occur in heavy rainfall events. These flood flows spill overland but generally rejoin the main
channels before they enter the urban area. These overland flows will generally be caught by
the diversion channels which cut across the lay of land.
1.9 Climate
Because of its exposure to disturbed weather systems from the Tasman Sea, the Taranaki
region is often quite windy, but has few climate extremes. The most settled weather occurs
during summer and early autumn.
The mountain and
‘Drain Decision’. Winning a Council prize was not a new experience for Shan as he
received an award last year. Congratulations to all three winners.
Science and Technology Fair awards
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SITE OCTOBER 2011 ISSUE NO.59
Altitude and rainfall
In most cases there is a direct
link between rainfall figures and
altitude. Below are some
figures for both.
Multi choice mountain quiz
Te Maunga the mountain
Mt Taranaki rises to 2,518 metres making it the
North Island’s
confines of Port Taranaki.
The Taranaki region has a temperate climate with
generally abundant rainfall. The incised nature of
ring plain streams means that flooding is not a
major problem. However, occasional intense rainfall
events can lead to rapid rises in river levels and
flooding in hill country valleys and elsewhere.
Figure 1: The Taranaki Region
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Working with people. Caring for Taranaki 19
The people
Figures from the 2023 census show Taranaki total
population
and detaching or detached mats accumulating on the river’s edge triggered the
‘Alert’ level at the same four sites (Waingongoro River at Ohawe, Kaupokonui River at the mouth, and
Waiwhakaiho River at the last riffle and at Merrilands Domain) on a total of 8 surveys. Levels of
cyanobacteria were higher than in the previous season; and lower than the preceding three seasons,
probably a reflection of the relative amounts of rainfall causing freshes that scour streambeds of
between the
relatively ‘shallow’ groundwater table and the Haehanga Stream.
This may vary at different times of the year, for example, depending
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5
on rainfall and stream flows. This information is needed to assess
the impact of the discharge to the irrigation areas (and potentially
the composting pads and ponds) on the groundwater and the
subsequent effect due to contaminated groundwater entering
surface water.
18 An initial review undertaken by LEI identified a
Revised Assessment of Environmental Effects (AEE) - June 2020
caddisflies). The MCI index (widely used to monitor macroinvertebrates in
streams) is high (typically >100) in streams dominated by mayflies, stoneflies and caddisflies and low
(typically <80) in streams dominated by worms, snails and chironimids.
In Taranaki, nutrients are not such a problem because of fast flowing and relatively short rivers and
streams. High rainfall leads to frequent flushing events in rivers and streams that provide natural
scouring. Even in summer, most Taranaki rivers do
on aquatic life.
4.4.3 Climate
NIWA virtual Climate Station -38.975, 174.525 Thirty years of rainfall and evaporation data is
summarised in Table 1 below
Table 1: NIWA Virtual Climate Station 30-year data for a site near Uruti Site
Uruti Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec Total
Rainfall 120.0 107.0 119.2 151.2 181.2 189.5 181.8 178.0 175.4 188.4 149.4 149.0 1890.
Evaporation 134.5 108.0 88.6 52.7 31.1 21.4 25.4 39.0 57.5 85.1 109.3 126.0 878.6
4.4.4
heavily fished.”
Kayaking and rafting
The Waiwhakaiho River is one of the five main whitewater kayaking rivers in Taranaki, along
with the Stony, Mangorei and Manganui Rivers and Kiri Stream. The Waiwhakaiho is navigable
from the National Park to the sea, and flow recommendations are for after rainfall at 20m3/s,
although it is possible to ‘scrape by with less’.
There is no advertised commercial rafting on the Waiwhakaiho River, but it is offered by
TOPEC as one of their adventure
performance for consent 7470-1.1 16
List of figures
Figure 1 Location of TTR site production and monitoring bores 5
Figure 2 Daily abstraction volumes under consent 7470-1.1 (July 2014-June 2015) 10
Figure 3 Daily abstraction volumes under consent 7470-1.1 (2009-2015) 10
Figure 4 Maximum daily abstraction rate under consent 7470-1.1 (2014-2015) 11
Figure 5 Maximum daily abstraction rate under consent 7470-1.1 (2009-2015) 11
Figure 6 Observed groundwater levels and rainfall