The judging took place as part of the eighth Water Industry Operators Association Annual NSW Conference where the water watchers rated H2O from various NSW councils based on its clarity, colour, taste and aroma.

More than 700 delegates and visitors attended the two day conference which featured more than 20 guest speakers from across the state including Wingecarribee Council's water and sewer co-ordinator, Alan Butler.

"The judging and competition was a bit of fun at the end of what was a very serious and informative conference," Mr Butler said.

"But it did highlight something we've always known, that the Southern Highlands has some of the cleanest and purest water in the state."

The four finalists were chosen using a Masterchef style tasting by delegates at the welcome reception with the grand finalists judged by a panel comprising of technical water experts and industry connoisseurs. The NSW Water Taste Test Award was about raising awareness of the quality of the state's drinking water.

"The recognition is a real credit to council's water and sewer team who do a fantastic job ensuring our residents have year round access to clean, safe and fresh water at the turn of a tap," Mr Butler said.

Rounding out the top four finalists from across the state were Bega Valley Shire Council, who took home the top gong, Orange City Council and Nambucca Shire Council.