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

Hunt511 - Krui River at Cassilis Merriwa Road

Site Condition Summary

This site on the Krui River was surrounded by grazing lands. The riparian zone had been cleared and replaced with exotic grasses and a few willow trees. Visual assessments indicated water quality and instream habitat were degraded, which was attributed to cattle and sheep access to the river.

On both sampling occasions, the river water was super-saturated with oxygen, which may reflect the high primary productivity in the stream, as evidenced blooms of filamentous green algae. In October 1997, the water was noted to have an oily surface film and foam.

Despite the apparently degraded habitat, the macroinvertebrate fauna were similar to those expected if the site were in reference condition. Assessments for all single season models were greater than 0.97 (band A). Assessments for combined season models were also in band A, with O/E-Taxa values of 1.08 and 0.86 for edge and riffle models respectively.

Location Map

Location Details
Map Name	Borambil 8933-4-N
Map Zone	56
Map Scale	1:25000
Easting	227900
Northing	6445100
Distance from source (m)	42908
Elevation (m asl)	310
Average Annual Rainfall (mm)	650

Single Season Assessments

Edge
	Autumn '97	Spring '97
	14-Apr-97	20-Oct-97
O/E Taxa	1.04	1.27
Band	A	X
O/E SIGNAL	0.99	1.03

Riffle
	Autumn '97	Spring '97
	14-Apr-97	20-Oct-97
O/E Taxa	0.97	1.05
Band	A	A
O/E SIGNAL	0.98	0.93

Combined Season Assessments

Edge
Seasons	AUT97SPR97
Model	Eastern
O/E Taxa	1.08
Band	A
O/E SIGNAL	1.00

Riffle
Seasons	AUT97SPR97
O/E Taxa	0.86
Band	A
O/E SIGNAL	0.91

Taxa Collected

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

Edge
			Autumn '97	Spring '97
Phylum	Class/Order	Family	14-Apr-97	20-Oct-97
Arachnida	Hydracarina		+	+
Crustacea	Decapoda	Atyidae	X	X
Crustacea	Ostracoda		+
Insecta	Coleoptera	Dytiscidae	X	X
Insecta	Coleoptera	Elmidae		+
Insecta	Coleoptera	Hydraenidae	+
Insecta	Coleoptera	Hydrophilidae	O	X
Insecta	Coleoptera	Psephenidae	+
Insecta	Diptera	Ceratopogonidae		+
Insecta	Diptera	Chironominae	X	X
Insecta	Diptera	Dixidae		+
Insecta	Diptera	Orthocladiinae	X	X
Insecta	Diptera	Simuliidae		+
Insecta	Diptera	Tanypodinae	X	X
Insecta	Ephemeroptera	Baetidae	X	X
Insecta	Ephemeroptera	Caenidae	X	X
Insecta	Ephemeroptera	Leptophlebiidae	X	X
Insecta	Hemiptera	Corixidae	X	X
Insecta	Hemiptera	Gerridae	O
Insecta	Hemiptera	Mesoveliidae	+
Insecta	Hemiptera	Notonectidae	X	X
Insecta	Hemiptera	Veliidae	X	X
Insecta	Odonata	Aeshnidae	+
Insecta	Odonata	Coenagrionidae	+	+
Insecta	Odonata	Corduliidae		+
Insecta	Odonata	Gomphidae	O	X
Insecta	Trichoptera	Glossosomatidae	+
Insecta	Trichoptera	Hydrobiosidae		+
Insecta	Trichoptera	Hydroptilidae		+
Insecta	Trichoptera	Leptoceridae	X	X
Mollusca	Gastropoda	Lymnaeidae		+
Mollusca	Gastropoda	Physidae	+	O
Platyhelminthes	Turbellaria	Dugesiidae	+	+

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

Riffle
			Autumn '97	Spring '97
Phylum	Class/Order	Family	14-Apr-97	20-Oct-97
Annelida	Hirudinea	Erpobdellidae	+
Annelida	Hirudinea	Glossiphoniidae	+
Annelida	Oligochaeta		X	X
Arachnida	Hydracarina			X
Crustacea	Decapoda	Atyidae		+
Crustacea	Decapoda	Palaemonidae	X
Insecta	Coleoptera	Dytiscidae		+
Insecta	Coleoptera	Elmidae	X	X
Insecta	Coleoptera	Psephenidae	+
Insecta	Coleoptera	Scirtidae	+
Insecta	Diptera	Ceratopogonidae		+
Insecta	Diptera	Chironominae	X	X
Insecta	Diptera	Orthocladiinae	X	X
Insecta	Diptera	Simuliidae	X	X
Insecta	Diptera	Tanypodinae	X	X
Insecta	Diptera	Tipulidae		O
Insecta	Ephemeroptera	Baetidae	X	X
Insecta	Ephemeroptera	Caenidae	O	X
Insecta	Ephemeroptera	Leptophlebiidae	X	X
Insecta	Hemiptera	Corixidae		+
Insecta	Megaloptera	Corydalidae	X	O
Insecta	Odonata	Gomphidae	X	X
Insecta	Plecoptera	Gripopterygidae	O	O
Insecta	Trichoptera	Glossosomatidae		+
Insecta	Trichoptera	Hydrobiosidae	O	X
Insecta	Trichoptera	Hydropsychidae	X	X
Insecta	Trichoptera	Leptoceridae	+	+
Mollusca	Bivalvia	Corbiculidae	X
Platyhelminthes	Turbellaria	Dugesiidae	O

Water Quality Data

	Autumn '97	Spring '97
Variable	14-Apr-97	20-Oct-97
Water Temperature (°C)	20.7	21.1
Conductivity (µS/Cm)	700	604
Alkalinity (mg CaCO₃ /L)	300	250
pH	8.5	8.42
Dissolved Oxygen (mg/L)	10	10.7
Turbidity (NTU)	8	2.7
Low Total Phosphorus (µg/L)	200	180
Free Reactive Phosphorus (µg/L)
NOx Nitrogen (µg/L)	<10	40
Total Kjeldahl Nitrogen (mg/L)	<0.3	0.44
Nitrate (µg/L)
Nitrite (µg/L)

Key

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