(the Council) to assess the environmental
performance during the period under review, and the results and effects of the consent
holder’s activities.
The Council’s monitoring programme included three regular inspections, one additional
inspection, and two biological receiving water surveys. Three short duration overflows (four
to nine days) following prolonged and intensive rainfall events, occurred between mid April
and late June 2015.
Regular inspections indicated no problems
cyanobacteria were higher than in the previous
three seasons, and similar to the preceding two seasons, probably a reflection of the relative amounts of
rainfall causing freshes that scour streambeds of periphyton.
page
Timely reporting of the results of bacteriological water quality and cyanobacteria numbers/cover was
undertaken by use of the Taranaki Regional Council website (www.trc.govt.nz) and LAWA website
(www.lawa.org.nz), as well as liaison with territorial local
rainfall sites recorded figures well above their
averages for the three winter months. Our site
at Patea recorded rainfall figures that were 167%
above its average amount for those months, yet
it was still the driest of our 27 rainfall monitoring
sites around the region. Perhaps you could spare
a thought for the people working in the Dawson
Falls area, as a staggering 2,723mls of rain fell at
that site over the winter period.
Congratulations to the 55 schools, 51 early
2018-June 2019) 9
Figure 4 Daily abstraction volumes under consent 7470-1.2 (July 2009-June 2019) 10
Figure 5 Maximum daily abstraction rate under consent 7470-1.2 (July 2009-June 2019) 10
Figure 6 Observed groundwater levels GND2102 and rainfall (July 2018-June 2019) 11
Figure 7 Observed groundwater levels GND2102 and abstraction (July 2018-June 2019) 12
Figure 8 Observed groundwater levels GND2103 and rainfall (July 2018-June 2019) 12
Figure 9 Observed groundwater levels
variation of annual
rainfall
mm y-1r
usRainDays10 Catchment average frequency of rainfall > 10 mm days month-1
usRainDays20 Catchment average frequency of rainfall > 20 mm days month-1
usRainDays100 Catchment average frequency of rainfall > 100 mm days month-1
segAveTCold Segment mean minimum winter air temperature degrees C x 10
Hydrology MeanFlow Estimated mean flow m3 s-1
nNeg Mean number of days per year on which flow was less
than that of the previous day
Year-1
months,
increased water temperature, reduced rainfall
and increased daylight hours provide ideal
conditions for cyanobacteria to grow, sometimes
resulting in algal blooms. When in bloom,
cyanobacteria can produce toxins that can pose a
risk to the health of people and animals entering
the water.
Sites monitored for benthic cyanobacteria were
suitable for recreational use on 20 of 77 (26%)
routine surveys, and elevated to a cautionary
status during one (<2%) survey. Conditions were
Daily abstraction volumes under consent 7470-1.2 (July 2009-June 2018) 10
Figure 5 Maximum daily abstraction rate under consent 7470-1.2 (July 2009-June 2018) 10
Figure 6 Observed groundwater levels GND2102 and rainfall (July 2017-June 2018) 11
Figure 7 Observed groundwater levels GND2102 and abstraction (July 2017-June 2018) 12
Figure 8 Observed groundwater levels GND2103 and rainfall (July 2017-June 2018) 12
Figure 9 Observed groundwater levels GND2103 and abstraction (July
.................................................................................................................................................. 8
2.3 CLIMATE .................................................................................................................................................... 8
Table 2: Kaka Road Rainfall Events 2011-17 ............................................................................................. 10
Table 3: High Intensity rainfall data (NIWA) for site ................................................................................ 10
2.4 HYDROLOGY / HYDROGEOLOGY
wet weather from mid July to early
August 2008 resulted in further intermittent overflows of very dilute, treated wastewater to
the stream until mid August 2008. Similar intermittent overflows were recorded after very
wet weather late in the 2009-2010 period, over a four week period in September 2010 and
again, more briefly late in the 2010-2011 period. Seven intermittent overflows, each of one to
four days duration, occurred following heavy rainfall events in the 2011-2012 period. One
boundary during any of the four routine inspections.
Results of effluent monitoring
With the diversion of wastes to the Hawera WWTP in the 2010/11 period, discharges from the Eltham
WWTP now occur only as a result of high rainfall events that exceed the storage capacity of the primary and
holding ponds, and the pumping capacity of the reticulated system to Hawera.
Analysis of the primary pond effluent was not required during the monitoring period, although the
condition of the pond and