Urban Drainage Issues

Natural Ground Water and Surface Water Flows

Following a rain event, hillsides may slowly release stored water which may travel overland (as sheet flow) or underground and end up ponding on or travelling across low-lying properties.

As this is a natural occurrence, any issues arising from these flows are the responsibility of the property owner to manage.

During the development of a property, the property owner is required to minimise disturbance to natural overland and/or underground water flows across their property.

In the event that disturbance to these flows occur, then the property owner is responsible to provide an adequate drainage system to minimise changes to the natural water flows and also prevent structural damage to their own and neighbouring properties.

Any work required to be undertaken that impacts on natural water flows across a property must comply with the following conditions:

1. The natural drainage characteristics of the land must not be altered. This includes fencing recessed into the ground that diverts flows.
2. You must not direct water onto another person's property. Refer to Concentrated Water Flow below.
3. All drainage pits, pipes and trenches must drain to Council's drainage system or to an approved point of discharge. Connection into a Council pit or pipe requires Council approval, is subject to an inspection and must be certified to current construction standards.
4. Sediment and erosion controls must be in place prior to and during works being undertaken.

For further information contact Council's Approvals and Regulatory Group on 6581 8111 or go to our Water, Sewerage and Stormwater Approvals webpage.

Specific details regarding the location of your property, such as lot number, deposited plan number, street address and town/location will assist Council in providing you with sound advice.

Concentrated Water Flow

Concentrated water flow can occur when neighbours discharge or divert storm water onto your property. This is an illegal practice.

If it can be proven that a neighbour has directed stormwater flow towards your property by an open downpipe, or has concentrated natural surface flow through landscaping, retaining walls etc which is causing nuisance water flows onto your property, then you may have grounds to make a formal complaint to Council.

Council will investigate the matter and determine an appropriate course of action.

Prior to making a formal complaint to Council, it is necessary to follow the steps below:

1. Approach the adjoining property owner, explain the problem and request him/her to rectify the problem. This is the ideal time for the problem to be rectified, as continuing on with a formal complaint to Council may cause animosity between neighbours.
2. If the offending property owner refuses to rectify the problem, make a formal complaint to Council's Approvals and Regulatory or Building Compliance sections. Outline the problem in as much detail as possible and inform Council of the actions you have taken to try to rectify the problem.
3. Council will investigate the problem. If it is proven that the neighbour is illegally diverting stormwater towards your property, Council will hold impartial discussions with both parties to see if a common sense approach can be achieved.
4. Failing a mutual agreement, Council will write a letter to the offending property owner giving a reasonable timeframe for the problem to be rectified.
5. If the problem is not rectified within the timeframe specified, Council can, under the Local Government Act 1993, order the offending property owner to redirect concentrated stormwater flow to the street or other approved means of stormwater disposal, including inter-allotment drainage or via an on-site dispersion trench.
6. For further information contact Council's Approvals and Regulatory Group or go to: Water, Sewerage and Stormwater Approvals. You will need to provide specific details regarding the location of your property, such as Lot, DP and street name.

Inter-allotment Drainage

Inter-allotment drainage lines are installed within dedicated easements by the developer at the time of construction of the subdivision to facilitate the draining of surface water from lots that are unable to drain to the street.

These easements are generally vested in the owners of the properties that benefit from the easement and maintenance of pipelines and the easement is generally the responsibility of the owners of the lots benefited.

Council is not responsible for the maintenance and control of these inter-allotment drainage systems unless listed as a benefiting authority on the Section 88B Instrument (Planning instrument setting out terms of easements).

Failures of these systems due to design or construction errors or omissions should be referred to the certifying consultant for rectification.

Property buyers should make themselves aware of the provisions for stormwater drainage from both their prospective property and potential run-off from upstream properties prior to purchase.

If you are not sure if you have inter-allotment drainage on your property or if you are entitled to drain to an inter-allotment drain, contact Land and Property Information NSW for details on your property entitlements/burdens.

Maintenance of Private Stormwater Connections

The provision of drainage from the boundary of private properties, under the footpath to the kerb is a 'grace and favour' exercise by Council.

This means that Council allows the pipe to be within the road reserve, however Council is not responsible for repairs or maintenance of the private stormwater connections to the street drainage systems within the road reserve.

It is the property owner's responsibility to ensure that stormwater outlets to the street are intact, serviceable, safe and comply with Council specifications.

Building Over Drainage Easements

Building over or on a drainage easement is generally prohibited, except (subject to approval by Council's drainage engineer) for extremely light buildings such as open carports or other open structures.

Council can request the removal of these structures when access to the easement is required.

For further information on your rights and responsibilities with regards to an easement on your property contact Land and Property Information NSW and obtain a copy of the 88B Planning Instrument. You will need to provide specific details regarding the location of your property, such as Lot, DP and street name.

Non-conforming Driveway Crossovers

It remains the responsibility of the property owner to ensure driveway crossovers through Council road reserves are constructed and maintained to Council standards.

Council will not be responsible for street stormwater flows entering a property via a non-conforming layback and crossover.

The construction or alteration of driveway/gutter crossings requires an application to be made to Council's Technical Services section for a roadworks approval under S138 of the Roads Act 1993.

DE151 application forms are available at Council offices, and upon approval, 24 hours notice prior to pouring concrete is to be given to Council so an inspection can be arranged. Council approved contractors may only undertake these works.

Design specifications for driveway crossovers can be obtained by contacting Council's Technical Services section.