New Zealanders are being encouraged to jump on the site and check out water quality at their local watering holes before diving in.
On the lawa.org.nz website, a warning is in place for swimming in the river, saying recreation is not advised.
People face a high risk of infection (greater than five per cent) from contact with the water.
However, when it comes to beaches, Castlecliff Beach is assessed as having a low risk of infection, and Kai Iwi has a moderate risk, but is still considered safe for swimming.
"Beaches are a key part of many New Zealanders' lifestyles and it's important that people can swim without getting sick from contaminated water," said Horizons Regional Council chairman Bruce Gordon.
"By reviewing bacteria levels at beaches over time, Lawa allows us to assess to what extent the water at our beaches is affected by bacteria and whether this poses a health risk to the public."
As well as a seasonal guide, the website provides the results of the most recent weekly beach monitoring.
However, Mr Gordon said people still needed to think twice before swimming after heavy rain.
It was also important people remembered other hazards such as rips or currents.
Lawa's website was launched in March and would eventually show information on water quantity, air quality, land and biodiversity, and more data on fresh and coastal water quality.
