Westernport Water is a regional water corporation whose core functions are to provide drinking water, recycled water and wastewater services to properties and communities throughout its district in accordance with the standards listed in the Westernport Water Customer Charter 2018-23, or by agreement.

Westernport Water is one of 18 water corporations operating and reporting to the State Government of Victoria. It is responsible for servicing 22,064 customers from 27 townships across an area covering 300 square kilometres, encompassing Millowl (Phillip Island) and mainland communities from The Gurdies to Archies Creek.

The region has one of the highest ratios of visitors to residents of any destination in Australia. During peak periods, there can be approximately 120 visitors to every permanent resident.

Drinking water is produced at Ian Bartlett Water Purification Plant (IBWPP) at Candowie Reservoir in Almurta, then pumped to waterline communities and the San Remo Basin for distribution to customers. Water is sourced from Tennent Creek, the Corporation’s main water supply source, with additional entitlements on the Bass River, the Melbourne Supply System and groundwater from Corinella Aquifer.

Westernport Water operates two wastewater treatment plants: The Cowes site services Phillip Island and surrounds and the King Road site services mainland waterline communities. There are also 99 pump stations across the wastewater network that are used to service approximately 90 percent of properties that receive drinking water. Effluent collected from the townships of Kilcunda and Dalyston is treated under an agreement with South Gippsland Water at its Wonthaggi Wastewater Treatment Plant.