Lake Mangamahoe 23
5.1 Historic aerial imagery analysis 23
5.2 Observed morphology and processes 25
5.3 Bathymetric surveys 26
5.4 Annual sediment infill rate 29
6 Summary 32
7 Applicability 35
8 References 36
Appendix A : Catchment scale sediment sources
Appendix B : Downstream geomorphic assessment
page
Tonkin & Taylor Ltd
Mangorei HEPS Consent Renewal - Lake Mangamahoe Sediment Assessment
Trustpower Ltd
November 2020
Job
extent of compliance by the consent holders,
this report also assigns a rating as to each Company’s environmental and administrative performance during
the period under review. The rating categories are high, good, improvement required and poor for both
environmental and administrative performance. The interpretations for these ratings are found in
Appendix II.
For reference, in the 2021-2022 year, consent holders were found to achieve a high level of environmental
performance and
their resilience too, and as a
region, we’ll continue to rise to the challenge.
page
4
The bottom line
The changing environment has impacted our budget with spending now forecast to be $46.8m (compared with
$45.2m signalled in the 2021/2031 Long-Term Plan). As a result, general rates will move from the proposed 5.5%
to 7.9% for 2022/2023, which for most ratepayers will be less than $20 per annum extra. Targeted rates remain
consistent with those
Manganui River residual flow 13
Table 3 Details of consents and special conditions in relation to abstraction rates, discharge rates and
water levels and the recording 14
Table 4 Summary of summer Manganui River daily water temperatures (°C) prior to the increase in
residual flow to 400 L/s (1992-2002) and for the years since, upstream and downstream of the
Motukawa HEP weir 16
Table 5 Summary of maximum daily water temperatures in the Manganui River, upstream and
downstream of the
document containing your answers, please refer to the document name and the relevant
page number in the text box.
Give full details of the source of the discharge and any
treatment it will receive prior to discharge:
These details are provided in sections 3 and 5 of the attached
Assessment of Environmental Effects.
Liquids discharged to water
What is the proposed maximum rate of discharge?
Rate 150000
Unit Litres per second
How frequent is the discharge? Not
management and, ultimately, through the refinement of methods
and considered responsible resource utilisation, to move closer to achieving sustainable development of the
region’s resources.
1.1.4 Evaluation of environmental performance
Besides discussing the various details of the performance and extent of compliance by the consent holders,
this report also assigns a rating as to each Company’s environmental and administrative performance during
the period under review. The rating categories are
rates (Statistics NZ)
KPI 2: Mode share for commuter trips for modes
other than single occupancy vehicle
KPI 3: Percentage of active mode and public
transport use for journey to work and school trips
KPI 4: Total public transport network coverage
across region (kms or towns connected to
network)
KPI 5: Number of residents living within x km of
high frequency public transport
KPI 6: Average household spend on transport
page
BTC Part A – Regional
5.2 Site Address (Including: Street/road
name, number, and nearest
settlement/town)
5.3 Assessment/Valuation number (refer
to land title or rates notice)
5.4 Map reference/s NZTM Co-ordinates at
point of activity
E N
5.5 Closest Waterbody
Provide the name of the closest
river or stream to the activity
page
08/22 - Doc # 3091239 Page 4 of 18
6) Description of
rates (Statistics NZ)
KPI 2: Mode share for commuter trips for modes
other than single occupancy vehicle
KPI 3: Percentage of active mode and public
transport use for journey to work and school trips
KPI 4: Total public transport network coverage
across region (kms or towns connected to
network)
KPI 5: Number of residents living within x km of
high frequency public transport
KPI 6: Average household spend on transport
page
BTC Part A – Regional
comprising 18% of the district’s population. Iwi and hapū of the Taranaki region
are Ngāti Maniapoto, Ngaa Rauru Kiitahi, Ngāruahine, Ngāti Maru (Te Iwi o Maruwharanui), Ngāti
Mutunga, Ngāti Ruanui, Ngāti Tama, Taranaki Iwi, and Te Atiawa.
In June 2020, Taranaki’s unemployment rate was at 4.3% with only small variations from one district to
another (compared to 4% nationally).
Households without access to a motor vehicle is highest in New Plymouth district (7.2% of