Frequently asked questions about drainage

What is stormwater? Stormwater is rainfall from a storm as it flows overland within natural watercourses through pipes, channels, drains, buildings etc.

What is drainage? Drainage is a network of pipes, pits, channels, creeks, gutters, flow paths etc used to capture and remove stormwater. Council drainage is under Council’s care and control and is located on public and/or private land that drains water from the public road system. Private drainage is any system used to convey stormwater from private property to waterways of Council’s drainage system, e.g. down pipes, grates across a driveway. Council is not responsible for private drainage.

What is an easement? An easement is a nominated section of land across public or private property which allows other parties access for drainage, sewer, water, gas, and electricity etc. An easement basically restricts use of that part of land for any major construction, development etc.

What is an interallotment drainage easement? Often with new developments, stormwater from one property is not able to drain directly to the street without having to pass through another private property first. In this instance an interallotment drainage easement must be created on the downstream property which allows this to occur. It is the responsibility of the applicant to negotiate with the affected property owners to secure an easement. Property owners are under no legal obligation to burden their lots with an easement for interallotment drainage (unless they have been required to do so by the Supreme Court exercising the powers available to it under section 88K of the Convincing Act 1919, or required to do so by way of a condition of development consent). These easements are the vested interests of property owners and maintenance is their shared responsibility. It is an offence to obstruct, concentrate or divert the natural flow of water from the easements. Council will not become involved in disputes between neighbours regarding the obstruction of interallotment drainage.    

What is on-site detention? On-site detention (OSD) provides temporary storage of stormwater runoff from a property and restricts the discharge from the site to a rate at which Council’s existing drainage system can accommodate. The aim of OSD is to ensure that the amounts of stormwater runoff doesn't increase as a result of any development on the site, thus reducing the chance of flooding downstream. Examples of OSD include car parks, driveways, landscaped areas, underground tanks and pits.    

Can I build over an easement or adjacent to a drainage easement? Building over or on a drainage easement is generally prohibited. However, we may give consideration to proposals such as extremely light buildings including open carports or other open structures, strictly on merits based approach, and subject to conditions set by the Design Division. Building adjacent to a drainage easement is subject to conditions set by the Design Division. Building adjacent to a drainage easement is also subject to conditions set by our Design Division.   

Who is responsible for watercourses and drainage systems? The majority of natural watercourses (including a creek, overflow path or drainage pipe) lie within private property and maintenance of these watercourses is the responsibility of the property landowner. In some cases (but not all) the watercourse through private land may lie within drainage easements (which are shown on the title of the land) and any party benefited by the easement may be allowed to legally enter the property to carry out construction and/or maintenance of the facility within the easement. In instances where the watercourse through private property does not have an easement, Council is unable to enter or perform any work to the watercourse. Therefore if you have a creek or watercourse on your property it is your responsibility to maintain it. In instances where the system or watercourse lies within Council land (i.e. roadways and reserves), Wollongong City Council is responsible for the system and will perform routine maintenance to maximise the performance of the system during storm events. In instances where the system or watercourse lies within private property and Wollongong City Council is listed as a party benefiting from the easement, Council may perform maintenance on the system if required.

I have a watercourse/creek on my property, will Council come and maintain it? No. If the watercourse is not contained within an easement that is benefited by Council, it is the responsibility of the land owner to maintain the watercourse.

There is a drain/creek that has a lot of reeds and overgrowth in it - can this be cleaned out? If the drain/creek lies within Cuoncil's land, you can contact Council either in writing, by phone or in person and make an action request to have the creek/drain inspected by our Works and Services Division. Council unfortunately does not have the resources to inspect every drain or creek on a regular basis and therefore relies on the public to notify them of any potential problems. It is important to note that in some instances, the reeds that grow in drains and creeks actually assist in slowing down the flow of waters, allowing sediments to drop out and nutrients to be absorbed. Ultimately this helps to keep our beaches and lakes clean by reducing the pollutants flowing to the beaches.

I have a problem with stormwater in my street? Contact Council by phone, in writing or in person and place an action request to have the drainage inspected. Similarly if you believe a stormwater pit may be blocked or obstructed contact Council who will be able to inspect the site and take appropriate action.

Why do urban or street drainage systems overflow? Most urban underground drainage systems, including street systems, are designed for frequent storm events and not large, less frequent storms. Therefore, from time to time the capacity of underground systems will be exceeded during a significant/large rainfall event. It is not feasible to design drainage systems to cope with infrequent large storms. It is important that all inlets such as stormwater drains are kept clear and are free from obstructions at all times, as blocked inlets will cause stormwater to divert elsewhere as overland flow, often resulting in localised flooding.

What happens to the natural surface water runoff / overflow? Water that is unable to enter the underground drainage system will find its natural way to the nearest watercourse as above ground flow via overflow paths.  These overflow paths are typically roadways, public reserves, pathways and often through private property. Many new developments have been designed to use roadways and pathways as dedicated overflow paths. It is important to keep the drainage system clear of litter and debris to avoid blocked drains that can cause flooding. This is also necessary to protect and improve the health of Wollongong’s creeks and beaches.