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Vegetation Mapping Project


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C u d g e g o n g R i v e r


& Tributary

Vegetation Mapping Project

Sj Landscape Constructions

Cudgegong River & Tributary Vegetation Mapping Project

Prepared for


The Cudgegong Catchment Committee

(s.355 committee of Rylstone Shire Council)

August 2002


Prepared by


Scott Lillis

Sj Landscape Constructions

ABN 52 448 593 648
Barigan Street Wollar NSW 2850

Email: sjland@hwy.com.au










Acknowledgements

A special thank you is extended to the following people who worked on this project, and whose technical knowledge, support and dedication assisted in making this study a success.


Bill Lang, BushPC, Mapping, data management, CD production and technical support.

Helen May, BushPC, Report production and technical support.

Danny Lewer, River Style®, debris and erosion classifications and recommendations, and site visits.

Travis Peake, Native vegetation classifications and research, and site visits.

Grant Millar, Mapping and site visits.

Chris Cherry, Weed control recommendations and site visits.

Matt Hollingdale, Commercial Helicopters Australia Pty Ltd, pilot.

Noel Dawson, Noel Dawson Photography, for filming and video production.


I would also like to thank the following people and organisations:

David Crust (NPWS), Jamie Lees (DLWC), Nicky Schnitler (CCC), Grant O’Leary (Rylstone Shire Council), for assistance with data and identification of landowners; and the numerous landholders for permitting access to the survey sites.


Scott Lillis

Sj Landscape Constructions.

Table of Contents


List of Tables 6

List of Maps 7

1.Executive Summary 9

2.Introduction 11

1.1.Study Area 11

1.2.Objectives 11

1.3.Key Findings 12

3.Overview 13

1.4.Land-use 13

1.5.Weeds 13

1.6.Native Vegetation 15

1.7.River Styles® 15

1.8.Debris 15

1.9.Erosion 16

1.10.Recommendations 17

1.10.i.Weed Control 18

1.10.ii.Revegetation 20

1.10.iii.Debris Management 21

1.10.iv.Erosion Control 22

1.11.Maps 25

4.Methodology 39

1.12.Survey Sites 39

1.13.Data Collection 39

1.14.Classifications 40

5.Lower Cudgegong 45

1.15.Weeds 45

1.16.Native Vegetation 46

1.17.Debris 46

1.18.Erosion 47

1.19.Recommendations 47

1.20.Maps 53

6.Mid Cudgegong 61

1.21.Weeds 61

1.22.Native Vegetation 61

1.23.Debris 62

1.24.Erosion 62

1.25.Recommendations 62

1.26.Maps 67

7.Upper Cudgegong 73

1.27.Weeds 73

1.28.Native Vegetation 73

1.29.Debris 74

1.30.Erosion 74

1.31.Recommendations 74

1.32.Maps 79

8.Carwell Creek 89

1.33.Weeds 89

1.34.Native Vegetation 89

1.35.Debris 90

1.36.Erosion 90

1.37.Recommendations 91

1.38.Maps 95

9.Cumber Melon Creek 103

1.39.Weeds 103

1.40.Native Vegetation 103

1.41.Debris 104

1.42.Erosion 104

1.43.Recommendations 104

1.44.Maps 109

10.Coxs Creek 115

1.45.Weeds 115

1.46.Native Vegetation 115

1.47.Debris 116

1.48.Erosion 116

1.49.Recommendations 116

1.50.Maps 121

11.Legislation 129

12.Appendix A – Species List 131

13.References 135





    List of Tables

Table 1 - Major Weeds 14

Table 2 - Weed Control Priority 19

Table 3 - Weed Classifications 41

Table 4 - Native Vegetation Classifications 42

Table 5 - Debris Classifications 43

Table 6 - Erosion Classifications 44

Table 7 - Weeds of the Lower Cudgegong 45

Table 8 - Lower Cudgegong Revegetation Species 51

Table 9 - Weeds of the Mid Cudgegong 61

Table 10 - Mid Cudgegong Revegetation Species 65

Table 11 - Weeds of the Upper Cudgegong 73

Table 12 - Upper Cudgegong Revegetation Species 77

Table 13 - Weeds of Carwell Creek 89

Table 14 - Carwell Creek Revegetation Species 93

Table 15 - Weeds of Cumber Melon Creek 103

Table 16 - Cumber Melon Creek Revegetation Species 107

Table 17 - Weeds of Coxs Creek 115

Table 18 - Coxs Creek Revegetation Species 119





    List of Maps

Map 1 - Study Area Location 25

Map 2 - Study Area Sections 27

Map 3 - Willow Distribution 29

Map 4 - Blackberry Distribution 31

Map 5 - River Styles® 33

Map 6 - Native Vegetation 35

Map 7 - Bank Erosion and Stock Erosion 37

Map 8 - Survey Sites - Lower Cudgegong 53

Map 9 - Other Significant Weeds - Lower Cudgegong 55

Map 10 - Debris Origin - Lower Cudgegong 57

Map 11 - Native Vegetation Canopy Cover - Lower Cudgegong 59

Map 12 - Survey Sites - Mid Cudgegong 67

Map 13 - Willow Distribution - Mid Cudgegong 69

Map 14 - Blackberry Distribution - Mid Cudgegong 71

Map 15 - Survey Sites - Upper Cudgegong 79

Map 16 - Willow Distribution - Upper Cudgegong 81

Map 17 - Blackberry Distribution - Upper Cudgegong 83

Map 18 - Erosion Upper Cudgegong 85

Map 19 - Native Vegetation - Upper Cudgegong 87

Map 20 - Survey Sites - Carwell Creek 95

Map 21 - Blackberry Distribution - Carwell Creek 97

Map 22 - Other Significant Weeds - Carwell Creek 99

Map 23 - Native Vegetation - Carwell Creek 101

Map 24 - Survey Sites - Cumber Melon Creek 109

Map 25 - Blackberry and Tree of Heaven - Cumber Melon Creek 111

Map 26 - Native Vegetation and Canopy Cover - Cumber Melon Creek 113

Map 27 - Survey Sites - Coxs Creek 121

Map 28 - Willow Distribution - Coxs Creek 123

Map 29 - Blackberry Distribution - Coxs Creek 125

Map 30 - Native Vegetation - Coxs Creek 127





  1. Executive Summary

This study was commissioned by the Cudgegong Catchment Committee (s.355 committee of Rylstone Shire Council, and referred to in this report as CCC) to establish the current status of vegetation within certain riparian corridors of the Cudgegong catchment. The study area encompasses the Cudgegong River from Kandos weir to Mudgee town weir and the three main tributaries. The study was carried out during the winter of 2002. Ideally, the collection of data should have been extended through spring 2002, however this was not possible due to constraints of the Commonwealth Government funding.


The native vegetation throughout the entire study area lacks continuity and the displacement of native vegetation by exotic species amplifies this fragmentation. Where native vegetation exists in the riparian corridor it lacks key components of vegetation structure. Negative impacts associated with degradation have substantial effects on the ecological health and biodiversity of the entire catchment. Development of a sustainable river system can be achieved by revegetating degraded areas.
There is an over-abundance of weeds in the study area and in many cases they are the only vegetation within the riparian corridor. There is some evidence of weed control, however it is sporadic and disjunct and as a result, has had little or no impact on reducing infestation levels. Weeds are capable of spreading large distances and this attribute must be recognised and taken into account when implementing planning controls. Consequently, control objectives should consider the remainder of the Cudgegong catchment.
Additional data was collected to assess the current status and levels of debris and erosion. These vary considerably throughout the study area and are affected by a number of factors including land-use, the health of native vegetation communities and the presence of exotic species in the riparian corridor. Thus weed control and revegetation must form an integral part of long-term planning to reduce the negative impacts of erosion and in turn enhance water quality.
The rehabilitation of the riparian corridor within the Cudgegong catchment is a realistic and achievable goal. It must be seen as a long-term project that requires careful planning. In addition to strategic planning, a commitment to the ongoing funding of these objectives is paramount. Early intervention and regular maintenance will ensure long-term costs are reduced.



  1. Introduction

The Cudgegong Catchment Committee (CCC) has commissioned a variety of studies to establish the current status of the catchment and highlight social, economic and environmental issues that impact on the catchment in its entirety. Sj Landscape Constructions was contracted by the Committee to prepare a report that identifies the location of native and exotic vegetation, debris and erosion. The study area was limited to the riparian corridors of specific creeks and rivers within the catchment. A study of tributaries not included in this report would provide a more complete picture of the status of the catchment. The dams within the catchment were not requested as part of this study.

1.1.Study Area

The study area is situated approximately 150km northwest of Sydney (see map 1 on page 25) and encompasses the Cudgegong River from Kandos weir to Mudgee town weir. It also studies three tributaries in the upper half of the catchment: Carwell, Cumber Melon and Coxs Creek. The linear distance of the creeks and rivers combined is approximately 160km.
A total of one hundred sites were surveyed and in order to present the information logically, the area is divided into six sections as illustrated in Map 2 on page 27. In this report the sections are referenced as:


Lower Cudgegong (LCD) -

30 sites in 37km from Mudgee town weir to Windamere Dam wall.

Mid Cudgegong (MCD) -

11 sites in 14km from Windamere Dam (high water mark) to Rylstone Dam wall.

Upper Cudgegong (UCD) -

24 sites in 30km from Rylstone Dam (high water mark) to Kandos weir.

Carwell Creek (CAR) -

15 sites in 33km from Windamere Dam (high water mark) to Mount Vincent (Ilford).

Cumber Melon Creek (CMB) -

10 sites in 15km from the confluence of the Cudgegong River to Haystack Mountain.

Coxs Creek (COX) -

10 sites in 31km from the confluence of the Cudgegong River to Nullo Mountain.

At each of these one hundred sites, data for both sides of the river was recorded. In this document, “site” refers to both banks of the river at a given location while “sub-site” refers to one bank of the river at a given location.

1.2.Objectives



The main objectives of this report and the accompanying CD are to present the data that was collected and provide recommendations to be used as a guide in planning future projects for the rehabilitation of the river system. In order to achieve these goals, four key components were studied:

  1. type and degree of woody weed infestations,

  2. location and structural diversity of native vegetation,

  3. position and geomorphic influence of debris, and

  4. location and severity of erosion.

1.3.Key Findings

Weeds

  • Thirteen different genera of woody weed species were identified: Salix spp. (Willow), Rubus sp. (Blackberry), Cinamomum sp. (Camphor-Laurel), Ligustrum spp. (Privets), Ailanthus sp. (Tree of Heaven), Populus spp. (Poplars), Robinia sp. (False Acacia), Cotoneaster sp. (Cotoneaster), Pyracantha sp. (Firethorn), Ulmus sp. (Elm), Rosa sp. (Briar Rose), Pyrus spp. (Pears) and Schinus sp. (Peppertree).

  • The dominant genera are Rubus and Salix.

  • There are four main species of Willow within the study area: Salix babylonica (Weeping Willow), Salix alba var. vitellina (Golden Upright Willow), Salix fragilis (Crack Willow) and Salix x rubens (Gold-Crack Willow).

  • There is no evidence of Willow spreading by seed.

  • In many cases the weeds are the only vegetation within the riparian corridor.

  • There is evidence that weeds are maintaining bed and bank stability.

  • Tributaries outside the study area are a significant propagule source for vegetative spread.


Native Vegetation

  • There are a wide variety of native vegetation communities.

  • The native vegetation present is fragmented over the study area.

  • Where native vegetation exists, small and tall native shrubs are severely under represented in all but a few locations.

  • The Sphagnum Bog community in Coxs Creek is likely to be the rarest vegetation community in the study area.

  • One rare native plant species was identified, Eucalyptus alligatrix subsp. alligatrix.

  • Natural regeneration is being suppressed by both weed infestations and grazing regimes.


Debris and Erosion

  • Certain sections of the riparian corridor lack large woody debris, resulting in bed lowering.

  • Excessive quantities of debris are present in areas heavily infested with weeds.

  • Severe active bank erosion is limited to a few sites.

  • Current bank erosion is predominantly due to stock accessing the waterway.

  • Previous bank erosion is evident at numerous sites but now appears to be stabilised.

  • Previous bed lowering is widespread across the study area.



  1. Overview

1.4.Land-use

The study area houses a diverse range of land-uses ranging from recreation and urban interface, to intense horticulture and agriculture, with the upper reaches running through State Forests and National Park.


The dominant land-use identified throughout the study area is grazing by sheep and cattle and this practice has a varying impact on the streams. Natural regeneration of native vegetation is evident where the riparian corridor is fenced as a separate paddock. In these cases bank erosion from stock is also limited. On the other hand, where stock do have access to the river, they can help suppress weed infestations.
Lucerne is the dominant crop whilst horticultural industries are comprised of market gardens, grapes and olives. Cropping and horticulture enterprises were most likely to have the riparian corridor fenced and these intense production areas also have a high incidence of weed control. Unfortunately, this control does not always extend into the riparian corridor.
In addition to the State Forests and National Park, other recreational uses consist of parks, in both Mudgee and Rylstone, and tourism at a variety of rural accommodation enterprises along the river. The parks contain an array of ornamental plantings and expanses of lawn areas that adjoin the water’s edge. This style of landscape provides good bank stability and weed control within the park. However, it must be noted that these ornamental plantings, which consist of some woody weeds, have the potential to be a propagule source for spread downstream. One of the attractions in the area that tourists enjoy is the natural beauty of the river and enhancing this may be beneficial.

1.5.Weeds



Table 1 lists the major species of weeds identified in the study area, and includes their noxious weed status1 and infestation levels. Other weeds that were identified are included in Appendix A – Species List, but are not discussed here due to their low infestation levels and lack of evidence of spread within the riparian corridor. It must be noted that the positive identification of Salix fragilis (Crack Willow) and Salix x rubens (Gold-Crack Willow) is extremely difficult due to the lack of flowers and foliage at the time of sampling. As they are both Crack Willow, they should be considered together when analysing the data.
The two most aggressive and widespread genera are Salix and Rubus. The distributions of these genera are illustrated in the relevant maps on pages 29 and 31. Their infestation levels vary considerably throughout the study area and are not limited to any particular land-use or location. When interpreting the information in Table 1 it is important to distinguish between the number of sub-sites a species was recorded at, and its infestation level. For example, although Crack Willow and Gold-Crack Willow combined, were recorded at fewer sites than Weeping Willow, their infestation levels are significantly higher.
Willow are present in numerous catchments throughout the state, and in many cases programs have to accommodate the control of Willow developing via seed. The fact that seeding is not evident in this study area is a positive sign. However, there is a considerable amount of infiltration by means of vegetative spread (via propagules).





Number of Sub-sites* at each Infestation Level

Scientific Name

Status

Low

Medium

High

Total

Rubus ulmifolius

W3

41

22

44

107

Salix babylonica

n/a

45

25

13

83

Salix fragilis

W4g S

20

16

16

52

Salix x rubens

W4g S

4

17

6

27

Ailanthus altissima

W2

2

2

2

6

*Data relates to sub-sites, 200 in total.

W2 - The weed must be fully and continuously suppressed and destroyed on land that is the responsibility of all private landowners and managers.

W3 - The weed must be prevented from spreading and its numbers and distribution reduced.

W4 - The action specified in the declaration must be taken in respect of the weed.

(g) - The weed must not be sold, propagated or knowingly distributed

S - All Salix spp. other than S. babylonica, S. X calodrendron, S. X reichardtii. S. nigra is also a W2 weed in the Maclean Local Control Area.Error: Reference source not found

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