River Health in the New South Wales Lower North Coast, Hunter and Central Coast Catchments

A report of AusRivAS assessments 1994 - 1999
Grant Hose and Eren Turak
Environment Protection Agency, 2004
ISBN 0 642 55099 9 ISSN 1447-1280

Hunt543 - Wollombi Brook at Williams Bridge

Site Condition Summary
Sampling Data and Assessments
Site report cards

Site Condition Summary

This site was in grazing country upstream of the township of Wollombi. The native riparian vegetation had been partly cleared which had led to some bank erosion and infestation of blackberries.

Visual assessments indicated the instream habitat was degraded by sedimentation and rubbish in the stream. Along with this, water quality was degraded with an odour and foam noted on both sampling occasions. In both seasons, oxidised nitrogen (NOx) concentrations were high. In Autumn 1998, pH was low and nitrogen (TKN) concentration was high. In Spring 1998, conductivity was high.

The AusRivAS assessments for this site showed large variation between seasons. In Autumn 1998, the richness of macroinvertebrates in both edge and riffle habitats was much poorer than predicted (O/E-Taxa values in band C and D respectively). Assessments for Spring 1998 returned O/E-Taxa values in band B for both habitats. Combined season assessments gave values in band B and C for edge and riffle habitats respectively.

In the edge habitats, the predicted Ephemeroptera and Hemiptera taxa were rarely collected. In Autumn 1998 riffle samples, only Chironominae and Atyidae were collected. Hydracarina and Caenidae were predicted in all habitats and samples but never collected.

Location Map

Location Details
Map Name	Wollombi 9132-3-S
Map Zone	56
Map Scale	1:25000
Easting	324500
Northing	6355400
Distance from source (m)	43218
Elevation (m asl)	95
Average Annual Rainfall (mm)	950

Single Season Assessments

Edge
	Autumn '98	Spring '98
	13-May-98	15-Oct-98
O/E Taxa	0.16	0.72
Band	C	B
O/E SIGNAL	0.77	0.78

Riffle
	Autumn '98	Spring '98
	13-May-98	15-Oct-98
O/E Taxa	0.12	0.70
Band	D	B
O/E SIGNAL	0.49	1.01

Combined Season Assessments

Edge
Seasons	AUT98SPR98
Model	Eastern
O/E Taxa	0.73
Band	B
O/E SIGNAL	0.82

Riffle
Seasons	AUT98SPR98
O/E Taxa	0.55
Band	C
O/E SIGNAL	1.03

Taxa Collected

X= Taxa Predicted & Collected, O = Taxa Predicted & NOT Collected, + = Taxa Collected & NOT Predicted

Edge
			Autumn '98	Spring '98
Phylum	Class/Order	Family	13-May-98	15-Oct-98
Annelida	Oligochaeta			X
Arachnida	Hydracarina		O	O
Crustacea	Decapoda	Atyidae	X	X
Crustacea	Decapoda	Palaemonidae		+
Crustacea	Isopoda	Oniscidae	+
Insecta	Coleoptera	Dytiscidae	O	X
Insecta	Coleoptera	Elmidae	O	O
Insecta	Coleoptera	Hydraenidae		X
Insecta	Coleoptera	Hydrophilidae	X	X
Insecta	Coleoptera	Scirtidae	O	O
Insecta	Diptera	Ceratopogonidae		O
Insecta	Diptera	Chironominae	O	X
Insecta	Diptera	Culicidae		+
Insecta	Diptera	Orthocladiinae	O	+
Insecta	Diptera	Simuliidae		+
Insecta	Diptera	Tanypodinae	O	X
Insecta	Diptera	Tipulidae	+
Insecta	Ephemeroptera	Baetidae	O	X
Insecta	Ephemeroptera	Caenidae	O	O
Insecta	Ephemeroptera	Leptophlebiidae	O	O
Insecta	Hemiptera	Corixidae	O	O
Insecta	Hemiptera	Gerridae	O	O
Insecta	Hemiptera	Hydrometridae		+
Insecta	Hemiptera	Mesoveliidae		+
Insecta	Hemiptera	Notonectidae		X
Insecta	Hemiptera	Pleidae	+
Insecta	Hemiptera	Veliidae	O	X
Insecta	Lepidoptera	Pyralidae		+
Insecta	Odonata	Aeshnidae	+
Insecta	Odonata	Coenagrionidae	+	+
Insecta	Odonata	Gomphidae	O	+
Insecta	Odonata	Libellulidae	+
Insecta	Plecoptera	Gripopterygidae		O
Insecta	Trichoptera	Calamoceratidae		O
Insecta	Trichoptera	Hydroptilidae		O
Insecta	Trichoptera	Leptoceridae	O	X
Mollusca	Gastropoda	Lymnaeidae	+
Mollusca	Gastropoda	Physidae	+	+
Mollusca	Gastropoda	Planorbidae	+
Platyhelminthes	Turbellaria	Dugesiidae		+

X= Taxa Predicted & Collected, O = Taxa Predicted & NOT Collected, + = Taxa Collected & NOT Predicted

Riffle
			Autumn '98	Spring '98
Phylum	Class/Order	Family	13-May-98	15-Oct-98
Annelida	Oligochaeta		O	X
Arachnida	Hydracarina		O	O
Crustacea	Decapoda	Atyidae	X	X
Crustacea	Decapoda	Palaemonidae	+
Insecta	Coleoptera	Dytiscidae		+
Insecta	Coleoptera	Elmidae	O	X
Insecta	Coleoptera	Gyrinidae		+
Insecta	Coleoptera	Hydrophilidae	+
Insecta	Coleoptera	Psephenidae	O	O
Insecta	Diptera	Chironominae	X	X
Insecta	Diptera	Orthocladiinae	O	X
Insecta	Diptera	Simuliidae	O	X
Insecta	Diptera	Tanypodinae	O	O
Insecta	Diptera	Tipulidae	O	O
Insecta	Ephemeroptera	Baetidae	O	X
Insecta	Ephemeroptera	Caenidae	O	O
Insecta	Ephemeroptera	Leptophlebiidae	O	X
Insecta	Megaloptera	Corydalidae	O	O
Insecta	Odonata	Aeshnidae	O	O
Insecta	Odonata	Gomphidae	O	O
Insecta	Plecoptera	Gripopterygidae	O	X
Insecta	Trichoptera	Hydrobiosidae	O	X
Insecta	Trichoptera	Hydropsychidae	O	O
Insecta	Trichoptera	Leptoceridae	O	O
Insecta	Trichoptera	Philopotamidae	O	X
Mollusca	Bivalvia	Corbiculidae	+
Platyhelminthes	Turbellaria	Dugesiidae	O

Water Quality Data

Water Quality Data
	Autumn '98	Spring '98
Variable	13-May-98	15-Oct-98
Water Temperature (°C)	13.1	18.5
Conductivity (µS/Cm)	256	495
Alkalinity (mg CaCO₃ /L)	12	36
pH	5.84	7.2
Dissolved Oxygen (mg/L)		9
Turbidity (NTU)		5.6
Low Total Phosphorus (µg/L)	28	12
Free Reactive Phosphorus (µg/L)	3	2
NOx Nitrogen (µg/L)	180	94
Total Kjeldahl Nitrogen (mg/L)	0.46	0.44
Nitrate (µg/L)	180	91
Nitrite (µg/L)	4	3

Key

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