Water Treatment

The Central Coast water supply has three water treatment plants that deliver quality water complying with Australian Drinking Water Guidelines.

A water treatment plant is where the water from our rivers, creeks, dams and bores is filtered and disinfected to make it safe to drink.

Watch a behind the scenes video below to find out exactly how water is treated on the Central Coast.

Mardi Water Treatment Plant

Mardi Water Treatment Plant was built in 1982 with further augmentation in 1992 to increase the capacity. The plant can treat water from Mardi Dam and has a maximum supply capacity of 160 million litres per day, or 1850 litres per second. The capacity equates to 64 Olympic swimming pools per day. The plant produces water 365 days a year and operators attend the site every day.

Mardi Water Treatment plant uses direct filtration treatment, and includes the following processes:

  • flocculation
  • filtration
  • pH correction
  • disinfection
  • fluoridation

Somersby Water Treatment Plant

Somersby Water Treatment Plant was built in two stages in 1971 and 1986 and can treat water from Mangrove Creek Dam or Mooney Mooney Dam. The plant has a maximum supply capacity of 144 million litres per day, or 1666 litres per second. The capacity equates to 57.6 Olympic swimming pools per day. The plant produces water 365 days a year and operators attend the site every day.

Somersby Water Treatment plant uses conventional treatment, and includes the following processes:

  • flocculation
  • sedimentation
  • filtration
  • pH correction
  • disinfection
  • fluoridation

See our Somersby-Water-Treatment-Plant-Brochure (979.96KB)