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

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

4. Results from AusRivAS Assessments in the Lower North Coast, Hunter and Central Coast Catchments of NSW

This report has been developed to present the results obtained from the sampling program undertaken over the period 1994-99 in the Lower North Coast, Hunter, and Central Coast catchments of NSW. The need for such a report was identified in discussions between Department of Infrastructure, Planning and Natural Resources, Hunter Region staff (formerly DLWC) and the NSW EPA AusRivAS project team. It was thought that the specific site data could provide a valuable reference resource to support ongoing regional assessment work in these catchments.

4.1 Data included in this report

The data contained in this report has been derived from sites covered by the catchments of the Hunter, Karuah (including Great Lakes), Tuggerah and Manning Rivers. Sites assessed were selected from a wide range of landscapes. It includes the steep mountainous terrain of Barrington Tops, the coastal swamps and lagoons of the Great Lakes area, and the low rainfall regions of the upper Hunter Valley. The region also supports a diverse range of human activities including coal mining, power generation, grazing, cropping, urban development, heavy industry, conservation and tourism.

Work on the NSW component of the MRHI project began in 1994 and culminated in June 2000 with the development of predictive models. The NSW component involved sampling some 300 'reference sites ' at various times between 1994 and 1999. This included 27 reference sites within the Hunter, Karuah, and Manning River Catchments and the Tuggerah, Myall and Wallis Lakes catchments. The data collected from these reference sites contributed to the data sets from which the AusRivAS predictive models were developed.

The process of selecting sites within the study area began with the identification of different landscape types within the region. Approximate locations for sites were initially chosen so as to include as many landscape types as possible. Specific locations of sampling sites were determined after consultation with state and local government-agencies and community groups. As the sampling program progressed additional sites were selected to provide a more comprehensive geographic spread and include regions and stream types not very well represented previously. The regions included in the latter sampling included Tuggerah, Lake Macquarie, the Karuah River, Wallis Lake, Myall Lake, the south western section of the Manning River catchment and much of the southern part of the Hunter catchment. The stream types targeted by this additional sampling were primarily mainstream river sites on the Hunter and Manning rivers; low gradient coastal streams in the Tuggerah, Myall and Wallis Lake catchments; and sandy river sites in the Goulburn River catchment.

In addition to the representation of regions and stream types, an effort was made to represent all the major land use types in the region. Choosing sites to fill gaps in stream type and land use was a consultative process with direct involvement of staff from NSW EPA, DLWC, NPWS, State Forests, local government, and the community.

4.2 Presentation of data and use of this report

The results from the AusRivAS assessments and data collected from sites in the Hunter region are presented in report card format, with a separate report card compiled for each of the sampling sites.

A catchment-scale map (Fig. 1 above) is provided to show the location of sites within the catchments. To allow for a systematic identification of sites, a unique AusRivAS site code and name was developed for each site. The site code indicates the river catchment (Hunt = Hunter, Karu = Karuah (includes Wallis and Myall lake catchments) Tugg = Tuggerah and Mann = Manning) and a numeric site identifier. The site name gives a brief description of site location. A list of sites ordered by both site code (and hence catchment) and site name (and hence river/stream name) is also provided. The site code, however, are unique identifiers only for the NSW component of the Monitoring River Health Initiative (MRHI)

For each site, an individual report card providing a summary of AusRivAS assessments, including O/E values for the various models and lists of predicted, collected and missing taxa is presented. In each report card a general statement is made regarding the overall richness of the macroinvertebrate fauna; an example report card is shown in Fig. 2. The report cards also include some water quality data and a brief interpretation of these data. This interpretation is based on the range of values obtained for reference sites in different types of streams in this region. This approach to assessment of water quality is in line with the philosophy of the new water quality guidelines for Australia (Hart et al. 1999, ANZECC/ARMCANZ 2001) which encourages the use of ecosystem-specific and region-specific criteria for assessment of water quality based on reference sites.

The report cards include representative photographs of each site and document observations made by the sampling team on the appearance of the water, instream habitat, banks and riparian vegetation and evidence of human disturbance that may affect these components of the river ecosystem. It is envisaged that the information provided in these report cards will provide a basis for further assessing trends in river health in the Hunter Region.

It is recognised that the information provided in this report does not evaluate all aspects of the river ecosystem, however it does include data relating to key components such as fauna, water quality and some aspects of the available habitat, providing a broader basis for assessing river health. Short river reaches represented by sites that have rich macroinvertebrate fauna, good water quality and good riparian condition may be considered to be in good ecological health. Rivers on which many sites have been sampled and where all the sites (or almost all) were assessed as being in good condition may be considered as healthy rivers. It must, however, be remembered that whether we are assessing the macroinvertebrate fauna, water quality or state of the riparian vegetation, our relative judgments is based on the perceived reference condition, which is determined from data collected from the "best available sites".

With the establishment of the Lower North Coast, Hunter and Central Coast catchment Boards and the subsequent development of catchment health targets, the importance of having suitable reporting tools cannot be under stated. Data contained in this report has been used to assist the development of catchment health targets for these Catchment Boards and to assist in the identification of the ongoing monitoring and evaluation programs to report on the progress towards the Catchment Board targets.

Hunt777 - Example Creek

Site Condition Summary

Example Creek

Site Condition Summary provides information describing the site, its surroundings, its condition and actual or potential impacts.

The summary is based on visual assessments of the riparian zone, water quality and instream habitat at the site as well as water quality analysis. The raw data for the water quality analyses are given in the "Sampling data and assessments" page.

The results of AusRivAS assessments are given and described, with additional comments on any particular patterns or trends that are evident. Comments on the type of macroinvertebrates that were found (or not found) at a site are also provided.

Left and right banks are assigned when looking downstream.

The page title gives the NSW MRHI code and name for the site. The site code indicates the river catchment (eg Hunt = Hunter, Mann = Manning) and a numeric site identifier.

Maps have been sourced from Geoimage and AUSLIG (1998a,b).

Sampling Data and Assessments

Location Map

Location Map

Feint grid lines indicate 1 km square

Location Details
Map Name Allynbrook 9233-3-N
Map Zone 56
Map Scale 1:25000
Easting 359900
Northing 6423400
Distance from source (m) 33420
Elevation (m asl) 110
Average Annual Rainfall (mm) 850