Community and Public Health is involved with the quality of coastal waters and freshwater waterways which are used for a range of recreational activities such as swimming, sailing, boating, surfing, water skiing, underwater diving and shellfish gathering.
The quality of recreational water is an important environmental health and resource management issue.
Improving our water quality with the Clean Water Package
The NZ Government has announced a plan to improve our waterways so that 90 percent are ‘swimmable’ by 2040. Currently 72 percent are considered safe to swim in most of the time. Improving our lakes and rivers will take time and there is more we need to do in the years ahead to make it happen.
New Zealand is lucky to have good quality waterways compared to many parts of the world. However our waterways are under pressure in rural and urban areas. New Zealanders are clear that more needs to be done. Healthy rivers and lakes are important not just for swimming but for cultural, recreational and economic reasons too.
You have the opportunity to give feedback on the proposed improvements to manage freshwater until 5pm on Friday 28th April 2017.
Health Risks Associated with Contaminated Water
Water can be contaminated by human or animal excreta containing disease causing micro-organisms such as viruses, bacteria and protozoa.
Contamination poses a health hazard when the water is used for recreational activities such as swimming and other high contact water sports.
There is a risk that water will be swallowed, inhaled or come into contact with ears, nasal passages, mucous membranes or cuts in the skin, allowing pathogens or algal toxins to enter the body.
The symptoms of exposure to contaminated water are usually minor and short lived, however there is the potential for more serious diseases including hepatitis A, giardiasis and cryptosporidiosis.
Health Risks associated with Algal Blooms
Algal blooms are appearing more frequently in our waterways. Algal blooms in lakes can be blue/green in colour floating on the surface or colourless globules suspended in the water.
Algal blooms are also found in rivers as blackish benthic mat-forming cyanobacteria clinging to rocks or collecting at the riverbank. Some cyanobacteria species are known to produce toxins.
Symptoms of exposure to toxic algae can range from allergic reactions, asthma, eye irritations, and rashes to rapid onset of nausea and diarrhoea to gastroenteritis to other specific effects such as liver damage and possibly developing cancers.
Health Risks associated with Mahinga kai
Water containing micro-organisms, chemicals, phytoplankton or cyanobacteria can pose a risk to health through recreational contact, drinking and gathering Mahinga kai.
Mahinga kai species associated with water are fish (including tuna and inanga), kanakana shellfish (such as mussels, oysters, scallops, tuangi and tuatua) as well as seaweed and watercress.
Responsibility for Monitoring Water Quality
Regional councils like Environment Canterbury coordinate the monitoring of the various sites throughout our region and inform Community and Public Health and the territorial local authority (TLA) if contamination levels present a potential health risk.
The Territorial Local Authority places warning signs to inform the public where a health risk is identified, and takes steps to remove the contamination if possible.
Community and Public Health supports the TLAs in advising the public of the risk and ensuring that they deal with the contamination appropriately.
Contact your local CPH office for further information:
Ph: +64 3 364 1777
Fax: +64 3 379 6125
Ph: +64 3 687 2600
Fax: +64 3 688 6091
Ph: +64 3 768 1160
Fax: +64 3 768 1169
For additional information or to report water pollution, contact:
Environment Canterbury Pollution Hotline
Ph: 03 3664 663 or
0800 765 588
West Coast Pollution Hotline
Ph: 0508 800 118
Toxic algae present in some Canterbury waterways
Updated 13th April 2017
All recreational water users are being reminded to avoid contact with some Canterbury and South Canterbury waterways.
Potentially toxic algae is currently present in the following locations in the region:
- Lake Ellesmere/Te Waihora
- Lake Forsyth/Te Roto o Wairewa
- Lake Pegasus
- Lake Rotorua (Kaikoura) – this is a permanent warning
- Te Nga Wai River at Te Nga Wai Bridge (near Pleasant Point)
- Opihi River at Raincliff, Saleyards Bridge (near Pleasant Point), State Highway 1, Allandale/Fairlie Bridge, and Waipopo Huts
- Waihao River near Bradshaws Bridge
- Waihi River at Waihi Gorge and in Geraldine township
Visit the Environment Canterbury website for more information. Routine monitoring of waterways during the summer season has now ended.
Blue bottle jellyfish wash up on Christchurch beaches
Adapted from Christchurch City Council media release: 8th March 2017
Visitors to Christchurch beaches are being warned to watch out for Portuguese man o’ war (blue bottle) jellyfish, with hundreds washing up on the city’s beaches over the last week.
The blue bottle jellyfish are a regular summer nuisance, and Christchurch City Council coastal park rangers are warning people to stay well away from them.
“We would just warn people to be careful, as the sting is particularly painful and can be very dangerous to some people, including children” said Council Head Ranger Kelly Hansen.
The main risk associated with the blue bottle was its venomous tentacles that can deliver a painful – and sometimes fatal – sting, resulting in red, whip-like welts on the skin normally lasting about 2 to 3 days. The intense pain with the sting should subside after about one hour.
Call an ambulance immediately if someone developed symptoms of a serious allergic reaction after a sting.