A temporary health warning is in place for the inner harbour near Chapel Street.

A heavy rain event over Sunday night/Monday morning saw some areas in the city receive between 40 and 60mm of rain in one hour. Read more here.

Tauranga City Council drainage services manager Radleigh Cairns says this put pressure on the city's stormwater and wastewater networks and potentially created a peak flow exceeding Chapel St's ability to send treated wastewater to Te Maunga and the Outfall.

'Council has an extreme weather emergency discharge consent for exactly this type of situation.

'For around 20-30 minutes Chapel St potentially discharged treated wastewater to the harbour area by Maxwells Road.”

Radleigh says this was on an outgoing tide and, given the significant stormwater inputs from urban areas into the harbour at the same time, is unlikely to have had a significant environmental impact.

'Bay of Plenty Regional Council and Toi Te Ora were informed, and signage was placed in potentially impacted areas as a precautionary measure.

'We encourage the community to follow Toi Te Ora's advice to not swim in areas impacted by heavy rain events for at least 48 hours due to the potential for contamination.

'Water Quality sampling will be undertaken from today.”