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.

2023 overflows

Discharge began Discharge ceased ID Overflow location Receiving waterway Cause
25 December 6pm 25 December 7.05pm 478 270 Sparks Road, Halswell Heathcote River Vandalism
11 December 8.40am 11 December 9.10am 477 14 Otamahua Lane, Diamond Harbour Lyttelton Harbour Pump broken
9 November 10.30am 9 November 3.30pm 476 Hamish Hay Bridge, Victoria Square Avon River Cross connection
2 November 1.30pm 2 November 4pm 475 Red Zone, Avonside Drive Avon River Powercut
24 October 1am 24 October 11.20am 474 Seagar Lane, Hillmorton Heathcote River Blockage - fat
24 October 9.45am 24 October 10.30am 473 Clarendon Terrace, Woolston Heathcote River Pipe joint malfunction
14 October 11.59pm 15 October 12.40pm 472 Tikao Bay Beach Akaroa Harbour Powercut  
30 September midnight 4 October 9.50am 471 Rawhiti Street, Diamond Harbour Lyttelton Harbour Broken clay pipe
15 September 7.30am 15 September 2pm 470 Drayton Reserve Ihutai Estuary Blocked pipe – roots
14 August 7pm 14 August 8.30pm 469 Sutherlands Road, Cashmere Heathcote River Pressure line fault
13 August 9am 13 August 1pm 468 86 Worcester Street Avon River Pipe blockage – gravel
7 August 9am 7 August 11.45am 467 Ramahana Road, Huntsbury Heathcote River Pipe blockage – rags
22 July 11.30pm 24 July 8am 466 Thames Street / Malvern Street Avon River Heavy rain
22 July 11.30pm 23 July 3.30am 465 Grassmere Street / Rutland Street Park, St Albans Avon River Heavy rain
23 July 12.15am 25 July 1.15am 464 Heathcote Milns Reserve Heavy rain
22 July 6pm 24 July 3.30pm 463 Sandwich Road / Eastern Terrace Heathcote River

Heavy rain

23 July 1.20am 23 July 12pm 462 Waltham Road / Eastern Terrace Heathcote River Heavy rain
23 July 12.55am 24 July 9am 461 Pamela Street / Chelsea Street Ihutai Estuary Heavy rain
23 July 12.15am 24 July 1.15am 460 Halswell Milns Reserve Heavy rain
23 July 12.20am 23 July 3.15am 459 Grassmere Street / Rutland Street Park, St Albans Avon River Heavy rain
23 July 12.15am 24 July 8am 458 Thames Street / Malvern Street Avon River Heavy rain
22 July 11.10pm 23 July 12pm 457 Waltham Road / Eastern Terrace Heathcote River Heavy rain
22 July 7.45pm 24 July 2am 456 Fisher Ave / Eastern Terrace Heathcote River Heavy rain
22 July 7.15pm 24 July 4pm 455 Beach Road, Akaroa Akaroa Harbour Heavy rain
22 July 4pm 24 July 12.45am 454 Recreation Ground, Akaroa Akaroa Harbour Heavy rain
17 July 6pm 17 July 7.40pm 453 Louisson Place, Opawa Heathcote River Blocked pipe – roots
9 July 7pm 9 July 11.30pm 452 Sandwich Road / Eastern Terrace Heathcote River Heavy rain
9 July 2pm 9 July 5pm 451 Akaroa Recreation Ground  Akaroa Harbour Heavy rain
9 July 8am 9 July 3pm 450 Duvauchelle Petrol Station Akaroa Harbour Heavy rain
6 July 1pm 6 July 5pm 449 Cressy Terrace, Corsair Bay Lyttelton Harbour Blocked pipe
29 June 8am 29 June 8.30am 448 Eastern Terrace end of the Bowenvale Ave Bridge Heathcote River Blocked pipe 
21 June 10.30am 21 June 11.30am 447 Bellvue Ave, Papanui Dudley Creek Blocked pipe (by rags)
14 June 10am 14 June 11am 446 Opposite 2 Heberden Ave Sumner Beach Blocked pipe
28 May 5pm 28 May 5.30pm 445 Corner of Hay Street and McGregors Road Ihutai Estuary Leaking valve
26 May 1.10pm 26 May 6.30pm 444 Opposite 254 Springs Road Heathcote River Broken pipe
19 April 8.10am 18 April 5.30pm 443 Opposite 179 Beach Road Akaroa Harbour Broken clay pipe
3 April 5.10pm 3 April 7pm 441 Naval Point Pump Station Lyttelton Harbour Blockage of rags
22 March 11am 22 March 11.45am 440 51 Tikao Bay Road Akaroa Harbour Wet weather
22 March 2.10am 24 March 12.30pm 439 Corner of Eastern Tce and Tennyson Street Heathcote River Wet weather
22 March 1.40am 24 March 11am 438 Corner of Eastern Tce and Waltham Road Heathcote River Wet weather
21 March 6.10pm 21 March 6.30pm 437 Duvauchelle Petrol Station Akaroa Harbour Wet weather
15 March 5.30pm 15 March 6.45pm 436 Beckenham Park Heathcote River Blocked sewer
26 February 2.15pm 26 February 2.45pm 435 Opposite 3A Centaurus Road Heathcote Blocked sewer
22 February 3.30pm 22 February 4.15pm 434 Opposite 22 Godley Quay Lyttelton Harbour Burst pipe
7 February 3.30pm 9 February 3pm 432 Opposite 181 Beach Road Akaroa Harbour Broken clay pipe