commenced in
early November 2009 with three of the sampling surveys performed prior to January
2010. The majority of the surveys were performed over the latter half of the summer
period. Bathing water samples were normally taken between the hours of 0900 and
1800 hours (NZDST) with none collected within a three day period following
significant river fresh conditions. [NB: regional differences in rainfall patterns have
caused difficulties at various sites in the past as localised rainfall may
involved flow metering at key locations in the network to identify
catchments with high I&I, and installation of fibre optic cables throughout 2,681 m of pipes in the
catchment with the biggest reaction to rainfall, to monitor the temperature differences before, during, and
after rainfall events. A report was produced that included recommendations to support a targeted I&I
remediation plan and deliver reductions in I&I, which NPDC will implement moving forward. This
investigation was completed to
Council’s hydrological monitoring team, as the weather conditions meant the demand for
irrigation was high, with irrigation starting as early as the middle of October.
The Council carried out compliance monitoring inspections at 68 sites during the 2015-2016
irrigation season. The inspections included visual checks of the intake structures, screens, staff
gauges, fencing around the pump sheds, downloading of data and stream gaugings.
For the summer irrigation period, the rainfall recorded at
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
increasing, and measures of water quality are trending in the right
direction. The region is not facing an unmanaged crisis in water quality, quite the opposite situation
is evident.
22) Over 300 rivers and streams radiate from Mount Taranaki across the ring plain. These are generally
short, narrow, incised, cool, and fast flowing, and water leaving the Egmont National Park has usually
reached the sea within 24 hours. High rainfall on the mountain generally means that most ring plain
stormwater sampling and release records and inspections of the discharge
point and receiving waters in the Herekawe Stream. Scheduled inspections were carried out on 16 August
2021, 4 February 2022, 11 March 2022 and 21 June 2022. Notes from these visits are summarised below.
16 August 2021
On site 10:45 to 11:15. Weather was fine with a light northwesterly wind. 15 mm of rainfall had been
recorded over the previous week at the Brooklands Zoo station. Stormwater ponds were sampled for
‘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
established environmental limits.
Environmental effects of exercise of consents
Potential environmental effects on the receiving environment at this site include contamination by
hydrocarbon spills and increased sediment during high rainfall events. These effects are considered to be a
low likelihood. At the time of the sampling on 21st August 2023 it was found that the exercise of the consent
was having no more than a minor effect on the tributary.
Evaluation of performance
A tabular
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
Revised Assessment of Environmental Effects (AEE) - June 2020