Search all sites near me now
Search your favourite swimming spots

Lake Rotorangi

Lake Rotorangi was formed in May 1984 by the construction of an earth fill dam on the Patea River. The lake is the largest hydro-generation artificial storage lake in Taranaki and is also a popular recreational location within the region.

Lake Rotorangi was formed in May 1984 by the construction of an earth fill dam on the Patea River. The power scheme harnessed the flow of the Patea River to produce sufficient power for Egmont Electricity to meet approximately 60% of its consumer needs. The initial Lake Rotorangi programme was designed to keep a watching brief on lake water quality and productivity trends, in order to assess the way in which the new lake was settling down and its overall environmental consequences.

The Council continues to undertake sampling of the lake at two sites on four seasonal occasions. Phytoplankton monitoring is also conducted at the two sites. The most recent lake water quality trend analysis indicates that the lake is eutrophic (nutrient enriched) and that the trophic level continues to increase at a very small annual rate of change.

For more details, the full report is available at www.trc.govt.nz/council/plans-and-reports/environmental/environmental-monitoring-technical-reports/

Lake Summary
  • Lake size
    {{lakeDetails.size}}
  • Maximum depth
    {{lakeDetails.maxdepth}}
  • Catchment size
    {{lakeDetails.catchmentsize}}
  • Mixing pattern
    {{lakeDetails.mixingpattern}}
  • Geomorphic type
    {{lakeDetails.geomorphictype}}
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)

    {{rating() | uppercase}}

    {{comment()}}

    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.

    Show more information Hide information

    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

    Showing:
    to
    TLI history for Lake Rotorangi
    Year

    What do the icons mean?

    VERY GOOD
    Very good water quality. Trophic Level Index of 0-2. Microtrophic lake conditions.
    GOOD
    Good water quality. Trophic Level Index of 2-3. Oligotrophic lake conditions.
    FAIR
    Average water quality. Trophic Level Index of 3-4. Mesotrophic lake conditions.
    POOR
    Poor water quality. Trophic Level Index of 4-5. Eutrophic lake conditions.
    VERY POOR
    Very poor water quality. Trophic Level Index of greater than 5. Supertrophic lake conditions.
    NO DATA
    No data available.
    TLI history for Lake Rotorangi data table
    Year TLI Score
    Year TLI Score
     Download data
  • Ecological Conditions

    Lake Submerged Plant Indicators (LakeSPI)

    {{rating() | uppercase}}

    {{comment()}}

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

    LakeSPI data provided by NIWA

    Show more information Hide information

    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
    Showing:
    to
    LakeSPI history for Lake Rotorangi
    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
    Excellent ecological health. A LakeSPI score of 75-100%.
    HIGH
    High ecological health. A LakeSPI score of 50-75%.
    MODERATE
    Moderate ecological health. A LakeSPI score of 20-50%.
    POOR
    Poor ecological health. A LakeSPI score of 0-20%.
    NON-VEG
    Non-vegetated. A LakeSPI score of 0% (there are no plants present).
    NO DATA
    No data available.
    LakeSPI history for Lake Rotorangi data table
    Sample Date LakeSPI Status LakeSPI % Native Condition Index % Invasive Impact Index %
    LakeSPI information has been provided by NIWA.
Sites

Monitored sites on Lake Rotorangi

...retrieving sites.

No sites found.

Latest news and stories

Upcoming events