Dudding Lake and the Kai Iwi Stream are unsafe for swimming - but Whanganui's South Beach has had a clean record for a full 12 months.
The new online tool for finding out where the swimming is good has thrown up some surprising results in the Whanganui region.
The Land, Water, Air Aotearoa website has a new Can I Swim Here? online tool updated several times a day. To find it type LAWA Can I Swim Here? into a computer search engine.
The site uses information from the 80 swim spots monitored weekly during summer by Horizons Regional Council staff. It's national, with 700 swim spots covered.
In this hot summer a lot of people are taking a dip. And population pressure, a warming climate and intensifying farming is putting pressure on New Zealand water quality.