Swimmers are urged to stay out of Lake Hāwea near the holiday park following recent water quality testing.
Otago Regional Council's tests suggested an abnormally high level of E coli that made that part of the lake unsuitable for swimming.
The council said they expected the high bacteria reading was caused by strong winds over the region this week stirring up sediment, and blowing dust and debris into rivers.
Queenstown Lakes District Council is conducting follow-up testing with results due back tomorrow.
People are encouraged to check the Land Air Water Aotearoa for water quality before having a dip this summer.