A wastewater overflow is when sewage flows out from the pipes or manholes where it is usually contained, due to an incident, and into the stormwater system, which then drains into a stream, river or the sea.

Wastewater overflow details are listed below. Information will be updated as soon as possible. If you see signs about polluted water around the city and have further questions, please contact us(external link)

This is a manual process, so there may be delays during busy periods.  Event identification (ID) numbers are not consecutive, due to false alarms, etc. Pollution may take up to two days to completely clear after the discharge has ceased.

2025 overflows

Discharge reported Discharge ceased ID Overflow location Receiving waterway Cause
14 February 7am 14 February 11am 542 Emerson Crescent Lyttelton Harbour Blockage (condom)
23 March 5.35pm 23 March 5.40pm 546 Bridge at Harbour Road West Styx River Burst Pipe
10 March 2.30pm 10 March 5pm 543 Cressy Terrace, Lyttelton Lyttelton Harbour Fat Blockage