What we measure
We measure the number of enterococci bacteria in coastal water.
- Enterococci are bacteria that naturally occur in the gut of humans and animals as well as birds, fish and reptiles.
- In water used for swimming and other recreation, low counts of enterococci are acceptable, but too much contamination can cause gastroenteritis or infections of ears, eyes, nasal cavity, skin, and the upper respiratory tract.
- Enterococci are counted under the microscope as Colony Forming Units (cfu) per 100 mL.
- When enterococci are detected above 280 cfu per 100 mL (in two consecutive samples within 24 hours), swimming is not recommended.
Find out more about monitoring results here:
And enterococci testing here:
There are multiple testing programmes carried out at and around Ōwhiro Bay, all of which help us understand water quality and where any contamination is coming from.
Coastal waters testing
To assess whether Ōwhiro Bay beach is safe for swimming, on behalf of Greater Wellington Regional Council, we take measurements as part of the LAWA safe to swim sampling programme (which we call Baywatch). These samples are taken knee-deep in the sea (0.15 metres from the surface).
In summer these tests are taken weekly and in winter they are taken fortnightly.
Dry weather recreational testing standards are:
- Green: <140
- Amber alert: 140> (re-test)
- Red alert: 280> (re-test, open signs and public warnings)
We also take samples from Ōwhiro Bay stream at:
- the Happy Valley Tip and below it,
- Happy Valley Tip Bridge
- Lower Careys Gully
- Maori Gully
- 3 sites near the Ōwhiro Stream Mouth
- Ōwhiro Bay parade (coastal)
Some of these are taken for the Global Stormwater Consent (GSC) and others are used for investigation purposes. They are collected and analysed by an independent lab to the satisfaction of the regulator, Greater Wellington Regional Council. The most recent annual report is available on the Wellington Water website.