Data on our awa
Research and measurement of the health of our Awa is critical to our work to restore it to it's natural state. We work closely with Auckland Council and scientific research helps guide our strategy to achieve our goals.
Computer Animation of how a Sewage Overflow is likely to behave in our Awa
Check out this computer simulation of what could happen when tidal movements interact with a sewage overflow. The first couple of movements show the exposure of mudflats before the sewage outflow occurs and then you can see how the contaminants could behave as the tide comes in and out.
Notes:
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At the start of the simulation, no contamination, but you can see the wetting and drying of intertidal areas over the tidal cycle.
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The rain occurs (30mm of rain in approximately 5 hours, followed by patchy rain. You can then see the contaminant plumes.
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The model seems to match well to the contaminant measurements we have taken so far.
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This model has been derived by the water quality test data used to underpin SafeSwim's predictions in this area of the harbour. In particular it is based off the test results from Taipari Strand and Chapman Road boat ramps. However, please note that the model does not accurately reflect the pollution flows at the mouth of the Huruhuru Creek and beyond towards the upper reaches of the Awa.
Coastal and Estuarine Water Quality: 2019 Annual Data Report
The Auckland Council released this report in August 2020 which is the technical report for Water Quality at 31 sites around Auckland and includes our awa Te Wai o Pareira (Henderson Creek).
This report reviews the monitoring of nutrients in Te Wai o Pareira (Henderson Creek). Nutrients are a measure of parameters that affect biological growth such as algae in the waters, visual clarity and level of oxygen required to support aquatic species. The water quality is expressed in terms of WQI (Water Quality Index).
Te Wai o Pareira / Henderson Creek is classified as Marginal (and better than expected) with a WQI of 60. The minimum WQI for the next rating of fair is 65.
It is not as good as the Whau River, which is Fair with a WQI of 75.
The Upper Harbour creeks - Brigham's Creek, Paremoremo, Lucas Creek and Rangitopuni Creek are rated as Poor, with WQI ranging from 38 to 50 (i.e. much worse that Henderson Creek).
This monitoring doesn't cover biological contamination from sewage outflows or toxic discharges from urban and industrial land use. All this illustrates the importance of including regular monitoring of sewage and toxic parameters so we understand the health of our awa. It is the mission of this group to promote regular independent testing and share the results with our community.
The Auckland Plan 2020
The Auckland Plan has this to say about our Awa:
Te Atatu - Henderson Creek
"This is an area of saltmarsh, mangroves, shell-banks and estuarine harbour intertidal banks forming a complex habitat for a variety of animal and plant communities.....
Saline vegetation also grows in the shelter of Henderson Creek. Here the edges of the creek are lined with mature mangroves which grow in association with areas of saltmarsh at the mouth of the creek and sedges and eelgrass further up the creek. In one place 955d) there is an important gradation between saline vegetation in the intertidal areas and native towai forest on the slopes above.
On part of the coast at Te Atatu North (55c) are found remnants of swamp and estuarine vegetation of Pleistocene age now exposed at intertidal levels. The site is considered to be a regionally important geological site."
[Reference - Auckland Council Coastal Plan: Coastal Map 26, Schedule 3 and Schedule 7]
Taipari Strand water test results June 2020
Between 1965 and 1974 there was an active landfill on Taipari Strand. We have recently been able to get some analysis performed on the impacts of this landfill on the Awa by Dr Peter Nelson, who has reviewed the available data. Read Peter's report here.
Media Articles
Here are some links to relevant press articles on our Awa:
Research
Here are some links to current research:
History
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A brief history of Te Kawerau ā Maki, Mana Whenua (people of the land) of Waitākere
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Te Wai o Pareira among many West Auckland place names restored to the Māori names