What is Safe Networks?
Where water quality poses a risk to public health – as indicated by the Safeswim programme – Safe Networks conducts monitoring and investigations in our streams, watercourses and stormwater network to identify contaminants and track them to their source.
Where contaminants are identified as being from natural or non-human sources (for example, birds, dogs, stock), we look at options for management and control.
There is a high risk of poor water quality at our beaches, particularly:
- after heavy rain
- in areas serviced by ageing pipe infrastructure
- in areas with ageing onsite wastewater systems (private septic tanks)
- following long spells of dry weather when rainfall can carry dirty water to our beaches, including water contaminated with bird and dog faeces.
How to check water quality investigation areas
To check which areas our water quality investigation team are working in, visit the
Safe Networks viewer website.

Types of investigation
Different investigations may be conducted at the same time or more than once.
The method of investigation used is determined by the water quality issue, size and complexity of the water catchment area involved.
Water quality investigations are used to help find where contaminants are coming from. The types of sampling done are referred to as:
- Outlet screening: samples are taken at the Safeswim site from stormwater outlets or streams
- Network screening: samples are taken from locations upstream of the Safeswim site in the stormwater network (manholes) or upper stream reaches
- Public asset investigations: evaluate the condition of public stormwater and wastewater assets using techniques such as CCTV, smoke testing and dye testing
- Private property investigations: check commercial and residential private drainage pipes are correctly connected so wastewater and stormwater drain into the right places, and that they are in good condition.
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Investigations takes time (up to six months for each type of screening investigation). This is because we need enough results under differing weather conditions (wet and dry) to understand the causes of contamination.
We will always notify residents prior to an inspection.
If issues are identified on private property, these will be followed up directly with the property owner.
Checks include looking for cracked pipes, ensuring downpipes connect to the stormwater network rather than the wastewater network, and that gully traps are raised off the ground.
When we find public assets with issues, we refer them to the relevant Healthy Waters or Watercare teams to follow up.
More information
To learn how you can reduce overflows and protect our local waterways, visit the
watercare.co.nz website.
To get involved in improving your local waterway, see
Programmes promoting water quality.