Dilwyn Aquifer

Who does it supply?

The Dilwyn Aquifer is a deep geological formation that stretches across South West Victoria and into South Australia.

It is the source of water for:

• Dartmoor
• Heywood
• Peterborough
• Port Campbell
• Port Fairy
• Portland
• Timboon

Where does the water come from?

The aquifer consists of strongly confined quartz sand that is up to 1.5 kilometres deep in places. It’s isolated from more shallow aquifers by layers that prevent water moving from one aquifer to the other.

The water in the aquifer is very old, having fallen as rainfall between 900 and 30,000 years ago. In some areas, there is enough natural pressure for the water to be classified as artesian. These means it can rise to the surface under pressure without the need for pumping. Because the water comes from deep underground, it has naturally occurring mineral salts which can impact the taste.