Water Supply Services

Raw Water

Pejar Dam

Pejar Dam is located downstream of the former junction of Pejar Creek and the Wollondilly River. It is approximately twenty seven kilometres northwest of Goulburn. Pejar Dam has a current capacity of 9000ML.

When required water from Pejar Dam is released and flows to Goulburn down fifty four kilometres of the Wollondilly River. This water is impounded at Rossiville Weir and is then drawn from Rossiville Weir for treatment at the Goulburn Water Filtration Plant.

Sooley Dam

Sooley Dam is located on Sooley Creek and Bumana Creek. It is approximately five kilometres west of Goulburn. Sooley Dam has a current capacity of 6250ML.

Sooley Dam is connected directly to the Goulburn Water Filtration Plant.

Rossi Weir

Rossi Weir is a river storage located on the Wollondilly River. It has a capacity of 330ML.

Water is taken primarily from this source. The Rossi Weir Pump Station has three pumps. A single pump is used to transfer water to the Goulburn Water Filtration Plant. One pump can be used to transfer water during high flow conditions into Sooley dam, when the dam levels are low.


Goulburn and Marulan Weekly Demand and Storage Information

Weekly Demand and Storage Information for Goulburn and Marulan Water(PDF, 384KB)

Water Treatment

Goulburn's current Water Filtration Plant was built in 1950 and takes water direct from Rossi Weir and Sooley Dam. The plant has been refurbished over the years with the latest being completed in 2016.

Raw water from these sources are subjected to the following treatment processes when it passes through the plant including coagulation/flocculation, clarification (or sedimentation), filtration, stabilisation and disinfection. Following the water treatment process water flows into two low level reservoirs located in Goulburn. From these reservoirs the water is then pumped/gravity fed to other reservoirs throughout Goulburn. 


Coagulation/Flocculation is the process of separating particles from the water. This is achieved by adding polymers (coagulant chemical) to produce easy settleable particles from the disolved matters and fine suspended colloidal matters that do not settle easily in the water.

The flocculation tank is fitted with mixers and baffle boards which thoroughly mix the coagulated water. The coagulated particles bond together and grow to form larger particles called flocs while it passes through the flocculator. The larger size and weight of the flocs causes them to settle rapidly in the sedimentation process. 

Coagualtion/flocculation processes are also very effective at removing fine suspended particles that attract and hold bacteria and viruses to their surface.


Clarification is the process in which solids are separated from the liquid. This achieved by sedimentation which is the removal of solids by gravity.

Two larger circular clarifier tanks with conical shaped floors receive water from the flocculation tanks. The larger particles settle to the bottom of the tank during the detention time and are removed to a central pit by a rotating scraper blade. The sludge is intermittently released to a settling pond where the sludge settles out from the water.


Filtration is the process of removing and remaining unsettled particles and floc from the clarifier tanks through a bed of porous material.

From the clarifiers, water passes to four multimedia filters. The bottom of the multimedia filters are fitted with lateral pipes. On top of the laterals there are four layers of gravel in layers of decreasing size. Floc can be effectively removed by passing the water through the filter. The process is controlled so that the coagulant chemical is removed along with the contaminants.

Water Stabilisation

Water stabilisation is the process of adding an alkali compound to the water to raise the pH to a level above 7. This is the prevent corrosion in piping systems and hot water services. The ideal pH range for water is 6-7.


Disinfection is the process of adding chlorine to the filtered water. This is to destroy harmful microorganisms (pathogens) that may be present in the water supply and to prevent micro organisms regrowing in the distribution and reticulation systems. 


Fluoridation is the process of adding fluoride to Goulburn's treated water. Optimum fluoride level in the treated water is 1mg/l.


Goulburn's treated water has an average hardness of 200 milligrams per litre as equivalent calcium carbonate hardness. It can range from 150 to 250.

European dishwashers have a water setting that requires the level of hardness to be entered into the machines program. These dishwashers require the hardness to be entered in millimoles per litre (mmol/L). The table below provides the conversion for the two units based on one millimoles per litre = one hundred milligrams per litre of calcuim carbonate (1 mmol/L = 100 mg/L).

Hardness in milligrams per litre (mg/L)  Millimoles per litre (mmol/L) 
 150   1.5 
 160   1.6 
 170   1.7 
 180  1.8
 190  1.9
 200   2.0
 210    2.1 
 220    2.2 
 230   2.3
 240   2.4
 250   2.5


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Water Infrastructure

Water Infrastructure

Goulburn Mulwaree Council's water infrastructure network consists of water mains that distribute treated water to consumers in both Goulburn and Marulan. To provide the ongoing quality of Goulburn Mulwaree Council's infrastructure Council networks staff and experienced contractors maintain and upgrade the networks with yearly works and capital programs.

Goulburn Network

Goulburn’s network is fed from the Goulburn Water Treatment Plant that produces treated water which is delivered to ten reservoirs in the network by three pump stations. Water is than distributed from the reservoirs into six zones via trunk and reticulation mains. Goulburn currently has approximately two hundred and sixty six kilometre of trunk and water main throughout the city.   

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Marulan Network

The Marulan water supply system consists of the Marulan WTP, one pump station, one reservoir and a raw water pipeline delivering water from the Wollondilly River. The Water Treatment plant pumps treated water to Medway Reservoir via a common water main which also supplies reticulation within the town. The water distribution network consists of approximately eighteen kilometres of trunk and reticulation main. 

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Water Quality


Backflow is water flow in a direction against the normal or intended direction that results in the flow of water from a potentially polluted source into a drinking water supply.

How can backflow occur? 


Event 1 - Water pressure is reduced in the water main. If the water pressure is not maintained, there is a chance. The water could be drawn backwards into the water main. Water pressure can be affected by:

  • pumping water from the main water
  • a break in the water main
  • supply during a fire
  • using water at a higher pressure than the pressure supplied by Council
  • heavy water use downstream, reducing water pressure upstream
  • water outlet at a property being higher
  • than the water main, causing constant back pressure

Event 2 - Reverse pressure is created by a drop in water pressure. This draws dangerous chemicals into the drinking water supply through a cross connection. A number of different property types can pose a risk to public health through cross connections. These could include:

  • mechanical repairers
  • shopping centres/malls
  • market gardens / nurseries
  • golf courses/sporting ovals
  • smash repairers
  • restaurants / takeaway
  • properties with bores and or greywater
  • treatment systems

Event 3 - Dangerous chemicals entering the drinking water supply come out of neighbouring showers and taps. If this water is used, occupants could be seriously or fatally injured.

Types of Backflow Prevention

Reduce Pressure Zone Device - Hazard Rating High

Two independent action non-return valves arranged to be force loaded to the closed position, with a relief valve positioned between the non-return valves arranged to be force-loaded to open to the atmosphere. 

Testable Double Check Valve - Hazard Rating Medium

Two independent action non-return valves arranged to be force loaded to the closed position. 

Testable Double Check Detector Assembly (Fire Services) - Hazard Rating Medium

A specially designed assembly composed of a line-sized approved double check valve assembly, with a specific by-pass water meter and a meter sized approved double check valve assembly. 

Non-Testable Dual Check Valve - Hazard Rating Low

Two independently acting non-return valves in series arranged to be force loaded to the closed position.

Your Water Connection

Most residential properties within Goulburn and Marulan are connected to Council’s water supply system via a water connection into each lot. This includes the water meter, which measures water usage.     

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Internal Plumbing

This includes all water pipes within the premises, including indoor and outdoor taps. Internal Plumbing is classed as all pipework on the owner’s side of the water meter (but not including the water meter). Owners are responsible for maintaining and repairing the Internal Plumbing.

Water Meter

The water meter is the device installed by Council which the records the amount of water used at a property so Council can correctly charge for water usage. The location of the water meter is usually at the front of your property, just inside the front boundary or fence. There are some exceptions in which the water meter is located in the back yard or elsewhere within the property.

Water meters are read on a quarterly basis by Council. When reading a water meter the figures on the left (usually white) show the number of kilolitres used, the figures on the right (red) show tens of litres used and the graduations (lines on the right dial show litres). See diagram below.

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All water used on the property must pass through the water meter. Under Section 636 of the Local Government Act (1993), it is an offense to tamper or damage a water meter, fitting, fixture or other infrastructure owned by Council in connection with the supply of water, or prevent the water meter from correctly reading the water supplied to the property, and carries a $2,200 fine. Council is responsible for installing, maintaining and repairing/replacing water meters however please ensure the area around the meter is clear and accessible so Council can read, repair or replace it. If you notice a leaking or damaged water meter, please contact Council on (02) 4423 4444 during office hours, or Council’s Duty Officer (02) 4822 1080 for after hours.

Water Service

The water service is the water pipe that feeds the premises with water from the water main, and includes the tap or stop cock next to the water meter. Council is responsible for maintaining and repairing the water service. If you notice a leak water service, please contact Council on (02) 4423 4444 during work hours, or (02) 4822 1080 after hours. Please note that under Section 635 of the Local Government Act (1993), it is an offense to remove, damage, destroy or otherwise interfere with Council-owned water infrastructure that is part of the water supply Service of Council.

Water Use

Goulburn's usable water storage level as at 31 October 2019 is 66.7%.

Current restriction level is green. Green level allows:

  • Hand held hose with a control nozzle or bucket can be used at any time to water plants and lawns.
  • Watering systems and hose sprinklers can only be used between 5pm and 10am.
  • Paths, driveways and hard surfaces can be cleaned with a low volume, high pressure machine. They cannot be cleaned using a hose. In extraordinary circumstances for example following a flood or health threatening incident, a hose can be used to assist to clean up.
  • Vehicles can be washed at any time on a lawn or porous surface using a hose with a control nozzle, bucket or low volume high pressure machine.
  • Private pools can only be filled when a water offset plan for that residence has been met, including the mandatory use of a pool cover when the pool is not in use.

 For further information on water usage refer to Council's Water Use Policy.