Lake Wainamu

Lake Wainamu is a popular recreational lake on the west coast of Auckland, situated between the Te Henga wetland and Bethells beach. The lake is a drowned valley blocked by a large dune of black iron sand at its western end and is surrounded by native bush and the Te Henga wetland. Lake Wainamu is located in the Waitakere Ranges Regional Park and is a popular spot for swimming and walking during summer. There is a walking track around the entire edge of the lake, and this is part of the much longer Edmund Hilary walking track.

Lake Wainamu is a dune lake with a largely forested catchment (96% native forest/scrub). A permanent stream drains the bush into the lake, and there is an intermittent stream that drains the lake westward towards the coast.

Lake Wainamu seasonally stratifies which generally results in anoxic bottom waters. The lake is considered eutrophic and has poor water clarity. Previous monitoring showed lake water quality corresponded closely to changes in the distribution of submerged vegetation which tend to stabilise lake-bed sediments and reduce possible re-suspension of sediment. This was particularly apparent in Lake Wainamu where the invasion of submerged macrophytes corresponded to improved water clarity, and the loss of submerged macrophytes due to the introduction of grass carp in 2009 caused a reduction in water clarity.

Lake Wainamu was part of the Lakes380 project and information can be found here.

Lake Summary

Lake size

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Catchment size

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Scientific data for this lake

This dashboard shows information on the data collected by the regional councils and unitary authorities for two lake water quality and ecological condition measurements. LakeSPI (Lake Submerged Plant Indicators) and TLI (Trophic Level Index). Select an indicator to see the historical monitoring data.

Water Quality

Trophic Level Index (TLI)

This measure is the Trophic Level Index (TLI). The TLI indicates the life supporting capacity of a lake and is based on four water quality indicators.

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Trophic Level Index (TLI) history for this lake

Trophic Level Indicator (TLI) which measures four parameters: water clarity, chlorophyll content, total phosphorus and total nitrogen. From these parameters a TLI value is calculated. In cases where water clarity data is missing a three parameter TLI is calculated. The higher the value, the greater the nutrients and fertility of the water which encourages growth, including algal blooms. As a rule, higher TLI scores mean poorer water quality. View a factsheet on TLI

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TLI history for Lake Wainamu

Year

What do the icons mean?

Very good water quality. Trophic Level Index of 0-2. Microtrophic lake conditions.

Good water quality. Trophic Level Index of 2-3. Oligotrophic lake conditions.

Average water quality. Trophic Level Index of 3-4. Mesotrophic lake conditions.

Poor water quality. Trophic Level Index of 4-5. Eutrophic lake conditions.

Very poor water quality. Trophic Level Index of greater than 5. Supertrophic lake conditions.

No data available.

TLI history for Lake Wainamu data table

Year	TLI Score

Year	TLI Score

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Ecological Conditions

Lake Submerged Plant Indicators (LakeSPI)

The LakeSPI status describes the ecological condition of the lake and is based on plants present.

LakeSPI data provided by NIWA

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LakeSPI history for this lake

LakeSPI (Lake Submerged Plant Indicators) is a method of characterising the ecological condition of lakes based on the composition of native and invasive plants growing in them. A higher LakeSPI percentage result is associated with better ecological health:

LakeSPI	N/A
LakeSPI	{{spiData.details.Value}}%

The overall LakeSPI score is calculated using a Native Condition Index ('good' plants) and an Invasive Impact Index (introduced, non-native plants):

Native Condition	N/A
Native Condition	{{spiData.details.NativeIndex}}%

Invasive Impact	N/A
Invasive Impact	{{spiData.details.InvasiveIndex}}%	NA

A higher Native Condition value indicates better ecological condition, but a higher Invasive Impact value indicates invasive plants are negatively impacting native plant communities.
View a factsheet on LakeSPI for more information on these indicators.

LakeSPI
Native Condition
Invasive Impact

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LakeSPI history for Lake Wainamu

Year

What is this graph showing me?

This graph is displaying the overall LakeSPI score over time. The results denote the ecological condition of the lake.

Excellent ecological health. A LakeSPI score of 75-100%.

High ecological health. A LakeSPI score of 50-75%.

Moderate ecological health. A LakeSPI score of 20-50%.

Poor ecological health. A LakeSPI score of 0-20%.

Non-vegetated. A LakeSPI score of 0% (there are no plants present).

No data available.

LakeSPI history for Lake Wainamu data table

Sample Date	LakeSPI Status	LakeSPI %	Native Condition Index %	Invasive Impact Index %

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NIWA LakeSPI is licensed under a Creative Commons Attribution-Non Commercial 3.0 New Zealand License 2012. Visit the NIWA LakeSPI website.

LakeSPI information has been provided by NIWA.

Sites

Monitored sites on Lake Wainamu

...retrieving sites.

No sites found.