Swimming and shellfish collection in the Ahuriri Estuary is banned after wastewater was released into a stormwater stream early today.
The decision to deliberately discharge wastewater was made by the Napier City Council after staff became aware that manhole covers were beginning to lift, and the escaping water could have caused a public health risk.
Yesterday, Napier residents had been asked to conserve the release of wastewater, including only flushing toilets when necessary, to take pressure off the wastewater system struggling to cope with heavy rain.
At 1am today wastewater was released into the Purimu stormwater stream, which flows out to sea through the Ahuriri Estuary.
A council statement said almost all of the flow in the network at that time would have been stormwater.
Hawke's Bay Regional Council, the Hawke's Bay District Health Board and Mana Ahuriri were notified of the discharge.
Warning signs have been placed around the estuary advising the public not to swim or collect shellfish from the area.
Rain data taken from McLean Park recorded more than 90 mm of water falling on the city in the 24 hours to midnight last night. The average total rainfall for the whole month of September, according to NIWA, is usually 58mm.