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.
Health Risks Associated with Contaminated Water
Water can be contaminated by human or animal excreta (poo) 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 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.
Wai We Care: Join your local water zone committee
Environment Canterbury media release: 12th April 2021
Now is the time to join your local water zone committee and make a contribution towards the future of Canterbury’s precious water resource.
Nine of Canterbury’s 10 water zone committees are looking for new community members, with applications closing on Monday 10th May 2021.
Water zone committees develop actions and tactics to deliver on the 10 targets of the Canterbury Water Management Strategy in their geographical zone. Committees are made up of people with a wide range of interests in water who have a strong connection to the zone.
They oversee and champion the implementation of these targets, recommending Environment Canterbury fund biodiversity and water-focused projects to make on-the-ground impacts in the zone.
Apply if this sounds like something you could contribute to. If you are shortlisted after making an application, you will take part in a selection workshop at which you will make a presentation, and participate in an assessment workshop involving small group exercises.
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
Warnings to avoid some Canterbury waterways
Updated 13th April 2021
Recreational water users are reminded to avoid contact with some Canterbury and South Canterbury waterways. Recently added warnings are highlighted in bold.
Potentially toxic algae or cyanobacteria or a high level of faecal (poo) bacteria is currently present in the following locations in the region:
- Ashburton/ Hakatere River at Boundary Road, the hapua (mouth), Hills Road and State Highway 1;
- Lake Ellesmere/ Te Waihora;
- Lake Forsyth/ Te Roto o Wairewa;
- Lake Opuha;
- Lake Pegasus;
- Lake Rotorua (Kaikoura) – this is a permanent warning;
- Opihi River at Raincliff;
- Orari River at Parke Road; and
- Selwyn/ Waikirikiri River at Coes Ford.
Find out more about keeping dogs safe from toxic algae (Environment Canterbury).
Visit the Environment Canterbury website for more information on water health warnings. Routine monitoring of waterways for summer runs from October to March each year.