Dams and Catchments

The Central Coast’s drinking water is sourced from three dams and three weirs. The combined catchment area of the Central Coast drinking water supply is about 727 square kilometres. The maximum capacity of the dams and weirs is 202,700 million litres.


Mangrove Creek Dam

Mangrove Creek Dam is the Central Coast’s largest dam, located 50 km north-west of Gosford, in a narrow valley on Mangrove Creek. Constructed between 1978 and 1982, the dam provides 93 percent of the region’s water storage. The concrete face rockfill dam with a height of 80 metres can hold up to 190,000 million litres of water. Mangrove Creek Dam is a large storage dam, not primarily a collection dam.

Construction type: Concrete faced rockfill
Built: 1978-1982
Maximum capacity: 190,000ML
Height: 80 metres
Catchment area: 101km²

See our Mangrove-Creek-Dam-Brochure (1.27MB) for more information and historical photos.

Mardi Dam

Located 4km south-west of Wyong, Mardi Dam was built in 1962 and can hold up to 7,400 million litres of water. Mardi Dam is an earth fill dam and is an offstream storage meaning it is not fed directly by a stream and must be filled by pumping water from Wyong River and Ourimbah Creek. Water is pumped to Mardi Treatment Plant before being distributed to residents.

Construction type: Earth fill
Built: 1962
Maximum capacity: 7,400ML
Height: 26 metres
Catchment area: 4 km²

Mooney Mooney Dam

Mooney Mooney Dam is the region’s oldest dam being built in 1961. Located on Mooney Mooney Creek around 10km north-west of Gosford, the concrete arch dam has a capacity of 4,600 million litres. Water is pumped to Somersby Treatment Plant and then to residents.

Construction type: Concrete arch
Built: 1961
Maximum capacity: 4,600ML
Height: 28 metres
Catchment area: 39 km²


Water Catchments

A catchment is an area where water is collected by the natural landscape. In a catchment, all rain and run-off water eventually flows to a creek, river, lake or ocean, or into the groundwater system. Natural and human systems such as rivers, bush land, farms, dams, homes, plants, animals and people can co-exist in a catchment.

Healthy catchments provide:

  • a source of clean drinking water
  • habitat for plants and animals, and
  • healthy vegetation and waterways.

Managing and protecting our catchments effectively is a key process for ensuring good water quality, and a cornerstone of the Australian Drinking Water Guidelines. Council has catchment policies which identify specific activities which can be carried out within each catchment area.

Catchment Management

Access to the area directly surrounding the region’s dams is restricted to protect our water supply by acting as a buffer zone to help stop nutrients and other substances that could affect the quality of water entering the dam.

Limiting access to the dams will help by:

  • protecting water quality
  • protecting large areas of bush land and plant and animal habitats
  • protecting threatened plants and animal species, and
  • preserving evidence of Aboriginal occupation dating back many thousands of years.