A wastewater overflow is when wastewater flows out from the pipes or manholes from where it is usually contained into a stream, river or the sea. This is not normal and preventing this from occurring is a high priority for the Council.

Wastewater overflow details are listed below. Information will be updated as soon as possible, and once discharge has ceased.

Pollution may take up to two days to completely clear after the discharge has ceased. 

2021 overflows

Discharge began Discharge ceased Overflow location Waterway affected Cause
18/5/2021 12pm 18/5/2021 12.30pm Stark Bros/ Charlotte Jane Quay Lyttelton Harbour Sudden intense rainwater inflow
16/5/2021 11.15am 16/5/2021 12pm 7 Scarborough Road, Sumner Sumner Beach - Clock Tower End Blocked Sewer
14/5/2021 9.45am 14/5/2021 12.30pm 20 Marine Drive, Diamond Harbour Lyttelton Harbour Blocked Sewer
23/3/2021 10am 23/3/2021 1pm 170 Moncks Spur Road Glenstrae Stream, potentially on to Estuary at McCormacks Bay Blocked sewer
22/3/2021 8.30am 22/3/2021 8.40am Number 5 Wharf in Lyttelton Port Lyttelton Harbour Blocked sewer
23/1/2021 10.45am 23/1/2021 Midday Cnr Pratt St and New Brighton Road Avon River Air valve failure
6/1/2021 9.30am 6/1/2021 2pm 89 Beach Road, Akaroa Aylmers Stream, Akaroa Blocked sewer

Ongoing issues under investigation

Overflow location Waterway affected Possible cause
Lyttelton Wastewater Treatment Plant Outfall Lyttelton Harbour

Intermittent overloading of the reticulation during rainfall. Possible cause is cross-connection between stormwater and wastewater. A project is ongoing to reduce inflow and infiltration in the Lyttelton reticulation.

All overflow incidents will be recorded in the table above.