Cowarra Water Treatment Plant

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Water Treatment steps

• Raw Water Tank: receives raw water from the Cowarra Dam or the Hastings River and ensures a steady supply to the WTP.
• Powder Activated Carbon Contact Tank: adds powder activated carbon to improve water quality via adsorption of the dissolved organic matter.
•  Coagulation and Flocculation: addition of a clarifying agent to facilitate clumping of particulates in the raw water for effective separation and removal.
•  Dissolved Air Flotation on Filter (DAFF): the use of air bubbles to float the remaining particulates to the surface for removal. The remaining water is filtered to remove accumulated solids that build up during filtration.
•  UV Disinfection: kills harmful microorganisms that may be present in the raw water.
•  Fluoride and Chlorine: added for dental benefits and to maintain disinfection before it reaches customers.

Wastewater Recovery steps

• DAF Float Tank: separated particulates and solids are skimmed from the water surface and collected in the DAF float tank for further processing.
• Thickening and Sludge Separation: the collected float, along with backwash and drain water, is sent to thickener tanks where solids are concentrated and separated from the liquid.
•  Dewatering: thickened sludge is processed through dewatering centrifuges to remove excess water, producing a drier sludge for transportation and disposal.
•  Clarified Water Collection: the recovered liquid, known as supernatant, is collected from the thickener tanks and recycled back into the treatment process to minimise water loss.

 Why is the Cowarra Water Supply Scheme needed?

With the population expected to reach 119,027 by 2050, this project is essential for water security, infrastructure resilience, and sustainable development.

How will supply volume meet demand?

The scheme will increase water supply capacity, ensuring we can meet demand until around 2070, even with potential long dry periods due to climate change.

When are the works scheduled?

The final design stage will start in mid 2026, with construction beginning late 2026. The entire construction process, including commissioning, will take about two years to complete.

What will the hours of construction be?

Most construction activities will occur within standard hours:

• Monday to Friday: 7:00 am to 6:00 pm.
• Saturday: 8:00 am to 3:30 pm.
• No work on Sundays or public holidays In exceptional cases, some activities may take place outside these hours, subject to consultation with nearby residents and obtaining a permit.

Following environmental approvals from the State and Commonwealth Governments for the Cowarra Water Supply Scheme, two land matter Deeds between Council and Forestry Corporation NSW have now also been fully executed. These agreements provide the land acquisition, access and easement rights required for the construction and long-term operation of the scheme and enable Council to progress to the next phase of project delivery within the Cowarra State Forest.

We regularly seek businesses to work with us through:

• Expressions of Interest (EOI)
• Requests for Quotations (RFQ)
• Requests for Tenders (RFT)

Information about these opportunities, and how to apply is provided through our online procurement portal, eProcure.

For updates relating to current and upcoming opportunities please refer to Council Opportunities and Contracts.