pump stations (all due to high rainfall and power outages during Cyclone Dovi in
February 2022), and a further 14 reticulation overflows (the majority of which were due to high rainfall or
blockages due to fat and/or wet wipes). This total of 23 unauthorised incidents is similar to the previous two
monitoring periods.
During the year, NPDC demonstrated an overall high level of environmental and administrative compliance
and performance with the resource consents related to NPWWTP
page
Doc. No: 2813485
TARANAKI REGIONAL COUNCIL MONTHLY RAINFALL AND RIVER REPORT FOR June 2021
Provisional Data Only
Note: some sites record a number of parameters
Table 1: Rainfall at 27 sites throughout the region
Station Sub-region
Monthly Year to Date
Records Began Number of rain
days (>0.5mm)
Total Monthly
Rainfall (mm)
% of Monthly
Normal (%)
Total to date
(mm)
% of Normal for
year to date
% of average full
calendar year
Nth Egmont
of material in any kind of information retrieval system. The copyright for the
data, maps, figures and tables in this report is held by NIWA.
page
Contents
Executive Summary iv
1. Introduction 1
2. Present Climate 3
2.1 Taranaki regional environment 3
2.2 Climate of Taranaki region 4
2.3 Storms and high intensity rainfall 6
2.3.1 Methods 6
2.3.2 Observed trends in daily extremes 8
2.4 High winds and tornadoes 13
2.4.1 Winds 13
2.4.2 Extreme winds 15
investigation and design. No
construction occurred.
During the 2022/23 period expenditure on inflow and infiltration reduction consisted of:
• $457,127 spent on pipe renewals
• $17,774 spent on CCTV.
A wastewater network modelling project has recently been completed. This used rainfall and sewer flow
data to create a calibrated digital model of the entire Inglewood wastewater network. The calibrated model
will be used to assess network performance under different storm events of varying
page
Doc. No: 2747617
TARANAKI REGIONAL COUNCIL MONTHLY RAINFALL AND RIVER REPORT FOR March 2021
Provisional Data Only
Note: some sites record a number of parameters
Table 1: Rainfall at 27 sites throughout the region
Station Sub-region
Monthly Year to Date
Records Began Number of rain
days (>0.5mm)
Total Monthly
Rainfall (mm)
% of Monthly
Normal (%)
Total to date
(mm)
% of Normal for
year to date
% of average full
calendar year
Nth
and coastal receiving
environments including rivers, lakes and estuaries.
Climate change is expected to exacerbate soil loss and present challenges to the future
management of erosion-prone land. It is estimated that extreme storm events resulting in
flooding and slips are likely to occur somewhere in Taranaki about once every five to six
years. In coming years, the region is expected to experience more frequent and intense
heavy rainfall events, increasing both the frequency and
page
Doc. No: 2835178
TARANAKI REGIONAL COUNCIL MONTHLY RAINFALL AND RIVER REPORT FOR July 2021
Provisional Data Only
Note: some sites record a number of parameters
Table 1: Rainfall at 27 sites throughout the region
Station Sub-region
Monthly Year to Date
Records Began Number of rain
days (>0.5mm)
Total Monthly
Rainfall (mm)
% of Monthly
Normal (%)
Total to date
(mm)
% of Normal for
year to date
% of average full
calendar year
Nth Egmont
rainfall events and display a greater range of seasonal water level variation than
the region’s deeper aquifers. In general, groundwater levels across the region appear
relatively stable; however five sites are displaying statistically significant trends in water
level change. Three of these sites display positive trends, meaning water levels are
increasing at these sites. The remaining two sites, GND0508 (Taranaki volcanics aquifer) and
GND0708 (Whenuakura aquifer) display negative trends,
page
Doc. No: 2765952
TARANAKI REGIONAL COUNCIL MONTHLY RAINFALL AND RIVER REPORT FOR April 2021
Provisional Data Only
Note: some sites record a number of parameters
Table 1: Rainfall at 27 sites throughout the region
Station Sub-region
Monthly Year to Date
Records Began Number of rain
days (>0.5mm)
Total Monthly
Rainfall (mm)
% of Monthly
Normal (%)
Total to date
(mm)
% of Normal for
year to date
% of average full
calendar year
Nth
than 0 g/m3 in Pond 1 and 2 8
Figure 3 Daily discharge volumes (m3/day) from the HWWTP and daily rainfall data (mm) from a
Council rainfall station located approximately 5 km east of the site (2021-2022) 12
Figure 4 Location of intertidal survey sites in relation to the outfall 13
Figure 5 Mean number of species per quadrat for summer surveys (1986-2022) 14
Figure 6 Mean Shannon-Weiner Indices per quadrat for summer surveys (1986-2022) 14
Figure 7 Location of shoreline water