Level 2, 160 Clarence Street Sydney, NSW, 2000

Tel: 9299 2855 Fax: 9262 6208 Email: [email protected] Web: www.wmawater.com.au

WARREGO RIVER SCOPING STUDY

DRAFT REPORT JULY 2008

Project Project Number Warrego River Scoping Study 28011 WARREGO RIVER SCOPING STUDY Client Client’s Representative Western Catchment Management Authority Marita Pearson (02) 6883 3068 [email protected]

Authors Project Manager Linda Holz, Daren Barma, Paul Wettin Daren Barma

Revision Description Date FINAL1 First Draft 27th June 2008

TH 18 JULY, 2008

WMAwater 28011: FinalReport.doc:16 July 2008 1

Level 2, 160 Clarence Street Sydney, NSW, 2000

Tel: 9299 2855 Fax: 9262 6208 Email: [email protected] Web: www.wmawater.com.au

WARREGO RIVER SCOPING STUDY

FINAL REPORT JULY 2008

Project Project Number Warrego River Scoping Study 28011

Client Client’s Representative Western Catchment Management Authority Marita Pearson (02) 6883 3068 [email protected]

Authors Project Manager Linda Holz, Daren Barma, Paul Wettin (Independent Daren Barma Consultant)

Revision Description Date 1 First Draft 30/06/2008 2 Final Report 18/07/2008

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WARREGO RIVER SCOPING STUDY

TABLE OF CONTENTS

PAGE

EXECUTIVE SUMMARY ...... 1 1. Introduction...... 9 1.1. Project Rationale and Objectives...... 9 1.2. Methodology ...... 9 1.3. Report Structure...... 10 2. Background Information...... 11 2.1. Overview of Study Area ...... 11 2.2. Water Resource Planning in the Warrego...... 16 2.2.1. Queensland Warrego Legislation and Planning...... 16 2.2.2. New South Wales Warrego Legislation and Planning...... 16 2.2.3. Management Strategies, Rules and Performance Indicators for the Queensland Section of the Warrego...... 16 2.2.3.1. Water Entitlements – Management Strategies and Rules ...... 16 2.2.3.2. Managing Growth in Use ...... 18 2.2.3.3. Water Allocation Security Objectives and Performance Indicators...... 18 2.2.3.4. Environmental Objectives - Management Strategies and Rules...... 18 2.2.3.5. Environmental Objectives and Performance Indicators ...... 19 2.2.4. Management Strategies, Rules and Performance Indicators for the New South Wales Section of the Warrego...... 20 2.2.4.1. Water Entitlements – Management Strategies and Rules ...... 20 2.2.4.2. Managing Growth in Use ...... 20 2.2.4.3. Environmental Objectives – Management Strategies and Rules...... 20 2.2.4.4. NSW Performance Indicators ...... 21 3. Hydrological and Environmental Characteristics of the Warrego ...... 22 3.1. Hydrologic Overview ...... 22 3.1.1. Spatial Characteristics of Floods ...... 22 3.1.2. Seasonality ...... 25 3.1.3. Climate Variability ...... 27 3.2. Overview of Flow Dependent Environmental Assets ...... 29 3.2.1. Categories of Assets...... 29

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3.2.2. Instream Characteristics ...... 29 3.2.2.1. Waterholes...... 29 3.2.2.2. Water Quality ...... 33 3.2.3. Riparian assets ...... 36 3.2.4. Floodplain, Lakes and Wetland Assets...... 38 4. Hydrological Data and Impacts of Water Resource Development...... 43 4.1. Available Hydrologic Data...... 43 4.2. Quantifying Development Impacts on the Flow Regime ...... 44 4.2.1. The Warrego IQQM Model and Model Scenarios...... 44 4.2.2. Model Accuracy ...... 44 4.2.3. Evaluation of Results; Flow Exceedance Curves and Statistics ...... 45 4.2.4. Other Literature...... 46 RESULTS FROM EACH HYDROLOGICAL REGION...... 47 4.3. Warrego Basin to Wyandra...... 47 4.3.1. Available Hydrology and Water Resource Development Data...... 47 4.3.2. Impacts of ROP Levels of Development on the Flow Regime ...... 49 4.3.2.1. Model assumptions about level of use...... 49 4.3.2.2. Overall Flow Regime Impacts ...... 49 4.3.2.3. Impacts during wet and dry phases ...... 50 4.3.3. Difference in impacts under ROP and current levels of development...... 50 4.3.4. Impacts of Development on DIWA Environmental Assets ...... 51 4.4. Noorama and Widgeegoara Creeks ...... 52 4.4.1. Available Hydrology and Water Resource Development Data...... 52 4.4.2. Impacts of ROP Levels of Development on the Flow Regime ...... 54 4.4.2.1. Model assumptions about level of use...... 54 4.4.2.2. Overall Flow Regime Impacts ...... 54 4.4.3. Difference in impacts under ROP and current levels of development...... 55 4.4.4. Impacts of Development on DIWA Environmental Assets ...... 55 4.5. Warrego from Wyandra to NSW Border...... 56 4.5.1. Available Hydrology and Water Resource Development Data...... 56 4.5.2. Impacts of ROP Levels of Development on the Flow Regime ...... 58 4.5.2.1. Model assumptions about level of use...... 58

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4.5.2.2. Overall Flow Regime Impacts ...... 58 4.5.2.3. Impacts during wet and dry phases ...... 60 4.5.3. Difference in impacts under ROP and current levels of development...... 61 4.5.4. Impacts of Development on DIWA Environmental Assets ...... 61 4.6. Cuttaburra Creek ...... 62 4.6.1. Available Hydrology and Water Resource Development Data...... 62 4.6.2. Impacts of ROP Levels of Development on the Flow Regime ...... 64 4.6.2.1. Model assumptions about level of use...... 64 4.6.2.2. Overall Flow Regime Impacts ...... 64 4.6.3. Difference in impacts under ROP and current levels of development...... 66 4.6.4. Impacts of Development on DIWA Environmental Assets ...... 66 4.7. Thurrulgoonia and Tuen Creeks ...... 67 4.7.1. Available Hydrology and Water Resource Development Data...... 67 4.7.2. Impacts of ROP Levels of Development on the Flow Regime ...... 69 4.7.2.1. Overall Flow Regime Impacts ...... 69 4.7.2.2. Impacts during wet and dry phases ...... 70 4.7.3. Difference in impacts under ROP and current levels of development...... 70 4.7.4. Impacts of Development on DIWA Environmental Assets ...... 70 4.8. Irrara Creek...... 71 4.8.1. Available Hydrology and Water Resource Development Data...... 71 4.8.2. Impacts of ROP Levels of Development on the Flow Regime ...... 73 4.8.2.1. Model assumptions about level of use...... 73 4.8.2.2. Overall Flow Regime Impacts ...... 73 4.8.2.3. Impacts during wet and dry phases ...... 74 4.8.3. Difference in impacts under ROP and current levels of development...... 74 4.8.4. Impacts of Development on DIWA Environmental Assets ...... 75 4.9. Total Inflows to NSW – Plan Objective ...... 76 4.10. Warrego River from Barringun to Darling...... 77 4.10.1. Available Hydrology and Water Resource Development Data...... 77 4.10.2. Impacts of QLD ROP and NSW Current Levels of Development on the Flow Regime ...... 78 4.10.2.1. Model assumptions ...... 78

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4.10.2.2. Overall Flow Regime Impacts ...... 80 4.10.2.3. Impacts during wet and dry phases ...... 82 4.10.3. Difference in impacts under ROP /license conditions and current levels of development / use...... 83 4.10.4. Impacts of Development on DIWA Environmental Assets ...... 84 4.11. Summary and Discussion of IQQM model results ...... 85 4.11.1. Key Hydrological Results ...... 85 4.11.2. Environmental Flow Requirements of Significance of Impacts ...... 87 4.12. Hydrologic Impacts Published in Other Literature...... 88 4.12.1. Environmental Flows on the Paroo and Warrego Rivers ...... 88 4.12.2. CSIRO Sustainable Yields Report ...... 88 4.12.2.1. Summary of findings ...... 88 4.12.2.2. Discussion and comparison to findings of this report...... 89 4.12.3. Sustainable Rivers Audit (SRA) ...... 90 4.12.3.1. Summary of findings ...... 90 4.12.3.2. Discussion and comparison to findings of this report...... 91 5. Recommendations for Data Collection, Evaluation Tools and Planning Instruments...... 92 5.1. Recommended Upgrades and Additions to Evaluation Tools...... 92 5.1.1. Hydrologic Modelling...... 93 5.1.1.1. Methods for improved representation of floodplain losses...... 94 5.1.2. Hydraulic Model Development ...... 95 5.2. Recommendations for Additional Performance Indicators...... 96 5.2.1. Queensland Water Resource Plan and Recommended Indicators...... 96 5.3. Recommendations for Data and Information Required for Adequate Assessment of Planning Rules and Strategies ...... 97 5.3.1. Hydrologic Data ...... 97 5.3.1.1. Stream Gauging...... 98 5.3.1.2. Metering ...... 101 5.3.2. Environmental Data ...... 101 6. ACKNOWLEDGEMENTS ...... 102 7. REFERENCES...... 103

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LIST OF APPENDICES

Appendix A Environmental Data Sets Appendix B Hydrological Metadata Statements

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LIST OF TABLES

Table 1 - Rainfall and Runoff in the Warrego...... 12 Table 2 - Irrigated Area in Warrego River (NSW part only)1 ...... 12 Table 3 – Environmental Flow Objectives and Performance Indicators ...... 19 Table 4 – River flow objectives for the Barwon Darling and its Far Western Rivers...... 20 Table 5 – Draft Hunter Unregulated and Alluvial Water Sources Macro Water Sharing Plan Performance Indicators...... 21 Table 6 – Annual Flow Statistics for Wyandra and Fords Bridge gauged data1 ...... 22 Table 7 – Historic Area of Inundation in Selected Locations in the Warrego...... 23 Table 8 – Wet / Dry Months at Wyandra...... 26 Table 9 – Number of days of flooding recorded at Wyandra1 ...... 26 Table 10 – Existing Data Sources – Waterholes ...... 31 Table 11 – Existing Data Sources – Water Quality...... 34 Table 12 – Existing Data Sources – Riparian Vegetation ...... 37 Table 13 – Directory of Important Wetlands Australia – Warrego...... 38 Table 14 – Existing Data Sources – Floodplain, Wetlands and Lakes ...... 40 Table 15 – Summary of Metadata Statements in Appendix B ...... 43 Table 16 – Flood Thresholds for Wyandra (Source: BOM website)...... 50 Table 17 – Wyandra - Impacts during representative wet and dry phases...... 50 Table 18 – Widgeegoara and Noorama - Impacts during representative wet and dry phases ... 55 Table 19 – Flood Thresholds for Cunnamulla and Barringun (Source: BOM website) ...... 60 Table 20 – Cunnamulla - Impacts during representative wet and dry phases ...... 60 Table 21 – Barringun - Impacts during representative wet and dry phases...... 61 Table 22 – Cuttaburra at Border - Impacts during representative wet and dry phases ...... 66 Table 23 – Commence to Flow Thresholds for Tuen and Thurulgoonia Creeks ...... 69 Table 24 – Irrara Creek - Impacts during representative wet and dry phases ...... 74 Table 25 – Cross Border Modelled Flows – total volume (ML) from 1889 – mid 2006 ...... 76 Table 26 – Dry Phase Cross Border Modelled Flows – ...... 77 Table 27 – Flood Thresholds for Fords Bridge ...... 81 Table 28 – Fords Bridge - Impacts during representative wet and dry phases...... 82 Table 29 – End of System - Impacts during representative wet and dry phases...... 83 Table 30 – Warrego River - Summary of Flow Regime Impacts...... 86 Table 31 – Effluent Creeks start of system - Summary of Flow Regime Impacts...... 86 Table 32 – Critical Flow Dependencies of Environmental Assets1 ...... 87 Table 33 – Generalised Impacts on Instream Assets ...... 88 Table 34 – Changes in water availability for key hydrological indicators for Yantabulla Swamp and the Warrego River waterholes...... 89 Table 35 - Hydrologic Evaluation Tool Recommendations ...... 93 Table 36 – Recommendations for Performance Indicators...... 97 Table 37- Hydrologic Data Recommendations ...... 98 Table 38 – Research Recommendation – Ecological Data ...... 101

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LIST OF FIGURES

Figure 1 - Photos of Floodplain Inundation ...... 13 Figure 2 - Hydrological Features of the Warrego...... 15 Figure 3 – Gauge height (m) at Cunnamulla Bridge (pre-weir) required for small flood levels in creeks (Data source: Mottell, 1998) ...... 24 Figure 4 – 1986 and 1987 floods – Wyandra and Fords Bridge ...... 24 Figure 5 – Wet and dry phases - Fords Bridge Bywash Gauge* ...... 28 Figure 6 – Example flow exceedance curve ...... 46 Figure 7 – Warrego River to Wyandra – Hydrologic Summary...... 48 Figure 8 – Daily Flow Exceedance Curve – Wyandra ...... 49 Figure 9 – Noorama and Widgeegoara Creeks– Hydrologic Summary...... 53 Figure 10 – Daily Flow Exceedance Curve – Widgeegoara and Noorama...... 54 Figure 11 – Warrego from Wyandra to NSW Border – Hydrologic Summary...... 57 Figure 12 – Daily Flow Exceedance Curve – Cunnamulla...... 58 Figure 13 – Daily Flow Exceedance Curve – Barringun ...... 59 Figure 14 – Cuttaburra Creek– Hydrologic Summary...... 63 Figure 15 – Daily Flow Exceedance Curve – Cuttaburra Creek Start of System...... 64 Figure 16 – Daily Flow Exceedance Curve – Cuttaburra Creek @ NSW Border ...... 65 Figure 17 – Thurrulgoonia and Tuen Creeks– Hydrologic Summary...... 68 Figure 18 – Irrara Creek – Hydrologic Summary ...... 72 Figure 19 – Daily Flow Exceedance Curve – Irrara Creek Start of System ...... 73 Figure 20 - Assessment of Cross-Border Flow Objective ...... 76 Figure 21 – Warrego River from Barringun to Darling – Hydrologic Summary ...... 79 Figure 22 – Daily Flow Exceedance Curve – Fords Bridge ...... 80 Figure 23 – Daily Flow Exceedance Curve – Warrego End of System: 1922 - 2006 ...... 82 Figure 24 – IQQM Representation of Floodplain Losses (Source: Adapted from SMEC, 2002)95 Figure 25 - Existing Official and Unofficial Gauges and Suggestions for Additional Gauges ... 100

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EXECUTIVE SUMMARY

Objectives and Methodology

The Queensland portion of the Warrego is managed under the Warrego, Paroo, Bulloo and Nebine Water Resource Plan (WRP) (2003) and the Resource Operation Plan (ROP) (2006). At present, there is no planning instrument in NSW. As such, there was interest in the community that available information be consolidated and assessed for usability for the purposes of supporting development of a plan in NSW and for future reviews of the QLD plan. There was also interest in having an assessment undertaken to determine current hydrologic impacts due to water resource development and potential future impacts.

As a result, the Western Catchment Management Authority (WCMA) commissioned WMAwater to undertake a scoping study for the Warrego River and its tributaries and effluents. This study was to synthesise and identify gaps in knowledge / data relating to hydrology, flow dependent environmental assets and water planning instruments.

This project was based on a desktop study that collates and reviews information drawn from existing publications, reports and datasets. Some stakeholder consultation was undertaken but was focused on landholders in the Lower Warrego in accordance with the requirements of the project brief. The assessment of flow regime change due to development has been quantified through use of modelling data obtained from the Queensland Department of Natural Resource and Mines (QDNRM). Whilst the QLD model extends into NSW, there is scope for improvement in the representation of flows in the NSW section of the system. Therefore, WMAwater developed an IQQM model for the NSW portion of the system using information provided from the NSW Department of Water and Energy. It is important to note that due to the lack of streamflow data the model has not been verified and many additional improvements are possible.

Study Area

This scoping study examines the major distributary systems, in addition to the Warrego itself. Hydrologic data availability and an assessment on the impact of development on the flow regime have been presented separately for seven hydrologic regions identified for the purposes of this study. These are:

1. Warrego Basin down to Wyandra The upper part of the basin drains a large area with numerous creeks and rivers entering the Warrego River upstream of Wyandra.

2. Noorama and Widgeegoara Creeks These effluents leave the Warrego downstream of Wyandra and head south east, occasionally spilling into the Nebine.

3. Warrego River from Wyandra to NSW Border Downstream of Wyandra the river changes from a gaining river to a losing river due to the numerous effluents which leave the river.

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4. Cuttaburra Creek The Cuttaburra Creek has it’s main offtake from the Warrego immediately downstream of Cunnamulla weir however other high flow offtakes occur upstream of the weir and some 20-30 km downstream of the weir. Flows from the Cuttaburra occasionally connect with floodwaters from the Paroo/Darling - on average every 15 years (QDNR, 2004).

5. Thurrulgoonia and Tuen Creeks Numerous effluents leave the Warrego downstream of Cunnamulla heading in a south easterly direction draining into extensive floodplain areas. Two key creeks in the region are the Thurrulgoonia and Tuen.

6. Irrara Creek The Irrara Creek leaves the Warrego just upstream of the NSW border and re-connects upstream of Fords Bridge. The Irrara also feeds the Kerribree and Green Creeks; the latter may connect back into the Warrego downstream of Fords Bridge.

7. Warrego River from Barringun to Darling The NSW section of the Warrego is examined separately due to different regulatory arrangements. A special section on cross border flows is included in the report as this is a key performance objective of the QLD ROP and warrants careful consideration and clarification in this study due to stakeholder concerns over this objective.

Overview of surface water hydrology

Unlike southern basin rivers which generally experience some level of flow throughout the year, the Warrego is an ephemeral river. Flows generally occur in late summer to early autumn though winter flows also occur in some years. In addition to the seasonal basis of flows in the Warrego, wet and dry phases across groups of years can be established from the flow record.

Wyandra is the point at which the Warrego changes from a river that is generally gaining in flow volume to generally losing in flow volume. The flow volume downstream of Wyandra is dramatically reduced due to the distributary nature of the system. For example, the average flow at Wyandra is approximately 550 GL per year whilst it is only 83 GL per year at Fords Bridge.

Widespread flooding occurs periodically in the Lower Warrego, due to the gently sloping terrain, low banks and meandering nature of the drainage profile. These floods, which can occur without local rainfall, are highly desirable for maintaining fertility of the floodplain (Mottell, 1998). Many areas also rely on local runoff in addition to river flows.

Overview of Flow Dependent Environmental Features

The flow dependent environmental assets for the Warrego have included instream waterholes, terminal and floodplain wetlands, and various vegetation communities. These assets support a wide variety of fauna. For the purposes of reporting the flow dependent assets of the Warrego have been grouped into the following structural categories:

• Instream (waterholes including fish, water quality) • Riparian (riparian vegetation) • Floodplains, Lakes and wetlands (vegetation types, waterbird populations).

The following information for these categories was obtained from published reports and records from landholders.

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Waterholes

Waterholes on the Warrego River system provide a critical refuge for fish and waterbird populations during no flow periods. Refilling events for waterholes sustain fish populations, allows for movement between waterholes and into the river channel and act as a stimulus for some fish species to undertake recruitment events. The shape of waterholes is also important for sustaining different fish populations.

Detailed assessment of waterholes and fish populations has been undertaken for some sites in Queensland by Balcombe et al. (2006). Compared with other rivers in the Murray-Darling Basin, this study found that the Warrego waterholes had higher abundances and more species. There was also a relatively low proportion of alien species. The authors considered the Warrego to be “a model dryland river for the further investigation of ecological processes sustaining fish in variable environments both in the MDB and other similar systems.”

Although waterholes exist in NSW, particularly along the Cuttaburra and lower Warrego, no similar assessment has been undertaken. Preliminary information on waterholes in NSW was collated during this study, through topographic maps and interviews with residents. This information can be found in Appendix A of the main report. While the locations of waterholes in NSW are largely known, important information on their physical characteristics, water persistence, response to different flow events and aquatic biota is not available in a consistent and systematic framework. Consequently, it is recommended a rigorous inventory of waterholes on the Warrego be undertaken, particularly for the NSW portion.

Water Quality

Water quality information has been collected from spot samples at several locations for the Warrego River since the 1960’s, the record for most stations is sporadic, either due to the truncated nature of water quality monitoring programs or the intermittency of flow events, or both.

Analysis and reporting of the water quality results is only in very general terms, eg DWR (1990) and DNR (2000). Therefore it is difficult to develop an informed picture of the water quality characteristics of the river and/or changes over time. With the intensification of landuse in the catchment, it is likely water quality characteristics will change. There has been no pesticide sampling undertaken, yet landuse intensification often involves increasing use of these chemicals.

A detailed analysis and reporting of the existing water quality information is required, along with the identification of additional risks and the appropriate level of monitoring and reporting required to inform resource managers.

Riparian Assets Hale et al. (2008) have recently completed a report of the riparian vegetation of the Warrego and Cuttaburra catchments in NSW as part of a wider intersecting streams (and lower Bogan River) study. The study involved mapping and riparian zone condition assessment components.

The Warrego had 5 sites of medium overall condition and 4 of poor condition. The Cuttaburra had 2 of poor condition and 3 with very poor condition. These results are similar to other rivers which were studied. A flora and fauna survey of the eastern Warrego floodplain is warranted.

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Floodplain, Lakes and Wetland Assets

Wetlands and waterbirds are the most studied aquatic assets of the Warrego. The Warrego wetlands are considered to be of critical importance to waterbird populations of the Murray-Darling Basin.

Nationally important wetlands/ lakes/ waterholes have been identified since 1993 (ANCA, 1993). EA (2001) provides the most recent listing of nationally important wetlands (DIWA wetlands) in the Warrego system. The large number of listings attests to the overall significance of the catchment for wetlands. The information content for several of the DIWA sites on the Directory database is quite limited. Consolidation of the wetland and waterbird information should be undertaken and the Directory database updated.

Where sufficient information on the water requirements of a DIWA site is available, the impacts of flow regime changes due to development have been evaluated in this study.

Impacts of Water Resource Development

IQQM model results are used to quantify the impacts of development under both pre-development and developed conditions. The pre-development model represents the flow regimes prior to infrastructure and diversions. For the developed scenario, the IQQM model for the Queensland section of the Warrego assumes full utilisation of existing allocations and uptake of additional allocations based on the Resource Operations Plan (Warrego, Paroo, Bullo and Nebine ROP 2006). The IQQM model for the New South Wales section of the Warrego assumes current utilisation of existing licenses.

There is at present no model scenario for the Queensland section of the Warrego which approximates current development. Therefore the impacts of current development on the flow regime have been qualitatively determined by estimating the proportion of allocation volumes which have not been utilised. Current impacts also differ to modelled impacts in that the model assumes that additional unallocated volumes which are allowed in the ROP have been allocated. The potential location and volume of these allocations were taken into account when estimating the difference between current impacts and full ROP development impacts.

Current impacts upstream of Wyandra have been estimated to be around 1/5th of that which would result if full levels of development allowed in the ROP were implemented. Current impacts downstream of Cunnamulla have been estimated to be around half that which would result if full levels of development allowed in the ROP were implemented. The current levels of impact towards the end of system are difficult to quantify given the lack of metering.

Minor and moderate flood thresholds have been obtained from the Bureau of Meteorology (BOM). These thresholds are not available for the distributary creeks and as such the impact assessment for the creeks could not be site specific. Instead, the flow range of 100ML/D to 1,000 ML/D was used as an approximation of small to medium flooding.

The following points summarise the key results: • There is an increase in the loss of average daily flow, for both the Warrego and the effluent creeks, as you move down the system as a result of cumulative extractions due to water resource development. Assuming full development, average daily flows are reduced by approximately 1.5% at Wyandra, 16% at Fords Bridge and 44% at the end of system.

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• There is an increase in the loss of minor flooding days as you move down the system as a result of cumulative extractions due to water resource development. Assuming full development, frequency of minor flooding is reduced by approximately 0.5% at Wyandra, 17% at Fords Bridge and 36% at the end of system. • Excluding Barringun, there is an increase in the loss of moderate flooding days as you move down the system as a result of cumulative levels of development. Assuming full development, frequency of moderate flooding is not impacted at Wyandra, and is reduced by approximately 14% at Fords Bridge and 35% at the end of system. The flood thresholds at Barringun may need reviewing.

All statistics are estimates only and should be considered indicative. The impacts for the end of system are particularly difficult to quantify given the lack of gauging of flows and lack of accurate data regarding storage volumes, low flow outlet capacities and natural transmission losses. It has not been possible to verify the end of system results generated for this study.

Note that Tuen and Thurulgoonia creeks are not explicitly modelled in the IQQM. As such, the impact assessment for these creeks has been based on data for Cunnamulla and Barringun. The best estimate of impacts for the creeks was that:

• the number of days where the Tuen creek flows is reduced by between 6% and 11% as a result of full upstream development. • the number of days where the Thurulgoonia creek flows is reduced by 2% to 17% as a result of full upstream development

The minor flood threshold used in the hydrologic impact assessment approximates within channel high flows. The moderate flood threshold approximates the start of overbank high flows. As such, it is possible to establish a general relationship between impacts on flooding and the environmental significance of those impacts. Broadly speaking, instream assets are likely to be impacted by zero, low and within channel flows: • Increased frequency of zero and low flows downstream of Wyandra may be affecting instream waterholes and associated flora and fauna. These impacts are likely to be most felt in the more downstream waterholes: • The impacts of development on zero to low flows are moderately small upstream of Fords Bridge. However, below this point the impact is more severe. At Fords Bridge the maximum period of flows below 100 ML/D is increased from 373 to 596 days (an increase of 60%). • The decreased frequency of within channel flooding may be affecting waterhole and riparian habitats. • The impacts on frequency of minor flooding are reasonably small upstream of the border (8% at Cunnamulla and 9% at Barringun) but are moderate at Fords Bridge (17% reduction) and large at the end of system (36% reduction in minor flood frequency).

In the case of DIWA wetlands, site specific information about historic inundation frequency has been available which can be used to create a site specific flow threshold. Based on this assessment, impacts due to full ROP development are expected for the following DIWA sites: • Yantabulla Swamp (Cuttaburra Basin) (NSW019) • Warrego River Distributary System (QLD169) • Green Creek Swamp (NSW013) • Birdsnest Swamp (NSW163) & Racecourse Swamp (NSW166) & Toms Lake (NSW168)

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The hydrologic impact assessment in this report is limited to considering flow quantity/frequency characteristics of the region and impacts as a result of water extractions and construction of water storages. Land use in the region may also be impacting riparian and floodplain flora and fauna and water quality.

The impact assessment has also not considered economic issues as this is outside the scope of the brief. Grazing as a result of beneficial flooding has been reported to be an important component of the regional economy however (Mottell, 1998) and these activities may be affected by changes in the flow and inundation.

Recommendations for Data Collection, Evaluation Tools and Planning Instruments

The following tables summarise recommendations for data collection, improvement of evaluation tools and improvements or additions to planning performance indicators.

Table A1 - Research Recommendation – Hydrology Data and Tools No. Recommendation Significance of Recommendation

H1 Recalibration of the IQQM o The model was not calibrated at the gauge at Turra due to insufficient model should occur to take data, however there would now be sufficient data to conduct the advantage of additional calibration. information on streamflow o Some river height data collected by stakeholders might be suitable to refine the model if a suitable height – discharge relationship can be established. o Once a suitable length of record is obtained at the Wallen gauge this data should be useful to refine the modelled breakouts to Noorama and Widgeegoara Creeks. H2 Upgrade the IQQM to o It is recommended that the model be upgraded to explicitly model the explicitly Model all Major Tuen and Thurrulgoonia creeks as they are major components of the Distributary Creeks Warrego River Distributary System Systems H3 The IQQM model should o The current range of hydrologic models developed for assessment of be upgraded to enable water resource management have primarily focused on changes to the better representation of flow regime and impacts on irrigation users. Very little assessment of floodplain flows. floodplain losses and impacts of development on beneficial flooding has occurred.

H4 Upgrade the IQQM Further improvements could be made: model’s representation of o a distributed representation of storages instead of a lumped approach the end of system and improved estimation of storage volumes (ideally based on bathymetric data) o improved evaluation of low flow outlet capacities. The capacity used in this report is the high end, and actual capacity could be significantly smaller o improved infiltration and evaporation values for dams based on field monitoring which has recently been conducted (WCMA job number 3892007), o represent the breakout from Boera Dam to Darling, o re-assessment of inflows and losses at the end of system, calibration and verification (ideally using an end of system gauge)

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Table A1(Con) - Research Recommendation – Hydrology Data and Tools No. Recommendation Significance of Recommendation

H5 Pending the availability of o Warrego River end of system (NSW) (Fords Bridge is the gauge suitable sites, additional furthest downstream, below which are numerous in-stream dams stream gauging stations which would significantly alter flows). should be installed at the: Gauging of the following creeks near the border would assist in monitoring the cross border flow objective of the WRP: o Irrara Creek (NSW) o Widgeegoara Creek (NSW) o Warrego near Rocky or Coonberry Plains o A gauge between Cunnamulla and Baringun may be warranted for both modelling and river management purposes. There are a large number of distributary offtakes between Cunnamulla and Barringun. A gauge mid-way between offtakes may be useful for better establishing distributary losses and would be a more reliable reference gauge for licensing conditions. H6 Metering of usage in NSW There are currently no meters in place and there is a significant volume of should take place as a licensed allocations. Current use is believed to be significantly lower than matter of urgency licensed allocations but metering is still warranted to ensure compliance and would also assist in model calibration. H7 Additional River Gaugings o Gauging of Tuen Creek @ Bluegrass Bridge is recommended as this to Develop Height – Flow site has a significant historic height record and therefore could be Relationships useful in explicitly representing these creeks in the IQQM. o Additional high flow gaugings at Augathella, Charleville and Wyandra may also be warranted. H8 Improved Representation The IQQM model was not able to robustly represent the low flow regime of Low Flow Regime at several locations, particularly: o Charleville o Cunnamulla o Barringun Improvement of the model’s ability to represent low flows will most likely be dependent on the incorporation of data from the gauging stations of Barringun and Turra, additional rainfall data to improve system inflows, better representation of instream weirs, and a more robust representation of instream losses.

Table A2 - Research Recommendation – Ecological Data and Tools

No. Research Recommendation Significance of Recommendation E1 Recommend a rigorous inventory While the locations of waterholes in NSW are largely known, of waterholes on the Warrego be important information on their physical characteristics, water undertaken, particularly for the persistence, response to different flow events and aquatic biota is NSW portion. not available in a consistent and systematic framework. E2 A detailed analysis and reporting Analysis and reporting of the water quality results is only in very of the existing water quality general terms, eg DWR (1990) and DNR (2000). information is required, along Therefore it is difficult to develop an informed picture of the water with the identification of quality characteristics of the river and/or changes over time. additional risks and the appropriate level of monitoring There has been no pesticide sampling undertaken and reporting required to inform resource managers.

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Table A2 - Research Recommendation – Ecological Data and Tools

No. Research Recommendation Significance of Recommendation E3 Consolidation of the wetland and The information content for several of these sites on the Directory waterbird information should be database is quite limited and in some instances inaccurate undertaken and the Directory Findings from recent studies have not been added to the database database updated, and, where the data is limited, further data collection should be undertaken. E4 A flora and fauna survey of the While a recent study investigated and reported on riparian eastern Warrego floodplain is vegetation condition for the Warrego and Cuttaburra (Hale et al. warranted. 2008), “floodout” systems were not included. Thus, for example, large areas of the eastern Warrego floodplain were not surveyed. Also these areas reportedly are dominated by quite different vegetation communities, i.e. Warrego Summer grass and Mitchell grass plains, as well as some treed areas. The wetland studies cited in this Consultancy have also not covered this eastern floodplain. These areas are also susceptible to reduced flooding due to upstream extraction.

Table A3 - Research Recommendation – Planning performance Indicators

No Recommendation Significance P1 Zero flow planning No such indicator exists in the WRP and zero flows are a key performance indicator should component of the flow regime. be developed. P2 Low flow performance There is currently an indicator examining flows lower than indicator could be tied to median, however this part of the regime may not necessarily ecological flow thresholds be classified as a low flow such as minimum flows required to replenish instream waterholes. P3 Within channel high flow There is currently an indicator examining 1 in 2 year floods, indicator could be tied to site however this flow frequency may not necessarily correspond specific thresholds to within channel high flows P4 Include indicator assessing There is currently an indicator examining the median change in frequency/duration beneficial flooding flow however the change in duration / of moderate flooding frequency is not assessed.

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1. Introduction

1.1. Project Rationale and Objectives

The Queensland portion of the Warrego is managed under the Warrego, Paroo, Bulloo and Nebine Water Resource Plan (WRP) (2003) and the Resource Operation Plan (ROP) (2006). At present, there is no planning instrument in NSW. As such, there was concern in the community that available information be consolidated and assessed for usability for the purposes of supporting development of a plan in NSW and for future reviews of the QLD plan. There was also concern that an assessment be undertaken of current hydrologic impacts due to water resource development and potential future impacts.

As a result, the Western Catchment Management Authority (WCMA) commissioned WMAwater to undertake a scoping study for the Warrego River and its tributaries and effluents. This study was to synthesise and identify gaps in knowledge / data relating to hydrology, flow dependent environmental assets and water planning instruments.

The key objectives of the study include:

1. Provide an overview of the surface water hydrology of the Warrego River and its tributaries.

2. Review existing literature on flow dependent environmental features of the region.

3. Summarise available hydrology related data.

4. Evaluate the impacts that water resource development has had, or could have, upon the regional flow regime.

5. Identify gaps in the available data sets, assessment tools and performance indicators and make recommendations to assist future water resource planning and management. .

1.2. Methodology

This report provides an overview of the surface water hydrology of the Warrego River and its tributaries. The report describes the surface water hydrology and flow dependent environmental features of the region and the impacts that water resource development has, or could have, upon these values. Gaps in the available data sets, assessment tools and performance indicators are identified and recommendations made to assist future water resource planning and management.

Literature and Data Review and Gap Analysis

This project was based on a desktop study that collates and reviews information drawn from existing publications, reports and datasets. Some stakeholder consultation was undertaken from 5th – 7th May, primarily for the purposes of obtaining existing documentation. Consultation also assisted the authors in obtaining a better appreciation of the region, the highly distributed nature of flows and highlighted a number of landholder concerns regarding water management. Given the scope of the project, extensive consultation was not possible. The consultation conducted was focused on landholders in the Lower Warrego in accordance with the requirements of the project brief.

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Impact Assessment

The assessment of flow regime change due to development has been quantified through use of modelling data obtained from the Queensland Department of Natural Resource and Mines (QDNRM). The QLD model does not suitably represent flows at the end of the Warrego where it joins the Darling. As such, WMAwater developed an IQQM model of the end of system with some information provided from NSW. The model was developed with the best available information, including license information, however the model has not been verified and many additional improvements are possible (see Section 5.1).

The assessment of ecological impacts resulting from flow regime changes is limited to very broad comments in this study. More sophisticated assessment tools are required to properly assess these impacts, as is discussed in the report.

The impact assessment presented in this report assumes that the available historic climate records are representative of future climate patterns. This assumption may not be valid, not only due to climate change, but also because the level of climate variability that might have occurred in absence of climate change may not be well represented in the relatively short period of climate records available. The impact of climate change on the water resources and ecosystems of the Warrego was examined by CSIRO (2007) however a more detailed analysis of CSIRO’s results is warranted. It has not been possible to undertake this analysis for this report and as such it is recommended for future studies.

1.3. Report Structure

Chapter 2 presents background information on the Warrego Basin including a summation of water resource planning in both Queensland (QLD) and New South Wales (NSW). Chapter 3 discusses the hydrologic and environmental characteristics of the basin.

• Section 3.1 provides an overview of the flow regime of the basin based on recorded river flow data. • Section 3.2 contains a review of literature on flow dependent environmental assets in the basin.

Chapter 4 outlines the available data and impacts of water resource development. These have been discussed separately for the major hydrologic regions of the basin.

• Section 4.1 describes the methodology for impact assessment. This includes a description of the main hydrologic planning tool in the Warrego, the IQQM. • The sections on individual regions firstly present the available climate, streamflow and development data including any IQQM model results that exist and their associated accuracy. The impacts of development on the flow and flooding regime and environmental values and assets of each river section are then presented. • Section 4.9 examines the QLD plan objective relating to cross border flows. This objective has been considered in some detail in this study due to stakeholder concerns in relation to how the performance indicator associated with this objective has been calculated. • Chapter 4 concludes with a discussion about hydrologic impacts that have been calculated from other literature such as the CSIRO Sustainable Yields study and the Sustainable Rivers Audit section on hydrology data gaps.

Chapter 5 provides recommendations relating to evaluation tools, performance indicators and data collection / collation.

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2. Background Information

Any detailed assessment of the hydrologic and environmental characteristics of the Warrego should be preceded by a brief overview of the study area, and the planning instruments that govern the management of the catchments water resources. This is undertaken in sections 2.1 and 2.2.

2.1. Overview of Study Area

The Warrego Basin extends from the Great Dividing Range in QLD (in the Carnarvon) down to the Darling River in NSW, joining the Darling downstream of Bourke (see Figure 1). The mainstream length of the Warrego approximates 890km (QDNR, 2004) and elevation varies in 807m down to approximately 100m at the junction with the Darling.

The rivers of the Warrego flow intermittently. Streamflow records for Wyandra from 1967 to 1998 show that the monthly streamflow varies from zero for all 12 calendar months up to a maximum of 2,405 GL (DNR, 2000) which occurred in April, 1990.

Mean annual rainfall in the Warrego catchment is highly variable spatially and temporally:

• The average rainfall ranges from approximately 250mm in the south to approximately 650mm in the elevated headwaters of the Carnarvon Range (DNR, 2000).

• Rainfall can vary considerably from year to year with the regional coefficient of variation of annual rainfall of 0.35 (CSIRO, 2007). For Charleville, annual rainfall has ranged from 203mm (1890) to 1,203 mm (1899) (DNR, 2000).

• Rainfall is generally summer dominant with the majority of the catchment receiving 50% of its annual rainfall from December to March. There is an increasing winter component in the south however where only 40% of rainfall falls in the December to March period. (DNR, 2000)

• Drought conditions may occur even with near average rainfall volumes as the rainfall has not occurred as effective rainfall (rainfall which exceeds total evaporation over a 10 day growing period) (Mottell, 1998).

The rainfall, runoff and runoff coefficients (proportion of rainfall that becomes runoff) in the Warrego, summarised in Table 1, are amongst the lowest in the Murray Darling Basin (CSIRO, 2007).

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Table 1 - Rainfall and Runoff in the Warrego. (Source: QDNRM, 2004) Reach Reach Average Average Runoff / Comment Boundary Annual Annual Rainfall Rainfall Rainfall (mm/a) Runoff (mm/a) Low runoff attributed to Upstream of 1 556 4.8 0.9% recharge of Great Artesian Augathella Basin Augathella to 2 503 13.9 2.8% Charleville Charleville to 3 466 12.0 2.6% Wyandra Decreasing runoff as move Wyandra to south attributed to 4 353 4.6 1.3% Cunnamulla increasing dryness and Cunnamulla to distributary breakouts. 5 Barringun 336 2.9 0.9% (NSW Border) Higher runoff than reach 5 Barringun as effluents which bypass 6 (NSW Border) 326 7.3 2.2% flow gauge on reach 5 re- to Fords Bridge join the Warrego in reach 6.

The Warrego regional economy is largely based on primary production and is dominated by dryland grazing. However, grazing as a result of beneficial flooding and a small amount of irrigation development also occur on the floodplain (see Table 2).

Table 2 - Irrigated Area in Warrego River (NSW part only)1

Area Irrigated Area Irrigated Area Irrigated 1983/84 (ha) 1992/93 (ha) 1996/97 (ha) 968 1,852 1,925 1 Source: Australian Natural Resource Atlas

Widespread flooding occurs periodically in the Lower Warrego, due to the gently sloping terrain, low banks and meandering nature of the drainage profile (see Figure 1 for pictures from the latest flood event). These floods, which can occur without local rainfall, are highly desirable for maintaining fertility of the floodplain (Mottell, 1998). Warrego is an Aboriginal word meaning "river of sand". This name reflects the geomorphology of the lower part of the system where complex braided channels in the floodplain have highly mobile sand beds.

Mottell (1998) reported that in the Lower Warrego there is a total of 457,772 ha inundated in a major flood; approximately 26% of total holding area. Of this 3,949 ha are ‘improved irrigation areas’ which receive water predominantly through “water spreading/beneficial flooding” which maximises the value of flood waters during medium to large floods. These areas also receive some irrigation during periods of lower in bank flows.

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Figure 1 - Photos of Floodplain Inundation

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The environmental values and assets of the Warrego have developed in response to its highly variable flow regime. Figure 1 illustrates the key hydrological features of the Warrego including the location of wetlands listed on the Directory of Important Wetlands Australia (DIWA) database (Environment Australia, 2001). There are 14 DIWA wetlands illustrated within the Warrego / Cuttaburra basin.

For the purposes of this report, the study area (refer to Figure 2) has been grouped into the seven hydrologic regions and a section on cross border flows:

1. Warrego Basin down to Wyandra The upper part of the basin drains a large area with numerous creeks and rivers entering the Warrego River upstream of Wyandra.

2. Noorama and Widgeegoara Creeks These effluents leave the Warrego downstream of Wyandra and head south east, occasionally spilling into the Nebine and consequently the Culgoa.

3. Warrego River from Wyandra to NSW Border Downstream of Wyandra the river changes from a gaining river to a losing river due to the numerous effluents which leave the river.

4. Cuttaburra Creek The Cuttaburra Creek has it’s main offtake from the Warrego immediately downstream of Cunnamulla weir however other high flow offtakes occur upstream of the weir and some 20-30 km downstream of the weir. Flows from the Cuttaburra occasionally connect with floodwaters from the Paroo/Darling - on average every 15 years (QDNR, 2004).

5. Thurrulgoonia and Tuen Creeks Numerous effluents leave the Warrego downstream of Cunnamulla heading in a south easterly direction draining into extensive floodplain areas. Two key creeks in the region are the Thurrulgoonia and Tuen.

6. Irrara Creek The Irrara Creek leaves the Warrego just upstream of the NSW border and re-connects upstream of Fords Bridge. The Irrara also feeds the Kerribree and Green Creeks; the latter may connect back into the Warrego downstream of Fords Bridge.

7. Total Inflows to New South Wales

A special section on cross border flows is included prior to examining the NSW section of the Warrego as this is a key performance objective of the QLD ROP and warrants careful consideration and clarification in this study due to stakeholder concerns over the evaluation of this objective.

8. Warrego River from Barringun to Darling The NSW section of the Warrego is examined separately due to different regulatory arrangements.

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Figure 2 - Hydrological Features of the Warrego

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2.2. Water Resource Planning in the Warrego

2.2.1. Queensland Warrego Legislation and Planning

Water Resource Planning in the Warrego is carried out under the Queensland Water Act 2000 above the New South Wales Queensland border and the New South Wales Water Act 1912 below the border.

The Queensland Act provides for two levels of plans for the allocation and management of water, Water Resource Plans (WRPs), and Resource Operations Plans (ROPs). WRPs are the highest level of plan, and are subordinate legislation. A ROP is intended to detail how a WRP will be implemented. The plan can be amended and extended over time, providing it remains consistent with the Water Resources Plan.

The Warrego, was gazetted in 2003 as part of the (Warrego, Paroo, Bulloo, Nebine) WRP, whilst the ROP was finalised in 2006. Both plans deal with surface water only. The ROP treats the Warrego as two water management areas, the Upper Warrego, which extends down to Wyandra, and Lower Warrego, which runs from there to the New South Wales border.

2.2.2. New South Wales Warrego Legislation and Planning

There are currently two Acts governing water management and management of entitlements in New South Wales. These are the Water Act 1912 and the Water Management Act 2000. The New South Wales portion of the Warrego River is still covered by the Water Act 1912. A shift from the Water Act 1912 to the Water Management Act 2000 will occur when a macro water sharing plan for the far west region is completed. The macro planning process is designed to develop broader-scale statutory water sharing plans covering water sources not included in the initial round of water sharing planning. There is some question about the timing of development of the far west region macro plan because of uncertainty associated with the outcomes of the CSIRO sustainability assessments as part of the sustainable yields project, and the scope and nature of the Basin Plan proposed under Commonwealth water legislation.

2.2.3. Management Strategies, Rules and Performance Indicators for the Queensland Section of the Warrego

2.2.3.1. Water Entitlements – Management Strategies and Rules

Management of the Queensland surface water resources of the Warrego are controlled through a combination of account based and flow access rules. The major forms of water entitlements in the Warrego are:

• Water allocations which are tradeable: o Supplemented (regulation through Cunnamulla Weir) o Unsupplemented (relies on unregulated passing flows) • Overland Flow Authorities which are tied to licensed works.

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Supplemented Allocations

At the time of the formulation of ROP for the Warrego all supplemented allocations were medium priority, however the ROP includes provisions for conversion into high priority allocations.

The volumes that supplemented water allocations receive in the Warrego are a function of the volume stored in dams with no allowance made for expected inflows. Losses due to storage and transmission are factored into the announced allocation assessment. No water can be allocated to medium priority water allocations until high priority water allocations have received a 100% allocation. The ‘nominal volume’ stated on an allocation is used to determine the share of available water that each entitlement holder may receive on an annual basis. Supplemented water allocation entitlement holders can call on their water at any time they require it and at any rate at which they require it – subject to any practical system operational constraints. The accounting arrangements for both supplemented and unsupplemented water allocations are clearly specified in the ROP.

Supplemented water allocations may be amalgamated or subdivided subject to certain criteria as outlined in the ROP. Trading of supplemented water allocations can occur, however a change in zone is prohibited.

Unsupplemented Allocations

Unsupplemented water allocations are not controlled by regulating infrastructure. Movement of unsupplemented water allocations between zones is possible, subject to case by case assessment and the approval of the Chief Executive. Access to unsupplemented entitlements is often restricted through specification of passing flow conditions. Where conditions apply, extractions can not begin until:

• the peak of the event has passed the flow reference point and the flow in the river at the specified reference gauge exceeds the rate specified on the allocation. Where more than six months has passed since a passing flow greater than 1,000 ML/D has occurred at the reference point, extractions can not begin until 36 hours after the peak flow has passed. Or, • the passing flow exceeds the rate specified under the special conditions of the licence. The rate specified under the special conditions is substantially larger than the passing flow rate.

Accounting for unsupplemented water allocations comprises two elements - a ‘volumetric limit’ and a ‘nominal volume’. The volumetric limit is the maximum amount of water that may be taken under a water allocation during a water year. The average annual volume of water that may be taken under the volumetric limit accounting arrangements is referred to as the nominal volume. The nominal volume is based upon hydrologic IQQM modelling. In the case of the Warrego, the modelling assumes no restriction on farm storage capacity; hence the volumetric limits and nominal volumes represent ultimate development limits which cannot be exceeded through any increased development on the user side of the pump.

Overland Flow Authorities

The Warrego ROP allows the granting of water licenses to control the taking of overland flow water. Overland flow is either floodwater or rainfall runoff that has not yet entered a watercourse. Overland flow extraction must either be authorised or, if there is to be a change of works, licensed with a condition that ensures there is no increase in average extractions. Licensing may be triggered by a

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change in the water storage volumes or other works. The licence may include conditions such as rate of extraction, volume of storage, annual diversion limit and long term average diversion limit.

2.2.3.2. Managing Growth in Use

The accounting arrangements outlined in the previous section are formulated in such a way as to result in a long-term extraction limit for diversions in the Warrego (though this is not specifically stated in the water resource plan). The value of the long-term average extraction resulting from these conditions is also not specified in the ROP but is in the order of 50 GL per annum.

The Warrego ROP also states that water supply must be managed to comply with the Murray–Darling Basin Agreement, and that if following the audit process under the Murray–Darling Basin Agreement it is determined that action should be taken to bring the cumulative measured volume back into balance with the cap, then actions may be taken which may include amending the ROP. In the case of the Warrego compliance with the volumetric limit should ensure compliance with both the nominal volume and the Murray Darling Basin Ministerial Council (MDBCMC) Cap.

Metering of licensed diversions in the QLD portion of the Warrego has been largely rolled out; the remaining offtakes are awaiting the outcome of national metering standards (pers. comm. J. Weller QDNRM).

2.2.3.3. Water Allocation Security Objectives and Performance Indicators

The Warrego WRP contains two performance indicators which address water allocation security objectives. They apply to all relevant products identified in section 2.2.3.1 and are: • the 45% annual volume probability, and • the annual volume probability.

The 45% annual volume probability is the percentage of years where the volume of water that may be taken by the group is equal to or greater than 45% of the total of the nominal volumes for the group.

The annual volume probability is defined differently for unsupplemented and supplemented water. For unsupplemented water allocations it is defined as the “percentage of years in the simulation period in which the volume of water that may be taken by the group is at least the total of the nominal volumes for the group”. For supplemented water allocations it is defined as the “average annual volume of water that may be taken by the group in the simulation period as a percentage of the total of the nominal volumes for the group”.

2.2.3.4. Environmental Objectives - Management Strategies and Rules

The Water Resource Plan (WRP) for the Warrego does not establish specific environmental water allocations; rather environmental water is protected via water access rules such as pumping thresholds. The Warrego WRP does however contain environmental flow objectives, and the rules applying to operation of the system and management of surface water entitlements need to comply with those objectives. These rules specify flow objectives in terms of proportions of the pre- development flow regime. These are further discussed in the following section.

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2.2.3.5. Environmental Objectives and Performance Indicators

The Water Resources Plan for the Warrego establishes a series of environmental flow objectives based on five hydrologic performance indicator measured at: • Warrego River at the border of the Queensland and New South Wales • Warrego River at Cunnumulla Weir stream gauging station • Warrego River at Wyandra stream gauging station • Warrego River at Charleville stream gauging station

For the cross border flow objective the performance indicator is assessed at Barringun and also at the Cuttaburra, Irrara and Noorama & Widgeegoara Creeks at the border.

WRP plan objectives for the Warrego aim to maintain the performance indicators within a certain proportion of pre-developed value. If the indicator is already outside the stated range, the objective is to prevent any further deviation.

Flow objectives and performance indicators are presented in Table 3. Performance indicators for each objective were assessed for the purposes of the ROP through IQQM modelling. Two IQQM models were developed; one representing pre-development conditions and one representing the levels of development allowed under the ROP.

Table 3 – Environmental Flow Objectives and Performance Indicators

Flow Feature Indicator Objective (a) end of system flow; Total volume of water that flows past The indicator, under levels of development stated points1 during the entire IQQM allowed in the ROP, is at-least 89% of the simulation period. volume that occurred under pre-development conditions. (b) low flow; The total number of days in the At each node described in schedule 22 the extent simulation period in which the daily to which the low flow indicator for ROP flow is not more than half the pre- conditions is less than 66% or greater than 133% development median daily flow. of that which would occur given pre- development conditions is to be minimised. (c) summer flow; The average number of days in At each node described in schedule 22 the extent summer3 in which the daily flow is to which the summer flow indicator for ROP more than the pre-development conditions is less than 66% or greater than 133% median daily flow. of that which would occur given pre- development conditions is to be minimised. (d) beneficial flooding flow The median of the total flow volume At each node described in schedule 22 the extent occurring in each wet season4 to which the beneficial flooding flow indicator for ROP conditions is less than 66% or greater than 133% of that which would occur given pre- development conditions is to be minimised. (e) 1 in 2 year flood. The daily flow that has a 50% At each node described in schedule 22 the extent probability of being reached at least to which the 1 in 2 year flow threshold under once a year. ROP conditions is less than 66% or greater than 133% of that which would occur given pre- development conditions is to be minimised. 1 For the ROP the cross border flows in the following systems were included; Cuttaburra Creek, Irrara Creek, Warrego River, Noorama and Widgeegoara Creeks 2 Warrego River at the border, Cunnamulla Weir, Wyandra and Charleville 3 The summer period is defined as the period from 1 December until the end of February in the following year. 4 The continuous 90 day period with the highest total of daily flows.

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2.2.4. Management Strategies, Rules and Performance Indicators for the New South Wales Section of the Warrego

2.2.4.1. Water Entitlements – Management Strategies and Rules

As for the Queensland portion of the system, management of the New South Wales surface water resources of the Warrego are controlled through a combination of account based and flow access rules. The forms of entitlements in the Warrego consist of unregulated Water Act licences. Water Act licenses represent rights to construct works, to use those works to take water (often expressed as a quantity per annum), and to use that water for specified purposes. In general the Water Act licence is tied to the land. Most water Act licences for commercial purposes also have to be renewed every five years.

In 2000-01 Water Act Licences on the Warrego were converted from authorised areas to volumes. This was based on an assessment of crop type and area irrigated over the period from 1993/94 to 1998/99. Some allowance was also made for inactive / undeveloped areas. Accounting for extractions under unregulated volumetric licences in the New South Wales portion of the Warrego is based on extractions not exceeding the three times the annual licensed volume in any three year period.

2.2.4.2. Managing Growth in Use

A diversion limit for the New South Wales Portion of the Warrego Catchment has yet to be established. Until such time, a default limit equal to the sum of volumetric entitlements will apply. This is approximately equal to 3.5GL per annum for direct extractions plus an additional 6GL per annum from floodplain storage.

2.2.4.3. Environmental Objectives – Management Strategies and Rules

There are no specific environmental water provisions within the New South Wales section of the Warrego. However, water access licence rules do provide for: commence to pump values for pumped extractions; and passing flows for instream dams. The passing flow conditions are designed to ensure inflows to the dam, up to the capacity of low flow bypass pipes, are allowed to flow through the dam and not be captured.

NSW has also produced river flow objectives for the Barwon Darling and it’s Far Western Rivers (see Table 4). However, until such time as a Macro Water Sharing Plan is produced, these objectives remain unimplemented.

Table 4 – River flow objectives for the Barwon Darling and its Far Western Rivers • Protect natural water levels in pools of creeks and rivers and wetlands during periods of no flows. • Protect natural low flows. • Protect or restore a proportion of moderate flows ('freshes') and high flows. • Maintain or restore the natural inundation patterns and distribution of floodwaters supporting natural wetland and floodplain ecosystems. • Mimic the natural frequency, duration and seasonal nature of drying periods in naturally temporary waterways. • Maintain or mimic natural flow variability in all streams.

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• Maintain rates of rise and fall of river heights within natural bounds. • Maintain groundwater within natural levels and variability, critical to surface flows and ecosystems. • Minimise the impact of instream structures. • Minimise downstream water quality impacts of storage releases. • Ensure river flow management provides for contingencies.

2.2.4.4. NSW Performance Indicators

As the macro water sharing plan that incorporates the Warrego is still in the process of being developed, environmental and water security objectives are yet to be defined. An indication of the types of performance indicators that are likely to be considered can be taken from the draft Hunter Unregulated and Alluvial Water Sources macro water sharing plan (see Table 5). The method of assessment for these indicators has not been provided.

Table 5 – Draft Hunter Unregulated and Alluvial Water Sources Macro Water Sharing Plan Performance Indicators • Change in low flow regime, • Change in moderate to high flow regime, • Change in groundwater extraction relative to the long-term average annual extraction limit, • Extent of groundwater level fluctuations, • Change in local water utilities access, • Change in, or maintenance of, ecological value of key water sources and their dependent ecosystems, • Extent to which basic landholder rights requirements have been met, • Extent to which major and local water utility requirements have been met, • Extent to which native title rights requirements have been met, • Change in economic benefits derived from water extraction and use, and • Extent of recognition of spiritual, social, economic and customary values of water to Aboriginal people.

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3. Hydrological and Environmental Characteristics of the Warrego

3.1. Hydrologic Overview

Temporal and spatial features of historic flooding events are described in the following sections through reference to historic river gauge data and existing literature.

3.1.1. Spatial Characteristics of Floods

Wyandra is the point at which the Warrego changes from a river that is generally gaining in flow volume to generally losing in flow volume. Downstream of Wyandra, the Warrego River distributes flow to a number of creeks during floods, resulting in significantly reduced flows at Fords Bridge in comparison to Wyandra. The annual flow characteristics of Wyandra and Fords Bridge are summarised in Table 6 based on historic gauge data for a common period. These statistics also illustrate the enormous variability in annual flows volumes.

Table 6 – Annual Flow Statistics for Wyandra and Fords Bridge gauged data1

Gauge Annual Flow Statistics (ML/ yr)

Average Median Minimum Maximum

Wyandra 549,794 315,788 1,684 2,550,445

Fords Bridge (Main 83,345 44,957 2,055 483,267 Channel + Bywash) 1 Based on water year totals for 1972 / 73 to 2002/03 water years; a water year begins in October. Wyandra annual totals sourced from http://www.nrw.qld.gov.au. Fords Bridge sourced from PINNEENA (151 data). Additional gauge locations were not included as the available data does not span this period.

Due to the relatively flat nature of much of the lower basin, flood flows are distributed across numerous floodplain flow paths. This results in significant areas of inundation for parts of the Warrego Basin. Whilst not quantified, many areas also rely on local runoff in addition to river flows. This is generally from stony hill country with red soils that give rise to rapid runoff and local flows or flooding during rain events.

Several authors have examined the flood inundation characteristics of the Warrego: o Mottell (1998) estimated that a total of 457,772 ha is inundated in a major flood through community consultation. o Kingsford et al. (2002) estimated historic areas of inundation based on analysis of Landsat imagery. This is summarised in Table 7. The maximum area inundated was 284,410 ha in 1990 however it is important to note that this study does not represent total area of inundation in the

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basin1. o CSIRO (2007) reported that the maximum inundation area is approximately 2,066,000ha based on analysis of MODIS satellite imagery. The maximum refers to the period 1990 to 2006. The area inundated during the period 2000 to 2006 was based on automated analysis of MODIS imagery. A regression relationship of flow and inundation area was developed for this period. The area inundated during the 1990 to 2000 period was estimated based on application of this regression relationship.

Table 7 – Historic Area of Inundation in Selected Locations in the Warrego (Source: Kingsford et al., 2002)

Lower Upper Warrego Warrego Cuttaburra floodplain floodplain

Flood Event Basin (ha) (ha) (ha) 1983 22,391 3,841 1,271 1984 24,188 18,511 113,113 1985 19,771 28,731 154,794 1986 32,623 4,041 52,197 1987 45,221 21,802 121,491 1988 10,938 3,858 2,033 1989 18,956 11,831 17,639 1990 77,844 58,274 148,292 1991 12,775 8,066 46,897 1992 31,017 25,239 109,823

1993 36,897 6,796 128,736 1994 41,509 23,389 100,551

The relationship between river flows and floodplain inundation is somewhat complex. Mottell (1998) collated information on gauge heights required before flooding begins in the Lower Warrego. Figure 3 illustrates the flood heights required at Cunnamulla Bridge (pre-weir) for small floods to begin in the creeks. Based on this data, the Irrara will begin to be inundated at the lowest flood levels and Thurulgoonia at the highest. The exact height required at Cunnamulla Bridge will differ to those illustrated due, for example, to the impacts of the weir, impacts of downstream extractions and antecedent conditions, however this data conveys the relative point at which floodplain areas begin to be inundated.

There is not necessarily a single relationship between peak flood height and the area of floodplain inundated. For example, Kingsford et al. (2002) report that the area flooded in the 1987 event exceeds that flooded in the 1986 event. The peak flow rate of the 1987 event at Wyandra is significantly lower than that for the 1986 event however, as is illustrated in Figure 4. In contrast to the 1986 event, the 1987 event had some prior flow (wet antecedent conditions) and a follow up event. This resulted in higher flow rates at Fords Bridge which lasted for a significantly longer duration. The longer duration of the 1987 event is reflected in landholder records for the Tuen Creek at Bluegrass Bridge; the Tuen ran for 89 days from January to April in 1987 but only 19 days in 1986.

1 The Noorama and Widgeegoara are not included. Estimations for Cuttaburra, Upper and Lower Warrego are based on a sample area of these zones which covers a significant proportion of area inundated but not the entire area.

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Figure 4 also highlights the travel time of floods (approx 3 weeks in this example) and the reduction in flows as water moves down the system. Note that there are two axis for reading flow rate; the Fords Bridge flow rate is on the left and the Wyandra flow rate is on the right. The 1986 peak at Wyandra was approximately 48,000 ML/D whilst the peak at Fords Bridge was only approximately 800 ML/D, a reduction of around 98%.

Figure 3 – Gauge height (m) at Cunnamulla Bridge (pre-weir) required for small flood levels in creeks (Data source: Mottell, 1998)

Figure 4 – 1986 and 1987 floods – Wyandra and Fords Bridge

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3.1.2. Seasonality

Unlike southern basin rivers which generally experience some level of flow throughout the entire year, the Warrego is an ephemeral river. Table 8 highlights those months where there was no single day in the month where the Wyandra gauge recorded a flow (green shading). Late winter to early autumn months generally have some flow, though April has been much drier since 19852.

Flooding generally occurs in late summer to early autumn as is illustrated in Table 9. Winter flows do occur however and result in different vegetation response to summer flows, as is illustrated through the following interview extract. Note that stakeholder consultation indicated that winter flows can be damaging in the higher elevation areas where frost is a concern.

Box 1 – Interview extract from landholder in Lower Warrego (Source: Kingsford et. al., 2002)

Question: How do floods in different seasons affect plants?

Answer: Well, it depends. Maybe it's a winter flood or may be there is a summer flood and depending on which season the flood comes through, there will be substantial effects on plants. Different plants respond obviously in different seasonal cycles. So winter floods will bring you much more in the herby, back bushy, clover those sort of plants - more the variety that grow here in winter which are so wonderful to us from a lambing perspective. This is a wonderful breeding country. It's not grass that's the reason for that. It's the saline herbs and the variety of herbages that grow here. So, winter floods will bring those variety of winter plants which are certainly from a sheep breeding point of view absolutely marvellous. The summer flood on the other hand grows watergrass which is from an environmental point of view is also very good because it's the grass that holds the soil together and blocks off the water to a greater degree and ensure a more stable platform for the next few years, so, either way it is marvellous but there is a very different result from winter and to summer floods.

2 This trend may have multiple causes including: river extractions, climate shifts and changes in channel geomorphology resulting in increased losses at low flows. No information is available to verify changes to geomorphology. Climate shifts do not appear to be the underlying cause as there are wet and dry phases in both the 1967 – 1984 and 1985 – 2007 periods (see Section 3.1.3 for further discussion).

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Table 8 – Wet / Dry Months at Wyandra (Months which have a flow day are coloured blue, months with no flow days are coloured green) Year Jan Feb Mar Apr May June July Aug Sep Oct Nov Dec

1967 0 23845.16 19.736 0 364.859 15.738 0 0 0 0 0

1968 6939.597 10284.95 1161.084 3264.196 36267.91 262.891 26.223 55.421 6.161 0 0 0

1969 998.494 419.491 7229.594 1870.738 925.636 16.077 0 0 0 0 0 7937.719

1970 2425.494 11037.62 7697.365 266.498 18.996 0 0 0 6925.959 395.93 5.159 21186.64

1971 1425.7 10148.7 1586.941 32.885 0.948 0 0 0 1054.097 0 0 272105.7

1972 208242.1 277.9 71.434 28.875 1243.73 45.014 9.917 0 0 0 14739.28 27740.22

1973 1555.249 211032.9 11551.02 895.914 2972.442 42.665 193.683 193.683 193.683 1267.017 18769.47 18300.16

1974 52860.68 59114.91 376.27 818.353 1239.891 263.342 32.987 2342.981 833.625 27.173 155.598 113.042

1975 5527.444 6759.946 8568.83 6683.408 11.984 0 0 0 0 0 0 65559.59

1976 38414.9 62135.81 11446.08 4030.35 1660.031 14.138 0 0 0 0 0 0

1977 724.781 11881.69 88338.48 1140.834 6524.456 2280.966 32.329 0 0 0 0 0

1978 1695.782 1323.871 372.452 19.675 0 535.781 44005.54 184.792 15063.77 3672.121 6312.636 16.748

1979 430.671 10133.49 5268.477 22.532 0.455 0 0 0 0 0 0 0

1980 0 2224.65 1272.459 35.025 0 579.213 1.206 0 0 17200.94 269.114 1006.088

1981 332.501 3608.667 1241.958 25069.4 6166.861 160402.3 1935.773 1793.277 10.531 0.537 1791.475 2494.108

1982 3188.782 563.85 34955.38 313.095 4.262 17.038 6.915 0 0 0 0 0

1983 0 1471.34 8391.14 8920.125 185626.3 33241.49 2135.606 87.523 20.357 2.505 2665.337 8081.637

1984 23178.03 11741.26 152.35 3.46 9.11 0 1330.889 3793.654 19.446 0 103.671 327.776

1985 295.639 0 0 0 0 0 0 0 0 0 5459.208 7821.601

1986 7.644 48421.2 68.333 0 863.763 11.066 0.391 591.195 116.132 0 2397.281 6528.085

1987 18009.03 24252.39 3904.126 2341.6 5.948 3513.711 1131.274 270.58 64.038 118.668 2064.503 355.535

1988 0 1095.013 31.2 511.418 0 0 4317.728 32.061 65.248 2.273 0 1117.366

1989 1994.128 409.05 35191.29 35599.28 46890.31 30808.2 141.449 13.729 0.434 6.736 26.028 2916.721

1990 39.781 0 5054.02 343481.5 15444.3 5841.449 294.922 94.453 24.914 7.553 0 0

1991 7867.961 7867.961 88.272 0 0 0 0 0 0 0 0 0

1992 0 8161.987 5835.428 0 0 0 0 0 0 0 0 39387.63

1993 722.007 201.73 129.938 0 0 0 5617.094 20.762 5887.976 450.309 6944.654 7977.734

1994 0 88761.34 12729.27 253.874 0.534 0.685 0 0 0 0 0 5641.902

1995 1344.366 4180.957 53.781 0 0 0 0 0 62.791 7.866 18866.82 2059.813

1996 50117.19 2723.646 16.576 0 0 0 0 0 0 7985.257 800.096 2239.258

1997 1321.548 287068.9 28695.35 182.419 47.087 40.268 12.153 4.825 302.885 61.694 1260.315 4950.484

1998 1542.4 12459.95 390.762 0 4794.973 240.121 808.592 1943.564 642.832 356.843 474.525 2115.05

1999 12275 2240.942 7653.925 3139.454 1296.042 448.095 39.146 1.335 0 0 2545.9 2135.188

2000 3800.59 1471.117 621.717 7.64 1013.048 18.291 0 0 0 0 182454.7 10351.89

2001 857.123 2366.618 66.946 0 0 577.631 56.647 3.898 0 0 89.654 1263.599

2002 83574.46 4756.054 3701.05 14.783 0 0 0 0 0 0 0 0

2003 0 129094.6 675.675 81.485 27.939 1163.549 253.42 1.676 0 0 0 687.087

2004 68435.49 8676.786 1217.955 1.555 7.426 0 0 0 497.728 0 1546.298 19730.15

2005 524.665 0.659 0 0 7171.345 8063.238 2031.588 1.715 0 0 0 0

2006 0 2058.45 239.994 5971.97 128.213 1116.62 1061.081 107.009 0 0 0 1446.565

2007 6851.673 5691.193 3766.386 195.982 0 0 0 0

Table 9 – Number of days of flooding recorded at Wyandra1 January 14 February 41 March 4 April 20 May 8 June 6 July 1 August 0 September 0 October 0 November 8 December 6 1Based on max 141 daily data from 28/02/1967 - 2/08/2007. A day is defined as being in flood if the maximum flow rate on that day exceeds 42 GL/D

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3.1.3. Climate Variability

In addition to the seasonal basis of flows in the Warrego, wet and dry phases across groups of years can be established from the flow record. The gauge at Fords Bridge bywash has the longest period of recorded data (opened on 1/12/1921) and has been used to identify wet and dry phases3 as illustrated in Figure 5. Each wet and dry period illustrated was subjectively selected based on an examination of the deviation of annual flows from the mean annual flows. The mean annual flow over the entire period is approximately 52 GL/yr. A period where annual flows were generally higher than 52 GL/yr was defined as a wet period. A period where annual flows were generally lower than 52 GL/yr was defined as a dry period. Note that wet periods identified tend to short (between 2-4 years) whilst the dry periods extend up to 21 years.

Other researches have examined wet and dry phases through the influence of the El Nino/Southern Oscillation (ENSO). These effects are is now well known and reasonably well understood. ENSO effects are now thought to be responsible for many of the drought and flood periods that are experienced in eastern Australia. Numerous researchers have explored the effect of ENSO on flows in the Murray-Darling, and many farmers now take note of predictions based on Southern Oscillation Index (SOI) values. ENSO cycles appear to operate over 3 to 8 year periods. However, it is clear that there are even longer-term variations in the climate of eastern Australia and that these can have major effects on rainfall and river flows. The causes and mechanisms responsible for these longer period shifts are not as well understood or widely appreciated as ENSO. Some are now being assessed (Verdon D. and Franks S. 2006) and it seems that there is evidence that these mechanisms regularly cause substantial shifts that last decades.

The effect of development on the flow regime of the Warrego in the context of its highly variable climate is discussed further in sections 0 to 4.11. In the first instance, the overall impacts on the flow regime over the full range of available climate data are examined. Differentiation of impacts during wet and dry phases is then discussed through comparison of the following climatic periods: o 10/1948 to 9/1951 (representative wet period) o 10/1951 to 9/1954 (representative dry period)

3 The total flow at Fords Bridge is measured through both the bywash and the main channel. The relationship between flows at the two gauges was examined for the common period of data (from 1972) to ensure that there are no temporal trends which would indicate that the bywash has become wetter or drier due to local morphology changes.

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300,000

200,000

100,000 Annual Flow Volume (ML/Y)

0

10/1927 - 9/1948 10/1948 - 9/1951 10/1951 - 9/1954 10/1954 - 9/1956 10/1963 - 9/1973 10/1973 - 9/1977 10/1977 - 9/1988 10/1988 - 9/1990 10/1990 - 9/2007 Water Years

Figure 5 – Wet and dry phases - Fords Bridge Bywash Gauge*

*Key for box-whisker

Maximum Value

Median of upper half of annual flows Median of all years in period Median of lower half of annual flows

Minimum Value

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3.2. Overview of Flow Dependent Environmental Assets

3.2.1. Categories of Assets

Flow dependent assets can be both structural and functional aspects of aquatic ecosystems. Structural aspects are generally the different types of physical aquatic habitats, eg rivers, floodplains, lakes, wetlands, etc. Functional aspects are generally the processes that are critical to providing the existence of the biota of aquatic ecosystems such as primary production, organic carbon dynamics, food web interactions, etc.

The flow dependent environmental assets for the Warrego have included instream waterholes, terminal and floodplain wetlands, and various vegetation communities. These assets support a wide variety of fauna. For the purposes of reporting the flow dependent assets of the Warrego have been grouped into the following structural categories:

• Instream (eg instream habitats, fish populations, water quality) • Riparian (eg riparian habitats, vegetation) • Floodplains, Lakes and wetlands (eg vegetation types, waterbird populations).

The following information for these categories was obtained from published reports and records from landholders.

3.2.2. Instream Characteristics

3.2.2.1. Waterholes

Waterholes on the Warrego River system provide a critical refuge for fish and waterbird populations during no flow periods. Refilling events for waterholes sustains the fish populations, allows for movement between waterholes and into the river channel and act as a stimulus for some fish species to undertake recruitment events. The shape of waterholes is also important for sustaining different fish populations.

Detailed assessment of waterholes and fish populations has been undertaken for some sites in Queensland (see Table 10). Mottell also recorded fish species during landholder interviews which are also summarised in Table 10. There are some doubts about some of these sightings particularly the River blackfish and Mountain galaxsis which are well outside their recorded distributions which are in the southern rivers of the Murray-Darling Basin (Lintermans 2007). Also the purple spotted gudgeon and Unspeckled hardyhead are not recorded for the Warrego, although the latter is common in lowland streams of the northern MDB (Lintermans 2007).

Although waterholes exist in NSW, particularly along the Cuttaburra and lower Warrego, no similar assessment has been undertaken (although this may not be true depending the location and methods used in the Murray Darling Basin Sustainable Rivers Audit fish sampling program4). Preliminary information on waterholes in NSW was collated during this study, through topographic maps and interviews with residents. This information can be found in Appendix A, Table A1. The following points

4 There was not sufficient time to review this report as it was released after the draft for this section was finalised.

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summarise the information on waterholes in NSW:

o Interviewed landholders advised that there are no natural waterholes on the Warrego from just upstream of the Queensland border (Binya waterholes) to the Darling River. However there are several constructed dams along the downstream section of the River starting at Lower Lila dam. After flooding the Warrego channel dries, generally within 3-4 months.

o On the Cuttaburra Creek upstream of the Yantabulla swamp there are many natural waterholes.

While the locations of waterholes in NSW are largely known, important information on their physical characteristics, water persistence, response to different flow events and aquatic biota is not available in a consistent and systematic framework. Consequently it is recommended a rigorous inventory of waterholes on the Warrego be undertaken, particularly for the NSW portion. Boyes and Thoms (2006) provide a technique for this form of assessment.

Section 3.2.4 contains further information on waterbirds of a few waterholes/dams undertaken by Straw (1999). Straw (1999) provides no assessment of the hydrology of surveyed sites.

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Table 10 – Existing Data Sources – Waterholes

Source Key Data / findings

Scientific assessment of the status of fish populations during October 2001 and April 2002 in QLD waterholes at the following Balcombe et al. properties: (2006) – Dryland o Quillberry (2 on the River and 2 on nearby distributaries) Rivers Refugia project o Glencoe (2 on River, 1 on Cuttaburra Creek, 1 on Woggannorah Creek) o Thurulgoona (2 on Thurulgoona Creek, 1 on Noorama Creek) o Binya (1 on River, 2 on Cuttaburra, 1 on a nearby distributary)

Compared with other rivers in the Murray-Darling Basin, the Warrego waterholes had higher abundances and more species. There was also a relatively low proportion of alien species. The authors considered the Warrego to be “a model dryland river for the further investigation of ecological processes sustaining fish in variable environments both in the MDB and other similar systems.”

The native fish species found were: o Olive perchlet (Ambassis agasizzii) o Bony Bream (Nematolosa erebi) o Carp gudgeons (Hypseleotris spp) o Crimson-spotted rainbow fish (Melanotanenia fluviatilis) o Golden perch (Macquaria ambigua) o Hyrtl’s tandan (Neosilursus hyrtlii) o Eel-tailed catfish (Tandanus tandanus) o Australian smelt (Retropinna semoni) o Silver perch (Bidyanus bidyanus) o Spangled perch (Leiopotherapon unicolour) o Alien species were: o Goldfish (Carassius auratus) o Common carp (Cyprinus carpio) o Mosquitofish (Gambusia holbrooki)

Other findings included: o The fish assemblage in waterholes was differentiated after the no flow period at the commencement of the study, o The fish assemblage in waterholes was more similar after high summer flow in 2002, ie the fish had redistributed during

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the event, o Large, deep waterholes support fewer species and lower abundances but are key refugia for larger bodied fish such as yellowbelly and tandan. These waterholes are likely to be only aquatic habitat available in extended dry periods, o Small, shallow waterholes had more species and larger abundances, likely due to more of a littoral zone and greater primary production, o Snags are important for habitat, food production and predator avoidance, o Yellowbelly, Bony bream and tandan recruitment was linked to high flow events (eg January 2002) but not solely. Yellowbelly and Bony bream recruitment was also recorded in no flow periods. This is contrary to evidence from Southern MDB where breeding of these species is closely correlated with high flow events, o Carp recruitment was not correlated with high flows, likely due to the summer seasonality of the assessed events. Mottell (1998) – The following species, in addition to those listed above, were recorded during interview with both QLD and NSW residents: landholders interview o Murray cod o Mountain galaxias o River blackfish o Purple spotted gudgeon o Unspeckled hardyhead o Western Chanda perch o Lakes carp gudgeon o Midgley’s gudgeon o aquatic invertebrates, such as yabbies.

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3.2.2.2. Water Quality

Water quality is an important factor for the health of aquatic ecosystems as many naturally occurring chemicals, compounds and conditions (eg temperature and light) in water are needed for a range of functions, but also chemical contaminants can also cause a range of ecosystem dysfunctions. The importance of water quality is recognised in the “Framework for the Assessment of River and Wetland Health” (FARWH) approach to assessing ecosystem condition (AWR 2005).

Water quality information has been collected from spot samples at several locations for the Warrego River since the 1960’s, the record for most stations is sporadic, either due to the truncated nature of water quality monitoring programs or the intermittency of flow events, or both (see Table 11).

Analysis and reporting of the water quality results is only in very general terms, eg DWR (1990) and DNR (2000). Therefore it is difficult to develop and informed picture of the water quality characteristics of the river and/or changes over time. With the intensification of landuse in the catchment, it is likely water quality characteristics will change. There has been no pesticide sampling undertaken, yet landuse intensification often involves increasing use of these chemicals.

A detailed analysis and reporting of the existing water quality information is required, along with the identification of additional risks and the appropriate level of monitoring and reporting required to inform resource managers.

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Table 11 – Existing Data Sources – Water Quality

Source Key Data / findings DWR (1990). • This report proposed an Intersecting Streams water quality monitoring program to replace an outmoded program. The report also presents an assessment of past water quality data collected. For the Warrego the report identifies turbidity, suspended solids and nutrients as being higher than recommended levels. The sites at which water quality samples were assessed are not identified. The report recommended sampling continue to be undertaken at monthly intervals during flow events at Wyandra and Fords Bridge main channel. Recommended water quality parameters for assessment were; suspended solids, turbidity, conductivity, total phosphorus and total nitrogen. DNR (2000). • This report provides water quality descriptions for all catchments in Queensland where data has been collected since the 1960’s. It provides figures with pie charts rating the quality of water a large number of sampling stations. For the Warrego sampling sites are station numbers 423202 (Cunnamulla), 423203 (Wyandra) and 423204 (Augathella). The report indicates that the reliability of the data for these sites is poor (see Fig 3a of the report). The report also indicates biological monitoring sites near Charleville and Wyandra (see Fig 4 of the report) but no biological results are presented the report for the Warrego. The Warrego is reported on briefly as part of a broader Murray-Darling Region, and only in very general terms with regard to naturally high turbidity levels. Stream salinity levels are identified as being a significant issue, possibly arising due to tree clearing activities. Other possible “small-scale” water quality issues are nutrient enrichment, sediment load and heavy metal contamination. Appendix 2 of the report provides a preliminary risk assessment for the above sites for water use for domestic, irrigation, stock, recreation and aquaculture use. QDNR (2000). • This report provides only a very general statement about surface water quality monitoring undertaken on the Warrego, with no results presented.

Waters (2006). • This is a fact sheet presenting the results for sampling of a storm event on the Warrego at Cunnamulla weir between 10-13 April 2006. The storm run-off event was generated from the Langlo River catchment. The event mean concentration (EMC) of total suspended solids, filtered nutrients and organic carbon parameters was measured during the event. The fact sheet presents results for the estimated loads including over 8,700 tonnes of total suspended solids.

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Table 11 (Con) – Existing Data Sources – Water Quality

Source Key Data / findings D-BBRC (2004/5, • The Dumaresq-Barwon Border Rivers Commission provides Annual Statistics as part of their Annual Report. The Annual 2005/6, 2006/07a). Statistics reports include data on the results of water quality samples for the Warrego River at Ford’s Bridge bywash for electrical conductivity, total phosphorus, total nitrogen and turbidity for the years 2003/04, 04/05, 05/06 and 06/07 from the D-BBRC website. The Annual Report provides some analysis of the water quality, but it is brief and covers the entirety of the Commission’s area of operation and with most focus on the Border Rivers area (eg see D-BBRC 2006/07b).

McGregor et al. • As part the Dryland River Refugia project, McGregor et al. undertook analysis of the algal assemblage of waterholes of the (2006) Warrego River. This is a companion study to Balcombe (et al. 2006) with sampling at the same waterholes with the sampling periods being October 2001 and April 2002. A range of water quality analyses were also undertaken. High turbidity characterised the Warrego waterhole water quality which was felt to influence the characteristics of the phytoplankton which were dominated flagellated communities.

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3.2.3. Riparian assets

Riparian areas are known to provide a range of important ecosystem functions such as flora and fauna habitat, organic matter exchanges, filtering of soils particulates and nutrients with adjacent water ways. The importance of riparian areas is recognised in the FARWH approach to assessing ecosystem condition (AWR 2005).

Hale et al. (2008) have recently completed a report of the riparian vegetation of the Warrego and Cuttaburra catchments in NSW as part of a wider intersecting streams (and lower Bogan River) study. The study involved mapping the riparian zone and undertaking a condition assessment of the riparian zone.

Riparian woodlands that were considered likely on the Intersecting Streams and subject to mapping and condition assessment were: • River Red Gum open forest and woodland • Black Box woodland • Coolabah – River Cooba– Lignum woodland • Coolabah open woodland with chenopod/grassy ground cove • Yapunyah woodland of Cuttaburra-Paroo River system • Poplar Box-Coolabah floodplain woodland

Further information on the methodology employed can be found in Table 12 . Only the results for the overall condition assessment are reported here and these are based on an overall condition assessment using the Rapid Appraisal of Riparian Condition (RARC) methods, plus an assessment of, bank condition, tree regeneration and tree crown condition.

The Warrego had 5 sites of medium overall condition and 4 of poor condition. The Cuttaburra had 2 of poor condition and 3 with very poor condition. These results are not dissimilar to those of the other studied rivers. Only the Culgoa recorded one good quality site.

A few other publications have included descriptions and mapping of riparian vegetation (but not assessment of condition) as is summarised in Table 12.

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Table 12 – Existing Data Sources – Riparian Vegetation

Source Key Data / findings Green and Mapped riparian areas as part of a wetland inventory study. The mapping was done on the King (1995) basis of the following vegetation species, which are likely to apply to the vegetation of much of the riparian zone: o Black box (Eucalyptus largiflorens) o Cooliban (E. coolabah) o River Red Gum (E. camaldulensis) o Yapunyah (E. ochropholia) o Canegrass (Eragrostis australasica) o Gidgee (Acacia cambagei) o River Cooba (A. stenophylla) o Lignum (Muehlenbeckia florulenta) o Spiny lignum (M. horrida) o Nitre Goosefoot (Chenopodium nitrariaceum) o Golden Goosefoot (C. auricomum)

Further comments on this study are provided in Section 3.2.3.

Mottell (1998) Includes a vegetation mapping section, but provides no description of riparian areas. The mapping in this report appears to be based on flood extents.

King et al. Provides a description of vegetation along Cuttaburra Creek, including for the waterholes, (1995) which support large River Red Gums. The dominant tree vegetation for the upstream section of the creek is Coolibah, with Black Box dominating the downstream portion with Kulkyne Creek (King et al. 1995).

Hale et al. Mapping of riparian trees was done using satellite imagery (SPOT5) and included largely areas (2008) of dense trees within 50 meters of the top of channel banks. The Warrego catchment had a coverage of nearly 8,000 ha of riparian trees with some 9,000 ha on the Cuttaburra. Areas of “floodouts” with no distinct channels, were not mapped.

The riparian condition assessment was done using a variation of the Rapid Appraisal of Riparian Condition (RARC) technique. Three primary riparian attributes were used to assess condition on site, these being; bank condition, floodplain condition and riparian condition.

Satellite imagery was also used to undertake an assessment at the landscape scale. This involved the use of transects across a range of representative river reaches. On the Warrego 108 transects were undertaken and 96 on the Cuttaburra. The transects were assessed for both habitat value and threat attributes and the results were to make conclusions about on-ground management priorities.

It appears from information in Hale et al. (2008) that areas such as the Noorama, Widgeegoara, Tuen, Thurulgoonia and Irrara Creeks were not included in either the mapping or riparian condition assessment, possibly because they were considered to be “floodouts”.

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3.2.4. Floodplain, Lakes and Wetland Assets

Wetlands and waterbirds are the most studied aquatic assets of the Warrego. The wetlands are considered to be of critical importance to waterbird populations of the Murray-Darling Basin.

Nationally important wetlands have been identified since 1993 (ANCA, 1993). EA (2001) provides the most recent listing of nationally important wetlands in the Warrego system and the number of listings attests to the overall status of the catchment for wetlands. A summary of the DIWA listed wetlands in the Warrego is provided in Table 13. In addition to floodplain wetlands, the DIWA listing includes lakes and instream waterholes. The information content for several of these sites on the Directory database is quite limited.

Information in the DIWA database is sourced from existing publications however recent publications have not been included. See Table 14 for a summary of available literature on floodplain assets in the Warrego.

It is recommended that the DIWA database be updated through consolidation of existing information and that where limited information is available, further data collection be undertaken.

Table 13 – Directory of Important Wetlands Australia – Warrego [Data Source: DIWA directory database] Wetland/Lake/Waterhole Site Description Name A complex, contiguous wetland system, dominated by the large, Lake Dartmouth Area - ephemeral Lake Dartmouth (the terminal playa of Ambathalla Creek). QLD168 Also included are a long, narrow, more-or-less permanent waterhole at the end of the Ambathalla Creek, a large floodout, and an infrequently - flooded overflow swamp ("Oak Swamp") to the east. Warrego River The Warrego River distributary system fans out from north of Distributary System Cunnamulla to the New South Wales border. Widgeegoara and (QLD169) Noorama Creeks exit the river north of Cunnamulla, flowing to the south- east, while Thurulgoonia Creek and the Cuttaburra Channel leave the river south of that town, to the south-east and south-west respectively. The area is dominated by vast alluvial plains, interspersed by the main distributary channels and a myriad smaller watercourses and associated floodplain swamps. Numerous large waterholes have formed in the larger channels, and it is these waterbodies which form the main wetland habitats of the complex. Warrego River A string of large, permanent and intermittent waterholes/billabongs, Waterholes (Charleville- along the main Warrego River channel from Charleville to south of Wyandra) (QLD171) Wyandra. Significant bodies of deep, open water in many of the holes provide substantial habitat for aquatic fauna - invertebrates, fish, turtles and birds. T “Old Bando” Swamp A large depression on a tributary to the Warrego River, on its western (QLD 172) side. Mapped by QDPI in the WARLUS series as L1 (ephemeral lakes/claypans) land system. Murrawondah Lakes Three large ephemeral claypans and a number of smaller ones in the (QLD174) vicinity of "Murrawondah" Station, southeast of Cunnamulla. If these lakes support predominantly canegrass grasslands (as satellite imagery interpretation suggests), these would be the largest continuous areas of such habita east of the Warrego River in the Mulga Lands.

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Table 13 (Con) – Directory of Important Wetlands Australia - Warrego

Wetland/Lake/Waterhole Site Description Name Green Creek Swamp This "swamp" is part of Goodrick's (1984) Cuttaburra system. The creek (NSW013) is inundated for up to 5 months by run-off from the Warrego River at which time it provides valuable habitat for waterbirds including Black Swans (Cygnus attratus), Brolgas (Grus rubicundus), and Black-tailed Native Hens (Gallinula ventralis). The vegetation consists mainly of areas Lignum (Muehlenbeckia florulenta) with scattered River Cooba (Acacia stenophylla) in the deeper areas of the creek and areas dominated by Couch Grass (Sporobolus virginicus?), Spike Rushes (Eleocharis spp.), Common Nardoo (Marsilea drummondii) and Thin-leaf Nardoo (Marsilea angustifolia) in the shallow areas of the creek when flooded (Green 1992a). Lake Burkanoko Representative example of inland hypersaline lake. Contains Bimble (NSW014) Box (Eucalyptus populnea) and Belah (Casuarina cristata) woodland which are considered to be endangered and poorly conserved in NSW Lake Nichebulka Representative example of inland hypersaline lake. Little vegetation (NSW015) other than submerged algae and Sea Tassel. Lake supported over 10 000 Banded Stilts (Cladorhynchus leucocephalus) in 1988 Murphys Lake (NSW016) Representative example of freshwater clay pan in dunefields. Important breeding site for waterbirds Willeroo Lake (NSW018) Representative example of Cuttaburra system waterhole. Due to long term inundation (Goodrick 1984), provides important drought refuge. Important breeding area for waterbirds (Green 1992a). Yantabulla Swamp Representative example Goodrick's (1984) Cuttaburra system. The (Cuttaburra Basin) more permanent waterholes provide important drought refuge. Important (NSW019) breeding area for ducks and colonial waterbirds (Maher 1991; Kingsford et al.. 1994) Kingsford et al.. (1994) reported up to 40 700 birds and 31 species. Area floods regularly and therefore is a reasonably secure refuge. Birdsnest Swamp Floodplain wetlands. No further information provided in DEWHA (NSW163) & Racecourse database. Swamp (NSW166) & Toms Lake (NSW168)

Bottom Lila Lake Floodplain wetland. No further information provided in DEWHA database (NSW164)

Lake Yandaroo Saline lake. No further information provided in DEWHA database (NSW165)

The Dry Lake (NSW167) Floodplain wetland. No further information provided in DEWHA database

Yarran Swamp (NSW169) Floodplain wetland. No further information provided in DEWHA database

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Table 14 – Existing Data Sources – Floodplain, Wetlands and Lakes

Source Key Data / findings Goodrick (1984) • completed the first wetland survey of the area which was part of a wider study of the north-west portion of NSW. Goodrick (1984) used a landscape classification for mapping wetlands based on geomorphology, hydrology and vegetation. He identified and mapped 5 main wetland systems. Maher (1991) • undertook a detailed study of waterbird distribution and habitat, primarily for the Paroo, but also including part of the Cuttaburra during the 1990 flood and subsequent drying phase. Maher (1991) found 53 species of waterbird, 31 of which were recorded as breeding during the wet period. Green (1992) • conducted a (partial) survey of some wetlands of the Warrego. The study was undertaken because of a gap in wetlands nominated as being Nationally Important (ANCA 1988) in the Warrego area and to test the applicability of the criteria for determining national importance. Assessment of 27 wetlands was undertaken collecting information on location, flora, fauna, land features, water regime and social values. • Assessed the following wetlands: Lake Denman, Murphys Lake, Lake Coonany, Pirrilie Lake, Maghera Swamp, Green Creek at Shannon, Green Creek salt lake, Goonery, Multagoonah Creek, Lake Nichebulka, Mulchacera plain, Kerribee Creek at Shannon, Taylors Lake, Booka Dam, Green Creek, Utah Lake, Multagoonah Lagoon, Toorale, Avondale, Lower Lila Dam, Irrara Creek, Kings Bore, Yandaroo Lake, Kerribee Creek at Ella Vale, Janina, Willeroo Lake, Warrego River at Congarrara Timms (1993) • undertook a study of 25 lakes of the Paroo and Warrego systems (although it appears from Fig 1 of this paper that all sites were within the Warrego system), with a particular focus on saline sites. The study took place from 1988 to 1990 and a wide range of water quality parameters were measured. Plankton, macroinvertebrates and insects were also studied. • Assessed the following lakes: Gypsum, Mere, Rainbar, Middle Bell, Yandaroo Lake, Kings bore, South Nichebulka, Lower Bell, Willeroo Lake, near Lake Belora, Lake Nichebulka, Freshwater bore, Taylors Lake, Flowing bore, Lake Burkanoko, Bells bore, Ballymere, Utah, Horseshoe Lake, Woolshed, Barakee, Avondale salt, Gidgee Lake, Pirillee, Stathern Kingsford et al. • provide the results for a waterbird survey of north-western NSW including the Warrego, Paroo and Bullo river systems. The survey was (1994) undertaken every 3 months between 1987 and 1990, and also selected wetland surveys in 1993 and 1994 for 30 wetlands. • Nine wetlands were in the Warrego: Lower Bells Lake, Horseshoe Lake, Lake Nichebulka A, Lake Burkanoko, Manaral Claypan, Lake Nichebulka B, Gidgee Lake, Lake Nichebulka, Yantabulla Swamp • The study provides information on each wetland; location, tenure, general description (eg vegetation, freshwater or saline), hydrology and waterbird counts and breeding status. • The study supported the importance of wetlands of the north-west for the conservation of waterbird populations. For the Warrego sites, Lower Bells Lake, Lake Nichebulka and Yantabulla swamp supported very large numbers of waterbirds and many species. Yantabulla Swamp was considered to be the most important site in the study area for waterbird breeding. The study also expressed concerns about the potential effects on the ecology of the Warrego wetlands, particularly Yantabulla Swamp, due to water harvesting activities upstream.

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Table 14 (Con) – Existing Data Sources – Floodplain, Wetlands and Lakes

Source Key Data / findings Green and King • undertook an inventory of wetland and vegetation for the Warrego River downstream of Wyandra. They mapped an area of 345,000 ha of (1995) coolibah, lignum, canegrass, claypans and open lakes, and included riparian areas (see above). Data for 62 wetland areas was collected for location, geomorphology, dominant vegetation type, fauna, recreation values, hydrology, land use and tenure and any evidence of change. Of particular relevance to this Scoping study, the Warrego wetland system was divided into 6 divisions based on major hydrological connections. Wetland vegetation maps were produced. However it appears this report was not completed as only the draft, unpublished report is available. This report does not contain either the photographs or Appendix A (wetland site data). Also the digitised maps produced in GenaMAP GIS format were not able to be located following the Consultants inquiries. Landholders of the area have confirmed the non-completion of the report. The loss of the wetland inventory and mapping undertaken is regrettable as this information would likely be very useful into the future. Kingsford et al. • examined waterbird counts for over 18,500 wetlands in the Murray-Darling Basin for the period 1983-1994 to determine the most important sites (1997) for waterbirds. Seven of these sites supported more than 50,000 waterbirds including one Warrego site, Yantabulla swamp (80,000 waterbirds). Six floodplain areas were identified to host more 100,000 waterbirds and included Cuttaburra Creek (230,000 waterbirds). The reliance of some wetlands of the Paroo system on flows from the Cuttaburra Creek system is identified. Kingsford and • further emphasise the importance of the Warrego wetlands for waterbirds. The Warrego part of this paper relies on the information in Kingsford Porter (1999) et al. (1994). Straw (1999) • studied waterbirds of the Warrego and Cuttaburra floodplains during site inspections in 1993, 1994, 1996 and 1997. Both aerial and ground assessments were undertaken with the intention of describing the distribution of waterbirds within the Warrego and Cuttaburra systems. The study involved 29 sites (although 35 are listed) and the report provides information on the waterbirds observed. Information from Kingsford et al. (1994) is also incorporated in the results and discussion. Sites were separated into those receiving water from the Warrego River and Cuttaburra Creek and sites receiving primarily local run-off. • Sites flooded by Warrego/Cuttaburra flows: Yantabulla Swamp, Poloko Lake, Manaral Claypan, Cuttaburra channels, Yantabangie Lake, Peery Lake, Horseshoe Lake, Burkanoko Lake, Yamaramie Lake, North Kia Ora, Green Creek, Broken Dam, Tourale floodway, Mullawoolka Basin, Gilpoko Lake, Boera Dam, Tongo Lake, Nichebulka Lakes, Gidgee Lake, Bells Lake • Sites flooded mainly by local run-off: Yandaroo (wood), Willaroo Lake, Lake Bulla, Mowellan Dam, Yandaroo (home), Lauridale Lake, Top Blue Lake, Yandaroo Lake, Middle Blue Lake, Lake Womba • The report supports the findings of prior studies identifying the Warrego as being an important areas for waterbirds- with worldwide importance being claimed (in conjunction with the Paroo). Several sites surveyed are believed to satisfy the criteria for being internationally significant (eg under the Ramsar Convention). The report makes mention of the water requirements of the wetlands and the importance for waterbirds, both major and minor floods. No specific statistics for flood event, extent, duration and waterbird responses are provided.

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Table 14 (Con) – Existing Data Sources – Floodplain, Wetlands and Lakes

Kingsford et al. • investigated the extent, distribution and types of wetlands (based on floodplains, freshwater lakes and salt lakes) in the Paroo and Warrego (2001) catchments (inclusive of Queensland and NSW). Mapping of the areas was undertaken using Landsat imagery corresponding with the large 1990 flood and using geographic information analysis. The 1990 event flooded a total area of 898,250 ha made up of 890,534 ha of floodplain, 7,274 ha of freshwater lakes and 442 ha of saline lakes, or some 13% of the total area of the catchment. Of the total area of floodplain wetlands, 206,660 ha were in NSW and 683,874 in Queensland. Again, the reliance of some wetlands of the Paroo system on flows from the Cuttaburra Creek system is identified.

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4. Hydrological Data and Impacts of Water Resource Development

4.1. Available Hydrologic Data

A collection of ANZLIC compliant metadata statements providing information about datasets that describe, or could describe, various aspects of the hydrology of the system can be found in Appendix B. Table 15 lists the statements by data category type. A summary of available data is provided in each of the regional sections in this chapter.

Table 15 – Summary of Metadata Statements in Appendix B

Category Metadata Statement Title Details Climatic Data Daily Rainfall Data For The Includes details of BOM gauge data Warrego Catchment available for the Warrego Daily Evaporation Station data Includes details of BOM gauge data held by the Bureau of available for the Warrego Meteorology for the Warrego Catchment. Streamflow / Height Data HYDSYS - NSW Water Includes details on flow gauging stations in Resources Database NSW part of the Warrego HYDSYS - QLD Surfacewater Includes details on flow gauging stations in Resource Database QLD part of the Warrego River records and commence Includes details on unofficial sites with to flow notes for the Lower height data; Warrego River System - Volumes 1 and 2 Spot stream gauging data Includes description of known spot river gauging conducted by various parties Hydrologic Models Warrego River System IQQM QLD model of the Warrego - Includes details on data used to develop the model and quality of the model Barwon - Darling River IQQM NSW model which includes lower part of the Warrego Digital Elevation Models Murray Darling Basin NAP A course DEM which (+/- 5 metres Catchment Digital Elevation elevation accuracy) which is probably of Model - limited use for the Warrego MDB_DEM_25M_100K_X Compendium of Data - Darling ALS data, floodplain cross sections etc River Floodplain Flood Study - 2008 GIS layers – floodplain Wetlands of the Warrego River A NSW DECC dataset which at present characteristics / inundation cannot be located Wetlands of New South Wales Includes description of the process of Satellite Imagery analysis used to generate the layer Geosciences Australia Satellite Includes description of the types and Imagery attributes of imagery available. Imagery would need to be reviewed in further detail to identify suitability for floodplain inundation analysis

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4.2. Quantifying Development Impacts on the Flow Regime

4.2.1. The Warrego IQQM Model and Model Scenarios

River flows in the Warrego are the result of the complex interaction of many variable factors including climate, the construction of dams and other water control structures, the expansion of irrigation and other forms of water use and changes to water management and water use rules. A comparison of early stream-gauge data with recent stream-gauge data is not sufficient to determine the impact of water resource development of flows as differences may be a result of natural climatic variability. In order to determine the impact of water resource development over a long climatic period it is useful to use computer models.

All hydrologic computer simulation models attempt to represent the behaviour of water in the natural or man made world through a series of mathematical equations. An IQQM model of the Warrego has been developed by both the QLD and NSW governments. QLD model development focused on the system down to the NSW border whilst the NSW model includes more detail at the bottom end of the system. An IQQM model is a water balance model which means it tracks the movement of water as a series of additions and subtractions that are presumed to occur as flows move down the river system. This process generally occurs in daily time steps over the period for which flows are being simulated.

The benefit of using models is that different model scenarios can be evaluated over the same climatic period (often over 100 years) for various levels of development. In the case of the Warrego, different model scenarios have been developed to represent pre-development conditions and full-development conditions. The pre-development scenario is used to analyse flows that would have occurred if there was no water infrastructure, water use development or management rules in place for the entire climatic period modelled. In the case of QLD, the full-development scenario is used to analyse flows that would have occurred if the levels of license utilisation allowed in the ROP was in place for the entire climatic period being modelled. In the case of NSW, as no water sharing plan exists, the development assumed in the model reflects current levels of license utilisation.

By using model results, the flow regime that would occur given specified levels of water resource development can be evaluated over a long climatic period (often over 100 years) and compared to the flow regime that would have occurred during that same period if no development had been put in place.

There is at present no model scenario for the Queensland section of the Warrego which approximates current development. Therefore the impacts of current development on the flow regime have been qualitatively determined by estimating the proportion of allocation volumes which have not been utilised. Current impacts also differ to modelled impacts in that the model assumes that additional unallocated volumes which are allowed in the ROP have been allocated. The potential location and volume of these allocations were taken into account when estimating the difference between current impacts and full ROP development impacts.

4.2.2. Model Accuracy

By comparing the pre-development and full-development model results over the same climatic period it is possible to quantify the impacts of water resource development on the flow regime. The accuracy with which this quantification can occur is limited however by the accuracy of the model. In the case of

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the Warrego, the sparse river gauging network means that it is very difficult to accurately model the highly distributed nature of flows in the Warrego Basin.

To obtain reliable model results, the parameters in the model need to calibrated using gauged flow data. To verify the accuracy of the results, the model should be validated against an alternate period of flow data. Calibration and validation was performed for several locations on the Warrego. As there was no suitable gauge data on the effluents of the Warrego, the model results for these creeks can be considered an estimate only.

The QDNR (2002) Warrego calibration report details the model construction, calibration and validation process and results. A summary of the quality of the rainfall runoff model was provided in the CSIRO report (2007) in Table 5-4. The comments in that table relate to the accuracy with which the inflows were modelled in each river reach. These comments are based on Section 5 of the calibration report. For the purposes of this study, the accuracy of replicating inflows is of less interest as the accuracy with which flows at a particular location are replicated. Section 6 of the calibration report provides statistics and flow duration graphs for gauges on the Warrego River which can be used to ascertain model accuracy at gauge locations. A summary of these results is presented in Sections 4.3 to 4.11.

4.2.3. Evaluation of Results; Flow Exceedance Curves and Statistics

The IQQM model runs at a daily time-step; this means that graphical or statistical methods can be used to illustrate or compare daily (or monthly, yearly etc) flow rates.

The following sections employ flow-exceedance curves to obtain an initial impression of changes to the flow regime. Figure 6 illustrates an example curve. A flow exceedance curve illustrates how frequently different flow rates occur. In Figure 6, the vertical axis illustrates flow rates that occur at Wyandra and the horizontal axis indicates how frequently the flow rates are exceeded.

For Wyandra, there is little difference in the flow-exceedance curve for the full-development and pre- developed conditions (see Figure 8). For other locations (see Section 4.5.2.2.2 for example) there is a greater difference. By examining the flow-exceedance curve, it is possible to obtain an initial impression of whether low flows, minor floods, moderate floods or major floods have been altered. Where impacts do occur, a range of statistics is employed to further illustrate the significance of these impacts.

These statistics include the number of days of low flows, minor and moderate flooding and also the percentage of years in which these floods occur. The Bureau of Meteorology’s minor, moderate and major flood heights have been used to define flooding flow thresholds:

• Minor flooding- causes closing of minor roads and submergence of low level bridges • Moderate Flooding - causes inundation of low lying areas • Major Flooding - causes inundation of large areas

In the first instance, the overall impacts on the flow regime are examined. Differentiation of impacts during wet and dry phases is then discussed through comparison of the following climatic periods:

• 10/1948 to 9/1951 (representative wet period)

• 10/1951 to 9/1954 (representative dry period)

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Warrego @ Wyandra 1,000,000

100,000

10,000 Flow rate of 1,000ML/D exceeded on 10% of days 1,000 Flow rate of 100ML/D exceeded on 24% of days 100 Daily Flow Rate (ML/D) Rate Flow Daily

10 No flow on 1 54% of days 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% % Exceedance - Percentage of time flow rate exceeded

Figure 6 – Example flow exceedance curve

In the case of the Queensland portion of the Warrego, the IQQM model assumes that existing allocations are fully utilised and that unallocated volumes are allocated (see individual sections for where additional allocations are located in the model). This means that the model results presented do not reflect impacts as a result of current levels of development; rather the results represent impacts that would occur should full development within the constraints of the ROP occur. The difference between impacts as a result of current levels of development and impacts as a result of full ROP development has been determined on the basis of a qualitative assessment. Ideally the difference would be quantified through another IQQM model representing current levels of development, however no such model exists.

4.2.4. Other Literature

There has been a limited amount of impact assessment for the Warrego in other studies, notable the CSIRO Sustainable Yields Project (2007) report and the Sustainable Rivers Audit (2008). Section 4.11.2 briefly discusses these and makes a comparison to the impact assessment made in this report.

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RESULTS FROM EACH HYDROLOGICAL REGION

4.3. Warrego Basin to Wyandra

Summary : o Available hydrologic data was sufficient for developing a reliable IQQM model which can replicate the flow regime for Augathella, Charleville and Wyandra. The exception is low flows for Charleville which are not replicated well by the model. o There are 2,170 ML of unsupplemented water allocations, with the majority located downstream of Angellala Creek junction o Approximately 65% of existing allocations have been activated at present. o Under current levels of development water diversions have had a negligible impact on the flow regime at Wyandra. o Full activation of existing licenses includes activation of an additional 4,000 ML of unallocated volume near Charleville. o With full levels of development there would be an increase in the duration of low or zero flows at Wyandra; the duration of zero flow days would increase from 54% to 62% of days. Full development would not impact on flooding flows at Wyandra.

4.3.1. Available Hydrology and Water Resource Development Data

A snapshot of the available hydrology data and level of water resource development in the Warrego down to Wyandra is presented in Figure 7.

Rainfall gauges which were used in developing the QNDR IQQM model are illustrated through red raindrops on the map. Additional Bureau of meteorology gauges which were not used (usually due to unsuitable records) are illustrated through blue raindrops. As can be seen, the rain gauges used in IQQM modelling are generally concentrated along the rivers. Despite this, the IQQM model was of suitable quality to replicate flow regime in the medium to high flow range at Augathella, Charleville and Wyandra. The model replicates the low flow range reasonably well for Augathella and Wyandra but not for Charleville.

At present there are approximately 2GL of unsupplemented allocations in this sector. There are also a large number of storages however the total number and volume has at present only been estimated through stakeholder consultation.

WMAwater 28011: FinalReport.doc:16 July 2008 47 Hydrologic Data Available: Water Resource Development: Warrego River Scoping Study o Rainfall gauges: o Unsupplemented water allocations: ƒ 30 gauges used in IQQM model (see red ƒ 2,170 ML total nominal volume located at: raindrops on map) 260 ML on the Ward River o ƒ 48 additional BOM gauges not used in IQQM o 240 ML on Warrego near Charleville model (see blue raindrops on map) o 1,670ML on Warrego downstream of o Evaporation gauges: Charleville (1954-1996) Angellala Creek junction o Rated streamflow gauges: 1. Augathella, opened 1/10/1967 ƒ There are no restrictions on when 2. Charleville (closed), 13/09/1926 –31/01/1978 extractions occur except for one license 3. Ward River @ Binnowee, opened 2/12/1999 which has a commence to extract 4. Wyandra, opened 27/02/1967 restriction based on flows at Wyandra. This o BOM flood warning gauges: license has a large allocation (600ML) and 1. Drensmaine @ Nive River, opened 3/07/1991 extractions may occur once: 2. Lochinvar @ Warrego River, opened 3/07/1991 - The peak has passed Wyandra and 3. Wetlands @ Hoganthulla Creek, opened the flow rate there exceeds 1,100 3/07/1991 ML/D 4. Biddenham TM @ Nive River, opened OR 1/09/1984 - the flow at Wyandra exceeds 13,400 5. Oakpark @ Ward River, opened 19/03/1996 ML/D 6. 27 Mile Garden@ Warrego R, opened ƒ A maximum extraction rate is specified for 1/07/1982 each license. The average maximum 7. Warilda @ Langlo River, opened 18/03/1996 extraction rate, calculated by weighting 8. Charleville @ Warrego River, opened each rate by the size of the allocation, is 1/09/1926 9.8 ML/D. 9. Raceview Tm @ Bradley Creek, opened ƒ Estimated that 980 ML unactivated

14/01/2000 10. Authoringa @ Angellala Creek, opened o Estimated Constructed Storages (non-licensed) 22/05/1984 as of 1997 (QDNRM, 2004): 11. Bakers Bend @ Warrego River, opened ƒ Instream/gully dams: 616 structures, total 1/09/1978 storage approx 17.4 GL. 12. Murweh @ Warrego River, opened 1/09/1956 ƒ Other dams: 1,156 structures, total storage approx 8.7 GL. o IQQM modelling data: ƒ Climatic period of model data: 1889 - 2006 ƒ Gauged locations calibrated in model: 1. Augathella - model replicates flow well over full flow regime 2. Charleville – model replicates flow regime well for flows above 1000 ML/D however below this model overestimates flows. 3. Wyandra – model replicates flow well over full flow regime except that the model has a slightly long er duration of zero flows Figure 7 – Warrego River to Wyandra – Hydrologic Summary

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4.3.2. Impacts of ROP Levels of Development on the Flow Regime

4.3.2.1. Model assumptions about level of use

As described in Section 4.2, IQQM model results are used to quantify the impacts of development under both pre-development and full-development conditions. For the full-development scenario, the IQQM model assumes full utilisation of existing allocations and also assumes an additional 4,000 ML being allocated near Charleville. Approximately 65% of existing allocations have been activated at present (pers comm Department of Natural Resources & Water).

4.3.2.2. Overall Flow Regime Impacts

The flow regime at Wyandra is illustrated in Figure 8 for both the pre-developed and full-development model results. Figure 8 depicts the lowest and highest daily flow rates and the frequency that a particular flow rate is exceeded during the modelled period. Flow exceedance curves were described in Section 4.2.3.

Figure 8 also illustrates the percentage change in flow rate for each exceedance value on the horizontal axis. For example, a flow rate of 86 ML/D is exceeded on 25% of days in the modelled period for the pre-developed case. For the developed case, the flow rate exceeded on 25% of days is 62 ML/D. This represents a reduction in flow rate of 28%, as is illustrated through the blue dotted line in Figure 8. Note that the percentage reduction in flow rate should be read from the right hand vertical axis.

Predeveloped Wyandra Development allowed under the ROP % reduction in flow rate 1,000,000 100% 90% 100,000 80% 70% 10,000 60% 1,000 50% (ML/D)

40% (%) Rate

Daily Flow Rate 100 30% Reduction in Flow Flow in Reduction 20% 10 10% 1 0% 0% 5% 10% 15% 20% 25% 30% 35% 40% 45% 50% % Exceedance - Percentage of tim e flow rate exceeded

Figure 8 – Daily Flow Exceedance Curve – Wyandra5

As is illustrated in Figure 8 full-development results in a small impact on all flow rates greater than 1,000 ML/D. The impact on low flows is a result of extractions causing the river to cease to flow more quickly than would occur under pre-development conditions. However, the following statistics suggest

5 See Section 4.2.3 for explanation of flow-exceedance curves

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• Increase in duration of zero flow days from 54% to 62% of days • Maximum period of flows smaller than 500ML/D increased from 557 days to 559 days • Average period of flows smaller than 500 ML/D increased from 72 days to 75 days

There is virtually no impact on flow rates greater than 42,000 ML/D. Minor flooding only begins at Wyandra at a flow rate of 42,000 ML/D (see Table 16), thus it can be inferred that the flooding regime remains unchanged at Wyandra.

Table 16 – Flood Thresholds for Wyandra (Source: BOM website)

Flood Category Height Category Flow Category Begins At Begins At Minor flooding 6m 42,000 ML/D Moderate 8m 150,000 ML/D flooding Major flooding 9m 250,000 ML/D

4.3.2.3. Impacts during wet and dry phases

As was discussed in Section 3.1.3, the following climatic periods have been selected as a representative wet and dry phase:

• Wet phase: 10/1948 – 09/1951 • Dry phase: 10/1951 – 09/1954

As is summarised in Table 17, the impacts of development during both wet and dry phases are small and limited to low flows.

Table 17 – Wyandra - Impacts during representative wet and dry phases Average Number of Number of Daily Flow minor flooding moderate (ML/D) days flooding days Pre-development 2,630 13 1 Full-development 2,604 13 1 Wet % change -1% 0% 0% Pre-development 914 8 0 Full-development 895 8 0 Dry % change -2% 0% 0%

4.3.3. Difference in impacts under ROP and current levels of development

Modelled extractions (for the full development scenario) are approximately five times that which currently occurs. This means that at present, the impacts on the flow regime are lower than discussed above.

If the sleeper licenses were fully activated and if further allocations were made (4,000 ML near

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Charleville) there would be a small impact on low flows at Wyandra over that which currently occurs, however the impact would be relatively minor as was illustrated through the model results above.

4.3.4. Impacts of Development on DIWA Environmental Assets

The impacts of development on DIWA environmental assets for this section are presented below.

Wetland Hydrological Features Hydrological Impacts Name

Lake The long waterhole at the end of Ambathalla There are no licensed extractions Dartmouth Creek is more or-less permanent, probably upstream of the Lake therefore Area - nowhere greater than 2m deep, and holds turbid impacts are likely to be minimal. QLD168 but good quality fresh water. The floodout of this It is possible that land management, creek would be inundated on an almost yearly gully dams and stock and domestic basis, at least in part. This floodout slows and use upstream of the dam may be spreads the flow of water from the creek before having some impact however these it enters the lake basin proper. The Lake impacts could not be evaluated Dartmouth basin is only completely inundated within the scope of this study. about once every 5-10 years. This inundation may be as shallow as 5-10cm or up to 3m (1989). After a large fill (eg. 1989) the lake may remain inundated for up to 12 months (longer if further significant "top-up" flows are received). When these large floods occur, the water backs up Ambathalla Creek and spills over into the drainage depression to the east ("Oak Swamp").

Warrego Seasonal flooding down the Warrego River The small increase in duration of River would replenish these waterholes on a more-or- low to zero flows as a result of ROP Waterholes less annual basis. Most would be at least semi- levels of development may have (Charleville- permanent, only drying out during extended some impact however this is likely Wyandra) drought periods. Depths probably range from to be insignificant. (QLD171) lass than half a metre to around two metres, and all are fresh. Yarran No information provided in DEWHA database. There are no licensed extractions Swamp Based on the co-ordinates provided this site is in upstream of the Lake therefore (NSW169) QLD north east of Wyandra. impacts are likely to be minimal.

It is possible that land management, gully dams and stock and domestic use upstream of the dam may be having some impact however these impacts could not be evaluated within the scope of this study.

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4.4. Noorama and Widgeegoara Creeks Summary : o At present there is very limited data for this part of the system. The IQQM model explicitly represents the creeks, however the model could not be calibrated to any gauges on the creeks as there are at present no such official gauges. o There are 3,000 ML of unsupplemented water allocation in this section, which belongs to one license which is active o Impacts on the flow regime at the start of the creeks as a result of current levels of development is minor. o Full development and associated water diversions on the upper reaches of the Warrego cause some impact on the flow regime at the start of both creeks. There is approximately a 6% reduction in the frequency of flows between 900ML/D and 5ML/D and also a small increase in the duration of zero flow days.

4.4.1. Available Hydrology and Water Resource Development Data

A snapshot of the available hydrology data and level of water resource development is presented in Figure 9.

At present there is very limited data for the system. There are few rainfall gauges, no official river gauges and limited information on infrastructure.

The IQQM model explicitly represents the creeks, however the model could not be calibrated to any gauges on the creeks as there are at present no such official gauging sites. As such, the model results can only be considered a rough estimate.

WMAwater 28011: FinalReport.doc:16 July 2008 52 Hydrologic Data Available: Water Resource Development: Warrego River Scoping Study Unsupplemented water allocations: o Rainfall gauges: o ƒ Only one license which is in the Widgeegoara o 2 gauges along creeks used in IQQM model (see red raindrops on map). No rainfall- and has a nominal volume of 3,000 ML runoff modelling performed for the creeks ƒ Extractions under this license cannot occur until however. there is 10 ML/D at the point of take. ƒ Maximum extraction rate: 87 ML/D o 8 additional BOM gauges not used in IQQM model (see blue raindrops on map)

o Evaporation gauges: Gilruth Place (east of Cunnamulla) (1963-1967) o Estimated Constructed Storages: ƒ Limited development however details unknown o Rated streamflow gauges: Creeks are ungauged. o BOM flood warning gauges No BOM gauges on creeks o Other known stream-height gauges: No known gauges on creeks however likely that some landholders have kept records. o IQQM modelling data: o Climatic period of model data: 1889 - 2006 o Un-gauged locations estimated in model: 1. Noorama and Widgeegoara lumped start of system – loss from Warrego to creeks estimated through comparison of simulated and recorded flows at Cunnamulla 2. Noorama and Widgeegoara lumped at border /inflow to Nebine – Streamloss and routing upstream of border estimated based on Nebine Creek residual inflows

Figure 9 – Noorama and Widgeegoara Creeks– Hydrologic Summary

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4.4.2. Impacts of ROP Levels of Development on the Flow Regime

4.4.2.1. Model assumptions about level of use

As described in Section 4.2, IQQM model results are used to quantify the impacts of development under both pre-development and full-development conditions. Model results are presented for the start of the creek system. Whilst there is one allocation on the creeks (currently active and modelled as such) this allocation does not affect the flow regime at the start of system. The flow regime at the start of system may be affected by upstream development on the Warrego. For the full-development scenario, the IQQM model assumes full utilisation of existing allocations upstream of the creeks (only 65% activated at present) and also includes an additional 4,000ML of unallocated volume around Charleville, as was discussed in Section 4.3.2.

4.4.2.2. Overall Flow Regime Impacts

For the purposes of IQQM modelling, Widgeegoara and Noorama Creeks have been combined. The flow regime at Wyandra is illustrated in Figure 10 for both the pre-developed and full-development model results. Figure 10 depicts the lowest and highest daily flow rates and the frequency that a particular flow rate is exceeded during the modelled period. Flow exceedance curves were described in Section 4.2.3. Figure 10 also illustrates the percentage change in flow rate for each exceedance value on the X-axis. An explanation of this statistic was included in Section 4.3.

Predeveloped Widgeegoara & Noorama Creek - Development allowed under the ROP Start of System % reduction in flow rate 1,000,000 100% 90% 100,000 80% 70% 10,000 60%

1,000 50% (ML/D) 40% Reduction in in Reduction Daily Flow Rate 100 (%) Rate Flow 30% 20% 10 10% 1 0% 0% 10% 20% 30% 40% 50% % Exceedance - Percentage of time flow rate exceeded

Figure 10 – Daily Flow Exceedance Curve – Widgeegoara and Noorama6

As can be seen from Figure 10, full-development results in a reduction in the frequency of flows between 900ML/D and 5ML/D and also an increase in the duration of zero flow days. These impacts are further demonstrated through the following statistics:

• Increase in duration of zero flow days from 48% to 56% of days. • The number of days with flows between 5ML/D and 900ML/D is reduced from 8,969 to 8,448

6 See Section 4.2.3 for explanation of flow-exceedance curves

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days in the modelled period; a decrease of 5.8%.

4.4.2.3. Impacts during wet and dry phases

As was discussed in Section 3.1.3, the following climatic periods have been selected as a representative wet and dry phase: • Wet phase: 10/1948 – 09/1951 • Dry phase: 10/1951 – 09/1954

As is summarised in Table 18 the impacts of development are higher during dry climate phases.

Table 18 – Widgeegoara and Noorama - Impacts during representative wet and dry phases Average Number of Daily Flow days with flow (ML/D) >900 ML/D Pre-development 532 141 Full-development 521 136 Wet % change -2% -4% Pre-development 120 53 Full-development 114 48 Dry % change -6% -9%

4.4.3. Difference in impacts under ROP and current levels of development Section 4.3.3 discussed the difference between current and modelled levels of development in the Warrego upstream of the Noorama and Widgeegoara creek offtakes. Based on this, current impacts may be as little as 1/5th of the impacts under full development, as presented in Section 4.4.2.

4.4.4. Impacts of Development on DIWA Environmental Assets

The impacts of development on DIWA environmental assets for this section are presented below.

Wetland Name Hydrological Features Hydrological Impact

Murrawondah Ephemeral claypans/lakes The Lakes sit on the floodplain Lakes (QLD174) with an infrequent and between the creeks and are likely to unpredictable inundation only be inundated during high flows. regime (probably fill every 5- This flow threshold is unknown 10years). Probably less that however based on a 1 in 5 year event half a metre deep. Fresh- (estimated at 30,000 ML/D) there is water. almost no impact as a result on full development as allowed in the ROP. Therefore it is not likely that upstream water extractions / storage as allowed in the ROP will impact on the Lakes.

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4.5. Warrego from Wyandra to NSW Border

Summary : o Available hydrologic data was sufficient for developing a reliable IQQM model for representing flows at Cunnamulla however the model was not able to reliably replicate the flow regime at Barringun. o This section contains 2,612ML of supplemented allocations (which is fully activated) and 32,078 ML unsupplemented water allocations (of which 52% of the volume is activated). o As a result of current levels of development water diversions do cause some impacts on the flow regime at Cunnamulla and Barringun. However, this is approximately half the impact that would occur under full development as is discussed below. o The IQQM models the maximum levels of licence utilisation as allowed under the ROP including; full activation of existing licenses and an additional 4,000 ML allocated in this reach. o With full levels of development there would be a small decrease in the frequency of minor flooding; 8% reduction at Cunnamulla and 9% reduction at Barringun. There would also be a significant (22%) reduction in the frequency of moderate flooding at Barringun.

4.5.1. Available Hydrology and Water Resource Development Data

A snapshot of the available hydrology data and level of water resource development is presented in Figure 11.

The IQQM model has been calibrated at Cunnamulla weir and Barringun. The model represents the flow regime reasonably well at Cunnamulla but is unreliable at Barringun where flows are generally overestimated.

At the time of IQQM model development there was limited gauged streamflow data to determine the distribution of losses along this river reach. Since 1992, two rated streamflow gauges have been installed; at the weir and upstream at Wallen. The addition of the Wallen gauge should mean that the way in which the IQQM model represents losses upstream of Cunnamulla can be improved. Inclusion of an additional gauge between Cunnamulla and Barringun would be of assistance in determining the distribution of losses downstream of Cunnamulla, as has been discussed in Section 5.3.1.1.

A number of storages have been built in this reach, however the bulk of the storage volume is attributed to Cunnamulla weir. The total storage volume has at present only been estimated through stakeholder consultation by the Department of Natural Resources & Water (NRW).

WMAwater 28011: FinalReport.doc:16 July 2008 56 Hydrologic Data Available: Water Resource Development: Warrego River Scoping Study o Rainfall gauges: o Supplemented water allocations: o 2 gauges downstream of Wyandra used ƒ 2,612 ML total nominal volume in IQQM model (see red raindrops on o Unsupplemented water allocations: map) ƒ 32,078 ML total nominal volume o 3 additional BOM gauges not used in ƒ Most allocations have restrictions on when water IQQM model (see blue raindrops on may be extracted based on minimum flows map) required at Cunnamulla weir. Each allocation o Evaporation gauges: 0 has different minimum flows required. o Rated streamflow gauges: ƒ A maximum extraction rate is specified for each 1. Warrego River @ Wallen, opened license. The average maximum extraction rate, 2/11/2005 calculated by weighting each rate by the size of 2. Cunnamulla Weir, opened 16/01/1992 the allocation, is 186 ML/D 3. Warrego River At Barringun (closed), Estimated Constructed Storages (non-licensed) as of o 13/02/1968 –31/01/1981 1997 (QDNRM, 2004): 4. Warrego At Barringun N0. 2, opened ƒ Instream/ gully dams: 31 structures, total storage 1/01/1993 approx 4.6 GL most of which is attributed to o BOM flood warning gauges: Cunnamulla weir (4.48 GL) 1. Cunnamulla Bridge @ Warrego River, ƒ Other dams: 172 structures, total storage approx opened 1/08/1984 1.3 GL. 2. Rocky @ Warrego River, opened 4/11/1996 o Other known stream-height gauges: (Dates are as indicated by Mottell,1998) 1. Goolburra: 1973 – 1990 2. Baroona: 1942 – 1997 3. Glencoe: 1981 – 1997 4. Rocky: 1945 – 1997 5. Coonberry Plains: 1945 – 1995

o IQQM modelling data: ƒ Climatic period of model data: 1889 - 2006 ƒ Gauged locations calibrated in model: 1. Cunnamulla – model replicates flow reasonably well over full flow regime. Model slightly underestimates flows around 1000 ML/D and overestimates flows below 100 ML/D. 2. Barringun – Poor calibration, model generally overestimates flows and low coefficient of determination / efficiency

Figure 11 – Warrego from Wyandra to NSW Border – Hydrologic Summary

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4.5.2. Impacts of ROP Levels of Development on the Flow Regime

4.5.2.1. Model assumptions about level of use

As described in Section 4.2, IQQM model results are used to quantify the impacts of development under both pre-development and full-development conditions. For the full-development scenario, the IQQM model assumes full utilisation of existing allocations, plus the additional 4,000ML of unallocated water for this reach. Supplemented water allocations are fully activated, however only 52% of existing unsupplemented allocations have been activated at present (pers comm NRW).

4.5.2.2. Overall Flow Regime Impacts

The flow regime for Cunnamulla and Barringun is illustrated in Figure 12 and Figure 13 respectively. These figures depict the lowest and highest daily flow rates and the frequency that a particular flow rate is exceeded during the modelled period. Flow exceedance curves were described in Section 4.2.3. These figures also illustrate the percentage change in flow rate for each exceedance value on the horizontal axis. An explanation of this statistic was included in Section 4.3.

Predeveloped Cunnamulla Development allowed under the ROP % reduction in flow rate 1,000,000 100% 90% 100,000 80% 70% 10,000 60% 1,000 50% (ML/D)

40% Rate (%)

Daily Flow Rate 100 30% Reduction in Flow Flow in Reduction 20% 10 10% 1 0% 0% 5% 10% 15% 20% 25% 30% 35% 40% 45% 50% % Exceedance - Percentage of time flow rate exceeded

Figure 12 – Daily Flow Exceedance Curve – Cunnamulla7

7 See Section 4.2.3 for explanation of flow-exceedance curves

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Predeveloped Barringun Development allowed under the ROP % reduction in flow rate 100,000 100% 90% 10,000 80% 70% 1,000 60% 50% (ML/D)

100 40% (%) Rate Daily Flow Rate 30% Reduction in Flow Flow in Reduction 10 20% 10% 1 0% 0% 5% 10% 15% 20% 25% 30% 35% 40% 45% % Exceedance - Percentage of time flow rate exceeded

Figure 13 – Daily Flow Exceedance Curve – Barringun8

4.5.2.2.1. Description of Impacts at Cunnamulla

Minor flooding begins at Cunnamulla at a flow rate of 4,000 ML/D (see Table 19). As is illustrated in Figure 12, full-development results in a small decrease in frequency of flows between 1,000 ML/D and 10,000 ML/D which means that there has been a small impact on the flooding regime at Cunnamulla. This is further illustrated through the following statistics:

o The number of days with flows between 4,000 ML/D and 10,000 ML/D is reduced from 957 to 852 days in the modelled period; a decrease of 11%.

o The number of days with flows between 200 ML/D and 1,000 ML/D is reduced from 4386 to 4130 days in the modelled period; a decrease of 6%

o Increase in duration of zero flow days from 54% to 60% of days.

The lower level of impact for flows in the range of 200ML/D to 1,000ML/D is to be expected as the largest allocations have flow conditions which prevent extractions to occur in this flow range.

There is also no impact on the number of years with moderate to high flooding: o Moderate – high flooding (greater than 25,500 ML/D) occurs in 30% of years for both pre- development and full-development conditions.

8 See Section 4.2.3 for explanation of flow-exceedance curves

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Table 19 – Flood Thresholds for Cunnamulla and Barringun (Source: BOM website)

Cunnamulla Weir Barringun Flood Height Category Flow Category Height Category Flow Category Category Begins At Begins At Begins At Begins At Minor flooding 6m 4,000 ML/D 3m 2,168 ML/D Moderate 6.8m 25,500 ML/D 4m 7,400 ML/D flooding 29,000 ML/D (there has not been any Major flooding 7.5m 48,000 ML/D 5m river gauging this high so rate uncertain)

4.5.2.2.2. Description of Impacts at Barringun

Minor flooding begins at Barringun at a flow rate of approximately 2,200 ML/D with moderate flooding beginning at 7,400 ML/D (see Figure 13). As is illustrated in Figure 13, there are some impacts on the flooding regime at Barringun. This is further illustrated through the following statistics: o The number of days of minor flooding (flow between 2,200 ML/D and 7,400 ML/D) is reduced from 722 to 656 days in the modelled period (a decrease of 9%). o The number of days of moderate flooding (flow between 7,400 ML/D and 29,000 ML/D) is reduced from 147 to 114 days (a decrease of 22%) o Moderate – high flooding (greater than 7,400 ML/D) occurs in 15% of years under pre- development conditions and 12% of years under full-development conditions.

4.5.2.3. Impacts during wet and dry phases

As was discussed in Section 3.1.3, the following climatic periods have been selected as a representative wet and dry phase: o Wet phase: 10/1948 – 09/1951 o Dry phase: 10/1951 – 09/1954

As is summarised in Table 20 and Table 21, the impacts of development are higher during dry climate phases. Table 20 – Cunnamulla - Impacts during representative wet and dry phases Average Number of Number of Daily Flow minor flooding moderate (ML/D) days flooding days Pre-development 2,253 81 20 Full-development 2,170 74 21 Wet % change -4% -9% 5% Pre-development 857 31 8 Full-development 817 28 7 Dry % change -5% -10% -13%

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Table 21 – Barringun - Impacts during representative wet and dry phases Average Number of Number of Daily Flow minor flooding moderate (ML/D) days flooding days Pre-development 445 41 6 Full-development 395 41 5 Wet % change -11% 0% -17% Pre-development 186 15 3 Full-development 164 17 2 Dry % change -12% 13% -33%

4.5.3. Difference in impacts under ROP and current levels of development

The modelled unsupplemented extractions in this reach are approximately twice as high as that which currently occurs (though this may vary at different locations along the reach). This means that at present, the impacts on the flow regime are lower than discussed above. Whilst the flow regime impacts as a result of current development can not reliably be quantified without relevant model data, one could infer that current impacts are around half that indicated through the full development model results. For example, the number of days of moderate flooding at the Barringun gauge might currently only be reduced by around 11%. This would mean that if the sleeper licenses were fully activated and if further allocations were made there would be a further 11% reduction in number of days of moderate flooding over that which currently occurs.

4.5.4. Impacts of Development on DIWA Environmental Assets

The impacts of development on DIWA environmental assets for this section are presented below.

Wetland Name Hydrological Features Hydrological Impact

Warrego River Described in section 4.5 Development on the Warrego may be Distributary System having some impact as is described in (QLD169) section 4.5

“Old Bando” A periodically inundated swamp of No licensed extractions upstream of the Swamp (QLD 172) ephemeral lake with a relatively Lake therefore impacts are likely to be small catchment. Partial inundation minimal. probably occurs most seasons, but It is possible that land management, extensive flooding probably only gully dams and stock and domestic use one year in 5-10 and only for upstream of the dam may be having several months. some impact however these impacts could not be evaluated within the scope of this study.

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4.6. Cuttaburra Creek

Summary : o A limited amount of hydrologic data was available for developing a reliable IQQM model for representing Cuttaburra Creek flows. Whilst the creek is explicitly represented in the model it was not possible to calibrate to a gauge at the time of model development. The model can be calibrated to gauged data at Turra in the future. o There are 2,755 ML of unsupplemented water allocations along the Cuttaburra. (9% of volume is activated) o As a result of current levels of development and water diversions upstream on the Warrego, there would be some impacts on the flow regime of the Cuttaburra; This is approximately half the impact that would occur under full development as is discussed below. o Under full levels of development there would be an 11% decrease in the frequency of moderate flows (between 1,000 ML/D and 10,000 ML/D) and a 17.0% decrease in the frequency of small flows (between 100 ML/D and 1,000 ML/D)

4.6.1. Available Hydrology and Water Resource Development Data

A snapshot of the available hydrology data and level of water resource development is presented in Figure 14.

At the time of IQQM model development there was limited gauged streamflow data available for the Cuttaburra. As such, the model representation of the creek can be considered an estimate only. The relationship between Warrego and Cuttaburra flows was determined through limited hydrographic measurements.

A number of storages have been built in this reach however the total storage volume has at present only been estimated through stakeholder consultation by QLD NRW.

The Cuttaburra weir is located on a creek which leaves the Warrego upstream of Cunnamulla weir. Downstream of Cuttaburra weir, flows connect into the main Cuttaburra Creek channel. The Cuttaburra weir is a contentious piece of infrastructure. Some stakeholders believe that the increased river heights due to the Cunnamulla weir pool cause increased flows to enter the creek and flow into the Cuttaburra. Other stakeholders believe that the Cuttaburra weir has been set too high and as such has resulted in decreased flows down the Cuttaburra. The Whitehouse (1996) study noted that there was a lack of streamflow records to examine whether the weir has affected instream flows down the creek. In the absence of such suitable data, it should be possible to determine whether a changed flow relationship has occurred by conducting a hydraulic assessment of the study area.

There is also stakeholder concern that road crossings should not be raised and thereby prevent low flows from moving through the system.

WMAwater 28011: FinalReport.doc:16 July 2008 62 Hydrologic Data Available: Water Resource Development: Warrego River Scoping Study o Rainfall gauges: o Unsupplemented water allocations: o 7 BOM gauges (see blue raindrops on ƒ 2,755 ML total nominal volume map) ƒ Restrictions on when extractions may occur o No gauges used in IQQM model (rainfall apply to the three 3 largest allocations. Two allocations require a minimum flow at runoff was not modeled in area) o Evaporation gauges: 0 Cunnamulla weir before extractions may being o Rated streamflow gauges: and the o ther refers to minimum flow at the 1. Cuttaburra channel at Turra, opened point of take. 31/05/1993 ƒ A maximum extraction rate is specified for each o Other known stream-height gauges: license. The average maximum extraction rate, 1. Tinneburra, 1902 on (pers comm. Carol calculated by weighting each rate by the size of Godfrey) the allocation, is 96 ML/D 2. Maronoa, 1954 on (pres comm. Chris o Estimated Natural and Constructed Storages: Sharp) ƒ 22 GL (includes Yantabulla Swamp) (pers Dates are as indicated by Mottell,1998: comm. NRW) 3. Mowellan, 1991 – 1994 4. Wancobra, 1978 – 1995 5. Yantabulla, 1968 – 1997 (monthly)

o IQQM modelling data: ƒ Climatic period of model data: 1889 - 2006 ƒ Un-gauged locations estimated in model: 1. Cuttaburra start of system – estimated through hydrographic measurement during 1986, 1990 and 1994 events which established a relationship between Warrego flows and Cuttaburra flows. 2. Cuttaburra creek at border –Limited gauge data at Turra at time of calibration hence losses and routing was estimated. Losses upstream of border estimated through stakeholder consultation. Routing parameters, excluding lag time, was based on Cunnamulla to Barringun reach parameters.

Figure 14 – Cuttaburra Creek– Hydrologic Summary

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4.6.2. Impacts of ROP Levels of Development on the Flow Regime

4.6.2.1. Model assumptions about level of use

As described in Section 4.2, IQQM model results are used to quantify the impacts of development under both pre-development and full-development conditions.

Model results are presented for the Cuttaburra at the start of system and at the border. The start of system results are affected by upstream development on the Warrego, which have been discussed in Section 4.5 .As described in Section 4.5.3 the modelled extractions along the Wyandra to NSW Border reach are approximately twice as high as that which currently occurs. It is likely therefore that the modelled impacts upstream of the Cuttaburra are twice as high as that which currently occurs, though further detail about the distribution of unactivated licenses would be required to verify this.

The Cuttaburra Creek at the border is also affected by extractions along the creek itself where it is estimated that 91% of existing allocations are unactivated. The model assumes full activation and also assumes that an additional 1,000 ML of unsupplemented allocations have been activated along the Creek.

4.6.2.2. Overall Flow Regime Impacts

The flow regime for the start of Cuttaburra Creek is illustrated in Figure 15. This figure depicts the lowest and highest daily flow rates and the frequency that a particular flow rate is exceeded during the modelled period. Flow exceedance curves were described in Section 4.2.3. This figure also illustrates the percentage change in flow rate for each exceedance value on the horizontal axis. An explanation of this statistic was included in Section 4.3.

Predeveloped Cuttaburra Start of System Development allowed under the ROP % reduction in flow rate 100,000 100% 90% 10,000 80%

70% 1,000 60% 50% (ML/D)

100 40% Rate (%) Daily Flow Rate 30% Reduction in Flow 10 20% 10% 1 0% 0% 1% 2% 3% 4% 5% 6% 7% 8% 9% 10% % Exceedance - Percentage of time flow rate exceeded

Figure 15 – Daily Flow Exceedance Curve – Cuttaburra Creek Start of System9

9 See Section 4.2.3 for explanation of flow-exceedance curves

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As is illustrated in Figure 15, full-development results in a decrease in frequency of non-zero flows below 10,000 ML/D. This is further illustrated through the following statistics: o The number of days with flows between 1,000 ML/D and 10,000 ML/D is reduced from 1602 to 1424 days in the modelled period (a decrease of 11%) o The number of days with flows between 100 ML/D and 1,000 ML/D is reduced from 1235 to 1021 days in the modelled period (a decrease of 17%) o There is a small increase in duration of zero flow days from 87% to 88% of days

Due to the limited availability of data at the time of model calibration, the flow regime of Cuttaburra Creek at the border is only estimated in the model, however the pre-development and full development results are illustrated in Figure 16. As can be seen there is a reduction in the frequency of non-zero flows below 5,000 ML/D. Mottel (1998) reports that medium floods begin when flows at Turra reach 2.61m. Based on the DWE Turra gauge, this corresponds to a flow rate of about 3,700 ML/D. This means that full-development results in some impact on the flooding regime at the border. This is further illustrated through the following statistics for the Cuttaburra at the border: o The number of days of moderate-high flooding (flows greater than 3,700 ML/D) is reduced from 874 to 819 days in the modelled period (a decrease of 6%). o The number of days with flows between 1,000 ML/D and 3,700 ML/D is reduced from 1284 to 1058 days (a decrease of 18%). This flow range is estimated to represent low flood levels.

There is little impact on the number of years with moderate – high flooding however: o This occurs in 44% of years under pre-development conditions and 43% of years under full- development conditions. Full-development results in an increase in the duration of very low or zero flows as is further illustrated through the following statistics for the Cuttaburra at the border: o The maximum period of flows below 100 ML/D is increased from 589 to 615 days (an increase of 4%). o The average period of flows below 100 ML/D is increased from 103 to 115 days (an increase of 11%).

Predevelopment Cuttaburra @ Border Developed % reduction in flow rate 100,000 100% 90%

10,000 80% 70% 1,000 60% 50% 100 40% 30% 10 20% Daily Flow Rate (ML/D) 10% Reduction in Flow Rate (%) Rate Flow in Reduction 1 0% 0% 2% 4% 6% 8% 10% 12% 14% 16% 18% 20% % Exceedance - Percentage of time flow rate exceeded

Figure 16 – Daily Flow Exceedance Curve – Cuttaburra Creek @ NSW Border10

10 See Section 4.2.3 for explanation of flow-exceedance curves

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4.6.2.3. Impacts during wet and dry phases

As was discussed in Section 3.1.3, the following climatic periods have been selected as a representative wet and dry phase: o Wet phase: 10/1948 – 09/1951 o Dry phase: 10/1951 – 09/1954

As is su mmarised in Table 22, the impacts of development are similar during the representative wet and dry phases.

Table 22 – Cuttaburra at Border - Impacts during representative wet and dry phases Average Number of Number of Daily Flow minor flooding moderate (ML/D) days flooding days Pre-development 615 121 49 Full-development 572 107 47 Wet % change -7% -12% -4% Pre-development 218 42 19 Full-development 197 37 19 Dry % change -10% -12% 0%

4.6.3. Difference in impacts under ROP and current levels of development

As was discussed previously, it has been estimated that current impacts are likely to only be half that which was presented in Section 4.6.2 above. The flow regime impacts as a result of current development can not reliably be quantified without relevant model data.

4.6.4. Impacts of Development on DIWA Environmental Assets

The impacts of development on DIWA environmental assets for this section are presented below.

Wetland Name Hydrological Features Hydrological Impacts

Yantabulla Yantabulla Swamp is a large basin of Full development as allowed in the Swamp channels and swamps of Goodrick's ROP would result in a reduction of (Cuttaburra (1984) Cuttaburra system. Medium term low to medium flood frequency Basin) (long term in waterholes) inundation by which would result in less frequent (NSW019) regional run-off from Paroo overflow, replenishment of waterholes. This Clarks Creek, Brindingabba Creek, and may also impact on the broader Cuttaburra Creek from the north east floodplain. along the Cuttaburra Channels. Water is It should be noted that the results initially fresh. Most of the water comes presented need to be verified when from the Warrego River of which the IQQM model is calibrated to the Cuttaburra Creek is a major effluent gauge at Turra. Also, the impacts stream. Water flows out of the swamp and on floodplain inundation are difficult branches into Cuttaburra Creek and to ascertain with hydrologic Kulkyne Creek to the south. Floods occur information alone. once in every 3 years on average (Kingsford et al., 1994).

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4.7. Thurrulgoonia and Tuen Creeks

Summary : o These creeks are not explicitly represented in the IQQM model. There is limited hydrologic data, however unofficial river gauge height data could be of assistance in upgrading the model to include these creeks. o No licensed allocations exist on the creeks. o The flow regime impacts on the creeks have been estimated by examining flows on the Warrego at Cunnamulla and Barringun. The flow required at Cunnamulla before the creeks commence to flow was obtained from the literature and an estimated equivalent flow was derived for Barringun. o Based on these thresholds, current levels of upstream water diversions would have some impacts on the flow regime of the creeks. This might be around half that which would occur given full development; however it is not possible to reliably quantify impacts without further data.

4.7.1. Available Hydrology and Water Resource Development Data

A snapshot of the available hydrology data and level of water resource development is presented in Figure 17.

At present there is very limited data for the system. There are few rainfall gauges, no official river gauges and limited information on infrastructure.

The IQQM model does not explicitly represent the creeks. As such, impacts of upstream development on the flow regime of the creeks can only be inferred from results for the Warrego at Cunnamulla and Barringun.

WMAwater 28011: FinalReport.doc:16 July 2008 67 Hydrologic Data Available: Water Resource Development: Warrego River Scoping Study o Rainfall gauges: o Unsupplemented water allocations: o 1 gauge on Thurrul goonia use d in IQ QM ƒ No allocations model (see red rain drop on m ap) o Estimated Constructed Storages: o 2 additional BOM g auges not used in ƒ Unknown IQQM model (see b lue raindr ops on map) o Evaporation g auges: 0 o Rated streamflow gaug es: 1. None on creeks o Other known stream-hei ght gauge s: (Dates are as indi cated by Mo ttell,199 8) 1. Tuen @ Bluegrass from 1954 (streamflow and rai nfall recor ds)

o IQQM modelli ng data: • Creeks are not expl icitly mod eled

Figure 17 – Thurrulgoonia and Tuen Creek s– Hydro logic Summary

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4.7.2. Impacts of ROP Levels of Development on the Flow Regime

4.7.2.1. Overall Flow Regime Impacts

As there is no model data available for the Tuen or Thurrulgoonia creeks, the assessment of flow regime impacts has been inferred from mode l results at Cunnamulla Weir. Green and King (1995) published estimates of when the creeks commence to flow based on heights at the Cunnamulla flood warning gauge11 (see Table 23).

Table 23 – Commence to Flow Thresholds for Tuen and Thurulgoonia Creeks (Source: Green and King, 1995) Tuen - Commence to Flow Thurulgoonia - Commence to Flow

Height 6.2m @ Cunnamulla Weir 6.6m @ Cunnamulla

Flow Estimated 6,500 ML/D @ Estimated 18,200 ML/D@ Cunnamulla Cunnamulla Weir Weir

The flow-exceedance curve f or Cun namulla weir (see Figure 12) indicates that flow rates, around the point at which Thurulgoonia would commence to flow, are only minimally altered as a result of development. o a 2% reduction in the number of days exceeding the commence-to-flow threshold for the Thurulgoonia (based on modelled flows at Cunnamulla).

The same analysis for the Tuen indicate s that greater impacts occur, though these are still moderately small; o a 6% reduction in the number of days exceeding the commence-to-flow threshold for the Tuen (based on mode lled flows a t Cunnamulla).

This analysis of course does not take into account the impacts of development downstream of Cunnamulla weir. It has not been possible to verify the distribution of allocations in this sector, however it appears (based on stakeholder consultation) that a significant proportion of the allocations are upstream of the Tuen offtake. In an effort to consider the effect of these allocations, the impacts upon flooding at the Barringun gauge can be used as an indicator of possible impacts on the Tuen. A flow threshold of 2,700 ML/D at Barringun has been used as an indicator that the Tuen has commenced to flow12. There is an 11% reduction in the number of days where flows at Barringun exceeds this threshold. As such, the best estimate of impacts on the Tuen that can be established for the purposes of this report is that: o the number of days where the Tuen creek flows is reduced by between 6% and 11% as a result of full upstream development.

11 based on public consultation relating to historic events

12 This threshold is 10% of the way between the minor and moderate flood thresholds for Barringun. This was chosen as an indicative indicator as the commence to flow threshold for the Tuen is 10% of the way between the minor and moderate flood thresholds for Cunnammulla weir.

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Similarly, if a flow threshold of 5,600 ML/D at Barringun is indicative of events which would cause the Thurulgoonia to flow, there may be a 17% reduction in the number of days in which the Thurulgoonia flows. The best estimate possible for this report is therefore that: o the number of days where the Thurulgoonia creek flows is reduced by between 2% and 17% as a result of full upstream development.

4.7.2.2. Impacts during wet and dry phases

It is expected that the impact of development on the creeks would be higher during dry phases than wet phases, as is indicated by the results for Cunnamulla and Barringun in Section 4.5.

4.7.3. D ifference in impacts under ROP and current levels of development

As was discussed in Section 4.5.2.1, it has been estimated that current impacts are likely to only be half that which was presented in Section 4.7.3 above. The flow regime impacts as a result of current development can not reliably be quantified without relevant model data however.

4.7.4. Impacts of Development on DIWA Environmental Assets

The impacts of development on DIWA environmental assets for this section are presented below.

Wetland Name Hydrological Features Hydrological Impact

Warrego River Seasonal flooding occurs along most of the Water resource development as Distributary distributary system and adjacent floodplain, allowed in the ROP would result System with occasional large floods spreading out in a reduction in the frequency (QLD1 69) over the vast alluvial plains. The larger with which the effluent systems waterholes are permanent or semi- would flow. It is difficult to quantify permanent, although many dry out these impacts however as the completely during prolonged drought. Most IQQM model does not represent waterholes are in the order of half to two the effluents in the region. metres deep under normal flow and natural conditions. However, many holes, such as the one at Noorama Station, have been augmented by the construction of levees across outflow, thus prolonging the period of inundation, and increasing depths. Some have also bore drains flowing into them (eg. The mail hole on Thurulgoonia Station).

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4.8. Irrara Creek

Summary : o Only limited amounts of hydrologic data was available for developing a reliable IQQM model for representing Irrara Creek flows. Whilst the creek is explicitly represented in the model it was not possible to calibrate to a gauge at the time of model development. o There are no licensed allocations along the creek. o As a result of current levels of development and water diversions upstream on the Warrego, there would be some impacts on the flow regime of the Irrara. This is approximately half the impact that would occur under full development as is discussed below. o Under full levels of development there would be a 13% decrease in the frequency of small flows (between 100 ML/D and 1,000 ML/D) but minimal impact on higher flows.

4.8.1. Available Hydrology and Water Resource Development Data

A snapshot of the available hydrology data and level of water resource development is presented in Figure 18.

At present, there is very limited data for the system. There are no official river gauges and limited information on infrastructure.

The IQQM model explicitly represents the creeks, however the model could not be calibrated to any gauges on the creeks as there are at present no such official gauges. As such, the model results can only be considered a rough estimate.

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o Rainfall ga uges: o Unsupplemented water allocations: o 6 BOM gauges in vicinity of cr eek (see ƒ No allocations blue raindrops on map) o Estimated Constructed Storages: o No gauges on creek used in I QQM ƒ Details unknown model o Evaporation gauges: 0 o Rated streamflow gauges: No gauges on creek o Other known stream-height gauge s: No known gauges.

o IQQM modelling data: ƒ Climatic period of model data: 1889 - 2006 ƒ Un-gauged location s estimate d in model: 1. Irrara Creek start of system – estimated by assuming that 30 % of the l osses between Cuttaburra offtake and Barringun gauge ca n be attrib uted to inflows to Irrara Creek 2. Irrara Creek at bor der – Sam e as start of system. 3. Irrara Creek return t o Warrego – Routing parameters based o n Barring un to Fords Bridge reach. Losse s estimate d estimated at 50% a cross the w hole flow regime. High flows are then re turned to the Warrego howev er the cali bration report does not prov ide details on this relationship.

Figure 18 – Irrara Creek – Hyd rologic S ummary

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4.8.2. Impacts of ROP Levels of Development on the Flow Regime

4.8.2.1. Model assumptions about level of use

As desc ribed in Section 4.2, IQQM model results are used to quantify the impacts of development under bo th pre-development and full-development conditions. For the full-development scenario, the IQQM model assumes full utilisation of existing allocations and uptake of additional allocations on the Warrego, as was described in Section 4.5. There are no unsupplemented allocations in the Irrara Creek system and the model does not assume any such allocations.

4.8.2.2. Overall Flow Regime Impacts

The flow regime for Irrara Creek is illustrated in Figure 19. This figure depicts the lowest and highest daily flow rates and the frequency that a particular flow rate is exceeded during the modelled period. Flow exceedance curves were described in Section 4.2.3. This figure also illustrates the percentage change in flow rate for each exceedance value on the horizontal axis. An explanation of this statistic was in cluded in Section 4.3.

Predeveloped Irrara C reek - Start of System Development allowed under the ROP % reduction in flow rate 10,000 100% 90%

80%

1,000 70%

60% 100 50% (ML/D)

40% (%) Rate Daily Flow Rate

30% Reduction in Flow 10 20%

10% 1 0% 0% 1% 2% 3% 4% 5% 6% 7% 8% 9% 10% % Exceedance - Percentage of time flow rate exceeded

Figure 19 – Daily Flow Exceedance Curve – Irrara Creek Start of System13

As is illustrated in Figure 19, full-development results in a decrease in frequency of non-zero flows below 1,000 ML/D. This is further illustrated through the following statistics: o The number of days with flows between 100 ML/D and 1,000 ML/D is reduced from 1881 to 1633 days in the modelled period (a decrease of 13%). o There is a small increase in duration of zero flow days from 86% to 88% of days. o The maximum period of flows below 100 ML/D is increased from 1249 to 1338 days (an increase of 7%). o The average period of flows below 100 ML/D is increased from 267 to 322 days (an increase of 20%).

13 See Section 4.2.3 for explanation of flow-exceedance curves

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4.8.2.3. Impacts during wet and dry phases

As was discussed in Section 3.1.3, the following climatic periods have been selected as a representative wet and dry phase: o Wet phase: 10/1948 – 09/1951 o Dry phase: 10/1951 – 09/1954

As is summarised in Table 24, the impacts of development are actually higher during wet climate phases.

Table 24 – Irrara Creek - Impacts during representative wet and dry phases Average Number of days Daily Flow with flows >100 (ML/D) ML/D Pre-development 95 144 Full-development 83 123 Wet % change -12% -15% Pre-development 32 41 Full-development 28 37 Dry % change -10% -10%

4.8.3. Difference in impacts under ROP and current levels of development

As was discussed in Section 4.5.2.1, it has been estimated that current impacts are likely to only be half that which was presented in Section 4.8.2.3 above. The flow regime impacts as a result of current development can not reliably be quantified without relevant model data however.

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4.8.4. Impacts of Development on DIWA Environmental Assets

The impacts of development on DIWA environmental assets for this section are presented below.

Wetla nd Name Hydrological Features Hydrological Impacts

Green Creek Green Creek is a flood effluent of Irrara With ROP levels of Swamp Creek. Green Creek generally maintains a development, there is a 13% (NSW013) small, well defined channel until it reaches reduction in the number of the property (?) where it spreads out days where the Irrara Creek becoming a broad, shallow floodway. In start of system exceeds 800 large floods Green Creek flows back into the ML/D which is approximately a Warrego River. The flood history for the area 1 in 2 year flood threshold. suggests that Green Cr eek would be flooded Based on this, full every 2-3 years. Water generally remains for development as allowed in the four to five months in the deeper areas to up ROP would result in reduced to one month in the shallo wer areas (Gree n, inundation of the swamp. 1992a).

Lake Nichebulka Short-term inundations by local run-off. The Given that the Lake is primarily (NSW015) lake usually holds shallow saline water for dependent on local runoff with approximately one month (Green, 1992a). inflows assumed to only occur Kerribree Creek flows into the lake from the during large floods, there south and originates from the north east would appear to be minimal where it is joined by Irrara Creek, and impact as a result of ROP effluent of the Warrego River (Kingsford et development. al., 1994). Kerribree Creek contributes only a minimal amount to the lakes hydrology. Groundwater has a role in maintaining the Lakes water levels (Green, 1992a). A low bank had been constructed to restrict water from Kerribree Creek entering the lake [present status unknown]. Based on the Irrara Creek Murphys Lake Water is fresh and the lake can retain water Start of System results there (NSW016) for up to 18 months after a flood. Water enters Murphys Lake from Kerribree Creek may be some impact as a in the north (Green, 1992a). result of development allowed in the ROP. However it is difficult to ascertain impacts without information regarding flood thresholds required for the Lake to be inundated.

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4.9. Total Inflows to NSW – Plan Objective

As was summarised in Section 2.2.3, the Water Resources Plan for the Warrego establishes a flow objective for cross border flows. The environmental flow objective is that the end of system flow that crosses the border from the State into New South Wales be at least 89% of the end of system flow of the pre-development flow pattern.

The objective is assessed through IQQM modelling of the cross border flows of Cuttaburra and Irrara Creeks and Warrego @ Barringun (See Figure 20). The Noorama and Widgeegoara flows are routed through the Nebine and as such are considered to be part of the Nebine cross border flow assessment.

The IQQM pre-development scenario is used to assess the total volume of water at these locations over a long climatic period. For the purposes of the ROP, the pre-development scenario volume represents the total volume of water that would have occurred at the border locations over the period 1889 to 2002 if no development or extractions had been in place during this period. This is then compared to the volume that would have occurred at the border locations if the levels of development allowed in the ROP had been in place for the entire 1889-2002 period.

Cunnamulla

Cuttaburra Noorama and Creek @ border Warrego @ border Widgeegoara @ border Irrara Creek @ (Barringun) border Figure 20 - Assessment of Cross-Border Flow Objective

The IQQM representation of cross border flows could be improved with additional streamflow data as has been discussed. Nonetheless the available results indicate that the objective is met (see Table 25).

Table 25 – Cross Border Modelled Flows – total volume (ML) from 1889 – mid 2006

ROP ROP volume as a % Pre-development Location development of Pre-development total flow volume total flow volume Volume Barringun 9,699,654 8,503,343 88% Cuttaburra @ border 11,744,132 10,697,943 91% Irrara @ border 5,612,822 4,945,349 88% 27,056,608 24,146,635 89% Total Flows

There appears to have been some confusion about how the cross border flow objective is assessed. It is a comparison of flows at the border under pre-development and developed conditions. It is not a comparison of flows at Cunnamulla with flows at the border. Many of the losses between Cunnamulla and the border would naturally occur. Therefore a comparison of Cunnamulla and Barringun gauged

WMAwater 28011: FinalReport.doc:16 July 2008 76 Warrego River Scoping Study flows during an event will not clearly convey the impact of development.

Whilst the cross border flow objective aims to place limitations on impacts of development, the assessment does not evaluate impacts on small to medium flows or impacts during wet and dry climate phases. Rather, the use of total flow volume means that the assessment is biased by the medium to large floods where most of the flow volume occurs. The assessment also does not differentiate between wet and dry climate phases. It is possible that a target of minimum 89% cross border flows is met during dry phases however (see Error! Reference source not found.) courtesy of the management rules in place.

Table 26 – Dry Phase Cross Border Modelled Flows – total volume (ML) from 10/1951 – 9/1954 Pre-development ROP ROP volume as a % total flow volume development of Pre-Development Location total flow volume Volume Barringun 487,306 432,809 89% Cuttaburra @ border 673,514 625,955 93% Irrara @ border 298,879 269,590 90% Total Flows 1,459,699 1,328,354 91%

4.10. Warrego River from Barringun to Darling

Summary : o Available hydrologic data was sufficient for developing a moderately reliable IQQM model for representing flows at Fords Bridge. o The QLD model does not represent the license conditions on instream dams at the end of system which require that low flows are not captured. A new IQQM model was therefore developed to represe nt these conditions using information from NSW DWE. The model results for this section are estimates only as there is no gauge with which to calibrate the model. o There are 3,462.5 ML of licence volume allocations along this section of the Warrego, plus an additional 6,009 ML which can be extracted from a floodplain storage. o Level of current use is not known. There is no metering of extractions. o Flooding thresholds for Barringun are not known and analysis has been based on Fords Bridge thresholds. o Under full levels of development there would be a decrease in the frequency of minor flooding corresponding to a 17% reduction at Fords Bridge and a 36% reduction at the end of system. There would also be a significant reduction in the frequency of moderate flooding; 14% at Fords Bridge and 35% at the e nd of system. As a result of full developm ent there would also be a significant increase in the frequency of days with zero flow at both locations.

4.10.1. Available Hydrology and Water Resource Development Data A snapshot of the available hydrology data and level of water resource development is presented in Figure 21. The QDNR IQQM model has been calibrated at Barringun and Fords Bridge. The model represents the flow regime moderately well at Fords Bridge, however as discussed in section 4.3.1 the representation of flows at Barringun is poor.

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The QDNR IQQM model does not represent the passing flow conditions for instream dams at the end of the Warrego River. As such, an IQQM model which simulates these license conditions has been developed for this study to analyse the changes to the end of system flow regime. As there is no calibrated flow gauge on the Warrego below Fords Bridge, validation of this model can only be inferred from unattributed inflows on the Darling River. It has been outside of the scope of this project to conduct this validation and as such the results presented should be considered a rough estimate only and used cautiously.

4.10.2. Impacts of QLD ROP and NSW Current Levels of Development on the Flow Regime

4.10.2.1. Model assumptions

As described in Section 4.2, the IQQM model results are used to quantify the impacts of development under both pre-development and QLD full-development conditions and NSW current development conditions.

For the QLD full-development scenario, the IQQM model assumes full utilisation of existing allocations and uptake of additional allocations on the Warre go, as was described in Section 4.3.2. This scenario is referred to as ‘full development’ and differs from current development.

The new IQQM model of the lower Warrego has been configured to incorporate the passing flow license conditions for the instream dams located between Fords Bridge and the end of the system. The model results presented in this section have been obtained from this model. As highlighted in Section 4.10.1, these results should be considered an initial estimate only as verification is required. The model has only been developed to run over the 1922 to 2006 period and hence the results for the end of s y stem are based on a shorter climatic period.

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o Rainfall gauges: o Unregulated Water Access Licenses: o 3 gauges used in IQQM model (see red ƒ 3,4 62.5 ML total volume allocations direct raindrops on map) from Warre go, plus additional 6,009 ML which o 8 additional BOM gauges (excluding Irrara can be extr acted from a floodplain storage and Darling regions) not used in IQQM which is filled during flooding in the Warrego model (see blue raindrops on map) ƒ Licenses subject to flow thresholds before o Evaporation gauges: Nearest gauge is Bourke pumping ca n begin or storage of water Airport (1994 – 2007) allowed in i nstream dams. o Rated streamflow gauges: ƒ A m aximum extraction rate is specified for 1. Warrego River At Barringun (closed), each licens e. The average maximum 13/02/1968 –31/01/1981 extraction r ate, calculated by weighting each 2. Warrego At Barringun N0. 2, opened rate by the size of the allocation, is 785 ML/D 1/01/1993 (rate restric ted through specification of pump 3. Warrego River At Fords Bridge (Main size- result s based on pump capacity from Channel), opened 1/01/1972 department’s database) 4. Warrego River At Fords Bridge Bywash, o Estimated Cons tructed Storages: opened 1/12/1921 ƒ A number of instream dams however total volume is u nknown. For the purposes of o Other known stream-height gauges: (Dates are as indicated by Mottell,1998) modeling th e storage volume has been 1. Barringun, 1926 to 1981 estimated a t 35 GL. 2. Belalie, 1949 to 1993 (monthly) 3. Fords Bridge, 1921 to 1992

o IQQM modelling data: ƒ Climatic period of model data: 1889 – 2006 but end of system only 1922 – 2006 ƒ Gauged locations calibrated in model: 1. Barringun - Poor calibration, model

generally overestimates flows and low coefficient of determination / efficiency 2. Fords Bridge – Good accuracy for flows above 1,000 ML/D, small amount of overestimation for lower flows. The coefficient of determination / efficiency was moderate (around 0.75). ƒ Ungauged locations estimated in model: 1. Warrego End of System – Neither the QLD NRW or the NSW DWE IQQM model represents the passing flow conditions on instream dams. WMAwater have updated the DWE model to reflect this.

Figure 21 – Warrego River from Barringun to Darling – Hydrologic Summary

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4.10.2.2. Overall Flow Regime Impacts

4.10.2.2.1. Fords Bridge

The flow regime under pre-developed an d QLD full-development conditions/NSW current development conditions at Fords Bridge is illustrated in Figure 22. This figure depicts the lowest and highest daily flow rates and the frequency that a particular flow ra te is exceeded during the modelled period. Flow exceedance curves were described in Section 4.2.3. This figure also illustrates the percentage change in flow rate for each exceedance value on the horizontal axis. An explanation of this statistic was included in Section 4.3.

Predeveloped Fords Bridge Development allowed under the ROP % reduction in flow rate 100,000 100% 90% 10,000 80%

70%

Rate 1,000 60% 50% (ML/D)

100 40% (%) Rate Daily Flow

30% F low in Reduction 10 20% 10% 1 0% 0% 10% 20% 30% 40% 50% 60% % Exceedance - Percentage of time flow rate exceeded

Figure 22 – Daily Flow Exceedance Curve – Fords Bridge14

As is illustrated in Figure 22, the developed scenario results in a decrease in frequency of non-zero flows below 1,000 ML/D. Development also results in a substantial increase in the frequency of zero flow day s.

This is further illustrated through the following statistics: o The number of days with flows betw een 100 ML /D and 1,000 ML/D is reduced from 9681 to 7853 days in the modelled period (a decrease of 19%) o There is an increase in duration of zero flow days from 43% to 59% of days o The maximum period of flows below 100 ML/D is increased from 373 to 596 days (an increase of 60%). o The average period of flows below 100 ML/D is increased from 47 to 77 days (an increase of 64%).

Minor flooding is estimated to begin at around 323 ML/D (see Table 27) and moderate flooding at arou nd 1,176 ML/D. Full upstream development on the Warrego would therefore result in decreased small to medium flooding: o The number of minor flood days (flows between 323 ML/D and 1,176 ML/D) has decreased from 4,460 to 3,694 days (a decrease of 17%). o The number of moderate flood days (flows between 1,176 and 9,410 ML) has decreased from 1807 to 1550 days (a decrease of 14%). o Moderate – high flooding (greater than 1,176 ML/D) occurs in 45% of years under pre development conditions and 39% of years under developed conditions.

14 See Section 4.2.3 for explanation of flow-exceedance curves

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Table 27 – Flood Thresholds for Fords Bridge

Fords Bridge (Total) Height Category Begins At1 Total Fords Bridge Flow Flood Category Estimated

Minor flooding 1.7m @ bywash and 0.7m @ main channel 323 ML/D

Moderate flooding 2.3m @ bywash and 1.3m @ main channel 1,176 ML/D

Major flooding 3.2m @ bywash and 2.2m @ main channel 9,410 ML/D 1 Estimated based on flood levels for Bywash published in SES Bourke shire local flood plan

4.10.2.2.2. Warrego End of System – Inflow to the Darling

The frequency with which small to medium flow rates occur at the end of system (see Figure 23) is illustrated for both the pre-developed and developed15 model results. The figure also illustrates the percentage change in flow rate for each exceedance value on the X-axis. An explanation of this statistic was included in Section 4.3. .

NOTE – the end of system results have been evaluated over a shorter climatic period (from 1922) than the rest of the system as it was only possible to obtain appropriate long-term climatic data sets for this section over this period.

This means that the results presented for the end of system cannot reliably be compared to previous results. See Section 4.10.2.3 for a further discussion and comparison of end of system results with results at Fords Bridge over the same climatic period.

Assuming the flood thresholds at Fords Bridge apply to the end of system, upstream development as allowed in the ROP (QLD) and current license conditions (NSW) would result in reductions in duration of minor and moderate flooding: o The number of days of minor flooding is reduced by around 36% o The number of days of moderate flooding is reduced by around 35% o Moderate – high flooding (greater than 1,176 ML/D) occurs in 53% of years under pre- development conditions and 36% of years under full-development conditions

Development would also result in an increase in the duration of zero flow days from 78% to 88% of days though the model is likely to be unreliable in predicting flows in the very low to zero flow range.

As was previously noted, these results should be used cautiously as it has not been possible to verify the model results within the scope of this study.

15 Development that is allowed in the ROP (QLD) and current license conditions (NSW)

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"Predevelopment" Warrego End of System "Development allowed under the ROP (QLD) / current licenses (NSW)" % reduction in flow rate

100,000 100% 90% 10,000 80% 70% L/D) 1,000 60%

ate 50% 100 40% ow R (M 30%

ily Fl ily 10 20% Da 10% 1 0% 0% 5% 10% 15% 20% 25%

% Exceedance - Percentage of time flow rate exceeded

Figure 23 – Daily Flow Exceedance Curve – Warrego End of System: 1922 - 200616

4.10.2.3. Impacts during wet and dry phases

As was discussed in Section 3.1.3, the following climatic periods have been selected as a representative wet and dry phase: o Wet phase: 10/1948 – 09/1951 o Dry phase: 10/1951 – 09/1954

As is summarised in Table 28 and Table 29, the impacts of development are significantly higher during dry climate phases.

Table 28 – Fords Bridge - Impacts during representative wet and dry phases

Average Number of Number of Daily Flow minor flooding moderate (ML/D) days flooding days Pre-development 406 218 113 Full-development 352 206 98 Wet % change -13% -6% -13% Pre-development 150 75 33 Full-development 122 66 27 Dry % change -18% -12% -18%

16 See Section 4.2.3 for explanation of flow-exceedance curves

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Table 29 – End of System - Impacts during representative wet and dry phases

Average Number of Number of Daily Flow minor moderate (ML/D) flooding days flooding days Pre-development 255 79 164 Full-development 164 58 134 Wet % change -36% -27% -18% Pre-development 79 26 32 Full-development 31 16 11 Dry % change -60% -38% -66%

4.10.3. Difference in impacts under ROP /license conditions and current levels of development / use

The impacts on the end of system are a result of cumulative development on the Warrego. In the case of QLD, the difference in impacts between the current level of use and the level of use assumed in the model have been discussed in the previous sections. In the case of NSW, the modelling assumes the level of development allowed under current license conditions. As there is no metering on the Warrego, the amount of licensed use which is un-activated could not be quantified for the purposes of this project. Information obtained during stakeholder consultation suggests that license conditions are not fully activated and as such current impacts are likely to be lower than that presented above.

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4.10.4. Impacts of Development on DIWA Environmental Assets

The impacts of development on DIWA environmental assets for this section are presented in the adjoining table.

Wetland Name Hydrological Features Hydrological Impact Lake Burkanoko Short-term inundations b y local run-off Based on th e co-ordinates given this lake (NSW014) from the floodplain. During floods wate r would appear to be outside of the from one of the effluent s of the Warrego Warrego B asin – connection with the River could reach the lake. Water is Warrego pro bably only likely during very saline becoming hypersaline. large floods upon which water resource development (as allowed in the ROP) would have no impact. Willeroo Lake Willeroo Lake is a freshwater lake of Difficult to ascertain impacts as no (NSW018) Goodrick's (1984) Cuttaburra system with information available on flow maximum depth of about 1.8m. Long requirements. term inundation by regional and local run- off. Willeroo Lake normally holds water for up to 12 months but has been recorded as holding water for 8 years after flooding 1983 (Green, 1992a). No database information. Pers Comm The 1 in 10 year flood threshold for Fords Birdsnest information obtained from Willy from Bridge has been estimated at 5,000 ML/D Swamp Tuncoona: (based on pre-development data). Full (NSW163) & Racecourse swamp / birds nest development results in a 13% reduction Racecourse swamp / Toms Lake – fill in the number of days that exceed this approximately every 10 years. Filled threshold (115 days to 100 days). Based Swamp in 74/76 and 1950. In 1990 he on this, full development results in a (NSW166) & blocked off water as if this area fills reduction in the number of days where Toms Lake then his road gets cut. In 2008 it just the swamps / lake commence to be (NSW168) started to run into the area but the inundated. river dropped so inflow stopped. If it

would have continued running for a week it would have filled. Bottom Lila Lake No database information. Based on location of the lake it appears (NSW164) that flows from the Warrego would only contribute during large floods and therefore minimal impact is expected to have occurred as a result of upstream development. Lake Yandaroo No information provided in DEWHA (NSW165) database

No information provided in DEWHA Assuming that the Lake is outside the The Dry Lake database. This lake may in fact be basin, or at the very lest is on the south (NSW167) outside of the Warrego basin based on east periphery, it is not likely that water the co-ordinates give. resource development on the Warrego would be impacting on the Lake.

WMAwater 28011: FinalReport.doc:16 July 2008 84 Warrego River Scoping Study 4.11. Summary and Discussion of IQQM model results

4.11.1. Key Hydrological Results

Impacts on average daily flows and minor and moderate flood frequency are summarised in Table 30 for key locations on the Warrego River. Table 31 summarises impacts on average flow, zero flows, and minor to moderate flooding at the start of major effluent creeks.

Minor and moderate flood thresholds have been obtained from the Bureau of Meteorology (BOM). These thresholds are not available for the distributary creeks and as such the impact assessment for the creeks could not be site specific. Instead, the flow range of 100ML/D to 1,000 ML/D was used as an approximation of small to medium flooding.

The following points summarise the key results: ¾ There is an increase in the loss of average daily flow, for both the Warrego and the effluent creeks, as you move down the system as a result of cumulative extractions due to water resource development. Assuming full development, average daily flows are reduced by approximately 1.5% at Wyandra, 16% at Fords Bridge and 44% at the end of system. ¾ There is an increase in the loss of minor flooding days as you move down the system as a result of cumulative extractions due to water resource development. Assuming full development, frequency of minor flooding is reduced by approximately 0.5% at Wyandra, 17% at Fords Bridge and 36% at the end of system. ¾ Excluding Barringun (see below for discussion), there is an increase in the loss of moderate flooding days as you move down the system as a result of cumulative levels of development. Assuming full development, frequency of moderate flooding is not impacted at Wyandra, and is reduced by approximately 14% at Fords Bridge and 35% at the end of system.

The flooding thresholds used for flooding at Barringun, Fords Bridge and end of system may need review. ¾ The number of days which have been classified as minor flooding increases between Barringun and Fords Bridge for the pre-development scenario. The same occurs for moderate flooding. This result does not seem likely given the small amount of inflows in this reach. ¾ The flooding thresholds for end of system were not known and as such Fords Bridge thresholds were adopted. All statistics are estimates only and should be considered indicative. The impacts for the end of system are particularly difficult to quan tify given the lack of gauging of flows and lack of accurate data regarding storage volumes, low flow outlet capacities and natural transmission losses. It has not been possible to verify the end of system results generated for this study.

Note that Tuen and Thurulgoonia creeks are not explicitly modelled in the IQQM. As such, the impact assessment for these creeks has been based on data for Cunnamulla and Barringun. The best estimate of impacts for the creeks was that:

• the number of days where the Tuen creek flows is reduced by between 6% and 11% as a result of full upstream development. • the number of days where the Thurulgoonia creek flows is reduced by 2% to 17% as a result of full upstream development

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Table 30 – Warre go Riv er - S ummary of Flow Regime Impa cts

Average Daily Flow (ML/D) Number of minor flooding days Number of moderate flooding days % % decrease % % decrease % Pre- decrease full Pre- decrease full Pre- decrease % decreas e full development current development development current development development current developm ent 1889 - 2006 climatic period

Wyandra 1,248 negligible 2% 209 negligible negligible 30 0% 0% Cunnamulla 1,057 2% 5% 1,604 4% 8% 307 negligible 1% Barringun 226 6% 12% 722 negligible 9% 147 11% 22% not not Fords Bridge 200 known 16% 4,460 known 17% 1,807 7% 14% 1922 - 2005 climatic pe riod not not Fords Bridge 191 known 17% 3,029 known 19% 1,157 7 % 15% not not not End of system 110 known 44% 1,204 known 36% 826 known 35%

Table 31 – Effluent Cre eks st art of system - Summary of Flow Regime Impacts

Number of days w ith flow betw een 100 and Average Daily Flow (ML/D) Percentage of time with zero flows 1,000 ML/D % % decrease % Pre- decrease full Pre- Current Full Pre- decrease % decrease full developme nt current development development development D evelopment development current development 1889 - 2006 climatic pe riod Noorama and Widgeegoara 276 negligible 3% 48% 50% 56% 7,953 1% 6% Cuttaburra 408 3% 6% 87% 88% 1,235 9% 17% Irrara 42 6% 13% 86% 87% 88% 1,881 7% 13%

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4.11.2. Environme ntal Flow Requirements of Significance of Im pacts

Environmen tal assets are dependen t on var ying a spec ts of the flow regime depending on whe re they are located. A generalise d relationship between environmental assets a nd flow reg ime features is presented in Table 32. The stu dy assessed impacts on all of these features ex cept for short term variability and seasonality which are o nly a concern in systems with high river regulation, which is not the case for the Warrego. The study al so assesse d average flows which while not linke d to any ecosystem requirements, virtually all aquatic, riparian and fl oodplain communi ties would be affected by significant c hanges in average flow (Davies et al,2008).

Table 32 – Critical Flow Dependencies of Environmental Assets1 Instream Floodplains Flow regime element refuge riparian and low lying areas zone wetlands Zero flow √√ √ Low flow √√

Within channel high flows √√ Overbank high flows √√ Short term flow variability √ Seasonali ty √ √ √ 1 Source: (WMA, 2007))

The minor flood threshold used in the hydrologic impact assessment approximates within channel high flows. The moderate flood threshold approximates the start of overbank high flows. As such, it is possible to establish a gener al relationship betwe en impacts on floodin g and the env ironmental sign ificance of those impacts. A generalised asse ssment of impact of flow regime changes on instream habitats is summarised in Table 33.

In the case of D IWA wetlands, site specific information about historic inunda tion frequency has been available which can b e used to crea te a site speci fi c flow thres holds. This has been used in the preceding sections to conduct a site specific impa ct asses sment. Bas ed on this assessment, impacts due to full ROP development are expected for the following DIWA sites: o Yantabulla S wamp (C uttaburra B asin) (NSW01 9) o Warrego River Distributary System (QLD169) o Green Creek Swamp (NSW 013) o Birdsnest Swam p (NSW163) & Racecourse Swamp (N SW166) & Toms Lake (NSW168)

The hydrologic impa ct assessmen t in this rep ort is limite d to considering flow quant ity/ frequency characteristics of the region and i mpacts as a result of water extractions and constructio n of water storages. Land use in the region may also be impacting ripar ian and floodplain flora and fauna and water quality, as was discussed in Section 3.2 where existing literature was available.

The impact assessment has also not consid ered economic issues as this is outside the scope of the brief. Grazing as a result of b eneficial flooding has been reported to be an important component of the regional economy however (Mo ttell, 1998) and these a ctivities may be affected by changes in the flow and inundation.

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Table 33 – Generalised Impacts on Instream Assets

Zero flow and Low Flows

• Increased frequency of zero and low flows downstream of Wyandra may be affecting instream waterholes and associated flora and fauna. These impacts are likely to be most felt in the more downstream waterholes. • The impacts of development on zero to low flows are moderately small upstream of Fords Bridge. However, below this point the impact is more severe. At Fords Bridge the maximum period of flows below 100 ML/D is increased from 373 to 596 days (an increase of 60%). Within channel high flows • The decreased frequency of within channel flooding may be affecting waterhole and riparian habitats. • The impacts on frequency of minor flood ing are reasonably small upstream of the border (8% at Cunnamulla and 9% at Barringun) but are moderate a t Fords Bridge (17% reduction) and large at the end of system (36% reduction in minor flood frequency).

4.12. Hydrologic Impacts Published in Other Literature

4.12.1. Environmental Flows on the Paroo and Warrego Rivers

This project intended to investigate impacts of hydrologic changes but no published quantitative esults have been found. Some interim results have been published as follows:

• Kingsford et al. (2002) (draft report) provides interim, progress results of a study which investigated the relationships between river flows, wetland flooding and waterbird distribution for the Paroo and Warrego catchments. The report provides some valuable information on flooding events, development of a hydrology model and the development of a model for waterbird responses to flooding.

• Young et al. (2006) describes the development of a hydrological model

4.12.2. CSIRO Sustainable Yields Report

4.12.2.1. Summary of findings

The CS IRO (2007) Sustainable Yields Project report is part of a series of regional assessments of water availabil ity in the Murray Darling Basin taking into account climate change and other risks.

The report presents results illustrating differences between current development and pre-development conditions based on an assessment of these scenarios over historic climatic conditions. These scenarios are referred to in the report as scenario P (predevelopment) and scenarios O (QLD model) and A (CSIRO amended model). The data used by CSIRO for P and O are almost identical to that used in this report. The CSIRO report illustrates the differences between P and A flow regimes for a limited number of locations (end of system flows, Wyandra and Charleville) and statistics in comparison to this report.

The study quantitatively analysed the impacts of water extraction on 2 environmental assets. The scope of the analysis for this study was very limited as it was part of whole of Murray-Darling Basin study. The

WMAwater 28011: FinalReport.doc:16 July 2008 88 Warrego River Scoping Study analysis was for waterholes in Queensland which are important for fish, and Yantabulla Swamp in NSW which is important for waterbirds.

The Balcombe et al. (2006) study was used in the choice of flow indicator for the waterholes and the Kin g sford et al. (2002) study used in the choice of flow indicator for Yantabulla Swamp, with the results presented in Table 34 below.

Tab l e 34 – Changes in water availability for key hydrological indicators for Yantabulla Swamp and the Warrego River waterholes. (Source: CSIRO 2007). P= predevelopment conditions, A= current development conditions, Cdry= dry 2030 scenario, Cmid= best estimate 2030 scenario, Cwet= wet 2030 scenario. P A Cdry Cmid Cwet Yan t abulla Swamp indicator Months Percent change from A 146,000 ML/month ave ra ge period between events in months 21 21 43% 10% -29% maximum period between events in months 97 97 14% 22% 0% Warrego River Waterholes indicator Days Percent change from 17,000 ML/day A average period between events in days 524 524 48% 9% -37% maximum period between events in days 2905 2905 3% 3% 0%

The study concluded: • The recurrence of the indicator events to both assets has not been affected by water resource development, • Under the best estimate 2030 scenario, there would be increases in the periods between the indicator events, • Under the dry 2030 scenario, there would be substantial increases in the periods between the indicator events, • Under the wet 2030 scenario, there would be some decreases in the average periods between the indicator events, but the maximum periods would not change from current conditions.

The report also examines the impact on cease to flow percentiles for the end of systems with significant impacts observable for Fords Bridge and the Noorama and Widgeegoara at the end of these systems. As a result of development, there is a significant increase in the frequency of zero flows (A) in comparison to predevelopment conditions (P).

The study attempted to model changes in the frequency and duration of no-flow periods for the Warrego waterholes, given the importance of these periods. However the hydrological model used for the study does not model low flows well at Charleville (the selected gauging station).

The CSIRO (2007) study for the Warrego involved only assessing the recurrence of events. Subsequent studies of other river catchments in the Sustainable Yield series, examined changes in volumes of these events.

4.12.2.2. Discussion and comparison to findings of this report

[Note that the CSIRO results for average annual flow for Norooma and Widgeegoara and Cuttaburra Ck reported in Table 4-6 of that report refer to the end of these creeks whereas the results presented in this report in Table 31 refer to the start of system.

The Warrego River Waterholes are DIWA listed and are a series of waterholes between Charleville and Wyandra. The CSIRO study used Charleville as a reference gauge to examine impacts on the waterholes

WMAwater 28011: FinalReport.doc:16 July 2008 89 Warrego River Scoping Study whereas this study has examined impacts at Wyandra. Both assessments indicate that water resource development is unlikely to be causing impacts on the waterholes.

This study’s findings with respect to the Yantabulla Swamp / Cuttaburra Basin differ to those in the CSIRO report. The CSIRO report’s assessment indicates that water resource development has no impact on the flow regime of the basin, whilst the analysis conducted in this study indicates that impacts are likely. Differences in the assessment processes used are outlined below: o The CSIRO Yantabulla Swamp assessment is based on river discharge at Wyandra. Whilst flow at Wyandra may be related to the flow / inundation characteristics of the basin, it is preferable to use modelled data for the Cuttaburra rather than interpolating from a remote gauge. The choice of Wyandra also does not convey the full impact on the basin, there is significant water resource development downstream of Wyandra and upstream of the Cuttaburra offtake. o In this study, flow regime impacts were presente d for Cuttaburra Creek a t Turra. An assessme nt of minor and moderate flood frequency was condu cted. The moderate flood threshold used was 3,700 ML/D which was based on the Mottel (1998) reporting that medium floods begin when flows at Turra reach 2.61m. The minor flood threshold could not be found in the literature and as such was based on 1,000 ML/D. Whilst minor and moderate flooding at Turra is assumed to be im portant for the basin, a flow-inundation relationship would b e required to improve the asse ssment o f the significance of these impacts.

4.12.3. Sustainable Rivers Audit (SRA)

4.12.3.1. Summary of findings

The SRA is an initiative of the Murray-Darling Basin Commission involving partner agencies in each state and territory within the Basin. The Audit provides river managers and users with the first comprehensive understanding of the health of the many rivers and streams that run across the Basin. The Audit uses scientific indicators of health to determine the current status of the Basin's rivers and any potential trends. Groups of indicators or “themes” for immediate implementation include fish, macroinvertebrates and hydrology.

Hydrology information will be collected every six years and evaluated using long term river flow sequences, developed by the State’s hydrologic models. In the 2008 report (Davies et al., 2008) data was collected for five sites on the Warrego; Augathella, Wyandra, Cunnamulla, Barringun and Fords Bridge.

A hydrological index is derived for each site based on 5 flow characteristics: o High Flow Events: o Indicator assesses change in magnitude of high flows; is the mean of the highest and second highest monthly flows in each year examined o All sites were near reference (pre-development) condition. Barringun and Fords Bridge had the biggest impacts with a reduction in high flow magnitudes of 19% and 14% respectively. o Low and Zero Flow Events: o Indicator is a composite of two indicators, one examining magnitude of low flows and the other examining the proportion of time with no flows. Based on monthly flows. o All sites were near reference condition with the exception of Fords Bridge where duration of zero flow events was substantially changed (indicator value 78 out of possible 100) o Variability: o Change in coefficient of variation of monthly flows. Based on monthly flows.

WMAwater 28011: FinalReport.doc:16 July 2008 90 Warrego River Scoping Study o All sites were near reference condition o Seasonality Indicator: o Indicator assesses change in timing of minimum and maximum flows. Based on monthly flows. o All sites were near reference condition o Gross Volume: o Indicator is a composite of two indicators, one examining mean annual discharge and one examining mean annual discharge. o No sites experienced significant changes in mean annual flow volumes however impacts upon median volumes occur at Wyandra, Barringun and Fords Bridge. The former two sites received a volume indicator score of 86 and 84 respectively. Fords Bridge received the lowest score of 60, with median volumes being 33% of the reference condition.

4.12.3.2. Discussion and comparison to findings of this report

Whilst the statistics generated in the SRA report differ to those in this report the impacts appear to be of a consistent magnitude. For example, the moderate flooding impacts identified in this report are of comparable magnitude to the change in magnitude of high flows listed in the SRA study: • This report: Assuming full development, frequency of moderate flooding is reduced by approximately 22% at Barringun and 14% at Fords Bridge • SRA report: Assuming full development, the high flow magnitude is reduced by 19% at Barringun and 14% at Fords Bridge.

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Summary : o Recalibration of the IQQM model should occur to take advantage of additional information on streamflow since model development. o The IQQM model should be upgraded to enable better representation of floodplain flows. o A complementary hydrodynamic model of the Lower Warrego floodplain could be developed to aid in understanding in changes that have occurred in the beneficial flooding regime. o Additional performance indicators for evaluating achievement of environmental objectives should be utilised. o Pending the availability of suitable sites, additional stream gaugings stations should be installed at the: - Warrego River end of system (NSW) - Irrara Creek (NSW) - Widgeegoara Creek (NSW) - Warrego River near Rocky (Qld)

o Metering of usage in NSW should take place as a matter of urgency. o A rigorous inventory of waterholes on the Warrego should be undertaken, particularly for the NSW portion. o A detailed analysis and reporting of the existing water quality information is required, along with the identification of additional risks and the appropriate level of monitoring and reporting required to inform resource managers. o Consolidation of the wetland and waterbird information should be undertaken and the Directory database updated, and, where the data is limited, further data collection should be undertaken.

5.1. Recommended Upgrades and Additions to Evaluation Tools

A number of evaluation tools have been used in assessing development impacts in the Warrego catchment. Despite a high level of sophistication, there are areas of improvement in these tools that can be potentially made in time to be used as part of the five year review of the WRP. Recommendations for hydrologic tools are summarised in

Table 35 and are discussed further in the following section. Hydraulic model development has been discussed however no recommendations have been made at this stage as development of these tools requires further consideration to determine whether the cost is justified.

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Table 3 5 - Hydrologic Evaluation Tool Recommendations

No. Recommendation Significance of Recommendation

H1 Recalibration of the IQQM o The model was not calibrated at the gauge at Turra due to insufficient model should occur to take data, however there would now be sufficient data to conduct the advantage of additional calibration. information on streamflow o Some river height data collected by stakeholders might be suitable to refine the model if a suitable height – discharge relationship can be established. o Once a suitable length of record is obtained at the Wallen gauge this data should be useful to refine the modelled breakouts to Noorama and Widgeegoara Creeks. H2 Upgrad e the IQQM to o It is recommended that the model be upgraded to explicitly model the explici tly Model all Major Tuen and Thurrulgoonia creeks as they are major components of the Distributary Creeks Warrego River Distributary System Systems H3 The IQQM model should o The current range of hydrologic models developed for assessment of be upgraded to enable water resource management have primarily focused on changes to the better representation of flow regime and impacts on irrigation users. Very little assessment of floodplain flows. floodplain losses and impacts of development on beneficial flooding has occurred.

H4 Upgrade the IQQM Further improvements could be made: model’s representation of o a distributed representation of storages instead of a lumped approach the end of system and improved estimation of storage volumes (ideally based on bathymetric data) o improved evaluation of low flow outlet capacities. The capacity used in this report is the high end, and actual capacity could be significantly smaller o improved infiltration and evaporation values for dams based on field monitoring which has recently been conducted (WCMA job number 3892007), o represent the breakout from Boera Dam to Darling, o re-assessment of inflows and losses at the end of system, calibration and verification (ideally using an end of system gauge)

5.1.1. Hydrologic Modelling

The current IQQM models for both the Queensland and New South Wales Warrego can be improved considerably through recalibration to new gauges and subsequent better representation of flow distribution and regime. The recalibration should occur for the gauges on the Warrego already included in the model but also for additional locations:

o Cuttaburra Creek @ Turra – will be useful for modelling losses and ensuring the cross border flows on the Cuttaburra are robustly modelled.

o Some river height data collected by stakeholders might be suitable to refine the model if a suitable height – discharge relationship can be established. It was not within the scope of the project to identify all such possible sites however the data collected on the Tuen at Bluegrass

WMAwater 28011: FinalReport.doc:16 July 2008 93 Warrego River Scoping Study Bridge appears to be worth considering. Currently the Tuen is not explicitly included in the model

o Warrego River @ Wallen – once a suitable length of record is obtained (this is a relatively new gauge) this data should be useful to refine the modelled breakouts to Noorama and Widgeegoara Creeks.

It is recommended that the model be upgraded to explicitly model the Tuen and Thurrulgoonia creeks as they a re major components of the W arrego River Distributary System.

As pr eviously stated, the QLD IQQM model does not suitably represent the Warrego end of system and the NSW DWE model has been used for this part of the Warrego. An IQQM model for the NSW portion of the Warrego has been developed for th e purposes of this report such that the low flow bypass conditions on instream storages at the bottom end of the system are explicitly represented in the model. Further improvements could be made to the model for the end of system including:

o a distributed representation of storages instead of a lumped approach, o improved evaluation of low flow outlet capacities. The capacity used in this report is the high end, and actual capacity could be significantly smaller, o improved infiltration and eva poration values for dams based on field monitoring which has recently been conducted (WCMA job number 3892007), o improved estimation of storage volume through bathymetric data (ALS data believed to be available for Lower Warrego u p to Keernie dam however not known whether bathymetric data is also available.) o represent breakout from Boera Dam to Darling, o re-asse ssment of inflows and losses alo ng reach along with re-calibration based on Darling gauges or gauging of Warrego end of system if implemented.

The current range of hydrologic model s developed for assessment of water resource management has primarily focused on changes to the flow regime and impacts on irrigation users. Very little assessment of floodplain losses and impacts of develo pment on beneficial flooding has occurred. Given the inadequacies associated with current representation a n d assessment of floodplain flows and losses and the importance of these flows to both users and the environment of the Lower Warrego there is a need for improvement in these estimates to occur. This can po t entially occur through improvement in the existing IQQMs and through complementary development o f a hydrodynamic model.

Section 5.1.1.1 discusses methods to improve representation of floodplain losses within IQQM. This section has been largely taken from SM E C (2002).

5.1.1.1. Methods for improved representation of floodplain losses

Floodplain losses can be simulated using either unregulated irrigation nodes or storage nodes that are already contained within the IQQM model. Currently, the IQQM model of the Warrego contains loss nodes located at strategic locations along the main channels. In order to better model floodplain losses between nodes it will be necessary to build several intermediate channel reaches between the existing main nodes and to incorporate a number of unregulated irrigation or storage nodes along each of these channels. In addition, the inundation area associated with each of these nodes will need to be determined either through adoption of historical flow versus inundation extent relationships or through the development of a hydrodynamic model of the Lower Warrego floodplain.

A schematic of this approach is presented in Figure 24. In essence there will be a network of irrigation or

WMAwater 28011: FinalReport.doc:16 July 2008 94 Warrego River Scoping Study storage nodes representing the floodplain between the main nodes. These nodes will represent the floodpl a in soil moisture store and are capable of simulating infiltration, pondage and evapo-transpiration losses . The existing IQQM modelling framework will readily accommodate this approach. The number of intermediate channel reaches in Figure 24 and the number of nodes required to accurately define the loss variation across a nd along the floodplain would be established during recalibration of the streamflow simulation component of the model. This approach is unlikely to require any modifications to the IQQM source code.

Floodplain Flow Infiltration and evaporative /

Main Channel Flow Storage Irrigation Node node Floodplain Flow

Figure 24 – IQQM Representation of Floodplain Losses (Source: Adapted from SMEC, 2002)

The development of a hydrodynamic model of the Lower Warrego floodplain would compliment the upgraded IQQM by providing information on how inundation areas and spatial distribution relate to river flows. Until such a model is developed, determination of how river flows relate to inundation areas and how development has impacted upon this relationship will be difficult to determine.

Development of a hydrodynamic model of the Lower Warrego floodplain will require information about surface topography, vegetation communities and soil types. The current DTM for the Lower Warrego is not of sufficient resolution to be used in the development of a hydrodynamic model. Consequently, the development of such a model will have to be proceeded by a Light Detection and Ranging (LiDAR) survey for the study area. The arid nature of the study area should make the results from such a survey of a suitable accuracy to be used to establish a DTM. However, some on ground and bathymetric survey (particularly for waterholes) would also be likely to be required to verify LiDAR results. It is recommended that a scoping study into the development of a hydrodynamic model of the Lower Warrego be investigated prior to any IQQM model upgrade in relation to better estimation of floodplain flows and losses. However, this does n ot preclude recalibration of the IQQM for additional streamflow data that has become available since model inception.

5.1.2. Hydraulic Model Development

Development of hydraulic models may be useful for improving understanding of instream and floodplain flow characteristics and impacts.

Development of hydraulic models for instream reaches could be useful to examine hydraulic characteristics such as flow height, velocity and wetted perimeter. This tool could also be useful for examining impacts on waterhole inundation.

WMAwater 28011: FinalReport.doc:16 July 2008 95 Warrego River Scoping Study Development of hydraulic models for floodplain systems could be useful to examine inundation behaviour how such models are likely to be very expensive and need careful consideration to determine if they are warranted.

5.2. Recommendations for Additional Performance Indicators

The performance indicators relating to environmental objectives of the Warrego were discussed in Section 2.2. Given that the macro plan for the NSW portion of the Warrego has yet to be developed there is scope for additional indicators to be included. Section 5.2.1 provides recommendations on performance indicators for capturing critical flow dependencies of environmental assets which are also relevant to NSW.

5.2.1. Queensland Water Resource Plan and Recommended Indicators

The performance indicators as currently specified in the Water Resource Plan for the Queensland p ortion of the Warrego are calculated over one time scale equal to the full simulat ion period for the IQQM computer program. Ideally these performance indicators should be calculated over a range of time scales (including wet and dry regimes), as viewing the hydrologic records for rivers in the Murray Darling Basin as a single homogenous set of data could result is misleading statistics of water security and reliability, and evaluation of environmental objectives.

As the current Warrego WRP is based upon full uptake of rights it is reasonable to assume that the performance indicators in the plan will only be calculated for this scenario. However, assessment of performance indicators at current degree of product utilisation would be informative.

The performance indicators contained in the Water Resource Plan for the Warrego do not capture all aspects of water availability, use or the flow regime. Ideally indicators should cover all important aspects of flow regime since the ecosystems, plants, and animals associated with Australian water sources have developed dependencies and responses to the natural hydrology of our rivers and groundwater systems.

Table 32 (Section 4.11.2) summarised critical flow dependencies of environmental assets. Table 36 summarises existing and recommended performance indicators for each flow regime element. In some instances performance indicators included in the WRP relate to an aspect of the flow regime however the flow threshold used is generic and could be refined by ensuring that physically relevant thresholds for the Warrego are chosen.

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Table 36 – Recommendations for Performance Indicators Flow Feature Indicator used in WRP Recommendations 1. zero flow None Could be monitored through use of an average or maximum duration performance indicator. Modelling of zero flows is less reliable however. 2. low flow; The total number of days in the Threshold could be tied more directly to simulation period in which the daily minimum flows required to replenish instream flow is not more than half the pre- waterholes. Performance indicators could be development median daily flow. average and maximum period of flows below mid-channel flow rate. 3. Within channel 1 in 2 year flood: The daily flow that The 1 in 2 year flood indicator is a generic high flows has a 50% probability of being indicator which does not necessarily coincide reached at least once a year. with bank-full flows. This report uses SES minor flood threshold which should be close to within channel high flows. 4. Overbank high Beneficial flooding flow: the median Change in duration of moderate flood levels flows of the total flow volume occurring in would be useful additional indicator. each wet season 5. Short term flow None As there is only a small amount of regulation, a variability performance indicator may not be required. 6. Seasonality None As there is only a small amount of regulation, a performance indicator may not be required. 7. Total flow End of system flow; Total volume of Could be examined over wet and dry phases and volume water that flows past stated points1 could be used for assessment of terminal during the entire IQQM simulation wetland impacts as well state water sharing period.

5.3. Recommendations for Data and Information Required for Adequate Assessment of Planning Rules and Strategies

5.3.1. Hydrologic Data

A number of data and information requirements that will assist in assessment and development of the various water planning rules and management strategies in the Warrego catchment have been identified during the course of this scoping study. This has included the need for additional gauges in some sections of the Lower Warrego, the requirements for meters to be installed on all users to enable compliance with nominal volumes and diversion limits. These needs are summarised in Table 37 and are discussed further in the following sections.

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Table 37- Hydrologic Data Recommendations

No. Research Significance of Recommendation Recommendation

H5 Pending the availability o Warrego River end of system (NSW) (Fords Bridge is the of suitable sites, gauge furthest downstream, below which are numerous in- additional stream stream dams which would significantly alter flows). gauging stations should Gauging of the following creeks near the border would assist in be installed at the: monitoring the cross border flow objective of the WRP: o Irrara Creek (NSW) o Widgeegoara Creek (NSW) o Warrego near Rocky or Coonberry Plains o A gauge between Cunnamulla and Baringun may be warranted for both modelling and river management purposes. There are a large number of distributary offtakes between Cunnamulla and Barringun. A gauge mid-way between offtakes may be useful for better establishing distributary losses and would be a more reliable reference gauge for licensing conditions. H6 Metering of usage in There are currently no meters in place and there is a significant NSW should take place volume of licensed allocations. Current use is believed to be as a matter of urgency significantly lower than licensed allocations but metering is still warranted to ensure compliance and would also assist in model calibration. H7 Additional River o Gauging of Tuen Creek @ Bluegrass Bridge is recommended as Gaugings to Develop this site has a significant historic height record and therefore Height – Flow could be useful in explicitly representing these creeks in the Relationships IQQM. o Additional high flow gaugings at Augathella, Charleville and Wyandra may also be warranted. H8 Improved Representation The IQQM model was not able to robustly represent the low flow of Low Flow Regime regime at several locations, particularly: o Charleville o Cunnamulla o Barringun Improvement of the model’s ability to represent low flows will most likely be dependent on the incorporation of data from the gauging stations of Barringun and Turra, additional rainfall data to improve system inflows, better representation of instream weirs, and a more robust representation of instream losses.

5.3.1.1. Stream Gauging

A map illustrating current official gauges, locations of unofficial river height gauge records and suggested locations for new river gauges is shown in Figure 25. The map focuses on the lower Warrego as this is the region of particular interested in the study.

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The suggested locations include the following in NSW:

A – Warrego end of system. Outflow from the Warrego is important to whole of basin modelling. Currently, Fords Bridge is the gauge furthest downstream, below which are numerous in-stream dams which would significantly alter flows. The end of system is quite deep and narrow and would be suitable for accurate gaugings up to small to medium flows. Gauging of the end of system may however be complicated from backwater effects from the Darling. Gauging of the outbreak from Boera to the Darling may also be warranted to accurately determine Warrego contributions to the Darling.

B – Irrara Cree k. The exact location needs scoping however Irrara Creek is a major tributary of the Warrego which is currently ungauged and warrants official gauging. The creek is represented in QLD’s IQQM model. The cross border model results for Irrara are included in the QLD ROP cross border flow target. Flows from the Irrara also flow into Green Creek (also ungauged) which contains a DIWA listed wetland.

C - Widgeegoara Creek @ Border. The Noorama and Widgeegoara are currently ungauged but are included in the QLD IQQM and cross border flow target for the ROP. The Noorama appears (upon looking at the Cunnamulla 1:250,000 map) to lack channelisation at the border so it would appear to be unsuitable for gauging near the border. The Widgeegoara appears to be suitable for gauging near the border.

The suggested locations include the following in QLD:

D – Warrego near Rocky or Coonberry Plains. Both sites have significant amounts of historic height data which, depending on site stability might be useful to extend the flow record. A gauge between Cunnamulla and Baringun may be warranted for both modelling and river management purposes. There are a large number of distributary offtakes between Cunnamulla and Barringun. A gauge mid-way between offtakes may be useful for better establishing distributary losses and would be a more reliable reference gauge for licensing conditions. It was noted whilst consulting with stakeholders that use of Cunnamulla Weir as the only reference gauge was not suitable where significant losses between the weir and downstream sites was not properly taken into account.

E – Tuen Creek @ Bluegrass Bridge. The suggested location is at the site of an unofficial gauge currently installed at the bridge. Gauging downstream of the bridge would be difficult as flow is spread into numerous floodplain channels. Development of a rating for the bridge gauge would be useful to assist in improved river modelling, particularly if the rating is suitable to use for the historic height data collated from 1954 to 1991. Installation of a telemetered gauge on the Tuen may not be warranted for river management or modelling purposes however.

Official gauges in the Warrego have generally been gauged up to a reasonably high flow rate. Augathella and Wyandra have the lowest, where the peak gauging is approximately 60% of the peak estimated flow. Additional gauging at these locations is therefore recommended.

Other gauging issues such as adequate gauging at low to medium flows, assessment of impact of backwater affects and localised vegetation impacts have not been examined for this study.

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Figure 25 - Existing Official and Unofficial Gauges and Suggestions for Additional Gauges

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5.3.1.2. Metering

Metering of usage in the Queensland portion of the Warrego is largely complete (Pers com QDNRM), however there are currently no meters installed for licenced water users in the New South Wales Section of the Warrego. The lack of diversion limit for the New South Wales portion of the Warrego heightens the urgent need for meters to be installed.

5.3.2. Environmental Data

A number of recommendations regarding data collection were discussed in Section 3.2 of the report and these have been re-iterated in Table 38 below.

Table 38 – Research Recommendation – Ecological Data

No. Research Recommendation Significance of Recommendation E1 Recommend a rigorous While the locations of waterholes in NSW are largely known, inventory of waterholes on the important information on their physical characteristics, water Warrego be undertaken, persistence, response to different flow events and aquatic biota particularly for the NSW is not available in a consistent and systematic framework. portion. E2 A detailed analysis and Analysis and reporting of the water quality results is only in very reporting of the existing water general terms, eg DWR (1990) and DNR (2000). quality information is required, Therefore it is difficult to develop an informed picture of the along with the identification of water quality characteristics of the river and/or changes over additional risks and the time. appropriate level of monitoring and reporting required to inform There has been no pesticide sampling undertaken resource managers. E4 Consolidation of the wetland The information content for several of these sites on the and waterbird information Directory database is quite limited and in some instances should be undertaken and the inaccurate Directory database updated, Findings from recent studies have not been added to the and, where the data is limited, database further data collection should be undertaken. E5 A flora and fauna survey of the While a recent study investigated and reporte d on riparian eastern Warrego floodplain is vegetation condition for the Warrego and Cuttaburra (Hale et al. warranted. 2008), “floodout” systems were not included . Thus, for example, large areas of the eastern Warrego floodplain were not surveyed. Also these areas reportedly are dominated by quite different vegetation communities, ie Warr ego Summer grass and Mitchell grass plains, as well as some treed areas. The wetland studies cited in this Consultancy have also not covered this eastern floodplain. These areas are also susceptible to reduced flooding due to upstream e xtraction.

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6. ACKNOWLEDGEMENTS

Many thanks to those agency staff and residents who assisted the project team to collate documentation and develop a better understanding of the Lower Warrego. In particular, thanks to James Leigo and John Oldfield for their effort in organising and partaking in the stakeholder consultation.

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7. REFERENCES

ANCA (1993) A Directory of Important Wetlands in Australia. Australian Nature Conservation Agency, Canberra. Balcombe SR, Arthington AH, Foster ND, Thoms MC, Wilson GG and Bunn SE (2006). Fish assemblages of an Australian dryland river: abundance, assemblage structure and recruitment patterns in the Warrego River, Murray-Darling Basin. Marine and Freshwater Research, 57, 619-633. Boys CA and Thoms MC (2006) A large-scale hierarchical approach for assessing habitat associations of fish assemblages in large dryland rivers. Hydrobiologia 572, 11-31. Cottingham P (1999) Scientific forum on river condition and flow management of the Moonie, Warrego, Paroo, Bulloo and Nebine River basins. Queensland Department of Natural Resources. CSIRO (2007) Water Availability in the Warrego. A report to the Australian Government from the CSIRO Murray-Darling Basin Sustainable Yields Project. CSIRO. 89 pp. Davies PE, JH Harris, TJ Hillman and KF Walker (2008). SRA Report 1: A Report on the Ecological Health of Rivers in the Murray–Darling Basin, 2004–2007. Prepared by the Independent Sustainable Rivers Audit Group for the Murray–Darling Basin Ministerial Council. D-BBRC (2004/05) Annual Statistics. Dumaresq-Barwon Border Rivers Commission. Available at www.brc.gov.au. D-BBRC (2005/06) Annual Statistics. Dumaresq-Barwon Border Rivers Commission. Available at www.brc.gov.au. D-BBRC (2006/07a) Annual Statistics. Dumaresq-Barwon Border Rivers Commission. Available at www.brc.gov.au. D-BBRC (2006/07b) Annual Report. Dumaresq-Barwon Border Rivers Commission. Available at www.brc.gov.au. DPI (2007) Lowland Darling River aquatic ecological community. Primefact 173, Second edition. NSW Department of Department of Primary Industries. DNR (2000) Preliminary Risk Assessment of Water Quality in Queensland River Basins. Department of Natural Resources, Queensland. Prepared by McNeil, VH, Churchill RC, Marshall CJ and Choy S. 53 pp. DWR (1990) Revised program for monitoring water quality in the Intersecting Streams. Report to the Management Committee of the Dumaresq-Barwon Border Rivers Commission. Department of Water Resources New South Wales. TS 91.004. Prepared by Rosie Bate. 42 pp. Environment Australia (2001). A Directory of Important Wetlands in Australia. Third Edition. Environment Australia, Canberra. (note: the Directory Data Base may contain information on individual wetlands compiled since 2001). Green, DL (1992) Survey of wetlands of the Warrego River. Report prepared by the Department of Water Resources, Technical Services Division for the Australian National Parks and Wildlife Service. TS 92.081. ISBN 0 7305 7893 3. 32 pp. Green DL and King AM (1995) Wetlands of the Warrego River System. Prepared by the NSW Department of Land and Water Conservation for the Warrego River System Water Users Association. Draft, unpublished report. Goodrick GN (1984) Wetlands of north-western New South Wales. National Parks and Wildlife Service Occasional Paper No. 6.

WMAwater 28011: FinalReport.doc:16 July 2008 103 Warrego River Scoping Study Hale J, Roberts J, Page K and Kobryn H (2008) Riparian Zone Management in the Western Catchment Phase 2: Intersecting Streams. A report to the Western Catchment Management Authority. King AM, Green DL and Brady AT (1995) Wetlands of the Paroo River and Cuttaburra Creek. Department of Land and Water Conservation Technical Services Division. TS 95.132. 23 pp. Kingsford R.T., M. Bedward and J.L. Porter (1994). Waterbirds and Wetlands in Northwestern New South Wales. National Parks and Wildlife Service Occasional Paper No 19. NSW National Parks and Wildlife Service, Hurstville. Kingsford, R.T., R.Thomas (1997). Significant wetlands for waterbirds in the Murray-Darling Basin. NSW National Parks and Wildlife Service, Hurstville. 111 pp. Kingsford RT and Porter J (1999) Wetlands and waterbirds of the Paroo and Warrego Rivers. In a free- flowing river: the ecology of the Paroo River. National Parks and Wildlife Service, Sydney. ISBN 0 7313 6022 2. Kingsford RT, Thomas RF and Curtin AL (2001) Conservation of wetlands in the Paroo and Warrego River catchments in arid Australia. Pacific Conservation Biology 7, 21-33. Kingsford R.T., K. Brandis, W.J. Young and S. Fryar (2002). Environmental Flows on the Paroo and Warrego Rivers: Progress Report Year 2. Department of Environment and Heritage, Canberra. Lintermans M (2007) Fishes of the Murray-Darling Basin: an introductory guide. 157 pp. Maher MT (1991) Waterbirds Back O’Bourke. An inland perspective on the conservation of Australian waterbirds. PhD thesis University of New England. McGregor GB, Marshall JC and Thoms MC (2006) Spatial and temporal variation in algal-assemblage structure in isolated dryland river waterholes, Cooper Creek and Warrego River, Australia. Marine and Freshwater Research, 57, 453-466. MDBC (Murray Darling Basin Commission) (2005/06) Water Audit Monitoring Report 2005/06 Published as per the requirement of the Murray-Darling Basin Agreement (Schedule F). Mottell (1998) Natural Resources of the Lower Warrego River System Overton I (2007) Determining environmental flows for vegetation water requirements on the River Murray floodplain. Proceedings of the 10th International Riversymposium and Environmental Flows Conference. Brisbane, Australia 3-6 September 2007. QDNR (Queensland Department of Natural Resources) (2003) Water Resource (Warrego, Paroo, Bulloo and Nebine) Plan 2003. Brisbane. 60+ pp. QDNR (Queensland Department of Natural Resources) (2000) Overview of Water Resources and Related Issues: The Warrego/ Paroo/ Nebine Catchments. QDNRM (Queensland Department of Natural Resources and Mines) (2004) Warrego River System Hydrology Volume 1- Calibration of Daily Flow Simulation Model from upstream of Augathella (QLD AMTD 447.4km) to Darling River / Paroo confluence (NSW AMTD 0km). Department of Natural Resources and Mines, Brisbane. SMEC Australia Pty Ltd. (2006). Lower Balonne Scoping Study – Hydrology Review Final Report, Report prepared for Western Catchment Management Authority and QLD Murray Darling Committee. Straw P (1999) Wetland Birds of the Warrego and Cuttaburra Floodplains. A report prepared for the Warrego River System Water Users Association. Phil Straw, Avifauna Studies.36 pp. Timms BV (1993) Saline lakes of the Paroo, inland New South Wales, Australia. Hydrobiologia 267, 269- 289.

WMAwater 28011: FinalReport.doc:16 July 2008 104 Warrego River Scoping Study University of Canberra (2007) Narran Factsheet #11 Hydrologic and Hydraulic Models. Narran Ecosystem Project. University of Canberra. Available at http://www.canberra.edu.au/centres/narran/docs/resources/factsheets/NFS_11.pdf Waters D (2006) Water quality event monitoring- Warrego River (Cunnamulla) April 2006: event summary load calculation (WQEM 0620). Department of Natural Resources and Water. ISBN 1-7417-2284-5. WMA (Webb, McKeown and Associates) (2007) State of the Darling – Stage 1 Hydrology Report Murray Darling Basin Commission Whitehouse, G (1996) Report on the Cunnamulla Weir and Lower Warrego River, Report to the Dumaresq-Barwon Border Rivers Commission. WMAwater (2008) Australian Water Entitlements, Report prepared for Land and Water Australia for the Environmental Water Allocation R&D Program Young W, Brandis K and Kingsford RT (2006) Modelling monthly streamflows in two Australian dryland rivers: Matching model complexity to spatial scale and data availability. Journal of Hydrology 331, 242-256.

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APPENDIX A: Environmental Data Sets / Publications

Table A1 summarises information on waterholes, both natural and constructed dams obtained from topographic maps or interviews with landholders. The interviews asked about the permanence of waterholes, fish populations or any other information the landholder offered. Only some waterholes/dams were observed during aerial inspections. Therefore the information collated is not comprehensive nor consistent for all waterhole sites as this would require a specific and more detailed survey, eg to establish the bathymetry of each site in relation to the Balcombe et al. (2006) findings about the relationship between fish assemblages in shallow and deep waterholes, and the persistence of water in each site.

Table A1 – NSW waterholes Waterhole or Dam Location/Property if Information from map or landholders, known etc Warrego River from Qld border to Darling River Multagoona Lagoon Near “Congarara” On Burns Creek just off the Warrego River. Green (1992) provides some information. Ten Mile waterhole “Tuncoona” A broken dam. Landholder advised he is trying to reinstall a bank to create a pool and flood some nearby floodplain, within license conditions (?). Storage dries after filling, eg dry from 2008 event. Landholder said thousands of fish died in drying pool, mostly carp. Boomery dam Just upstream of Map indicates a broken dam Lower Lila Dam Lower Lila dam “Lower Lila” Many fish seen here in past, yellowbelly, catfish, Murray cod. Lots of yabbies. Not many carp in the past but more recently. Green (1992) provides some information. Six Mile dam Downstream of Map indicates a broken dam Lower Lila Unnamed dam on Willarra Just north of Fords Creek Bridge Nigawalla dam “Nigawalla” Gumbalie dam “Gumbalie” Turtle waterhole and 20 Mile “Gumbalie” at dam upstream end of Boera dam Boera dam “Toorale” Large dam/storage constructed by early settlers, possibly in 1870’s. Storage has likely silted since established. Approximate volume of 3000 ML. Water lasts full year after filling without local rainfall inflows, which do occur off “red country”. Dried out in 2001, 2002 and a lot of dead fish, mostly carp and some quite large (60 cm). Also some Murray cod, yellowbelly and bony bream. Assessed by Straw (1999). Booka dam “Toorale” Site assessed by Straw (1999). Approximate volume of 1000 ML. Green (1992) provides some information.

Table A1 – NSW waterholes Mumpber dam “Toorale” Map indicates a broken dam. Possibly the site assessed by Straw (1999) as “Broken dam”. Keernie dam “Toorale” at current Approximate volume of 1500 ML. homestead Dicks dam “Toorale” at upsteam Approximate volume of 500 ML end of Peoples dam Peoples dam “Toorale” Large storage just upstream of the junction with the Darling River. Approximate volume of 10,000 ML. Also appears to connect with Ross billabong off the Darling. Cuttaburra Creek, from Qld border to Cuttaburra Basin (Yantabulla swamp) Murrechi waterhole “Tralee” Wancobra waterhole “Wancobra” Burrawantie waterhole On Burrawantie Creek just south of Wancobra waterhole Unnamed waterholes “Maranoa” Some smaller waterholes appear on the map just upstream of Maranoa waterhole Maranoa waterhole “Maranoa” Assessed by Straw (1999) as part of Cuttaburra channel. Yangaloe waterhole “Comeroo” Cummeroo waterhole “Comeroo” Assessed by Straw (1999) as part of Cuttaburra channel.. Mukudjeroo waterhole Large, permanent and deep (up to 3 m). Good water quality- not smelly. Mullarara waterhole Irara Creek Multagoona Dam “Bellenbar” Map indicates a broken dam just upstream of Irara Creek/Warrego River junction Green Creek None Tuon Creek None

ANZLIC Core Metadata Elements - Directory Item Report ANZNS0361900001 Title: Wetlands of the Warrego River

Short Title: Custodian Details Custodian: Department of Environment and Climate Change Jurisdiction: New South Wales Description Details Abstract: The project has involved the mapping and inventory of floodplain vegetation and wetlands for the Warrego River. Wetlands are mapped according to dominant perrenial vegetation, and information regarding wetland characteristics of particular sites has been collected. The mapping and site data are stored as part of the Departments GIS. The study area comprises the floodplain of the Warrego River and its effluents from Wyandra in Queensland south to the Darling River. Search Words: FAUNA Classification FLORA Classification HAZARDS Flood WATER Wetlands Geographic Extent Polygon: 145.5 -29,146 -29,146 -29.5,145.5 -29.5,145.5 -29 Data Currency and Status Beginning: Not Known Progress: Not Known Ending: Not Known Maintenance: Not Known Metadata: 30 April 2008 Access Stored DIGITAL Format: Database, Vector data, Image, Text Report Available DIGITAL Magnetic Tape Format: NONDIGITAL Paper Text Constraints: Not Known Data Quality Lineage: Not Known Positional Not Known Accuracy: Attribute Not Known Accuracy: Logical Not Known Consistency: Completeness: Not Known Contact Information

26/06/2008 Page 1 of 2 ANZLIC Core Metadata Elements - Directory Item Report ANZNS0361900001 Position: Neal Foster Address: 155-157 Marius Street PO Box 550

Locality: Tamworth Postcode: 2340 Country: Australia elephone: 0267019623 Fax: Email: [email protected] Additional MetaData Additional: Map Data Projection: Map No: Scale:

Horizonal Datum: Vertical Datum: File Path:

26/06/2008 Page 2 of 2 ANZLIC Core Metadata Elements - Directory Item Report ANZNS0361900002 Title: HYDSYS - NSW Water Resources Database

Short Title: Custodian Details Custodian: Department of Water and Energy Jurisdiction: New South Wales Description Details Abstract: HYDSYS stores all water resource time series data including stream level, flow, temperature, conductivity and bore levels. Related information includes site details, cross sections, gauging summary, instrument history, water quality, etc which are all stored in database files. The eight hydrographic districts in the state are responsible for the validation and storage of their local data. HYDSYS is a propriety software package used by water monitoring authorities, including Resource Management, throughout Australia. Data includes stream heights, mean daily, instantaneous, monthly and annual flows. Rainfall and water quality data is also recorded. Search Words: WATER WATER Monitoring Geographic Extent Name: Name Category Jurisdiction NEW SOUTH WALES State or Territory New South Wales Data Currency and Status Beginning: Not Known Progress: In Progress Ending: Current Maintenance: Continual Metadata: 28 April 2008 Access Stored DIGITAL Format: Multiple DBF files and compressed time series files Available DIGITAL ASCII Format: DIGITAL CSV DIGITAL DBF NONDIGITAL Reports NONDIGITAL Graphical output NONDIGITAL Plotted Maps Constraints: Conditions of use, copyright and charges apply Data Quality Lineage: Collection is done continuosly at gauging stations using recorders, data loggers and some telemetry. Collection is also done by physical inspection and by extraction of data from elsewhere. Positional Lat/long coordinates are available for all records. Data points have been located using the best Accuracy: available topographic map. Attribute There are over 100 attributes relating to water resources stored in this system. Each one has its own Accuracy: specific accuracy, resoluion and standards as laid out in work practices and procedures. The quality database defines the quality of all time series data stored. Logical Not Known Consistency: Completeness: For each gauging station the length of record and number of gaps in the record varies. See Additional Metadata below for details regarding the relevant gauges in the Warrego. Contact Information

26/06/2008 Page 1 of 3 ANZLIC Core Metadata Elements - Directory Item Report ANZNS0361900002 Position: Senior Natural Resource Officer, LIS Address: 10 Vallentine Avenue

Locality: Parramatta Postcode: 3720 Country: Australia elephone: 02 9895 7608 Fax: 02 9895 7742 Email: [email protected] Additional MetaData Additional: Gauge 423001 - WARREGO RIVER AT FORDS BRIDGE (MAIN CHANNEL): * Var 151.00 (Day total) from 1/01/1921 to current * Instantaneous height data available from 1/01/1921 however no rating table until 01/01/1972. Hence 141 data only available from 1972 to current. * Max rating 13,600 ML/D. Max 151 record 14,142 ML/D. Max 141 record 14,336 ML/D * No cross section available in Pinneena V8

Gauge 423002 - WARREGO RIVER AT FORDS BRIDGE BYWASH * Var 151.00 (Day total) from 1/01/1921 to current * Instantaneous height data available from 1/12/1921 however no rating table until 17/12/1972. Hence 141 data only available from 1972 to current. * Max rating 5,330 ML/D. Max 151 record 5,463 ML/D. Max 141 record 5,569 ML/D * No cross section available in Pinneena V8

Gauge 423003 - WARREGO RIVER AT BARRINGUN * Var 151.00 (Day total) from 1/01/1921 to 31/01/1981 (gauge is closed) * Instantaneous height data available from 1/11/1926 however no 141 data available in Pinneena V8. * Max rating 15,440 ML/D. Max 151 record 18,250 ML/D. Max 141 record 18,700 ML/D * No cross section available in Pinneena V8

Gauge 423004 - WARREGO AT BARRINGUN N0. 2 * Var 151.00 (Day total) from 1/01/1993 to current * Instantaneous height data and flow data available from 30/05/1993 * Max rating 15,440 ML/D, max 151 record 15,202 ML/D. Max 141 record 16,076 ML/D * Cross section available in Pinneena V8

Gauge 423005 - CUTTABURRA CHANNEL AT TURRA * Var 151.00 (Day total) from 31/05/1993 to current * Instantaneous height data and flow data available from 31/05/1993 * Max rating 70,940 ML/D. Max 151 record 60,773 ML/D. Max 141 record 63,022 ML/D * Cross section available in Pinneena V8

Map Data

26/06/2008 Page 2 of 3 ANZLIC Core Metadata Elements - Directory Item Report ANZNS0361900002 Projection: Geographical CoOrdinates ( Latitude & Longitude) Map No: Scale:

Horizonal Not Applicable Datum: Vertical Not Applicable Datum: File Path:

26/06/2008 Page 3 of 3 ANZLIC Core Metadata Elements - Directory Item Report ANZNS0361900003 Title: Daily Rainfall Data For The Warrego Catchment

Short Title: Custodian Details Custodian: Bureau of Meteorology Jurisdiction: Australia Description Details Abstract: Daily rainfall data as collected by the Bureau of Meteorology. 131 BOM gauges in the Warego Catchment. Search Words: CLIMATE AND WEATHER Meteorology

Geographic Extent Name: Name Category Jurisdiction AUSTRALIA INCLUDING EXTE Australia Australia Data Currency and Status Beginning: Not Known Progress: In Progress Ending: Current Maintenance: Daily Metadata: 28 April 2008 Access Stored DIGITAL Format: Text Files, BOM File Format Available DIGITAL ASCII Format: DIGITAL BOM file format Constraints: A charge is made for the provision of climate information, other than for very simple requests. The charge will depend on the complexity of your request and the time and resources required to service it. See http://www.bom.gov.au/climate/cdo/about/supply.shtml for details. Data Quality Lineage: Not Known Positional Latitude, longtitude values are often of poor accuracy. They are stored in degrees and minutes but Accuracy: some stations are many minutes out. Attribute Varying accuracy depending on site location and instrument type. Accuracy: Logical Not Known Consistency: Completeness: The amount of information available for each of these sites and its associated uncertainty is influenced by a number of factors including the type and purpose of the station and the time over which it operated. See Additional Metadata for further details on gauges in Warrego. Contact Information

26/06/2008 Page 1 of 2 ANZLIC Core Metadata Elements - Directory Item Report ANZNS0361900003 Position: Queensland Regional Office Address: PO Box 413

Locality: BRISBANE Postcode: 4001 Country: Australia elephone: 07 3239 8700 Fax: 07 3239 8679 Email: [email protected] Additional MetaData Additional: 131 BOM rainfall gauges. First three gauges opened in 1970s. One of these (CUNNAMULLA POST OFFICE) is still open. Half of the stations have less than 90% complete records. Average length of record is 40 years.

There are only 48 gauges which have data available from 2007 onwards (though additional gauges are reported to be open). Of these gauges only 28 have a completnesss of 90% or greater. The average length of record these gauges is 50.7 years. Map Data Projection: Map No: Scale:

Horizonal Datum: Vertical Datum: File Path:

26/06/2008 Page 2 of 2 ANZLIC Core Metadata Elements - Directory Item Report ANZNS0361900004 Title: Daily Evaporation Station data held by the Bureau of Meteorlogy for the Warrego Catchment. Short Title: Custodian Details Custodian: Bureau of Meteorology Jurisdiction: Australia Description Details Abstract: Daily Evaporation data as collected by the Bureau of Meteorology. Search Words: CLIMATE AND WEATHER Meteorology

Geographic Extent Name: Name Category Jurisdiction AUSTRALIA INCLUDING EXTE Australia Australia Data Currency and Status Beginning: Not Known Progress: In Progress Ending: Current Maintenance: Daily Metadata: 28 April 2008 Access Stored DIGITAL Format: Text Files, BOM File Format Available DIGITAL ASCII Format: DIGITAL BOM file format Constraints: A charge is made for the provision of climate information, other than for very simple requests. The charge will depend on the complexity of your request and the time and resources required to service it. See http://www.bom.gov.au/climate/cdo/about/supply.shtml for details. Data Quality Lineage: Not Known Positional Latitude, longtitude values are often of poor accuracy. They are stored in degrees and minutes but Accuracy: some stations are many minutes out. Attribute Varying accuracy depending on site location and instrument type. Accuracy: Logical Not Relevant Consistency: Completeness: 1 open gauge (CHARLEVILLE) with data from 1954 and is 99%. Another nearby open gauge exists at Bourke. Contact Information

Position: Queensland Regional Office Address: PO Box 413

Locality: BRISBANE Postcode: 4001 Country: Australia elephone: 07 3239 8700 Fax: 07 3239 8679 Email: [email protected]

26/06/2008 Page 1 of 2 ANZLIC Core Metadata Elements - Directory Item Report ANZNS0361900004 Additional MetaData Additional: Map Data

Projection: Map No: Scale:

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26/06/2008 Page 2 of 2 ANZLIC Core Metadata Elements - Directory Item Report ANZNS0361900006 Title: Murray Darling Basin NAP Catchment Digital Elevation Model - MDB_DEM_25M_100K_X

Short Title: MDB DEM Custodian Details Custodian: Department of Natural Resources and Water Jurisdiction: Queensland Description Details Abstract: A Digital Elevation Model (DEM / DTM) in a 25 metre grid covering the Queensland portion of Paroo, Warrego River, Balonne River, Condamine River, Moonie River, and Border Rivers Catchments, known colectivly as the Murray Darling Basin. A DEM refers to a model of elevation values. They may be used to derive other terrain attributes. DEMs are sometimes referred to as digital terrain models (DTM), a general term applied to models of elevation, slope, aspect or other terrain attributes. DEMs are built from datasets of varying type, scale and accuracy. They may be made from ground surveyed or photogrammetrically obtained heights, existing topographic maps usually originally obtained from analogue photogrammetry, or using radar or laser altimetry data from aircraft or satellites. Search Words: LAND Topography

Geographic Extent Polygon: 143.9704 -24.4169,152.5948 -29.5897 Data Currency and Status Beginning: Not Known Progress: Complete Ending: Not Known Maintenance: As required Metadata: 20 May 2008 Access Stored DIGITAL Format: SDE raster digital data Available DIGITAL SDE raster digital data Format: Constraints: Restricted to all levels of government and community. Dataset is available for use by government agencies, community groups and individuals under a signed licence agreement. Dataset will be available to registered users via web delivery tools, for example, through an access controlled internet site like NAP RIS portal. Conditions of use, copyright and charges apply. Data Quality Lineage: Source_Information: Source_Scale_Denominator: 100000 Process_Step: Process_Description: ANUDEM version 4.6.2 was used to produce a 25 metre floating point grid. Source digital data were contours and drainage (scanned repromats) from AUSLIG 1:100000 mapsheets with a 20 metre contour interval for most areas but 40 metre contours. Drainage lines were pointed in the direction of flow. A hillshade of the DEM was used to identify errors in source drainage and contour data that were previously missed. The errors, including wrongly directed drainage and wrongly labelled contours, were fixed though some errors may remain. Source_Used_Citation_Abbreviation: Source digital data were contours and drainage (scanned repromats) from AUSLIG 1:100000 mapsheets with a 20 metre contour interval for most areas but 40 metre contours. Positional The accuracy of this DEM depends on the accuracy of the source data and the error of ANUDEM`s Accuracy: interpolation. The average accuracy of AUSLIGs 1:100000 source data is +/- 25 metres in the horizontal position of well defined detail and +/- 5 metres in elevation for most mapsheets.

26/06/2008 Page 1 of 2 ANZLIC Core Metadata Elements - Directory Item Report ANZNS0361900006 Attribute +/- 5 metres in elevation (see above) Accuracy: Logical Not Known Consistency: Completeness: Not Known Contact Information

Position: Ross Mitchell Address: Level 3, Block C, 80 Meiers Road

Locality: Indooroopilly Postcode: 4068 Country: Australia elephone: Fax: Email: [email protected] Additional MetaData Additional: Map Data Projection: Albers Equal Area - 2 standard parallels Map No: Scale: 1:100 000

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26/06/2008 Page 2 of 2 ANZLIC Core Metadata Elements - Directory Item Report ANZNS0361900007 Title: Warrego River System IQQM

Short Title: Custodian Details Custodian: Department of Natural Resources and Water Jurisdiction: Queensland Description Details Abstract: A daily flow model was developed for the Warrego system for the Water Resource Planning Process using Integrated Quantity and Quality Model (IQQM) created by the Department of Land and Water Conservation in New South Wales. The IQQM for the Warrego is described in the Warrego IQQM Calibration report (2004). Search Words: WATER WATER Models Geographic Extent Name: Name Category Jurisdiction WARREGO RIVER Drainage Divisions and Major Rive Australia Data Currency and Status Beginning: Not Known Progress: In Progress Ending: Not Known Maintenance: As required Metadata: 23 June 2008 Access Stored DIGITAL Format: Text files Available DIGITAL Data File, System Files Format: NONDIGITAL Calibration Report Constraints: Conditions of use, copyright and charges apply Data Quality Lineage: IQQM built for the purposes of developing the Resource Operation Plan. Some previous hydrologic modelling had been undertaken (see calibration report for discussion) however this is the first IQQM for the region. Positional Not Relevant Accuracy:

26/06/2008 Page 1 of 3 ANZLIC Core Metadata Elements - Directory Item Report ANZNS0361900007 Attribute The IQQM has been calibrated to give a good representation of the flows recorded at the various Accuracy: stream gauges throughout the catchment. Details of the calibration and validation of the models can be found in the relevant calibration reports and the extensive audit reports.

Calibrated Locations: 1. Augathella - model replicates flow well over full flow regime 2. Charleville - model replicates flow regime well for flows above 1000 ML/D however below this model overestimates flows. 3. Wyandra - model replicates flow well over full flow regime except that the model has a slightly longer duration of zero flows 4. Cunnamulla - model replicates flow reasonably well over full flow regime. Model slightly underestimates flows around 1000 ML/D and overestimates flows below 100 ML/D. 5. Barringun - Poor calibration, model generally overestimates flows and low coefficient of determination / efficiency 6. Fords Bridge - Good accuracy for flows above 1,000 ML/D, small amount of overestimation for lower flows. The coefficient of determination / efficiency was moderate (around 0.75).

Un-calibrated locations estimated in the model: 1. Noorama and Widgeegoara lumped start of system - loss from Warrego to creeks estimated through comparison of simulated and recorded flows at Cunnamulla 2. Noorama and Widgeegoara lumped at border /inflow to Nebine - Streamloss and routing upstream of border estimated based on Nebine Creek residual inflows 3. Cuttaburra start of system - estimated through hydrographic measurement during 1986, 1990 and 1994 events which established a relationship between Warrego flows and Cuttaburra flows. 4. Cuttaburra creek at border -Limited gauge data at Turra at time of calibration hence losses and routing was estimated. Losses upstream of border estimated through stakeholder consultation. Routing parameters, excluding lag time, was based on Cunnamulla to Barringun reach parameters. 5. Irrara Creek start of system - estimated by assuming that 30% of the losses between Cuttaburra offtake and Barringun gauge can be attributed to inflows to Irrara Creek 6. Irrara Creek at border - Same as start of system. 7. Irrara Creek return to Warrego - Routing parameters based on Barringun to Fords Bridge reach. Losses estimated estimated at 50% across the whole flow regime. High flows are then returned to the Warrego however the calibration report does not provide details on this relationship. 8. Warrego End of System - Neither the QLD NRW or the NSW DWE IQQM model represents the passing flow conditions on instream dams. WMAwater have updated the DWE model to reflect this.

Logical Not Relevant Consistency: Completeness: The models reproduce the natural processes occurring in the stream including routing and transmission losses, as well as the impact of water resource development including the impact of impoundments, irrigation and water harvesting. In some instances details regarding losses and storage infrastructure have been estimated in consultation with stakeholders and may require review as further data is collated. Contact Information

26/06/2008 Page 2 of 3 ANZLIC Core Metadata Elements - Directory Item Report ANZNS0361900007 Position: Craig Johansen Address: QDNRW

Locality: Brisbane Postcode: 4001 Country: Australia elephone: 07 3896 9114 Fax: Email: [email protected] Additional MetaData Additional: Rainfall data used: 40 rainfall stations used to develop rainfall data grid (0.05 degree lat/long) for the period 1889-1999. The grid is used to derive an area weighted average daily rainfall for each reach in the Sacremento Model. This model is a module of IQQM used to simulate rainfall-runoff in the catchment.

Evaporation data used : 15 evaporation stations were used to develop an evaporation grid following the same procedure as for rainfall. Only one of the stations is actually in the Warrego however.

Streamflow gauges used: 6 gauges on the Warrego + 2 gauges on the Darling were used to calibrate the model. These are Charelville, Cunnamulla weir, Wyandra, Augathella, Barringun, Fords Bridge, Louth, Bourke. Other gauges exist but their records were considered too short or of poor quality to be used. Of particular note, a new gauge has been installed on the Cuttaburra at Turra however at the time of calibration there was insufficient data to be used.

Water resource develoment data: Assumed to be no diversions during calibration period as there is limited data available. Storage sizes were estimated however these were not included during the calibration period as it was assumed that storages were largely developed after the calibration period.

Natural storages - significant waterholes were identified through satellite imagery and local knowledge and included as seperate storages in the model - at 100% of estimated size for entire period.

Calibration:/ Validation: Reach 1 -

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26/06/2008 Page 3 of 3 ANZLIC Core Metadata Elements - Directory Item Report ANZNS0361900008 Title: HYDSYS - QLD Surfacewater Resource Database

Short Title: Custodian Details Custodian: Department of Natural Resources and Water Jurisdiction: Queensland Description Details Abstract: HYDSYS stores all water resource time series data including stream level, flow, temperature, conductivity and bore levels. Related information includes site details, cross sections, gauging summary, instrument history, water quality, etc which are all stored in database files. The eight hydrographic districts in the state are responsible for the validation and storage of their local data. HYDSYS is a propriety software package used by water monitoring authorities, including Resource Management, throughout Australia. Search Words: WATER

Geographic Extent Name: Name Category Jurisdiction QUEENSLAND State or Territory Queensland Data Currency and Status Beginning: Not Known Progress: In Progress Ending: Current Maintenance: As required Metadata: 16 June 2008 Access Stored DIGITAL Format: Multiple DBF files and compressed time series files Available DIGITAL ASCII Format: DIGITAL CSV DIGITAL DBF NONDIGITAL Reports Constraints: Conditions of use, copyright and charges apply. Data Quality Lineage: Initial data sets of stream levels were collected manually from 1909 to the 1960s. At that time instrumentation was introduced which lead to a progressive improvement in data quality and coincided with the expansion of the network across Queensland. Positional There are three existing grades of positional accuracy: Accuracy: 1. GPS (Global Positioning System) 2. 1:100,000 map 3. Estimation by local staff These details are coded into the database system. Attribute There are over 100 attributes relating to water resources stored in this system. Each one has its own Accuracy: specific accuracy, resoluion and standards as laid out in work practices and procedures. The quality database defines the quality of all time series data stored. Logical Not Known Consistency: Completeness: While this dataset covers the whole state the density of the coverage is highly variable and depends on assessment and management requirements. Subsequently each site also has a variability in attributes collected which is dependent on the sites role. Contact Information

26/06/2008 Page 1 of 2 ANZLIC Core Metadata Elements - Directory Item Report ANZNS0361900008 Contact Information

Position: Principal Hydrographer Address: Level 7 144 Edward Street

Locality: Brisbane Postcode: 4001 Country: Australia elephone: Fax: Email: [email protected] Additional MetaData Additional: River Gauges in Warrego - Gauge Number; Gauge Name; Period of Record; Maximum gauged flow; Maximum estimated streamflow (ML/D)

423204A; Warrego River @ Augathella; 1967 - curr; 3,2061 ML/D; 56,630 ML/D 423201A; Warrego River at Charleville; 1926 - 1978; 42,742 ML/D; 109,796 ML/D 423205A; Ward River @ Binnowee; 1999 - curr; not available; not available 423203A; Warrego River @ Wyandra; 1967 - curr; 206, 836 ML/D; 343,482 ML/D 423202C; Warrego River @ Cunnamulla Weir; 1992 - curr; 104,556 ML/D; 120,891 ML/D 423206A; Warrego River @ Wallen; 2005 - curr; 68,533 ML/D in 12/ 2007; available records do not include 2007 event Map Data Projection: Map No: Scale:

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26/06/2008 Page 2 of 2 ANZLIC Core Metadata Elements - Directory Item Report ANZNS0361900009 Title: River records and commence to flow notes for the Lower Warrego River System - Volumes 1 and 2

Short Title: Mottell Pty Ltd River Records Custodian Details Custodian: Mottell Pty Ltd Jurisdiction: Victoria Description Details Abstract: River records collected by Warrego residents were collated by Mottell and published in 2 volumes - one for QLD and one for NSW. The river records primarily comprise of river heights at unofficial gauges and commence to flow information for the effluent creeks. Other information includes rainfall and commentary on historic flood events. Search Words: WATER Surface

Geographic Extent Name: Name Category Jurisdiction WARREGO RIVER Drainage Divisions and Major Rive Australia Data Currency and Status Beginning: 01-01-1921 Progress: Complete Ending: Maintenance: Not Planned Metadata: 16 June 2008 Access Stored NON DIGITAL Format: Bound folder with photocopied records Available NONDIGITAL Bound folder with photocopied records Format: Constraints: None aware of. Data Quality Lineage: Not Known Positional Not Known Accuracy: Attribute Not Documented Accuracy: Logical Not Documented Consistency: Completeness: Length of record available and frequency of recording varies for each site and the accuracy and is assumed to vary. See Additional Metadata for sites and period of record available. Contact Information

Position: Manager Address: Land and Water Consultants

Locality: PO BOX 1210 South Melbourne Victoria Postcode: 3205 Country: Australia elephone: 0417494319 Fax: Email: Not Known

26/06/2008 Page 1 of 2 ANZLIC Core Metadata Elements - Directory Item Report ANZNS0361900009 Additional MetaData Additional: A copy of the records were temporarily obtained from John Oldfield ([email protected])

Unofficial sites with height data; years of record Belalie; 1949 - 1993 Wancobra (Cuttaburra); 1978 - 1995 Maranoa (Cuttaburra); 1978 - 1995 Yantabulla (Cuttaburra); 1968 - 1997 Goolburra; 1973 - 19997 Baroona; 1942 - 1997 Glencoe; 1981 - 1997 Rocky; 1945 - 1997 Coonberry Plains; 1945 - 1995 Tuen @ Bluegrass; 1954 - 1991 Mowellan (Cuttaburra); 1991 - 1994

Additional river height data was collated at official river gauge locations and additional information about commence to flow river heights was obtained for numerous effluent creeks.

Other river height data which is known to be available but no collected by Mottell includes the following: 1. Tinneburra, 1902 on (pers comm. Carol Godfrey) 2. Maronoa, 1954 on (pres comm. Chris Sharp) Map Data Projection: Map No: Scale:

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26/06/2008 Page 2 of 2 ANZLIC Core Metadata Elements - Directory Item Report ANZNS0361900010 Title: Spot stream gauging data

Short Title: Custodian Details Custodian: Water user associations - Lower Warrego (QLD) and Warrego River (NSW) Jurisdiction: Australia Description Details Abstract: Spot gauging has been conducted during various historic flood events. In February 1994 gauging was conducted for the Irrara, Thurulgoona, Middle, Little Tuen, Tuen and Blackfellows. This was conducted for the Warrego Water User Associations.

NSW DWE conducted gauging of the Warrego end of system (within channel flows) early in 2007.

QLD DNRW conducted hydrographic measurement during 1986, 1990 and 1994 events which established a relationship between Warrego flows and Cuttaburra flows. Search Words: WATER Hydrology

Geographic Extent Name: Name Category Jurisdiction WARREGO RIVER Drainage Divisions and Major Rive Australia Data Currency and Status Beginning: Not Known Progress: Not Known Ending: Not Known Maintenance: Not Known Metadata: 17 June 2008 Access Stored NON DIGITAL Format: Reports Available NONDIGITAL Reports Format: DIGITAL Data file Constraints: Unkown Data Quality Lineage: Not Known Positional Not Known Accuracy: Attribute Not Known Accuracy: Logical Not Known Consistency: Completeness: Not Known Contact Information

26/06/2008 Page 1 of 2 ANZLIC Core Metadata Elements - Directory Item Report ANZNS0361900010 Position: Principal Hydrographer Address: Level 7 144 Edward Street

Locality: Brisbane Postcode: 4001 Country: Australia elephone: Fax: Email: [email protected] Additional MetaData Additional: Map Data Projection: Map No: Scale:

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26/06/2008 Page 2 of 2 ANZLIC Core Metadata Elements - Directory Item Report ANZNS0361900011 Title: Wetlands of New South Wales

Short Title: Custodian Details Custodian: Department of Environment and Climate Change Jurisdiction: New South Wales Description Details Abstract: The purpose of this project was to map the wetlands across New South Wales. Wetlands were identified using a combination of classification of spectral classes of Landsat MSS and TM imagery and ancillary wetland information to create information classes of broad wetland groups (floodplain wetlands, freshwater lakes, saline lakes, reservoirs, estuarine wetlands and coastal lagoons and lakes). Imagery from 1987 - 1994 was used. The data will then be used to assess the wetland resource in each catchment. Search Words: WATER Wetlands Mapping

Geographic Extent Name: Name Category Jurisdiction NEW SOUTH WALES State or Territory New South Wales Data Currency and Status Beginning: Not Known Progress: Complete Ending: Not Known Maintenance: Not Known Metadata: 23 June 2008 Access Stored DIGITAL Format: DIGITAL Arc/Info 8.2, vector coverage, lamberts projection, 36,000 polygons. Available DIGITAL DIGITAL - ARC/INFO, Shape file. ARCExport Format: Constraints: Digital version available from the Coordinator GIS Support, GIS Group under license agreement with DEC. Data Quality Lineage: The wetlands of the inland catchments were identified using unsupervised classification of Landsat MSS imagery on the basis of the presence of water. The wetlands of the coastal catchments were mapped with Landsat TM imagery. Wetlands were identified using a band 5 slice In both instances the thematic grid was vectorised using Arc/Info. Wetland areas were grouped a posteriori using ancillary attribute data such as aerial survey of wetland data, 1:250000 hard copy maps sheets, AUSLIG 250K waterbody theme, existing wetland maps. Positional Each Landsat image scene was geometrically rectified and geocoded to UTM coordinates using Accuracy: topographic maps- 1:250000 scale for the inland catchments and 1:25,000 for the coastal catchments. A Root Mean Square Error of less than one was achieved for each image. Attribute Wetlands were grouped into 6 groups: floodplain wetlands, freshwater lakes, saline lakes, reservoirs, Accuracy: estuarine wetlands and coastal lagoons and lakes on the basis of spectral signature, geomorphological characteristics and ancillary information. These groups were further classified into subgroups where detailed information was available. Named freshwater lake, Unnamed freshwater lake, reservoir, sewage treatment pond, canal, dam, quarry, golfcourse, aquaculture, floodplain water body, estuarine water body, coastal vegetation, named coastal lagoons and lakes, unnamed coastal lagoons and lakes, coastal vegetation.

26/06/2008 Page 1 of 2 ANZLIC Core Metadata Elements - Directory Item Report ANZNS0361900011 Logical Arc/Info was used to do topological consistency checks to detect flaws in the spatial data structure Consistency: and to identify them as errors. This check ensures that all classified polygons are closed, nodes are formed at the intersection of lines, and that there is only one unique label within each. Multiple and dangling lines were also edited. All polygons were visually checked by draping over Landsat imagery using ERDAS Imagine to ensure that polygons were correctly coded. Completeness: Both the unsupervised classification and band 5 slice is reliant on imagery being acquired at a wet period (some areas may have been missed because of dry imagery and/or cloud cover). Accuracy assessment was performed on both coastal and inland mapping. Contact Information

Position: Coordinator:Spatial Information&Analysi Address: P.O. Box 1967

Locality: Hurstville Postcode: 2220 Country: Australia elephone: 02 95856834 Fax: 02 95856466 Email: [email protected] Additional MetaData Additional: Classifying landform at broad spatial scales the distribution and conservation of wetlands in New South Wales, Australia. Marine and Freshwater Research 55 17-31.

Or final report: Kingsford, R.T., Brandis, K., Thomas, R.F, Crighton, P., Knowles, E. and Gale, E. (2003) Distribution of Wetlands in New South Wales available at the DEC website: http://www.nationalparks.nsw.gov.au/ Map Data Projection: Map No: Scale:

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26/06/2008 Page 2 of 2 ANZLIC Core Metadata Elements - Directory Item Report ANZNS0361900012 Title: Barwon - Darling River IQQM

Short Title: Custodian Details Custodian: WMAwater Jurisdiction: New South Wales Description Details Abstract: A daily flow model was developed for the Barwon Darling system for the Water Resource Planning Process using Integrated Quantity and Quality Model (IQQM). This model includes the lower part of the Warrego up to Fords Bridge. Model inflows at Fords Bridge are supplied by QLD - from their Warrego IQQM. Further information is available in the BARWON-DARLING River Valley Calibration Report (DNR, 2006). Search Words: WATER WATER Models Geographic Extent Name: Name Category Jurisdiction DARLING RIVER Drainage Divisions and Major Rive Australia BARWON RIVER Drainage Divisions and Major Rive Australia Data Currency and Status Beginning: Not Known Progress: In Progress Ending: Not Known Maintenance: As required Metadata: 23 June 2008 Access Stored DIGITAL Format: Text files Available DIGITAL Data File, System Files Format: NONDIGITAL Calibration Report Constraints: Conditions of use, copyright and charges apply Data Quality Lineage: Not Known Positional Not Relevant Accuracy: Attribute Not Known Accuracy: Logical Not Relevant Consistency: Completeness: Not Known Contact Information

26/06/2008 Page 1 of 2 ANZLIC Core Metadata Elements - Directory Item Report ANZNS0361900012 Position: Richard Cooke Address: DWE

Locality: Parramatta Postcode: 2150 Country: Australia elephone: Fax: Email: [email protected] Additional MetaData Additional: Map Data Projection: Map No: Scale:

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