Central Coast Council

Overview

Central Coast Council provides water supply and sewerage services to approximately 340,000 people on the Central Coast of New South Wales. The council operates as a local water utility, managing the full cycle of water services from catchment to customer in the region between Sydney and the Hunter Valley.

History and Formation

Water supply on the Central Coast has been managed locally since the mid-20th century. The former Gosford City Council and Wyong Shire Council each operated water supply systems for their respective areas. When the two councils were amalgamated into Central Coast Council in 2016, the water operations were merged into a single system. The combined entity manages water and sewer assets valued at several billion dollars, making it one of the larger council-operated water utilities in New South Wales.

Service Area

The Central Coast region lies approximately 80 kilometres north of Sydney, stretching from the Hawkesbury River in the south to the Lake Macquarie area in the north. The service area covers approximately 1,680 square kilometres and includes the population centres of Gosford, Wyong, Terrigal, The Entrance, Woy Woy, Erina, and surrounding communities. The region is characterised by a mix of coastal towns, suburban areas, and semi-rural hinterland.

Water Sources

The Central Coast’s drinking water is sourced entirely from local surface water catchments. The system relies on a network of dams and weirs, including Mangrove Creek Dam (the primary storage, with a capacity of approximately 190 gigalitres), Mooney Mooney Dam, Mardi Dam, and Ourimbah Creek weirs. Mangrove Creek Dam is one of the largest concrete-faced rockfill dams in Australia.

The catchments are located in the forested ranges west of the coastal population centres. While not fully closed to public access like Melbourne’s catchments, they are managed to minimise contamination risks. During extended dry periods, the Central Coast’s water security has come under pressure, as the region does not have access to the scale of alternative sources available to larger utilities.

Treatment Infrastructure

Central Coast Council operates three water treatment plants: Somersby, Mardi, and Wyong. The Somersby plant is the largest, treating water from Mangrove Creek Dam. These plants use conventional treatment processes including coagulation, flocculation, sedimentation, filtration, and disinfection. Fluoride is added in compliance with NSW Health requirements.

Distribution Network

The water distribution system comprises approximately 2,800 kilometres of water mains, 100 reservoirs, and 77 pump stations. The sewerage network includes about 2,500 kilometres of sewer mains and multiple wastewater treatment plants. The varied topography of the Central Coast, from coastal lowlands to elevated ridge areas, requires a carefully managed system of pressure zones.

Water Quality Monitoring

Central Coast Council conducts regular water quality testing across its supply network, monitoring for compliance with the Australian Drinking Water Guidelines. Key parameters tested include microbial indicators (E. coli), turbidity, pH, chlorine residual, and a range of chemical constituents. Results are reported to NSW Health and published in annual drinking water quality management reports.

Recent Projects

In recent years, Central Coast Council has focused on improving water security for the region. Initiatives have included demand management programs, investigations into alternative water sources such as groundwater and recycled water, and upgrades to treatment plant infrastructure. The council has also invested in sewer network improvements to reduce wet weather overflows and environmental impacts. Mains renewal programs aim to reduce system losses and improve the reliability of the ageing pipe network.