing build-up of leaves and debris in gutters and drains, repairing holes in roof gutters and downpipes, removing blockages in pits and stormwater lines and repairing and replacing damaged sections of stormwater pipes. A plumber or other suitably licensed contractor will need to be contacted to undertake repairs. 

Regular maintenance and the removal of leaves are required to help prevent blockages and the deterioration of the stormwater drainage system. Damaged and deteriorated stormwater drainage systems can result in the surface flow of stormwater over the property creating a nuisance or flooding.  

When Council can take action

Council investigates and takes action on stormwater drainage complaints only where it relates to the flow of surface water from one property across the common land boundary onto another property, and where all of the following criteria is met:

  • surface water is the result of defective roof drainage from a dwelling or outbuilding;
  • evidence is provided that substantiates the surface water has caused or is likely to cause physical damage to land or building on the other land;
  • surface water has been directed to and/or concentrated in a particular area by a man-made structure or drain.


Natural overland flow of rain water

Rain water may run off areas like gardens and bushland because of factors such as the slope of the land, the volume of rain, presence of rock shelves and the ability of the soil to absorb rain water. If you reside on a sloping site, you should be aware that natural surface water run-off flows down the slope following the contours of the block.

Property owners are responsible for taking steps to protect their own property against the natural overland flow of rain water. Any diversion of natural overland flow must be carried out in a way that does not have detrimental impacts on other properties. A licensed plumber or other suitably qualified contractor should be engaged to carry out any works.

Seepage water

Natural underground water is a common cause of seepage, particularly after periods of heavy rain. Seepage can often be seen where sloping blocks have been excavated to obtain a flat yard, through retaining walls and rock shelves and may continue for many days following rain.

It is not the responsibility of uphill property owners to control natural seepage water. Downhill property owners are responsible for protecting their own property if affected by seepage. This can be achieved through installation of subsoil drainage. Subsoil drains are intended for the drainage of ground water or seepage from the subgrade and/or the subbase in excavations. Advice should be sought from a qualified civil/hydraulic engineer and a licensed plumber or other qualified contractor should be engaged to carry out any works.

Private Inter-allotment drainage easement

Private inter-allotment drainage easements and their maintenance are the responsibility of the respective beneficiaries of the drainage easement. There can be many properties burdened and benefitted by a private inter-allotment drainage easement and the on-going maintenance and any necessary repairs needs to be co-ordinated between all of the responsible property owners.

If there is a drainage easement on your property, it will be identified on the certificate of title, provided when you purchased the property. Inter-allotment drainage records are held by NSW Land Registry Services and additional information about private drainage easements and how to obtain further records is available here.

When Council can’t take action

Officers have the discretion to take no action or are unable to take action in circumstances where:

  • the surface water is natural run-off from the property or properties above due to the topography and isn’t redirected in any manner
  • the water is subsurface seepage or water seepage as a result of ground water
  • overflow occurs due to exceedance of the design capacity of an approved drainage system in extreme rainfall events
  • the drainage problem involves private inter-allotment drainage easement infrastructure
  • the location of a dwelling or outbuilding impacts on surface run-off
  • surface water is a result of overflows from stormwater absorption pits where contours of land and lack of access prevent direct connection of a building’s roof water to the council’s stormwater drainage system
  • the run-off is from new development work that is the subject of a development consent and has been constructed in accordance with that consent.

For emergency help in flood events, contact the State Emergency Service on 132 500.

If your concern is of a nature that Council can't assist with, the NSW Government's Community Justice Centres may be of help. These centres provide free, confidential mediation and conflict management.

Steps to take before lodging a complaint

You should try to contact your neighbour before taking formal steps to report a concern about the overflow of stormwater. Be tactful when bringing the concern to your neighbours notice as they might not realise there is a problem. In order to maintain neighbourly relations it could be beneficial to discuss the problem directly and enable your neighbours to undertake works such as clear blockages and engage plumbers to resolve the matter without involving Council in the process. 

When reporting a stormwater drainage concern on private land, please provide the following information:

  • what is occurring;
  • when it occurred and on how many past occasions;
  • what is happening on the neighbouring property to cause the overflow;
  • how your land and/or building are being damaged and if possible include a written report from a hydraulic engineer, licensed plumber or other suitably qualified person stating the land or building is likely to or is being damaged;
  • what discussions you have had with your neighbour about the issue;
  • photographs and/or videos of the stormwater overflow as it is occurring.

To report a concern contact us on 9424 0000 or


Household wastewater systems

The majority of homes within Ku-ring-gai are connected to Sydney Water’s sewer main system. Sewer mains are owned and maintained by Sydney Water and convey household wastewater from bathrooms, toilets, kitchens and laundries to wastewater treatment plants.

Property owners are responsible for the maintenance of the private wastewater pipes on their properties up to the connection point to the sewer main. The connection point is not always at the property boundary and it may be under the footway, roadway or across the street. More information about maintenance of private wastewater lines is available on Sydney Water’s website.

If there is a blockage or overflow at your property, you should contact a licensed plumber. Sewer service diagrams show private sewer pipes on a property and are available through Sydney Water’s Tap In online service

If you notice a wastewater leak in a public area such as on a road, park or footpath, you can report a leak online to Sydney Water or by calling them on 13 20 90 or send an email with details of the location and a photograph to

If your home is not connected to a Sydney Water sewer main, you may have an on-site wastewater management system, such as a septic tank, composting toilet or aerated system.

There are special regulations that apply to these systems. As the owner of the property, it is your responsibility to ensure that the system has been approved by your local council and that it is working properly. 

Council approval is required for all on-site wastewater management systems. To install a new system you will need to obtain two approvals from Council.

WaterNSW has more information for home owners about on-site wastewater management systems.