Marine health warnings
We monitor marine sites regularly over the summer to check for faecal indicator bacteria.
Sites that we monitor are given a long-term grade prior to each summer season for suitability for swimming . The grade is based on the last five years of sampling.
Sites that are not recommended for swimming, or any water-based recreation, because of their long-term grade are shown as red on the Land Air Water Aotearoa (LAWA) website and signage should be in place at the site.
This summer, the long-term grades at 13 bays in Whakaraupō Lyttelton Harbour and Akaroa Harbour are replaced with a new predictive water quality tool. This tool provides real-time information about the conditions. Learn more about the predictive water quality tool.
Temporary health warnings are issued when a site was graded as good to swim but there is now an increased risk of faecal contamination.
Faecal contamination poses a risk to health, it can cause gastrointestinal illnesses, respiratory diseases, and eye, ear, nose, throat and skin infections.
You can also help stop the spread of marine pests that pose a major threat to our region's beautiful coastal waters.
Temporary health warnings
Advisory Note - Rainfall Affected Water Quality
Incident date: Thursday 18 February 2026
Last updated: 2.00pm, Monday 16 February 2026
Don’t swim in estuaries, harbours, and beaches within 48 hours of significant rainfall!
Swimmers are urged to stay up to date on the quality of their favourite Canterbury estuaries, harbours and beaches to confirm they are safe to swim this summer.
When you’re heading for a swim, don’t forget to look out for the water quality information signs or visit ‘Can I Swim Here?’ section of the Land Water Aotearoa (LAWA) website at www.lawa.org.nz to view the latest information.
Swimmers should avoid getting in the water within 48 hours of significant rainfall as heavy rain flushes contaminants from urban and rural land into waterways, reducing the quality of water within a short period of time – even at sites that generally have good water quality. Check the water is clean and clear before taking a dip.
Find out more: Land, Air, Water Aotearoa (LAWA) - Can I Swim Here?
Te Waipapa | Diamond Harbour, Purau Bay, Kaioruru | Church Bay, Te Wharau | Charteris Bay
Health warning
Rāhui on the taking of kai moana within Whakaraupō.
Te Hapū o Ngāti Wheke (Rāpaki), through the Rāpaki Tangata Tiaki, has installed (as of 1700 hours Saturday) a seven (7)-day rāhui on the taking of kai moana within Whakaraupō. Eating shellfish, fish and other kai moana from Whakaraupō should be avoided. Te Hapū o Ngāti Wheke is attempting to make to contact those with permits given over the last 24 hours and no further issuing of permits will occur during the seven-day rāhui or possibly beyond.
Find out more: Land, Air, Water Aotearoa (LAWA) - Diamond Harbour
Motu-kauati-iti | Corsair Bay
Incident date: Saturday 10 January 2026
Last updated: 8.40pm, Saturday 10 January 2026
Health New Zealand | Te Whatu Ora has issued a health warning after being advised by authorities that there has been a discharge of untreated sewage into Motu-kauati-iti | Corsair Bay. This health warning includes Corsair Bay | Motu-kauati-iti, Cass Bay | Motu-kauati-rahi at jetty, Cass Bay | Motu-kauati-rahi at beach, and Rāpaki Bay at beach.
Water quality at the affected site is not considered suitable for recreational uses including swimming because of the risk to health from the bacteria and other pathogens.
Eating fish or shellfish from these sites should be avoided. If fish are eaten, remove the gut and liver and wash in clean water before cooking.
Find out more: Health warning - Unsafe water quality.