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
10/11/2021 8.30am 10/11/2021 9.30am 134 Cashmere Road Heathcote River Blocked sewer
6/11/2021 5.30pm 6/11/2021 6pm 78 Kellys Road, Mariehau Avon River (Dudley Creek) Blocked sewer
20/10/2021 3pm 20/10/2021 4.30pm 21 Marine Drive, Diamond Harbour Lyttelton Harbour Blocked sewer
13/10/2021 8am 13/10/2021 Diamond Harbour Wastewater Treatment Plant Lyttelton Harbour High flows caused by rainfall
13/10/2021 11.20am 13/10/2021  237 Main Road, Redcliffs Estuary High flows caused by rainfall
8/10/2021 12.15am 8/10/2021 12.20pm Diamond Harbour Wastewater Treatment Plant Lyttelton Harbour Equipment failure
2/10/2021 8.45am 2/10/2021 9.45am 110 Moncks Spur Road Estuary Blocked sewer
23/9/2021 10am 23/9/2021 11am 82 Centaurus Road Heathcote River Blocked sewer
21/09/2021 7.50pm 21/09/2021 9pm 19 Soleares Avenue Heathcote River Blocked sewer
3/08/2021 8.05am 3/08/2021 2.26pm Diamond Harbour Wastewater Treatment Plant Lyttelton Harbour High flows caused by rainfall
3/08/2021 7.50am 3/08/2021 7.50am Locarno Street Heathcote River High flows caused by rainfall
16/07/2021 3.40pm 16/07/2021 5pm 35 Seafield Road Akaroa Harbour Blocked sewer
1/6/2021 10am 1/6/2021 10.30am Grants Road (Erica Park) Avon River High flows caused by rainfall
1/6/2021 2.24 am 1/6/2021 2.55am Tennyson Street Heathcote River High flows caused by rainfall
1/6/2021 6.05pm 1/6/2021 9pm Locarno Street Heathcote River High flows caused by rainfall
31/5/2021 3.40pm 31/5/2021 10.10pm 121 Kennedys Bush Road Halswell River High flows caused by rainfall
31/5/2021 11.40am 1/6/2021 1am Shalamar Drive Heathcote River High flows caused by rainfall
31/5/2021 11.25am 31/5/2021 1pm  Lyttelton Wastewater Treatment Plant Lyttelton Harbour High flows caused by rainfall
31/5/2021 9.40am 31/5/2021 4pm 49 Beach Road Akaroa Harbour High flows caused by rainfall
31/5/2021 9.50am 1/6/2021 9am Diamond Harbour Wastewater Treatment Plant Lyttelton Harbour High flows caused by rainfall
30/5/2021 8pm 1/6/2021 6am Cnr Linwood Avenue & Hargood Street Lower Heathcote  High flows caused by rainfall
30/5/2021 8pm 1/6/2021 9am 21 Harrison Street Flockton Drain High flows caused by rainfall
30/5/2021 8pm 31/5/2021 10pm Lomund Place Estuary High flows caused by rainfall
30/5/2021 7.40pm 1/6/2021 2am Richardson Terrace Heathcote River High flows caused by rainfall
30/5/2021 4.15pm 30/5/2021 10.45pm Fisher Avenue Heathcote River High flows caused by rainfall
30/5/2021 7pm 1/6/2021 1am Cashmere Road Heathcote River High flows caused by rainfall
30/5/2021 8.20pm 30/5/2021 22.50pm Grassmere Street Avon River High flows caused by rainfall
30/5/2021 12.30am 30/5/2021 2.45am McKenzie Avenue Heathcote River High flows caused by rainfall
30/5/2021 6.50pm 1/6/2021 12.45pm Eastern Terrace Heathcote River High flows caused by rainfall
30/5/2021 6.35pm 1/6/2021 11.30am Milnes Drain to Cashmere Stream Heathcote River High flows caused by rainfall
30/5/2021 2pm 1/6/2021 8am Duvauchelle wastewater treatment plant Akaroa Harbour High flows caused by rainfall
30/5/2021 12.30pm 1/6/2021 10.30am Charlotte Jane Quay - Naval Point Lyttelton Harbour High flows caused by rainfall
30/5/2021 12.50am 1/6/2021 12.25am Moncks Bay west of Yacht Club  Estuary High flows caused by rainfall
30/5/2021 5.55am 30/5/2021 6.30am Akaroa Wastewater Treatment Plant Akaroa Harbour High flows caused by rainfall
30/5/2021 4.50am 30/05/2021 5.55 am Akaroa Recreation Ground Akaroa Harbour High flows caused by rainfall
29/5/2021 5.50pm 30/5/2021 3am Stark Bros/ Charlotte Jane Quay Lyttelton Harbour Sudden intense rainwater inflow
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.