Namoi Wetland Assessment Project - Extensionarchive.lls.nsw.gov.au/__data/assets/pdf_file/0004/496318/archive... · Eco Logical Australia Pty L td and Namoi Catchment Management Authority

Namoi Wetland Assessment Project - Extension U p l a n d W e t l a n d M a p p i n g a n d F u n c t i o n R e v i e w

PREPARED FOR Namoi Catchment Management Authority

PROJECT NO 0125-0005

DATE June 2009

N AM O I WE T L AN D AS S E S S M E N T P R O J E C T - E X T E N S IO N

© E C O L O G I C AL AU S T R AL I A P T Y LT D i

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Project Name Namoi Wetland Assessment Project - Extension

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Prepared by Hamish Mackinnon

Approved by Paul Frazier

Status Draft

Version Number 0.1

Last saved on 30 June 2009

ACKNOWLEDGEMENTS

This document has been prepared by Eco Logical Australia Pty Ltd.

Disclaimer

This document may only be used for the purpose for which it was commissioned and in accordance with the contract between

Eco Logical Australia Pty Ltd and Namoi Catchment Management Authority. The scope of services was defined in consultation

with and Namoi Catchment Management Authority, by time and budgetary constraints imposed by the client, and the availability

of reports and other data on the subject area. Changes to available information, legislation and schedules are made on an

ongoing basis and readers should obtain up to date information.

Eco Logical Australia Pty Ltd accepts no liability or responsibility whatsoever for or in respect of any use of or reliance upon this

report and its supporting material by any third party. Information provided is not intended to be a substitute for site specific

assessment or legal advice in relation to any matter. Unauthorised use of this report in any form is prohibited.


© E C O L O G I C AL AU S T R AL I A P T Y LT D ii

Contents

Contents ..................................................................................................................................................... ii

List of Figures ............................................................................................................................................ iii

List of Tables ............................................................................................................................................. iii

1 Introduction .............................................................................................................................. 4

1.1 Project Description................................................................................................................... 4

1.2 Study Area ............................................................................................................................... 4

2 Methods ................................................................................................................................... 6

2.1 GIS analysis ............................................................................................................................. 6

2.2 Field Survey ............................................................................................................................. 6

2.3 Literature survey ...................................................................................................................... 6

2.4 High-resolution mapping trial ................................................................................................... 6

3 Mapped Upland Wetlands in the Namoi Catchment ............................................................... 7

4 Field Survey ........................................................................................................................... 10

5 Upland Wetland Function ...................................................................................................... 16

5.1 What constitutes an upland wetland? .................................................................................... 16

5.2 LOcality .................................................................................................................................. 16

5.3 FUNCTION ............................................................................................................................ 16

5.4 importANCE ........................................................................................................................... 16

5.4.1 Ecosystem Services ........................................................................................................ 16

5.4.2 Likely function of the Namoi catchment upland wetlands ............................................... 17

6 High resolution wetland mapping .......................................................................................... 18

7 Key Limitations ...................................................................................................................... 20

7.1 Mapping Limitations ............................................................................................................... 20

8 Recommendations ................................................................................................................. 21

References .............................................................................................................................................. 22


© E C O L O G I C AL AU S T R AL I A P T Y LT D iii

List of Figures

Figure 1: Namoi Catchment Study Area .................................................................................................... 5

Figure 2: Overview of the Upland Wetlands in the Namoi Catchment ....................................................... 9

Figure 3: Field Assessed Wetlands (12-5-09) .......................................................................................... 12

Figure 4: Field Site 2 showing mapped palustrine wetland ...................................................................... 13

Figure 5: Field Site 7 showing unmapped palustrine wetland .................................................................. 13

Figure 6: Field Site 1 showing mapped artificial wetland ......................................................................... 14

Figure 7: Field Site 4 showing unmapped lacustrine wetland .................................................................. 14

Figure 8: Field Assessed Wetlands (25-6-09) .......................................................................................... 15

Figure 9: How upland wetlands work (Natural Resources Canada 2007) ............................................... 16

Figure 10: Areas of unmapped wetlands next to a mapped wetland ....................................................... 19

List of Tables

Table 1: Functional groups within the Namoi Catchment .......................................................................... 7

Table 2: Number and areas of the functional groups within the Namoi Catchment ................................... 8

Table 3: Field Survey 1 notes (12-5-09) ................................................................................................... 10

Table 4: Field Survey 2 notes (25-6-09) ................................................................................................... 11


© E C O L O G I C AL AU S T R AL I A P T Y LT D 4

1 Introduction

This report is an extension to the main Namoi Wetland Assessment and Prioritisation Project (125-005)

report and should be read in conjunction with the main report.

1.1 PROJECT DESCRIPTION

As an extension to the main project, the Namoi CMA wished to undertake a study to examine the

Upland wetlands in the catchment.

This extension project aimed to:

• Describe the known extent and type of the upland wetlands;

• Identify and describe the hydrological functional wetland groups;

• Present a simple model of upland wetland function;

• Indentify and list key information gaps and suggest techniques for filling these gaps.

1.2 STUDY AREA

The study area for the extension project is the upland area of the Namoi Catchment, located at

elevations of or greater than 700m (Figure1).


© E C O LO G I C AL AU S T R A L I A P T Y L T D 5

Figure 1: Namoi Catchment Study Area



2 Methods

2.1 GIS ANALYSIS

Analysis of the area, extent and nature of upland wetlands in the Namoi catchment was undertaken

using wetland data created in the main project. The location of upland wetlands was derived by

selecting wetlands that existed above 700 m ASL using the wetland mapping and catchment wide DEM.

Further analysis and database query was undertaken to create tables and maps of the location of

functional wetland types.

2.2 FIELD SURVEY

Field surveys were undertaken on the 12th May 2008 and 25

th June 2008 to examine a sample of upland

wetlands within the catchment. At each site GPS coordinates, digital photographs and field notes were

recorded. The purpose of this survey was to examine a subset of these wetlands, not to perform a

comprehensive survey of these upland wetlands.

2.3 LITERATURE SURVEY

A literature survey was undertaken to locate relevant published data on upland wetlands in the

catchment and of the wider region in general.

2.4 HIGH-RESOLUTION MAPPING TRIAL

A small area was remapped to determine the likely extent of all upland wetlands in the area and provide

an indication of the level of current under estimation in wetland extent in the area. A combination of

digitising the SPOT 5 data and field based survey was used to locate and map likely upland wetland

areas of 0.1 ha in size or greater. No accuracy assessment was undertaken although care was taken to

ensure the mapping accuracy.



3 Mapped Upland Wetlands in the Namoi Catchment

GIS analysis identified 131 mapped wetlands with four functional groups in the Upper Namoi Catchment

(Table 1). These wetlands were predominately Palustrine, however, constructed, highly modified and

Lacustrine wetlands were also present (Table 1).

The functional groups for the upland wetlands that were identified within the Namoi Catchment were

categorised by their hydrological function and were mapped accordingly. 131 wetlands within the four

functional groups were mapped in the upland areas of the Namoi Catchment, these wetlands cover a

total area of 1436.5 ha (Table 2).

Table 1: Functional groups within the Namoi Catchment

FUNCTIONAL GROUPS DESCRIPTION

Artificial with no ecological significance (ART1)

Constructed water storages with no surrounding vegetation, often very

large features connected to irrigation channels or artificial bodies of

water with no ecological significance.

Artificial with some ecological significance (ART2)

Highly modified natural features with some surrounding vegetation,

includes large farm dams with habitat value or artificial bodies of water

with some ecological significance.

Lacustrine, temperate inland, river-fed/ floodplain (LTI2)

Lacustrine, temperate inland, river-fed/floodplain. These are large

permanently wet open bodies of water, usually lakes or large dams.

Palustrine, temperate

inland, groundwater

(PTI1)

Palustrine, temperate inland, groundwater. These are primarily vegetated non-channel environments, such as billabongs, swamps, bogs and springs.



Table 2: Number and areas of the functional groups within the Namoi Catchment

The majority of the upland wetlands are located in the east of the catchment along the border of the

New England Tablelands region, with a large number situated north of Bendemeer. There is a patchy

group of wetlands located at the eastern extent of Nandewar Ranges near Barraba and another group

in the Coolah Tops National Park between the Warrumbungle and Liverpool Ranges, south-west of

Quirindi.

FUNCTIONAL GROUPS NUMBER SMALLEST

AREA (ha)

LARGEST

AREA (ha)

MEAN AREA

(ha)

TOTAL AREA

(ha)

Artificial with no ecological significance

24 0.352 32.0 4.5 43.8

Artificial with some ecological significance

11 0.241 13.2 4.0 107

Lacustrine, temperate inland, river-fed/floodplain

2 1.205 2.5 1.9 3.7

Palustrine, temperate

inland, groundwater 94 0.615 110.1 13.6 1282

Total 131 1436.5


© E C O L O G IC A L AU S T R AL I A P T Y LT D 9

Figure 2: Overview of the Upland Wetlands in the Namoi Catchment



4 Field Survey

A field survey was undertaken on the 12th May 2009 to examine the nature of several mapped and

unmapped wetlands (Figure 3). This survey revealed that while the mapped upland wetlands were

generally accurate, a large number of upland wetlands had been left unmapped. The majority of the

unmapped wetlands were adjacent to areas of mapped wetlands consisting of the same characteristics.

Overall, 10 sites were surveyed (Table 3) with three mapped wetlands confirmed and seven potential

unmapped wetland discovered. A second survey was undertaken on the 25th June 2009, where mapped

wetlands were ground-truthed, with six wetlands being confirmed (Table 4 & Figure 8).

Table 3: Field Survey 1 notes (12-5-09)

SITE MAPPED

(Y/N) TYPE NOTES REF FIGURE

1 Y ART1 Modified to farm dam, open water, willows,

fringing reeds Figure 6

2 Y PTI1

Network of chain-of-ponds and larger open water,

sedge communities on low-lying swamp land,

possibly some modification for farm dam,

degraded stream

Figure 4

3 N PTI1

Small floodplain depression adjacent to small creek

– creek fed and local run-off, 5-10m wide >100m

long, sedge communities

4 N LTI2 Road blocking watercourse, native wetlands plants

(reeds, rushes, sedges) Figure 7

5 N PTI1

Sedge communities in watercourse & flat region

with concentration of surface flow and likely longer

saturation and soil moisture

6 N PTI1

Depression beside MacDonald River (near

Woolbrook), natural depression modified by road

and culvert & native sedges and some natural

values

7 N PTI1 Floodplain wetland adjacent to hills and cropping

field on McDonald FP Figure 5

8 N PTI1

Upland fen along water course, concentrated flow

and seasonal saturation, chain of ponds with small

open water, long and linear, open water small

ponds <10m & native sedges and reeds

9 Y PTI1 Concentrated flow and seasonal saturation, long

and linear, native sedges and reeds, backed up



Table 4: Field Survey 2 notes (25-6-09)

against road, relatively steeply sloping

10 N PTI1

Concentrated flow and seasonal saturation, chain

of ponds with small open water, long and linear,

open water small ponds <10m & native sedges and

reeds

SITE MAPPED

(Y/N) TYPE NOTES

REF

FIGURE

1 Y PTI1 Wetland that drains into a chain of dams, could

have been chain of pond at one stage

2 N PTI1 Just outside boundary of Namoi catchment

3 Y PTI1 Broad wetland, expands across large area

4 Y PTI1 Part of wetland at site 3, more pronounced due to

road hindering water flow

5 Y PTI1 Alongside of creek adjacent to Macdonald river

6 Y PTI1 Alongside of creek adjacent to Macdonald river



Figure 3: Field Assessed Wetlands (12-5-09)



Figure 4: Field Site 2 showing mapped palustrine wetland

Figure 5: Field Site 7 showing unmapped lacustrine wetland on the McDonald River floodplain



Figure 6: Field Site 1 showing mapped artificial wetland

Figure 7: Field Site 4 showing unmapped lacustrine wetland


© E C O LO G I C AL AU S T R A L I A P T Y L T D 15

Figure 8: Field Assessed Wetlands (25-6-09)



5 Upland Wetland Function

5.1 WHAT CONSTITUTES AN UPLAND WETLAND?

An upland wetland is a vegetated freshwater area occurring in shallow basins/depressions located in

low hills or mountainous regions, usually adjacent to the tablelands. This wetland type includes shallow

marshes, sedge swamps, "hanging" swamps, wet heaths and peat swamps, which are rarely fed by

river flows but rely on groundwater and rainfall runoff. These areas may hold water permanently or fill

and drain on a seasonal basis (Bell et al., 2008).

5.2 LOCALITY

Upland wetlands have been defined as occurring above 700m ASL and can be found on a number of

different substrates. The majority of upland wetlands are on basalt-derived soils, with the others being

found on granite and sandstone rock types (DEH, 2005).

5.3 FUNCTION

Figure 9: How upland wetlands work (Natural Resources Canada 2007)

5.4 IMPORTANCE

Wetlands are highly diverse and productive ecosystems, critical in the conservation of biodiversity and

ecological productivity throughout an entire catchment.

5.4.1 Ecosystem Services

Upland wetlands are important as they provide a vital habitat which supports a wide variety of animals

including waterbirds, fish, frogs, invertebrates, as well as water-loving plants such as sedges, rushes



and various tree species. The larger upland lakes/swamps provide habitat and drought refuge for water

birds and other animals when large inland lakes have dried; with some also providing important

breeding areas for threatened species. Large upland lakes provide water storage / flood mitigation

functions within the catchment and the base flows of rivers can be sustained from these wetlands during

times of dry weather.

Some of the other important ecosystem services that upland wetlands provide are:

• biodiversity conservation;

• improvement and maintenance of water quality;

• biological productivity and nutrient cycling;

• flood attenuation;

• groundwater recharge;

• a sink for greenhouse gases;

• scientific research;

• education;

• recreation and visual amenity; and cultural heritage and spiritual values.

(NSW Government, 2008)

5.4.2 Likely function of the Namoi catchment upland wetlands

There is little or no published information on the upland wetlands of the Namoi catchment that describes how the wetlands function. However, given the location, nature of open water and ground cover, it is likely that these wetlands:

• Are fed by the local rainfall and shallow groundwater flows;

• Generally, don’t have surface water except for small ponds or surface flows associated with recent rainfall;

• Are generally underlain by bedrock within a few metres of the surface;

• Have organic rich soils or peat;

• Maintain shallow ground water flows in all seasons;

• Have low grass or shrub vegetative cover with few or no trees;

• Provide local habitat for rare or threatened species (flora and fauna) yet to be identified;

• Provide a local pasture resource;

• Contribute base flows into local streams;

• Alter water quality (reduced turbidity, increased nutrient load) entering streams;

• And provide a significant function in the water cycle within the Namoi catchment.



6 High resolution wetland mapping

To provide an indication of the likely extent of unmapped wetland areas a small region of known

wetlands was remapped using the Spot 5 data and data from the field survey (Figure 9). In this case

the mmu was 0.1 ha so small discontinuous features were mapped. For comparative purposes the

newly mapped and previously mapped areas were compared.

For this small section the mapped area was 57.7 ha while the newly mapped wetlands covered

137.4 ha. This means that the extent of upland wetlands in the site was under estimated by

approximately over 200% at this site.



Figure 10: Areas of unmapped wetlands next to a mapped wetland



7 Key Limitations

This study has found that there is a paucity of published information on Upland wetlands in Namoi

catchment. Although there was some published material relating to upland wetlands, the majority of it

was based on other areas with upland wetlands, such as the New England tablelands.

7.1 MAPPING LIMITATIONS

The previous mapping scales used to delineate the upland wetlands and the definitions for the types of

these wetlands have been found to be insufficient to map upland wetland extent accurately.

For the catchment wide mapping project, SPOT 5 pan-sharpened data were used as a base to map the

extent of previously identified wetlands and to extend the range of known mapping. Previously

unmapped wetlands were identified primarily using colour and pattern identification keys on a single

date SPOT 5 image. Any newly identified wetlands were cross-checked with Landsat data (pixel size

30 m) to evaluate the persistence of the feature in the landscape. The minimum mapping unit (mmu)

was 1 ha.

This combination of mapping conditions made the mapping of upland wetlands in the Namoi catchment

difficult for several reasons. The wetlands are generally narrow, have no or only small bodies of open

water and may be discontinuous. The land cover is generally grazed pasture and will show high levels

of variability due to different management regimes.

These conditions meant that many smaller wetlands were unmapped as they didn’t meet the 1 ha mmu

criteria. Initial identification of wetland sites on the SPOT 5 image makes mapping at 1:25000 possible.

However, Landsat TM data are useful at scales of approximately 1:100000 or broader and using these

data may have excluded small wetland areas. Further, comparing the two image dates may have been

confounded by land use management and seasonal changes to the pasture cover that may have made

wetland identification difficult.



8 Recommendations

• Develop a GIS-based mapping system, which incorporates elements such as underlying

geology, slope of terrain and the location of areas of open water. The methods for this process

are currently being developed through project 09ARMGIS-0001 by ELA, funded by the CCC-

CRC and the Namoi CMA.

• Undertake a comprehensive mapping program to map all occurrences of upland wetlands in the

Namoi catchment.

• Water processes (quality, quantity) studies should be undertaken at a number of wetlands, to

determine the contribution of these wetlands to water quality and quantity in the Namoi

catchment.

• Undertake flora and fauna surveys of the upland wetlands, in order to gain a better

understanding of the ecosystems and habitats.

• Undertake a programme to determine the condition of the identified wetlands and prioritise

wetlands for protection and/or rehabilitation.

• An overall management plan should be created and implemented to monitor and assess these

upland wetlands into the future.

• Given the isolation of a Coolah Tops National Park wetland group a separate study on the

ecology and function of these wetlands should be undertaken.



References

Bell, D., Hunter, J.T. and Howarth, R.J., (2008) ‘Montane lakes (lagoons) of the New England

Tablelands Bioregion.’ Cunninghamia 10(3).

Department of the Environment and Heritage (DEH) (2005) Commonwealth Information Sheet on

Upland Wetlands of the New England Tablelands and Monaro Plateau, Australian Government.

Hale, J., Kobryn, H., Butcher, R. and Phillips, B. (2006) Namoi Catchment Wetland Inventory and

Mapping. Report to the Namoi Catchment Management Authority.

Natural Resources Canada. (2007) River Restoration Framework.

NSW Government, (2008) Draft New South Wales Wetlands Policy



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Namoi Wetland Assessment Project - Extensionarchive.lls.nsw.gov.au/__data/assets/pdf_file/0004/496318/archive... · Eco Logical Australia Pty L td and Namoi Catchment Management Authority