Blue Mountains City Council
Aquatic Macroinvertebrate
Sampling Program
2005-2006
DRAFT REPORT
Introduction
Blue Mountains City Council conducts an annual audit of the
health of our creeks using a range of physical, chemical and
biological indicators. Macroinvertebrates are widely recognised as key indicators because they increase the temporal
scale of an audit. This is because their presence or absence
represents water quality over their entire lifespan. They also
reflect changes in physical habitats, including sediment
deposition and altered hydrology, as well as changes in biological interaction such as the introduction of pest plant and
animal species.
Macroinvertebrates are also ubiquitous– they are found in
almost all waterbodies. The type and diversity of Macroinvertebrate Families present can indicate what stressors may be
acting upon a given aquatic system.
Objectives
•
To increase knowledge and understanding of the state and
functioning of aquatic systems
•
To provide and assess baseline data for the identification of overall
trends and changes in aquatic system health.
•
To provide information for State of the Environment reporting
•
To aid in the prioritisation of catchments and issues for more detailed investigation, planning and on-ground action
2. Methods
2.1 Site Selection and Background to Sites
Fifty two sites were selected for sampling under the expanded levy supported program. Sites
was selected for several reasons including:
•
To have a uniform distribution across the LGA’s altitudinal zones
•
To maximize our understanding of the effect that residential areas have on water
quality in as many “villages” as possible
•
To encompass representative reference sites
•
To maximise the number of sites sampled within staff and budget constraints
•
To complement other projects, particularly on-ground works aimed at improved
catchment health
•
To amalgamate previous sites and ensure continuity of data
Figure: Site locations 2006.
Table: Site List 2006
CAPP Sub-catchment
Waterfall Ck (Bowens)
Koombanda Brook
Kerosene Creek
Grose River
Asgard Brook
Hat Hill Creek
Popes Glen
Govetts Leap Brook
Centennial Glen Ck
Pulpit Hill Creek
Greaves Creek
Yosemite Creek
Yosemite Creek
Katoomba Creek
Govetts Ck
Megalong Creek
Kedumba River
Leura Falls Creek
Valley of the Waters
Jamison Creek
Wentworth Creek
Blue Mountain Creek
Wentworth Ck (6)
Bedford Ck
Blue Mountains Creek
Lawson Creek
Terrace Falls Creek
Woodford Creek
Bulls and Woodford Cks
Linden Ck (12)
Springwood Ck
Magdala Creek
Glenbrook Creek (11)
Fitzgerald Creek
Blue Gum Swamp
Blue Gum Swamp
Frasers Creek
Cripple Ck
Nepean River (46)
Glenbrook Creek (9)
Lapstone Creek
Knapsack Creek
Glenbrook Ck residuals
Major Catchment
colo
Grose
Cox
Grose
Grose
Grose
Grose
Grose
Cox
Cox
Cox
Grose
Grose
Grose
Grose
Grose
Cox
Burragorang
Burragorang
Burragorang
Burragorang
Burragorang
Burragorang
Grose
Grose
Grose
Erskine-Nepean
Grose
Erskine-Nepean
Erskine-Nepean
Erskine-Nepean
Grose
Grose
Grose
Grose
GlenbrookNepean
GlenbrookNepean
Nepean
Nepean
Nepean
Grose
Nepean
Nepean
Nepean
Nepean
Nepean
Nepean
Nepean
Nepean
Nepean
Nepean
Blackheath
Blackheath
Blackheath
Blackheath
Blackheath
Megalong
Medlow Bath
Katoomba
Katoomba
Katoomba
Leura
Katoomba
Katoomba
Leura
Leura
W/falls
W/falls
W/falls
Leura
W/falls
Lawson
Site
Code
01CMW
02GBLR
03BMV
04GMV
05GMVR
06GBH
07GBH
08GBH
09GBH
10BMG
11BMG
12GMB
14GKT
15GKT
16GKT
17GLA
18BKT
19BKT
20BLA
21BCA
22BWF
23BWF
24BWF
25GWF
26GWF
27GLNR
Site Name
Waterfall Ck @ Mt Wilson
Jungaburra Brook
Fairy Dell Creek
Grose River trib@Mt Vic
Asguard Brook
Hat Hill Creek
Popes Glen Creek @Govetts walk
Bridal Vale Creek
Centennial Glen@Blackheath
Pulpit Hill Creek 2
Megalong Ck@Old Ford Reserve
Adams Creek
Minnehaha Falls Creek trib
Yosemite Creek @Nth Katoomba
Katoomba @ Hodgson Park
Govetts Creek@leura
Megalong Creek trib@Bonnie Doon
Kedumba River@Katoomba Falls reserve
Leura Falls Creek
Gordon Ck @ Leura
Walkers Glen
Jamison Creek
Wentworth falls lake
Wentworth creek @ Leura
Water Nymphs Dell
Lawson@Queens rd
Lawson
Lawson
Hazelbrook
Woodford
Hazelbrook
Hazelbrook
Faulconbridge
Springwood
28EWFR
29GLW
30ELW
31EHZ
32EWD
33GHZ
34GHZ
35GFB
36GSP
Aeroplane Hills
Dantes Glen
Lawson Creek
Terrace Falls
Garnett Ck @ Woodford
Hazelbrook Creek
Woodford Ck
Linden Ck @ Grose Rd Faulconbridge
Springwood Ck
Springwood
37NSP
Magdala Creek 2
Valley heights
Valley heights
Sun Valley
Winmalee
38NVH
39NSV
40NSV
41GWL
Winmalee
Winmalee
Yellow Rock
Blaxland
emu heights
Warrimoo
glenbrook
glenbrook
emu plains
glenbrook
Lapstone
42GWLR
43NWL
44NYR
45NBX
46NMR
47NBX
48NGK
49NGK
50NEP
51NGK
52NGKR
Glenbrook Creek
Fitzgerald creek @ Valley heights
Valley Heights CK@ Sun Valley
Blue Gum Swamp Creek@Winmalee
Blue Gum Swamp Creek@ Shaws Ridge
Winmalee
Frasers Creek@Winmalee
Frasers Ck @Yellow Rock Road
Cripple Ck@Blaxland
Strathdon
Florabella Pass Creek
Lapstone Creek
Glenbrook Lagoon
Knapsack Bridge
Glenbrook Ck@causeway
Campfire Ck @ Red Hands Trail
Town(nearest)
Mt Wilson
Bullaburra
Mt Victoria
Mt Victoria
2.2 Sampling and Analytical Methods
2.2.1 Water Quality
In addition to macroinvertebrate sampling, a range of
physical and chemical parameters are recorded. These
measurements provide a snapshot of the creek on the
day of sampling. Parameters such as alkalinity and salinity provide useful baseline data for the purposes of comparing creeks within the sample. Turbidity, dissolved
oxygen, pH, conductivity and faecal coliforms are recorded for each site. pH, dissolved oxygen, temperature,
electrical conductivity and salinity are recorded using a
Hyrolab Quanta probe. Analysis of Alkalinity, available
and/or total Phosphorus and Nitrate are undertaken in
Council’s Laboratory as per manufacturers instructions
and/or Streamwatch protocols. Faecal coliforms are cultured in Council’s Laboratory as per Millipore protocols.
Water temperature
What can it tell us?
Water temperature affects many attributes of an aquatic system. Several key water chemistry
parameters are temperature sensitive including oxygen solubility and pH. Temperature can be
altered by point source inputs but is more likely to be affected by changes to riparian vegetation
or natural variations in riparian vegetation composition. Limited or sparse canopy cover increases the time the water body is exposed to sunlight and
thus the range of temperatures experienced in the water column over a 24 hour period. A wider range of temperatures
over this period can lead to thermal stress in some organisms and may lead to declines and/or changes in species
composition and richness (ANZECC 2000).
Adams Creek at Medlow Bath. The creek traverses a
hanging swamp that provides little shade. The water temperature will fluctuate considerably over a day.
Waterfall Creek at Mount Wilson. The
dense riparian vegetation shades the
creek, cooling the water and moderating
temperature fluctuations.
pH – potential of Hydrogen.
What is it?
pH is measured on a logarithmic scale (reciprocal of H+) and is the measure of free
hydrogen ion concentrations (acidity) of water. The scale ranges from 1 (highly acidic)
to 14 (highly alkaline). Water with a ph of 7 has ten times the concentration of Hydrogen ions as water with a pH of 8.
What does it tell us about water quality?
pH is often affected by the underlying geology of a catchment. Many Blue Mountains
creeks tend to be slightly acidic, particularly those fed by groundwater via permanent
springs and seeps. Rapid
changes in pH can have adverse affects on the ionic balance and respiratory function of
creek biota. Under specific conditions changes in pH can mobilize contaminants such as
heavy metals bound in stream
sediments.
A groundwater-fed pool at Adams
Creek, Medlow Bath. Underlying
geology will affect the pH of the water column.
Conductivity and Salinity
Why are they measured?
Conductivity and salinity are measures of the amount of ions in water, based on the
ability of the water to conduct an electrical charge. Aquatic systems in the Blue Mountains are generally not affected by elevated salinity levels, however conductivity and
salinity are useful indicators in the detection of point sources of pollution such as sewage leaks.
Dissolved Oxygen
Why do we test this?
The composition of stream biota is directly influenced by the dissolved oxygen available in the
system. For all biota that respire aerobically, including fish and macroinvertebrates, certain levels of dissolved oxygen are required to retain normal functions. In aquatic systems where plant
biomass occupies a considerable proportion of
the water column (such as Glenbrook Lagoon)
plant respiration creates a high biological oxygen
demand. This also occurs when there is considerable microbial decomposition of organic debris
and wastes within an aquatic system.
Mayfly Larvae– the gills of this macroinvertebrate can be seen down the sides
of is abdomen (used for absorbing dissolved oxygen) . Animals such as these
rely on good levels of dissolved oxygen.
Turbidity
What is it?
Turbidity is a measure of water clarity. The more suspended particles– often sand
or clay but including organic material– carried in the water column the higher the
turbidity. Turbidity is not a measure of water colour. Many of the creeks in the Blue
Mountains have tannin stained water but the waters are generally clear with low turbidity. Turbidity is a relative measure. It is usually expressed as nephelometric turbidity units (NTU) .
Why is it important?
Turbidity affects the depth light can penetrate into a water column. Turbid waters
can affect the photosynthetic potential of water plants and ultimately change the floristic assemblage to favour plants that can photosynthesise in low light or control
their position in the water column– such as blue-green algae.
Suspended particles also absorb
heat and can increase the water
temperature, which in turn reduces
the dissolved oxygen available to
organisms in the water.
Suspended materials eventually settle out, changing the nature of the
creek bed substrates. Sand and silt
fill in pools and the spaces between
cobbles and pebbles. This reduces
the habitats available for macroinvertebrates and other stream organisms.
Highly turbid waters can
indicate erosion and
disturbance in a creek’s
catchment. Here a tributary of Yosemite Creek
meets the main Creek.
The clear waters of the
tributary are strongly
contrasted by the highly
turbid waters of the
main creek.
2.2.2 Aquatic Macroinvertebrates
Sampling of macroinvertebrates was based on the AUSRIVAS protocol for collecting and processing samples in NSW (DEC, 2004).
AUSRIVAS is a biological index system based on an observed/
expected (presence-absence) score. SIGNAL2 is another method
for gleaning information about stream health, based on sensitivity
grades and abundances of Macroinvertebrate Families/Genera/
Species. Family versions of SIGNAL2 sensitivity grades were used
in this survey (Chessman, 2001).
2.2.2.1 Sampling Technique
As per the AUSRIVAS protocol, sampling was conducted using a 0.25mm mesh size net. Two key habitats were targeted: edge and riffle zones. 10 metres of
edge habitat was sampled within a pre-determined 100
metres of reach and 10 metres of riffle habitat within
the same reach section (where available).
Different micro-habitats were targeted to maximise
catch, including stream substrates-cobbles, gravel,
bedrock etc; macrophytes; woody debris; overhanging
and trailing vegetation as well as the water column itself.
Edge habitat (above) and riffle habitat (right)
at Woodford Creek.
2.2.2.2 Sample Sorting
Samples are “picked” live on site. This involves emptying the contents of the nets into white
trays and catching macroinvertebrates using forceps, pipettes and spoons. Two field staff
pick for 40 minutes per major habitat. Conspicuous families, such as dragonflies and damselflies, are picked in the first ten minutes with the balance of time being spent looking for new
taxa. If any new taxa are collected in the last ten minutes of “picking” a further ten minutes of
picking is undertaken up to a maximum of 60 minutes. Specimens that are readily and accurately identified in the field are released, all other specimens are preserved in alcohol for
identification in Council’s laboratory.
Comprehensive keys are available for aquatic macroinvertebrates and these are used to
identify most taxa to Family level. Exceptions include Chironomidae (non biting midges)
which are sorted to Sub-family, and Acarina (mites), Oligochaeta (segmented worms) and
Nemotoda (unsegmented worms), which are sorted to Order. Binocular stereoscopes are
used to look at the very small distinguishing features of closely related Families.
2.2.2.3 Data/Statistical Analysis
Monitoring programs fall generally into two broad formats: comparative studies and descriptive studies. BMCC’s monitoring program is in its eighth year, allowing some comparative analysis of data. However, there are several potentially significant sources of
error when attempting to make meaningful comparisons of changes in water quality over
time. This is because aquatic systems are very dynamic and macroinvertebrate assemblages will reflect not only water quality but water quantity (prevailing rainfall patterns)
and changing instream habitats (particularly deposition of sediment). Additional sources
of error are changes in field operators which, although sampling techniques are standardized, may inevitably affect the result.
As the foundation of descriptive study and as an index of stream health, SIGNAL2
scores are nonetheless widely accepted. SIGNAL2 is reflective of anthropogenic
(human) influences such as sewage exfiltration from reticulated sewerage systems and
contaminants (both gross and chemical), more than natural factors such as altitude and
stream size (Growns et al. 1995).
Single factor analysis of variance (anova) of SIGNAL2 scores was undertaken between
years, between reference sites and non-reference sites and between the two habitat
samples (edge/pool and riffle). This analysis provides a test of the hypothesis that each
sample is drawn from the same underlying probability distribution against the alternative
hypothesis that underlying probability distributions are not the same.
A PET index was created for each site to represent the number of Plecoptera (stonefly),
Ephemeroptera (mayfly) and Trichoptera (caddisfy) Families found at the site. This is a
rapid way of assessing creek health as these three Orders are the most likely to disappear from the macroinvertebrate assemblage if creek health begins to deteriorate. The
PET results are presented in simple presence/absence format as well as number of
PET families at each site (see tables in the results section).
Trend data was calculated using the mean SIGNAL2 scores for pools and riffles for
each site, to allow comparison over time (as this is the way data has been treated in
previous years). Separate analysis of pools and riffles would be preferable, especially
considering that 14 sites contain only edge/pool habitats, however the riffle/pool average was used to ensure a consistent dataset for the examination of trends. SIGNAL2
versus richness (number of Families) bi-plots were created using only edge/pool habitat
scores—at sites where two edge/pool samples were taken (instead of one pool/edge
and one riffle), the higher scoring of the two was used. Bi-plots were analysed using the
‘remainder of Australia’ quadrant boundaries suggested by Chessman (2001).
3. Survey Results
3.1 Water Quality Results
See appendix
Table: summary of results
Site
SIGNAL2
Quadrant
PET pool/
edge#
PET riffle
Outside
ANZECC
guidelines ?
NO
Comments
Waterfall Ck
5.82
1
3
5
Jungaburra Brook
5.45
1
8
YES
Low DO
Fairy Dell Ck
6.01
1
6
7
YES
High EC
Grose River Trib
5.74
6
7
NO
Asgard Brook
6.24
3
6
7
NO
Hat Hill Ck
6.13
3
5
13
NO
Popes Glen Ck
5.37
3
3
6
NO
Bridal Veil Ck
5.10
3
4
8
NO
Centennial Glen
5.53
3
8
4
NO
Pulpit Hill Ck 2
5.91
1
7
10
YES
High DO
Megalong Ck
5.42
1
7
8
YES
High DO
Adams Ck
4.22
2
3
2
NO
Minnehaha Falls Trib
6.18
3
5
4
NO
Yosemite Ck
5.61
1
5
8
NO
Katoomba Ck
5.52
3
2
4
YES
Low DO^
Govetts Ck
5.02
1
4
7
YES
High pH*
Megalong Trib
5.80
3
3
6
YES
High pH*
Kedumba Ck
4.78
3
2
4
NO
Leura Falls Ck
4.89
3
3
6
YES
High DO
Gordon Ck
6.3
3
2
2
YES
Valley of the Waters
5.89
3
3
7
YES
High pH*, Low
DO^
High pH*
Jamison Ck
5.65
1
5
6
NO
Wentworth Falls Lake
3.98
3
6
Wentworth Ck
6.09
1
4
10
NO
Water Nymphs Dell
5.58
3
4
6
YES
Low DO^
Lawson@Queens Rd
5.38
3
2
YES
Low DO
Aeroplane Hills/Ingar
3.65
3
2
YES
High pH*
Dantes Glen
5.63
3
4
5
NO
Bedford Ck
5.36
1
6
8
NO
Terrace Falls Ck
5.41
1
5
7
NO
2.25
4
2
NO
High pH*, High
Turbidity, Low
DO
#PET for pool/edge habitat (where 2 pool/edge samples, the higher of the two reported); * high pH readings may have
been due to faulty meter; ^only slightly below ANZECC guidelines and not deemed to be concerning
Garnett Dam
YES
Table: summary of results (continued)
Site
SIGNAL2
Quadrant
PET pool/
edge#
PET riffle
Hazelbrook Ck
5.48
1
6
6
Outside
ANZECC
guidelines ?
YES
Woodford Ck
5.43
1
5
6
NO
Linden Ck
5.52
1
4
Springwood Ck
5.39
3
2
Magdala Ck
4.68
3
1
YES
Glenbrook Ck
5.16
3
4
YES
Fitzgerald Ck
5.08
1
5
7
YES
Long Angle Ck
4.50
1
3
3
NO
Blue Gum Swamp Ck
4.60
1
3
3
YES
Low DO
Frasers Trib
4.64
3
2
YES
High pH*
Cripple Ck
3.48
4
1
YES
Strathdon
4.73
3
4
YES
High pH*, Low
DO, High EC
Low DO
Lapstone Ck
3.67
2
2
Glenbrook Lagoon
2.99
4
0
YES
Low DO
Knapsack Bridge
4.06
1
4
YES
Glenbrook Ck
4.56
3
2
YES
High pH*, Low
DO
Low DO
Campfire Ck
5.21
1
5
YES
Low DO
YES
4
2
5
Comments
High pH*
High pH*
NO
High Turbidity,
Low DO
High pH*, Low
DO
High pH*, High
Turbidity
NO
#PET for pool/edge habitat (where 2 pool/edge samples, the higher of the two reported); * high pH readings may have
been due to faulty meter ; ^only slightly below ANZECC guidelines and not deemed to be concerning
3.2 Macroinvertebrate Survey Results
Table:SIGNAL2 Scores 1999 to 2006
NEW
CODE
01CMV
02GBLR
03BMV
04GMV
05GMVR
06GBH
NAME
Waterfall Ck
Jungaburra Brook
Fairy Dell Ck
Grose River Trib
Asgard Brook
Hat Hill Ck
1999
5
4.69
4.53
4.87
5.45
5.08
2000
07GBH
08GBH
09GBH
10BMG
11BMG
12GMB
13BMG
14GKT
15GKT
16GKT
17GLA
Popes Glen Ck
Bridal Veil Ck
Centennial Glen
Pulpit Hill Ck 2
Megalong Ck
Adams Ck
Pulpit Hill trib (Hydro)
Minnehaha Falls Trib
Yosemite Ck
Katoomba Ck
Govetts Ck
3.51
6.5
5.44
5.79
3.61
4.63
4.08
6.4
2.68
3.96
3.23
2.11
4.79
18BKT
Megalong Trib
5.8
19BKT
20BLA
21BCA
22BWF
23BWF
24BWF
25GWF
26GWF
27GLNR
28EWFR
29GLW
30ELW
31EHZ
32EWD
33GHZ
34GHZ
35GFB
36GSP
37NSP
38NVH
Kedumba Ck
Leura Falls Ck
Gordon Ck
Valley of the Waters
Jamison Ck
Wentworth Falls Lake
Wentworth Ck
Water Nymphs Dell
Lawson@Queens Rd
Aeroplane Hills/Ingar
Dantes Glen
Bedford Ck
Terrace Falls Ck
Garnett Dam
Hazelbrook Ck
Woodford Ck
Linden Ck
Springwood Ck
Magdala Ck
Glenbrook Ck
2.43
2.65
3.45
39NSV
40NSV
41GWL
Fitzgerald Ck
Long Angle Ck
Blue Gum Swamp Ck
42GWLR
43NWL
44NYR
45NBX
46NMR
47NBX
48NGK
49NGK
50NEP
51NGK
52NGKR
Blue Gum Swamp Ck2
Frasers Ck
Frasers Trib
Cripple Ck
Strathdon
Florabella Pass Ck
Lapstone Ck
Glenbrook Lagoon
Knapsack Bridge
Glenbrook Ck
Campfire Ck
2001
4.89
2002
4.65
3.99
4.19
4.33
3.06
4.25
4.69
3.91
3.39
5.9
4.18
3.46
5.08
3.87
3.51
3.83
4.27
4.335
5.24
6
4.265
4.625
4.675
5.82
5.37
5.10
5.53
5.91
5.42
4.22
Dry
6.18
5.61
5.52
5.02
5.5
5.29
5.80
4.165
4.94
4.78
4.89
6.30
5.89
5.65
3.98
6.09
5.58
5.38
3.65
5.63
5.36
5.41
2.25
5.48
5.43
5.52
5.39
4.68
5.16
5.5
6.3
3.85
3.28
3.15
4.1
3.45
5.48
3.91
5.69
5.55
6.03
2.68
2.98
3.24
5.67
5.375
4.97
5.795
5.51
4.57
5.51
5.64
5.54
6.21
4.87
5.07
4.625
2006
5.82
5.45
6.01
5.74
6.24
6.13
4.7
2.83
2.81
3.54
4.76
2005
5.95
4.63
5.4
4.4
5.59
5.15
4.61
4.69
5.89
2004
6.5
6.31
6.23
5.72
3.06
5.78
5.75
2003
1.8
6.37
5.18
6.1
4.29
3.64
5.63
3.385
2.81
2.03
5.17
3.24
3.09
4.03
3.26
5.2
4.1
3.88
4.42
ND
3.59
4.5
3.03
5.24
5.2
1.95
4.45
5.79
ND
5.24
3.75
2.6
5.1
3.45
3.32
5.425
5.125
5.915
5.855
5.095
5.54
5.125
5.13
5.46
5.345
4.785
4.33
4.39
3.63
4.23
3.79
3.94
4.47
4.23
4.2
4.67
1.94
3.29
3
3.44
4.36
4.39
3.4
3.1
3.5
4.375
4.495
3.2
5.08
4.50
4.60
Dry
Dry
4.64
3.48
4.73
Dry
3.67
2.99
4.06
4.56
5.21
ANALYSIS OF VARIANCE OF SIGNAL2 SCORES
Single factor analysis of variance (anova) was undertaken between years, between reference
sites and non-reference sites and between the two habitat samples (edge/pool and riffle). Only
the latter two variables were significantly different with riffles having significantly higher SIGNAL2 values than pools/edge. There was no significant difference within sites between different
years, or between reference sites and non-reference sites.
SIGNAL2 VERSUS RICHNESS
Plotting richness (number of Families ) against SIGNAL2 score provides a useful tool for interpreting results (Chessman, 2001).
For data handling purposes SIGNAL2 Vs Richness plots have been divided into 5 Areas.
These areas replicate the areas used for planning and management by Council, and those
used to map native vegetation. They loosely follow broad altitudinal zones with the exception
of Area 1 which covers the diverse areas of “The Mounts” to the North on basalt capped
mountains, the sandstone plateau and Western escarpment from Medlow Bath to Bell, and the
Megalong Valley.
The SIGNAL2 versus richness bi-plots for the 05-06 sampling season are displayed below and
on the following pages.
Area 1
7
Asguard Br ook
Hat Hill Creek
Grose River t r ib
6
Fair y Dell Cr eek
Cent ennial Glen
Pulpit Hill Cr eek
Jungaburr a Brook
Popes Glen Creek
Wat erf all Ck
5
Old For d Reser ve
Br idal Vale Creek
4
Adams Creek
3
2
1
0
0
5
10
15
N um be r o f M a c ro inv e rt e bra t e F a m ilie s
20
25
30
Area 2
7
Gordon Ck @ Leura
6
5
SIGNAL2 (family)
Govetts Creek@leura
Minnehaha Falls Ck trib
Valley of the Waters
Wentw orth creek @
Megalong Creek trib
@Leura
Leura
Jamison Creek
Katoomba ck
Yosemite
Creek
Water Nymphs Dell
Katoomba Falls reserve
Wentw orth falls lake
Leura Falls Creek
4
3
2
1
0
0
5
10
15
20
25
Number of macroinvertebrate families
Area 3
7
Lawson@Queens rd
6
SIGNAL2 (family)
Woodford Ck
Dant es Glen
5
Terrace Falls
Hazelbrook Creek
Bedford Creek
Aeroplane Hills/Ingar
4
3
Garnet t Ck @ Woodf ord (dam)
2
1
0
0
5
10
15
Number of macroinvertebrate families
20
25
Area 4
7
6
Linden Ck
Faulconbridge
Springw ood Ck
Magdala Creek 2
Glenbrook Creek trib
SIGNAL2 (family)
5
Frasers Ck @Yellow
Rock Road
Fitzgerald creek @
Valley heights
Blue Gum Sw amp
Creek@Winmalee
4
3
2
1
0
0
5
10
15
20
25
30
Number of macroinvertebrate families
Area 5
6
Glenbrook Ck trib @
Red Hands Cave track
SIGNAL2 (family)
5
Glenbrook
Ck@causew ay
4
Strathdon
Knapsack Bridge
Long Angle@ Sun
Valley
Lapstone Creek
Cripple Ck@Blaxland
3
Glenbrook Lagoon
2
1
0
0
5
10
15
Number of macroinvertebrate families
20
25
TABLE: SITES BY QUADRANT (2005-2006)
Quadrant 3 sites:
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Quadrant 1 sites:
Hat Hill Creek
Centennial Glen
Popes Glen
Bridal Veil
Gordon Creek
Valley of the Waters
Megalong Creek trib
Katoomba Creek
Water Nymphs Dell
Kedumba Creek
Wentworth Falls Lake
Leura Falls Creek
Minnehaha Falls Creek trib
Dantes Glen
Springwood Creek
Glenbrook Creek trib @ Springwood
Magdala Creek
Frasers Creek trib
Glenbrook Creek @ the Causeway
Strathdon
Asgard Brook (Reference)
Lawson @ Queens Rd (Reference)
Ingar (Reference)
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Quadrant 4 sites:
•
•
•
Garnett Dam
Cripple Creek
Glenbrook Lagoon
Megapodagrionidae
Grose River tributary
Pulpit Hill Creek
Fairy Dell Creek
Waterfall Creek
Megalong Creek
Govetts Creek
Wentworth Creek
Jamison Creek
Yosemite Creek
Woodford Creek
Bedford Creek
Hazelbrook Creek
Terrace Falls Creek
Linden Creek trib
Fitzgerald Creek
Blue Gum Swamp Creek
Knapsack Creek
Long Angle Creek
Jungaburra Brook (Reference)
Glenbrook Ck trib (Campfire Ck)
(Reference)
Quadrant 2 sites:
•
•
Gomphidae
Adams Creek
Lapstone Creek
Dytiscidae
PET (PLECOPTERA, EPHEMEROPTERA, TRICHOPTERA) DATA
Plecoptera (stonefly), Ephemeroptera (mayfly) and Trichoptera (caddisfly) are the
Orders most likely to disappear from the macroinvertebrate assemblage if creek
health begins to deteriorate. It is therefore useful to look the number of families in
these three orders and their presence/absence at each site. The table below shows
presence/absence data for each site. The table on the following two pages shows
the PET scores (number of PET Families found at each site).
Table: presence/absence of Plecoptera, Ephemeroptera & Trichoptera Orders
SiteNo
01CMV
02GBLR
03BMV
04GMV
05GMVR
06GBH
07GBH
08GBH
09GBH
10BMG
11BMG
12GMB
14GKT
15GKT
16GKT
17GLA
18BKT
19BKT
20BLA
21BCA
22BWF
23BWF
24BWF
25GWF
26GWF
27GLNR
28EWFR
29GLW
30ELW
31EHZ
32EWD
33GHZ
34GHZ
35GFB
36GSP
37NSP
38NVH
Site name
Waterfall Ck
Jungaburra Brook^
Fairy Dell Creek
Grose River trib@Mt Vic
Asguard Brook
Hat Hill Creek
Popes Glen Creek @Govetts walk
Bridal Vale Creek
Centennial Glen@Blackheath
Pulpit Hill Creek 2
Megalong Ck@Old Ford Reserve
Adams Creek
Minnehaha Falls Creek trib
Yosemite Creek @Nth Katoomba
Katoomba @ Hodgson Park
Govetts Creek@leura
Megalong Creek trib@Bonnie Doon
Kedumba River@Kat Falls res
Leura Falls Creek
Gordon Ck @ Leura
Valley of the Waters @Leura
Jamison Creek
Wentworth falls lake^
Wentworth creek @ Leura
Water Nymphs Dell
Lawson@Queens rd^
Aeroplane Hills/Ingar^
Dantes Glen
Bedford Creek
Terrace Falls
Garnett Ck @ Woodford (dam)^
Hazelbrook Creek
Woodford Ck
Linden Ck @ Grose Rd Faulconbridge^
Springwood Ck
Magdala Creek 2^
Glenbrook Creek trib @ Deakin(Swd)^
Plecoptera*
Ephemeroptera*
Tricoptera*
NO**
NO
YES
YES
YES
YES
YES
YES
YES
YES
YES
NO
YES
YES
YES
YES
YES
NO
NO
YES
YES
YES
NO
YES
YES
NO
NO
YES
YES
YES
NO
YES
YES
YES
YES
NO
NO
YES***
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
NO
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
NO
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
39NSV
Fitzgerald creek @ Valley heights
NO
YES
YES
40NSV
Long Angle@ Sun Valley
NO
YES
YES
41GWL
Blue Gum Swamp Creek@Winmalee
NO
YES
YES
44NYR
Frasers Ck @Yellow Rock Road^
NO
YES
YES
45NBX
Cripple Ck@Blaxland^
NO
NO
YES
46NMR
Strathdon^
NO
YES
YES
48NGK
Lapstone Creek
NO
NO
YES
49NGK
Glenbrook Lagoon^
NO
NO
NO
50NEP
Knapsack Bridge^
YES
YES
YES
51NGK
Glenbrook Ck@causeway
NO
YES
YES
52NGKR Glenbrook Ck trib @ Red Hands track^
YES
YES
YES
*”Plecoptera” = stonefly; “Ephemeroptera” = mayfly; “Trichoptera” = caddisfly
^ Only pool/edge habitats were sampled at these sites: therefore presence of Plecoptera is less likely
**”NO” = no families in the Order were detected ; ***”YES” = one or more families in the Order were detected
Table: PET scores (number of PET families found at each site)
Plecoptera Ephemeroptera Tricoptera
family count family count family count
PET
score
SiteNo
Site name
Habitat
01CMV
Waterfall Ck
02GBLR
Jungaburra Brook
03BMV
Fairy Dell Creek
04GMV
Grose River trib@Mt Vic
05GMVR
Asguard Brook
06GBH
Hat Hill Creek
pool
riffle
pool1
pool2
pool
riffle
pool
riffle
pool
riffle
pool
0
0
0
0
2
0
1
1
0
1
1
2
1
2
2
1
1
2
2
1
1
2
1
4
3
6
3
6
3
4
5
5
2
3
5
5
8
6
7
6
7
6
7
5
07GBH
Popes Glen Creek @Govetts walk
08GBH
Bridal Veil Creek
riffle
pool
riffle
pool
2
1
1
1
2
0
1
0
9
2
4
3
13
3
6
4
09GBH
Centennial Glen@Blackheath
10BMG
Pulpit Hill Creek 2
riffle
pool
riffle
pool
2
2
0
1
1
1
2
3
5
5
2
3
8
8
4
7
11BMG
Megalong Ck@Old Ford Reserve
12GMB
Adams Creek
riffle
pool
riffle
pool
1
1
1
0
3
3
3
2
6
3
4
1
14GKT
Minnehaha Falls Creek trib
15GKT
Yosemite Creek @Nth Katoomba
riffle
pool
riffle
pool
riffle
0
1
1
1
1
1
2
1
2
3
1
2
2
2
4
10
7
8
3
2
5
4
5
8
16GKT
Katoomba @ Hodgson Park
17GLA
Govetts Creek@leura
18BKT
Megalong Creek trib@Bonnie Doon stuarts road
19BKT
Kedumba River@Katoomba Falls reserve
20BLA
Leura Falls Creek
pool
riffle
pool
riffle
pool
riffle
pool
riffle
pool
1
1
2
1
0
1
0
0
0
0
1
1
1
1
1
1
2
1
1
2
1
5
2
4
1
2
2
2
4
4
7
3
6
2
4
3
21BCA
Gordon Ck @ Leura
riffle
pool
riffle
0
1
1
1
0
0
5
1
1
6
2
2
22BWF
Valley of the Waters @Leura
23BWF
Jamison Creek
24BWF
Wentworth falls lake
pool
riffle
pool
riffle
edge1
1
1
2
2
0
1
2
1
1
0
1
4
2
3
3
3
7
5
6
3
25GWF
Wentworth creek @ Leura
26GWF
Water Nymphs Dell
27GLNR
Lawson@Queens rd
28EWFR
Aeroplane Hills/Ingar
29GLW
Dantes Glen
edge2
pool
riffle
pool
riffle
pool1
pool2
pool
edge
pool
0
1
1
1
1
0
0
0
0
1
1
2
4
1
1
1
1
1
1
1
5
1
5
2
4
1
1
1
0
2
6
4
10
4
6
2
2
2
1
4
30ELW
Bedford Creek
31EHZ
Terrace Falls
riffle
pool
riffle
pool
1
1
2
1
1
2
2
3
3
3
4
1
5
6
8
5
32EWD
Garnett Ck @ Woodford (dam)
riffle
edge1
1
0
2
1
4
1
7
2
33GHZ
Hazelbrook Creek
edge2
pool
riffle
0
1
1
1
2
1
0
3
4
1
6
6
34GHZ
Woodford Ck
pool
riffle
1
1
2
2
2
3
5
6
35GFB
Linden Ck @ Grose Rd Faulconbridge
pool1
pool2
0
1
2
2
2
1
4
4
36GSP
Springwood Ck
37NSP
Magdala Creek 2
pool
riffle
pool1
pool2
0
1
0
0
1
0
0
0
1
3
1
0
2
4
1
0
Table (continued): PET scores (number of PET families found at each site)
Plecoptera
Ephemeroptera
Tricoptera
PET
SiteNo
Site name
Habitat
38NVH
Glenbrook Creek trib @ Deakin(Swd)
pool 1
pool 2
0
0
2
1
2
3
4
4
39NSV
Fitzgerald creek @ Valley heights
pool
0
2
3
5
riffle
0
2
5
7
pool
0
1
2
3
riffle
0
1
2
3
pool
0
1
2
3
riffle
0
1
2
3
40NSV
41GWL
Long Angle@ Sun Valley
Blue Gum Swamp Creek@Winmalee
44NYR
Frasers Ck @Yellow Rock Road
pool (1 only)
0
1
1
2
45NBX
Cripple Ck@Blaxland
pool1
0
0
1
1
pool2
0
0
1
1
pool1
0
1
1
2
pool2
0
1
3
4
pool
0
0
2
2
riffle
0
0
2
2
edge1
0
0
0
0
edge2
0
0
0
0
Knapsack Bridge
pool1
1
2
1
4
51NGK
Glenbrook Ck@causeway
pool2
pool
0
0
1
0
2
2
3
2
riffle
0
1
4
5
52NGKR
Glenbrook Ck trib @ Red Hands Cave track
pool1
1
2
2
5
pool2
1
2
2
5
46NMR
48NGK
49NGK
50NEP
Strathdon
Lapstone Creek
Glenbrook Lagoon
Left: two Plecoptera (stonefly) Families—Gripopterygidae and Austroperlidae; Above: two Ephemeroptera (mayfly) Families—
Baetidae and Leptophlebiidae; Below: three Trichoptera (caddisfly)
Families—Leptoceridae, Hydropsychidae and Helicopsychidae.
4. Discussion and Conclusions
It is difficult to give a generalized condition rating to Blue Mountains aquatic systems in 2006 as there is high variability in the results between sites within the sample. Many of these variations, however, can be understood when interpreted in the
context of sub-catchment characteristics, water body characteristics and rainfall
(and thus flow patterns) . Overall the SIGNAL2 scores follow a general trend of
higher scores in cooler, flowing waters (upper mountains sites) as the most sensitive families, and thus the higher scoring taxa, prefer high levels of dissolved oxygen and very low levels of suspended and dissolved substances (Chessman 2003)
while lower scores were generally recorded for lower mountains sites. This is further exacerbated by the intermittent or ephemeral nature of many of the streams.
Trends in SIGNAL2 scores over time
A cursory examination of the 1999-2006 SIGNAL2 scores table (results section)
suggests that SIGNAL2 scores at most individual sites have either improved or remained fairly stable over the period that they have been surveyed (up to 8 years).
However, when single-factor analysis of variance (ANOVA) was carried out on the
whole dataset, no significant difference was detected in the SIGNAL2 scores that
the set of sites achieved in different years. This may say as much about the limitations of using SIGNAL2 data for trend analysis as it does about the health of our
waterways over time.
Richness versus SIGNAL2 scores
Biplots (richness vs. SIGNAL2 scores) have at this stage been created only for
2006 data, disallowing the analysis of trends in these results over time. Analysis of
the 2006 biplots is nonetheless useful in increasing our understanding of the current
state of our waterways. Biplots created from the 2006 data are displayed in the results section of this report (separated into five areas for ease of interpretation).
Chessman (2001) developed a system for gleaning information about prevailing water quality and habitat condition at a site, based on the quadrant into which the site
falls when its richness (number of macroinvertebrate Families found) is plotted
against its SIGNAL2 score. This system is explained on the following pages
(extracted from the SIGNAL2 User Manual (Chessman, 2001)).
Chessman’s (2001) “remainder of Australia” quadrant boundaries were used to analyse BMCC’s 2005-2006 data—in future years this may need to be adjusted to reflect the conditions unique to the Blue Mountains.
The following is extracted from the SIGNAL 2 User Manual (Chessman, 2001):
Borders between quadrants vary with
SIGNAL 2 (family)
geographic area and habitat type
QUADRANT 3
QUADRANT 1
Results in this quadrant often indicate
Results in this quadrant usually indicate
toxic pollution or harsh physical
favourable habitat and chemically dilute
conditions (or inadequate sampling)
waters
QUADRANT 4
QUADRANT 2
Results in this quadrant usually indicate
Results in this quadrant often indicate high
urban, industrial or agricultural pollution,
salinity or nutrient levels (may be natural)
or downstream effects of dams
Number of macro-invertebrate families
Figure: The quadrant diagram for the family version of SIGNAL 2
Quadrant 1 (at the top right) represents high values of both SIGNAL 2 and the number of macro-invertebrate types. The presence of large number of types suggests that
the diversity of physical habitats is high and that stress factors like toxic chemicals
and harsh physical conditions are not present. The high SIGNAL 2 scores suggests
that turbidity, salinity and nutrient concentrations are low. Streams in undisturbed native forest will often fall in this quadrant.
Quadrant 2 (at the bottom right) represents lower SIGNAL 2 scores and a high diversity of macro-invertebrate types. Sites falling in this quadrant are likely to have higher
levels or turbidity, salinity or nutrients than those in quadrant 1, as suggested by the
lower SIGNAL 2 score. These levels may be high either naturally, because of local
geology and soil types, or as a result of human activities. The high number of macroinvertebrate types suggests that physical conditions are still benign and toxic chemicals are not present in large amounts. Many agricultural streams without severe impacts fall into this quadrant.
Quadrant 3 (at the top left) represents high values of SIGNAL 2 but few macroinvertebrate types. Sites with toxic pollution, such as those with below old mine sites
where acid rock drainage can result in low pH and high concentrations of trace metals, usually fall either in this quadrant or in quadrant 4. This occurs because the tolerances of some macro-invertebrate types differ according to the type of pollution. For
example, snails and segmented worms are tolerant of most forms of pollution but sensitive to metals. Certain caddis fly families, such as the Leptoceridae, stonefly families
such as the Gripopterygidae and Notonemouridae, and the alderfly family Corydalidae are tolerant of metals even though they are sensitive to many other forms of pollution. SIGNAL 2 is designed to respond to the most common forms of water quality
variation, such as organic and nutrient enrichment and salinity. Sites with unusual
forms of pollution may still have high SIGNAL scores.
Harsh physical conditions can also result in sites falling in quadrant 3. A very simple
habitat structure, such as occurs on mobile sand beds or bare muddy beds, can result
in few macro-invertebrate types being able to colonise and survive, even if water
quality is suitable for them. Extreme floods can wash macro-invertebrates away, so
that few types are collected if sampling occurs soon after the flood has receded.
Streambeds that have recently filled with water after drought may also harbour few
types of macro-invertebrates, until the macro-invertebrates have had time to colonise
and breed. Poor sampling technique or inadequate sampling effort can also result in a
site falling in quadrant 3, because few macro-invertebrates are collected even though
many are present.
Quadrant 4 (at the bottom left) represents low values of both the SIGNAL 2 score and
the number of invertebrate types. Most sites falling into this quadrant will be suffering
from one or more forms of human impact.
Reference: Chessman, 2001.
Analysis of the 2006 data using the biplot quadrants provides interesting results. 46.51% of test sites fell into quadrant 3 (high SIGNAL2 scores but low diversity suggesting either harsh physical conditions or toxic pollution), 41.86% of test
sites fell into quadrant 1 (indicating good water quality and favourable habitat),
6.98% of test sites fell into quadrant 4 (low SIGNAL2 scores and low diversity suggesting significant human impacts e.g. urban pollution), and 4.65% of test sites fell
in quadrant 2 (low SIGNAL2 scores but high diversity indicating high salinity or nutrient levels).
It is important to note that only 2 of the 5 reference sites (40%) fell into quadrant 1,
with the remaining 3 (60%) falling into quadrant 3. This may suggest that some reference sites are inappropriate/unrepresentative - for example the low pH at groundwater-fed sites such as Ingar and Asgard brook may reduce diversity, just as the
intermittent nature of the Queens Road Lawson site may also reduce diversity at the
site. An alternate view is that the quadrant boundaries require adjustment to suit
the lower Family richness that the reference site results may suggest is ‘normal’ for
Blue Mountains streams. This is an issue requiring further attention in future studies
– either more appropriate reference sites need to be selected, or quadrant boundaries need to be adjusted so that the majority (but not necessarily all) of the reference sites fall into quadrant 1 (Chessman, 2001).
Until further investigation we will assume that the provisional quadrant boundaries
are appropriate and interpret what we can from the distribution of sites on the
biplots. A fair proportion of test sites (41.86%) fell into quadrant 1, suggesting that
they were in good condition and were not significantly impacted by human activities.
A significant proportion of test sites (46.51%) fell into quadrant 3, indicating either
toxic pollution or poor/simple habitat conditions that do not support a diverse assemblage of macroinvertebrates. Most of the sites falling into quadrant 3, while impacted by urban areas, would not be expected to be subject to toxic pollution (such
as acid rock drainage from old mine sites). The more likely explanation is that the
limited habitat types at the sites (e.g. a lack of riffle habitat, macrophytes, overhanging banks or trailing vegetation) may disallow colonisation by large numbers of
macroinvertebrate Families. An alternative theory is that sampling effort/technique
was insufficient at sites falling into quadrant 3; however this is unlikely as sampling
followed standard protocols at each site (NSW AUSRIVAS field methods). Recommendation
Only two sites ‘landed’ in quadrant 2: Lapstone Creek and Adams Creek (Medlow
Bath).
Quadrant 4 sites included two of the most degraded waterways in the Blue Mountains – Glenbrook Lagoon (subject to ongoing sewage and stormwater pollution)
and Cripple Creek (downstream of the Blaxland Waste Management Facility
(WMF)), but also Garnett Dam (Hazelbrook) which is in a relatively unimpacted
catchment. The low SIGNAL2 scores and low diversity found at Garnett Dam cannot be explained by the water quality results collected at the time of sampling or by
an examination of recorded landuses in the catchment. Followup testing is recommended to further investigate this site. Council has conducted substantial works to
improve ecosystem health at Glenbrook Lagoon, and ongoing investigations and
work in collaboration with Sydney Water are required to address the issue of sewage pollution. Cripple Creek has long been impacted by the WMF but improvements
to the waste management site should in time lead to increasing ecosystem health in
the creek. See the Cripple Creek case study later in this document.
A CLOSER LOOK AT PET RESULTS
The worst Plecoptera-Ephemeroptera-Trichoptera (PET) scoring site was Glenbrook Lagoon, with no Families from these three Orders recorded during the survey.
The lagoon also had the dubious distinction of being the only site lacking Trichoptera (caddisflies). This result reflects the poor water quality at the site, particularly
the increased organic load from sewage pollution and urban stormwater. The lagoon’s infestation with noxious aquatic weeds (Salvinia and Cabomba) also disrupts
normal ecosystem functioning at the site.
Other sites devoid of Ephemeroptera (mayflies) were Gordon Creek in Leura, Magdala Creek in Springwood, Cripple Creek in Blaxland and Lapstone Creek in Lapstone. Gordon Creek recorded a very high SIGNAL2 score but the site lacked diversity and only one Trichoptera Family and one Plecoptera Family were detected
there.
Sites with suitable habitat for Plecoptera (stoneflies) but which were lacking Plecoptera Families were Waterfall Creek in Mount Wilson, Adams Creek in Medlow Bath,
Kedumba Creek in Katoomba, Leura Falls Creek in Leura and Glenbrook Creek in
Glenbrook.
The average PET score in reference site pool/edge samples was 4 (n=9). Only one
reference riffle sample was available (Asgard), with a PET score of 7. Some reference sites had very low PET scores (e.g. Lawson at Queens Rd (score of 2 in both
pools) and Ingar (score of 2 in the pool and 1 in the dam edge). This further supports the argument that current reference sites are inappropriate due to their inherent conditions—intermittency in the case of the Queens Rd Lawson site and possibly the characteristics of groundwater at Ingar.
The highest PET scores were found in riffle habitats in upper to mid-mountains
creeks—Hat Hill Creek in Blackheath (PET 13), Pulpit Hill Creek in Megalong Valley
(PET 10), Wentworth Creek in Leura (PET 10), Centennial Glen Creek in Blackheath (PET 8), Megalong Creek in Megalong Valley (PET 8), Yosemite Creek in Katoomba, and Bedford Creek in Hazelbrook (PET 8). The highest scoring pool/edge
samples were at Jungaburra Brook at Bell’s Line (reference site—PET 8) and Centennial Glen Creek at Blackheath (PET 8).
Low-scoring sites (PET of 3 and under in at least one sample) were Waterfall Creek
in Mt Wilson, Popes Glen Creek in Blackheath, Adams Creek in Medlow Bath, Katoomba Creek in Katoomba, Megalong Creek tributary in Katoomba (Bonnie Doon),
Kedumba Creek in Katoomba, Leura Falls Creek in Leura, Gordon Creek in Leura,
Valley of the Waters in Wentworth Falls, Wentworth Falls Lake, Garnett Dam in
Woodford, Springwood Creek in Springwood, Magdala Creek in Springwood, Long
Angle Creek in Sun Valley, Blue Gum Swamp Creek in Winmalee, Frasers Creek in
Yellow Rock, Cripple Creek in Blaxland, Strathdon Creek in Emu Plains, Lapstone
Creek in Lapstone, Glenbrook Lagoon, Knapsack Creek in Lapstone and Glenbrook
Creek in Glenbrook.
As 2005-2006 is the first sampling season in which PET scores have been examined, there is no baseline data for comparison in the Blue Mountains. NSW lacks
guidelines for PET scores and so at this stage the Blue Mountains PET results can
be interpreted only in the context of comparing sites. The way that PET scores are
interpreted in future years could be aided by the collection of data from more appropriate reference sites.
Intermittent/Ephemeral Creeks: It has been observed that even in streams of near
pristine condition that are intermittent or ephemeral in nature that very few of the
highest scoring taxa are present (Boulton et al. 2000), skewing these sites into lower
SIGNAL2 rankings than the actual quality of the water would suggest. This was particularly noted on the northern side of the study area in the Lower Mountains, where
three sites were completely dry and several others were intermittent chains of ponds.
Sites with no flow and very low water levels in remaining ponds had some of the lowest SIGNAL 2 scores in the study). These results also reflect the warmer temperatures of the lower mountains sites and the correlating lower dissolved oxygen levels
(that often fell well below ANZECC(2000) guidelines for ecosystem health). It is recommended that the sampling program be adjusted to include permanent sites only.
Florabella Pass Creek. This creek could not be sampled in
2006 due to the very small amount of water remaining in the
system.
Standing Water Bodies
The large standing water bodies that are tested are Wentworth Falls Lake, Glenbrook
lagoon and Garnett Dam. These sites all share characteristics that will produce lower
scoring macroinvertebrate assemblages including lower levels of dissolved oxygen.
All three water bodies are subject to stormwater inputs, but only Glenbrook Lagoon is a
closed system. Glenbrook Lagoon is the subject of ongoing and regular monitoring and
has elevated nutrient levels and sewage infiltration from all three major stormwater devices that deliver stormwater directly to the Lagoon. Not surprisingly the SIGNAL2
score was quite low, however, the diversity of macroinveretbrates collected at the Lagoon was still moderately good. This diversity was dominated by representatives of the
dipterans, in particular the Chironomidae, and the absence of Ephemeroptera and
Trichoptera. This sort of macroinvertebrate assemblage has been observed in several
studies (Wright, et al. 1995) where there are high levels of organic wastes entering an
aquatic system. The higher than expected diversity may also be a result of the extremely good habitat provided by the Lepironia articulata that fringe the Lagoon and the
large amount of woody debris in the sample sites. However, as water levels continue to
drop (as a result of the persistent drought like conditions) less suitable habitat will be
available and a decreasing trend in Family richness and SIGNAL2 scores for the Lagoon are expected to reflect the very poor water quality within the Lagoon.
Glenbrook Lagoon– woody debris and a variety of macrophytes provide excellent habitat for macroinvertebrates, however poor water quality impacts on
the assemblage found at the site.
Groundwater dependant/ Hanging Swamp Sites.
Two of the lower scoring sites in 2006 are Ingar Dam (Aeroplane Hills) and Adams Creek at
Medlow Bath. Both these site occur within large hanging swamp
communities and are not typical of
Blue Mountains Creeks. The bedrock riffle at Adams Creek contains no variety in micro habitats
suitable for Macroinvertebrates
and is directly above a waterfall
that creates a large plunge pool
where edge sampling is undertaken. Water quality at both sites
is characterized by low Ph and
low levels of dissolved oxygen.
The macro-invertebrate communities at both sites are quite different from those found at other sites
including taxa not collected at any
of the other sites in the study
area.
Ingar Dam
Bedrock riffle at Adams Creek Medlow Bath
Cripple Creek flows through BWMF
and landfilling operations have created environmental impacts on both surface water and associated shallow groundwaters.
Cripple Creek– A Special Case-study.
The two tributaries of the creek enter the site from the west. The southern tributary collects
fast flowing stormwater from Attunga Road only during heavy rain events and may be expected to contain typical pollutants associated with urban development. The northern tributary
is believed to be fed by natural spring water in addition to collecting stormwater from the bush
up hill from the site towards Spurwood Avenue and sampling indicates it is relatively unpolluted.
During the early 1980’s the creek channel was diverted into a large culvert. The landfill was
expanded over the culvert and currently the depth of buried waste is approximately 30 metres.
The pressure from the landfilled waste bearing of the pipe is a major risk to its structural integrity and could potentially crack the concrete and increase the amount of leachate which can
leak into the Cripple Creek waters. (Leachate is a product created by the decomposition of
the solid waste. It is typically high in nutrients and base metals.)
The culvert flows out the other side of the landfill and merges with the original creek channel
adjacent to a small stand of Melaleuca linariifolia alluvial swamp. This M linariifolia is a listed
vegetation community under Council’s LEP.
In addition to the leachate pollution of culvert and surface waters, a leachate plume from the
landfill has contaminated the shallow aquifer underlying the swamp.
Groundwater Remediation
In consultation with the EPA and landfill and groundwater experts, Council is currently undergoing significant amelioration works to protect the groundwater. This involves the construction
of an underground impermeable barrier to collect contaminated groundwater and minimise the
quantities leaving the site. Collected leachate will be disposed of to sewer removing it from the site and further
reducing the risk to the environment from the site. A
small portion, (less than 1 Ha) of the swamp has been
cleared to facilitate this highly complex construction project.
An upstream barrier has also been constructed to stop
clean groundwater flowing into the waste to reduce the
amount of leachate created which needs to be disposed
of to sewer.
Surface Water Remediation
The structural integrity of the existing culvert is at risk.
Any damage to the normal concrete pipes would be irreparable and retrofitting an internal liner to the culvert is
impossible.
A new culvert will be constructed during 2007 at a cost of
$1.8 M, using high strength concrete pipes overlaid with
an impermeable barrier. A new landfill will be constructed over the second culvert which has composite double lining system and full leachate
collection providing protection for the surface waters. Infiltration into the old culvert will be collected as leachate and disposed of to sewer. The design for these works have been subject to
substantial input from numerous environmental experts and has been approved by an extensive Environmental Impact Statement process.
References
Boulton, A.J., Sheldon, F., Thoms,M.C., and Stanley, E.H. (2000). Problems and
constraints in managing rivers with variable flow regimes. In “Global Perspectives
on River Conservation: Science, Policy and Practice’.(Eds P.J.Boon, B.R.Davies
and G.E.Petts.) pp 415-30. (Wiley: Chichester)
Chessman, B.C. (2003) New sensitivity grades for Australian river macroinvertebrates. Marine and Freshwater Research 54, 95-103.
Chessman, B. 2001, SIGNAL2: A Scoring System for Macro-invertebrates (‘Water
Bugs’) in Australian Rivers—User Manual Version 2
Department of Environment and Conservation (DEC) NSW, 2004, New South
Wales (NSW) Australian River Assessment System (AUSRIVAS) Sampling and
Processing Manual, DEC, Sydney
Growns, J.E., Chessman, B.C., McEvoy, P.K., and Wright, I.A., (1995) Rapid Assessment of rivers using macroinvertebrates: case studies in the Nepean and and
Blue Mountains, NSW. Australian Journal of Ecology 20, 130-41.
Wright, I.A., Chessman, B.C., Fairweather, P.G., and Benson, L.J., (1995) Measuring the Impact of sewerage effluent on the macroinvertebrate community of an upland stream: The effect on different levels of taxonomic resolution and quantification. Australian Journal of Ecology 20, 142-149.
Appendix 1:
Water Quality Results
Water quality parameters collected during 2006 are compared to the trigger values set down
in ANZECC (2000) guidelines. Those exceeding the default trigger values for Upland Rivers
or Freshwater Lakes( Garnett Dam, Wentworth Falls Lake and Glenbrook Lagoon only) are
highlighted in red. Note that not all parameters collected have default trigger values for ecosystem protection. These are recorded in Green.
Table: ANZECC 2000 Default trigger values for aquatic ecosystem protection*
*Physical and chemical stressors for south-east Australia
Ecosystem Type
Upland river
TP
(µg/L)
20
TN
(µg/L)
250
DO
(% sat)
90 -110
Lowland river
50
500
Freshwater Lakes & Reservoirs
Estuaries
10
30
pH
6.5 - 8.0
Turbidity
(NTU)
2 - 25
EC
(µS/cm)
30 - 350
85 -110
6.5 - 8.5
6 - 50
125 - 2200
350
90 -110
6.5 - 8.0
1 - 20
20 - 30
300
80 -110
7.0 - 8.5
0.5 - 10
N/A
Table:Water column features
Site
Waterfall Ck
Jungaburra Brook
Fairy Dell Creek
Grose River trib@Mt Vic
Asguard Brook
Hat Hill Creek
Popes Glen Creek @Govetts walk
Bridal Vale Creek
Centennial Glen@Blackheath
Pulpit Hill Creek 2
Megalong Ck@Old Ford Reserve
Adams Creek
Minnehaha Falls Creek trib
Yosemite Creek @Nth Katoomba
Katoomba @ Hodgson Park
Govetts Creek@leura
Megalong Creek trib@Bonnie
Doon stuarts road
Kedumba River@Katoomba Falls
reserve
Leura Falls Creek
Gordon Ck @ Leura
Valley of the Waters @Leura
Jamison Creek
Wentworth falls lake
Wentworth creek @ Leura
Water Nymphs Dell
Water Nymphs Dell
Lawson@Queens rd
Ingar
Dantes Glen
Bedford Creek
Terrace Falls
Garnett Ck @ Woodford (dam)
Hazelbrook Creek
Woodford Ck
Linden Ck @ Grose Rd Faulconbridge
Springwood Ck
Magdala Creek 2
Glenbrook Creek trib @ Deakin
(Swd)
Fitzgerald creek @ Valley heights
Long Angle@ Sun Valley
Blue Gum Swamp
Creek@Winmalee
Frasers Ck trib @Yellow Rock
Cripple Ck@Blaxland
Strathdon
Lapstone Creek
Glenbrook Lagoon
Knapsack Bridge
Glenbrook Ck@causeway
Glenbrook Ck trib @ Red Hands
Cave track
103
101
107
93.9
118
114
101
96.3
102
84.5
102
Conduct.
(ms/
cm)
0.05
0.03
0.55
0.042
0.033
0.033
0.075
0.049
0.042
0.034
0.054
0.04
0.062
0.079
0.066
0.048
Temp
(oC)
13.18
16.14
11.28
10.9
9.65
14.75
14.5
15.66
15.68
16.56
28.95
21
13.58
14
13.29
14.9
Faecal coliforms
(colonies/100
ml)
pH
7.09
7.12
7.96
7.54
7.53
7.55
7.9
7.72
7.39
6.76
6.9
6.57
7.68
7.37
7.52
8.45
Turbidity
NTU
9.4
17
18.3
35
240(?)
14
13.4
23
17.5
20.1
8
11.1
19.5
23.7
15.7
14.9
8.25
9.6
75.1
0.03
14.77
0.02
7.39
7.04
8.51
8.17
6
6
7.26
7.5
7.17
7.88
8.7
7.7
7.36
6.83
8.21
8.31
7.08
13.2
13.4
21.5
15.6
11
10.1
18.2
12.5
39.3
14
8.3
9.4
11.46
7.8
30.5
13.4
8.4
107
112
85.3
98.5
111
106
102
87
118
52.7
99
97
108
99
68.4
99.5
104
0.068
0.081
0.055
0.038
0.07
0.04
0.037
0.071
0.074
0.082
0.037
0.193
0.05
0.045
0.046
0.083
0.074
17.08
14.95
7.79
10.16
22.79
23.59
18.96
15.6
16.17
12.9
11.06
17.36
17.53
18.75
15.85
12.05
17.63
0.04
0.04
0.03
0.02
0.03
0.03
0.02
0.04
0.04
0.04
0.02
0.09
0.03
0.03
0.03
0.04
0.04
8.36
7.9
8.5
16.1
9.5
57.8
66.9
95.1
36.5
0.112
0.166
0.321
11.29
19.14
10.65
0.05
0.08
0.15
0
80
8.45
8.31
7.6
16.2
31.9
11.8
48
94
89.6
0.177
0.165
0.169
13.19
20.44
19.42
0.08
0.08
0.08
0
450
900
7.39
9
8.38
7.61
6.88
7.11
8.6
6.87
14.4
20.6
30
18.8
19.8
13.5
14.4
7.8
34.3
20.5
60
37.4
111
29.8
59.6
27.2
0.129
0.19
1.186
0.145
0.184
0.134
0.27
0.134
17.88
9.8
16.88
21.15
20.58
20.39
16.29
23.32
0.06
0.09
0.59
0.07
0.09
0.07
0.13
0.07
10
6700
10
420
7.37
13.7
55.8
0.156
20.56
0.08
0
DO (%
sat)
102
62
90.8
85
Salinity
(PSS)
0.03
0.02
0.026
0.02
0.02
0.02
0.04
0.03
0.02
0.02
0.03
0.02
0.03
0.04
0.03
0.03
0
170
80
0
0
50
10
30
100
10
300
80
40
0
120
40
320
0
2500
10
10
10
30
1200
250
190
560