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
Hunt504 - Williams River downstream of Clarence Town
Site Condition Summary
At this site, the Williams River was broad, deep and slow flowing. Only a single visit was made to this site. Visual assessments indicated the site had a degraded riparian zone, with weeds and rubbish present. Beyond the riparian zone, the primary land use was grazing. Water quality variables were as expected for a lowland river of this size.
Assessments of the edge habitat indicated the richness of the macroinvertebrate community to be much poorer than expected. The O/E-Taxa value derived was 0.44 (band C).
None of the Diptera (true flies), Ephemeroptera (mayflies) and Odonata (dragonflies) that were predicted were collected.
Location Map
| Map Name | Maitland 9232-4-S |
| Map Zone | 56 |
| Map Scale | 1:25000 |
| Easting | 380000 |
| Northing | 6387400 |
| Distance from source (m) | 103000 |
| Elevation (m asl) | 0 |
| Average Annual Rainfall (mm) | 1100 |
Sampling Data and Assessments
Single Season Assessments
| Autumn '97 | |
|---|---|
| 18-Apr-97 | |
| O/E Taxa | 0.44 |
| Band | C |
| O/E SIGNAL | 1.03 |
Riffle
Combined Season Assessments
Edge
Riffle
Taxa Collected
X= Taxa Predicted & Collected, O = Taxa Predicted & NOT Collected, + = Taxa Collected & NOT Predicted
| Autumn '97 | |||
|---|---|---|---|
| Phylum | Class/Order | Family | 18-Apr-97 |
| Arachnida | Hydracarina | O | |
| Crustacea | Decapoda | Atyidae | X |
| Crustacea | Isopoda | Sphaeromatidae | + |
| Insecta | Coleoptera | Dytiscidae | O |
| Insecta | Coleoptera | Elmidae | O |
| Insecta | Coleoptera | Hydrophilidae | X |
| Insecta | Diptera | Chironominae | O |
| Insecta | Diptera | Orthocladiinae | O |
| Insecta | Diptera | Tanypodinae | O |
| Insecta | Ephemeroptera | Baetidae | O |
| Insecta | Ephemeroptera | Caenidae | O |
| Insecta | Ephemeroptera | Leptophlebiidae | O |
| Insecta | Hemiptera | Corixidae | X |
| Insecta | Hemiptera | Gerridae | O |
| Insecta | Hemiptera | Hydrometridae | + |
| Insecta | Hemiptera | Veliidae | X |
| Insecta | Odonata | Coenagrionidae | + |
| Insecta | Odonata | Gomphidae | O |
| Insecta | Odonata | Isostictidae | + |
| Insecta | Odonata | Libellulidae | O |
| Insecta | Trichoptera | Calamoceratidae | X |
| Insecta | Trichoptera | Leptoceridae | X |
| Mollusca | Bivalvia | Corbiculidae | + |
| Mollusca | Gastropoda | Physidae | + |
| Mollusca | Gastropoda | Planorbidae | + |
Riffle
Water Quality Data
| Autumn '97 | |
|---|---|
| Variable | 18-Apr-97 |
| Water Temperature (°C) | 23 |
| Conductivity (µS/Cm) | 111 |
| Alkalinity (mg CaCO3 /L) | 38 |
| pH | 7.75 |
| Dissolved Oxygen (mg/L) | 9.25 |
| Turbidity (NTU) | 10.4 |
| Low Total Phosphorus (µg/L) | 68 |
| Free Reactive Phosphorus (mg/L) | |
| NOx Nitrogen (mg/L) | <10 |
| Total Kjeldahl Nitrogen (mg/L) | 0.53 |
| Nitrate (mg/L) | |
| Nitrite (mg/L) |
Key
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