Which lakes in Australia are the clearest?

19 named lakes in Australia have an official Secchi depth. This page ranks the 19 deepest readings. Secchi is a clarity measurement, not a swim-safety class and not a LakeQuality A–F grade.

Is clear water the same as clean water?

No. Secchi measures how far a disk stays visible. A clear lake can still have bacteria, toxins, or contaminants this catalog does not grade. Open a lake page for the authority's values.

Clearest lakes in Australia

Clearest lakes in Australia: 19 named lakes have an official Secchi depth. The 19 below are ranked by that reading — water clarity, not a LakeQuality A–F grade.

Lake map

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Highest Secchi readings in Australia

Lake	Place	Total phosphorus	Chlorophyll-a	Secchi	Year
Lake St Clair	NSW	—	2.3 µg/L	4.8 m	2016
Blowering Reservoir	NSW	—	2.8 µg/L	3.6 m	2021
Lake Dartmouth	VIC	—	1.5 µg/L	3.1 m	2020
Lake Eucumbene	NSW	—	3.2 µg/L	3.0 m	2021
Lake Argyle	WA	—	2.7 µg/L	3.0 m	2021
Lake Brockman	WA	—	0.40 µg/L	3.0 m	2021
Lake Jindabyne	NSW	—	3.3 µg/L	3.0 m	2021
Wellington Dam	WA	—	0.50 µg/L	2.3 m	2021
Lake Kepwari	WA	—	0.70 µg/L	2.2 m	2021
Waroona Dam	WA	—	0.90 µg/L	1.8 m	2021
Lake Hume	NSW	—	8.6 µg/L	1.8 m	2021
Burrinjuck Dam	NSW	—	7.1 µg/L	1.7 m	2021
Lostock Reservoir	NSW	—	12 µg/L	1.5 m	2016
Lake Liddell	NSW	—	23 µg/L	1.2 m	2016
Lake Burley Griffin	ACT	—	7.7 µg/L	1.2 m	2020
Lake Bonney	SA	—	19 µg/L	0.9 m	2021
Lake Tuggeranong	ACT	—	40 µg/L	0.4 m	2020
Lake Victoria	NSW	—	8.3 µg/L	0.4 m	2020
Lake Pamamaroo	NSW	—	3.4 µg/L	0.2 m	2021

Frequently asked questions

Which lakes in Australia are the clearest?: 19 named lakes in Australia have an official Secchi depth. This page ranks the 19 deepest readings. Secchi is a clarity measurement, not a swim-safety class and not a LakeQuality A–F grade.
Is clear water the same as clean water?: No. Secchi measures how far a disk stays visible. A clear lake can still have bacteria, toxins, or contaminants this catalog does not grade. Open a lake page for the authority's values.