Goulburn Mulwaree
Indicator: Riparian Conditions
Results for this indicator are also available for [an error occurred while processing this directive]
What the results tell us for Goulburn Mulwaree
No quantitative information was available to assess change in riparian condition within the Goulbourn Mulwaree Council area during the current reporting period and the previous reporting period. This current reporting period has seen six threatening process, which impact on riparian condition, listed under the Threatened Species Conservation Act 1995 and the Fisheries Management Act 1994.
During the previous reporting period, five riparian management demonstration sites were set up as part of a project to develop riparian management guidelines for Wollondilly River. Landholders, a range of community groups, Council and various government agencies participated in riparian management activities at these sites. Council or community groups, during the last reporting period, also undertook at least seven other projects between July 2000 and June 2004 to rehabilitate riparian areas within the Council area (OCE 2004).
Landcare groups facilitated by the Goulburn Mulwaree Council continued projects involving river rehabilitation during the current reporting period however specific details are unavailable (GMC 2008).
Condition of riparian zones in the Council area
The previous reporting period showed that five major rivers within the Council area had highly disturbed riparian vegetation or gully erosion in their catchments.
The previous Regional State of the Environment Report, reported that riparian vegetation along approximately 47 kilometres of Wollondilly River and Mulwaree Ponds in the area surrounding the city of Goulburn was in poor condition (McDonald 2003). Only 3% of the rivers in the study area had any native riparian vegetation and of this only 2% had relatively good quality native vegetation. The remaining 97% of the riparian zone was infested to some degree by exotic plants.
A snapshot of the Wollondilly River that included both floodplain and floodplain and hills sections of the river within the Council area (Crawford and Lewis 2002) found that in the floodplain section:
- riparian vegetation was dominated by willows (Salix spp) and pasture grasses with very little with native species; the diversity of native species increased slightly closer towards and through the city of Goulburn:
- the river channel was incised, with some bank erosion occurring throughout
- habitat and native vegetation had poor overall ratings.
In the floodplains and hills section of the Wollondilly River, Crawford and Lewis (2002) reported:
- more native remnant riparian vegetation was present than in the upstream reaches
- extreme gully erosion was present (due to the majority of the floodplain areas having been cleared for grazing)
- habitat and native vegetation had moderate to good overall ratings.
No detailed Council-wide information was available regarding the condition or changes in the condition of riparian vegetation, channel modification or streambank disturbance for the current reporting period.
Threats to riparian condition
Three processes relating to riparian condition have been listed as key threatening processes in the State (see Table 1) by the New South Wales (NSW) Scientific committee under the Threatened Species Conservation Act 1995. Fisheries Scientific Committee also listed, under the Fisheries Management Act 1994, three key threatening processes relevant to riparian areas.
| Name of threatening process | Date of Final Determination or Gazettal |
|---|---|
| Alteration to the natural flow regimes of rivers, streams, floodplains & wetlands (DECC 2008a) | Final: 31 May 2002 |
| Clearing of Native Vegetation (DECC 2008b) | Final: 21 September 2001 |
| Human-caused climate change (DECC 2008c) | Gazetted: 17 November 2000 |
| Removal and degradation of native riparian vegetation (DPI 2008a) | Final: 01 June 2005 |
| Installation and operation of in stream structures and other mechanisms that alter the natural flow regimes of rivers and streams (DPI 2008b) | Final: 01 June 2005 |
| Removal of large woody debris from NSW rivers and streams (DPI 2008c) | Final: 01 June 2005 |
The impacts of these key threatening processes on riparian conditions and waterways include (DECC 2008 a, b; DPI 2008, a, b; DPI 2005a):Source: DECC 2008
- bank erosion
- loss of biological diversity
- impairment of important ecosystem services for fish and invertebrates (e.g. removal of refuges used during flooding or drought or removal of spawning sites)
- reduced nutrient filtering capacity
- increased light penetration of the water-body and loss of shade and shelter for fish
- reduced inputs of organic carbon (for example, twigs and leaves)
- changes to stream behaviour (increased and decreased flow, seasonality, frequency, duration, magnitude, timing predictability, rate of rise and fall of water levels and altering surface and subsurface water levels)
- Exotic plants such as Alligator weed (Alternanthera philoxeroides) reducing stream flow
What is being done to protect riparian zones?
State government activities
In 2001 the State Government produced a statement of intent for the Hawkesbury Nepean River System (NSW Government 2001) in response to the Healthy River Commission inquiry into this system (HRC 1998). The Government's statement of intent outlines commitments of state agencies to implement the recommendations of the Commission's inquiry. Commitments relating to riparian condition within the Hawkesbury Nepean River System included the preparation of a State Riverine Corridor Policy by December 2001; this policy was to form part of an integrated approach across all sectors of government within NSW to riparian protection and management. The State Riverine Corridor Policy document had not been produced by the end of the current reporting period.
Council activities
The former Goulburn City Council commissioned a riparian vegetation study of rivers in the vicinity of Goulburn City (McDonald 2003). The study report included recommendations aimed at helping to restore and protect riparian zones along sections of the Wollondilly River and Mulwaree Ponds. The recommendations included:
- revegetation of the riparian zone with locally endemic species
- removal and control of weeds within the riparian zone
- fencing to prevent stock access to the riparian zone
- removal of old weirs (e.g. between McDermott Drive and Tarlo Street bridges)
- maintenance of tree plantings in the riparian zone to remove weeds and encourage growth
- removal of rubbish within the riparian zone
- control of stream bank erosion
- rabbit control.
None of the actions and recommendations from this report had been formally endorsed or implemented by Council during this current reporting period.
Catchment management committee activities
In 2002 the Wollondilly Catchment Management Committee commissioned the development of riparian management guidelines for Wollondilly River and Wingecarribee River (Crawford and Lewis 2002). As part of the Wollondilly River riparian management guidelines report, a number of sites were set up as riparian management demonstration sites. Five of these sites were located within Goulburn Mulwaree Council area—landholders, community groups, Council and various government agencies participated in a range of riparian management activities at these sites. Updated information on the progress of this project was unavailable for the current reporting period.
Other activities
Community groups, Council or other organisations may have undertaken projects during the reporting period that enhanced riparian conditions but updated information is currently unavailable.
Nationally funded activities undertaken during the reporting period in the Southern Rivers and Hawkesbury Nepean Catchment Management Authority area may have enhanced riparian conditions within Goulburn Mulwaree Council area.
References
DECC - see Department of Environment and Climate Change (NSW)
Department of Environment and Climate Change (NSW) (2008a) NSW Scientific Committee—Final Determination, Alteration to the Natural Flow Regimes of Rivers, Streams, Floodplains and Wetlands—Key Threatening Process Declaration, NSW Department of Environment and Climate Change, viewed 14 October 2008, http://www.threatenedspecies.environment.nsw.gov.au/tsprofile/profile.aspx?id=20002
Department of Environment and Climate Change (NSW) (2008b) NSW Scientific Committee—Final Determination, Clearing of Native Vegetation—Key Threatening Process Declaration, NSW Department of Environment and Climate Change, viewed 14 October 2008-10-14 http://www.environment.nsw.gov.au/determinations/ClearingNativeVegKTPListing.htm
Department of Primary Industries (NSW) (2008a) Removal of large woody debris from NSW rivers and streams, NSW Department of Primary Industries, viewed 10 October 2008 http://www.dpi.nsw.gov.au/fisheries/habitat/publications/threats/removal-large-woody-debris
Department of Primary Industries (NSW) (2008b) Degradation of native riparian vegetation along NSW water courses, NSW Department of Primary Industries, viewed 10 October 2008 http://www.dpi.nsw.gov.au/fisheries/habitat/publications/threats/degredation-native-riparian-vegetation
Department of Primary Industries (NSW) (2005a) Fisheries Scientific Committee Recommendation—Installation and Operation of Instream Structures and Other Mechanisms that Alter Natural Flow Regimes of Rivers and Streams, NSW Department of Primary Industries, viewed 11 August 2005, http://www.fisheries.nsw.gov.au/__data/assets/pdf_file/5284/FR21_dams.pdf.
DPI - seeDepartment of Primary Industries (NSW)
Goulburn Mulwaree Council (2008) Goulburn City Landcare Group, Goulburn Mulwaree Council, viewed 14 October 2008
http://www.goulburn.nsw.gov.au/environment/1266/1279.html
Office of the Commissioner for the Environment (2004) Australian Capital Region State of the Environment Report 2004, Office of the Commissioner for the Environment, Canberra (see Riparian Condition)
