Keeping an eye on water quality
Environmental monitoring of water quality in Te Waihora/Lake Ellesmere by Environment Canterbury happens monthly at 14 sites where stream ecosystem health is measured, and at 13 water quality monitoring sites on the lake. There are also two real-time stations in the lake itself.
Ongoing water monitoring around and in Te Waihora/Lake Ellesmere gives an understanding of changes happening within the lake, including things like water temperature and water salinity. Together, this data helps inform lake management tools.
In the early phases, the project involved monthly sampling at just four sites around the lake which were then sent to a laboratory for analysis of a range of attributes. There were also two conductivity meters in the lake providing continuous records that were downloaded when the samples were taken. This monitoring provided good long-term data about changes in water quality but very little about short term changes in water quality.
Since then, two telemetered real time water quality monitoring stations have been installed in Te Waihora/Lake Ellesmere to give a better understanding of changes happening within the lake.
The equipment, funded by Whakaora Te Waihora, monitors:
- beam transmission (a clarity measurement),
- dissolved oxygen in the water (one at lake bottom and one at the top),
- water acidity (PH),
- temperature throughout the water column,
- conductivity and salinity,
- and turbidity and fluorescence (algal concentrations).
The technology in the system then relays the data, via telemetry – back to Environment Canterbury in Otautahi/Christchurch every two or three hours. Meteorological conditions including air temperature, barometric pressure, relative humidity, wind speed and direction and solar radiation are also measured.
The enhanced data helps explain what may have caused things like a spike in algal blooms and to build information to feed into long term planning and lake management.
Water monitoring is managed and funded by the science team at Environment Canterbury.
Learn more about the intricate details of the water quality monitoring on Te Waihora/Lake Ellesmere.
16 Mar 2021
How to fix Te Waihora
Te Waihora/Lake Ellesmere is one of New Zealand’s most important wetland habitats, and it’s also one of our most polluted lakes. Restoring it to its former abundance of birds and fish will take generations, but it’s possible according to New Zealand Geographic.Learn more