Development of the Murraylands E2/Watercast Catchment Model
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A part of BMT in Energy and Environment Final Report: Development of The Murraylands E2/WaterCast Catchment Model R.B16618.001.02.doc May 2009 Final Report: Development of The Murraylands E2/WaterCast Catchment Model Offices Brisbane Denver Karratha Melbourne Prepared For: South Australian Environment Protection Authority Morwell Newcastle Perth Prepared By: BMT WBM Pty Ltd (Member of the BMT group of companies) Sydney Vancouver G:\ADMIN\B16618.G.TRW_MURRAYLANDS_E2\R.B16618.001.02.DOC DOCUMENT CONTROL SHEET BMT WBM Pty Ltd BMT WBM Pty Ltd Level 11, 490 Upper Edward Street Document : R.B16618.001.02.doc Brisbane 4000 Queensland Australia PO Box 203 Spring Hill 4004 Project Manager : Tony Weber Tel: +61 7 3831 6744 Fax: + 61 7 3832 3627 ABN 54 010 830 421 002 Client : South Australian EPA www.wbmpl.com.au Client Contact: Luke Mosley Client Reference Title : Final Report: Development Of The Murraylands E2/WaterCast Model Author : Dr Joel Stewart Synopsis : This report outlines the development of an E2/WaterCast/WaterCast catchment model to describe the rainfall-runoff and pollutant export dynamics of the South Australian Murray Darling Basin catchment and investigates land management options. REVISION/CHECKING HISTORY REVISION DATE OF ISSUE CHECKED BY ISSUED BY NUMBER 0 24/10/07 TRW JPS 1 05/12/08 TRW JPS 2 28/05/09 TRW JPS DISTRIBUTION DESTINATION REVISION 0 1 2 3 South Australia EPA pdf Pdf Pdf BMT WBM File pdf Pdf Pdf BMT WBM Library pdf pdf Pdf G:\ADMIN\B16618.G.TRW_MURRAYLANDS_E2\R.B16618.001.02.DOC CONTENTS I CONTENTS Contents i List of Figures ii List of Tables iv EXECUTIVE SUMMARY V 1 INTRODUCTION 1-1 2 CATCHMENT CHARACTERISTICS 2-1 2.1 Land Use and Catchment Management 2-3 2.2 Hydrology 2-4 2.3 Water Quality 2-6 3 METHODOLOGY 3-1 3.1 Catchment Model Background 3-1 4 DEVELOPMENT OF THE MURRAYLANDS E2/WATERCAST MODEL 4-1 4.1 Overview 4-1 4.2 Step 1 - Spatial Representation of the Catchment 4-1 4.2.1 Creating a Pit Filled DEM 4-1 4.2.2 Developing the E2/WaterCast Subcatchment Map. 4-2 4.2.3 Modifying the Subcatchment Map. 4-2 4.3 Step 2 Creation of the Node-Link Network 4-5 4.4 Step 3 – Functional Unit Definition 4-5 4.4.1 Land Use Map – Creating a Raster for E2/WaterCast. 4-5 4.4.2 Redefining Land Uses for the Murraylands E2/WaterCast Model 4-7 4.5 Step 4 – Node Model selection 4-8 4.6 Step 5 – Link Model Selection 4-8 4.7 Step 6 – Climatic Data Inputs 4-9 4.8 Step 7 – Parameterisation and Calibration 4-9 4.8.1 Flow Gauging Data 4-9 G:\ADMIN\B16618.G.TRW_MURRAYLANDS_E2\R.B16618.001.02.DOC LIST OF FIGURES II 4.8.2 Water Quality Data 4-10 4.8.3 Constituents and Generation 4-13 4.8.4 Hydrological Parameterisation 4-14 4.9 Accounting for Instream Losses 4-20 4.9.1 Identification of Overlapping Gauge Records 4-20 4.9.2 Gauged Stream Losses 4-21 4.9.3 Conceptual Representation of In-stream Losses 4-25 4.9.4 Loss Model Implementation 4-26 5 RESULTS AND DISCUSSION 5-1 5.1 Existing Scenario 5-1 5.1.1 Spatial Representation 5-1 5.1.1.1 Annual Rainfall 5-1 5.1.1.2 Flows 5-3 5.1.1.3 Total Suspended Solids 5-6 5.1.1.4 Total Nitrogen 5-7 5.1.1.5 Total Phosphorus 5-8 5.1.2 Temporal Representation 5-9 5.1.2.1 Pollutant Sources (land use loads) 5-12 5.1.2.2 Water Quality Objectives 5-13 5.1.3 Instream Losses 5-15 5.2 Predevelopment Scenario 5-15 5.2.1 Change Scenarios 5-17 5.3 Discussion 5-17 5.4 Summary 5-20 6 REFERENCES 6-1 APPENDIX A: DATA SUPPLIED A-1 APPENDIX B: UNGROUPED LAND USE CLASSES B-1 LIST OF FIGURES Figure 2-1 Extent of Murraylands E2/WaterCast Model 2-1 Figure 2-2 Lower Murray River and Adjacent Wetlands 2-2 Figure 2-3 The Shores of Lake Alexandrina 2-2 G:\ADMIN\B16618.G.TRW_MURRAYLANDS_E2\R.B16618.001.02.DOC LIST OF FIGURES III Figure 2-4 Finniss River Land Use and Water Monitoring Stations 2-3 Figure 2-5 Grazing Lands of the Eastern Mt Lofty Ranges. 2-4 Figure 2-6 Example Catchment Management Techniques 2-4 Figure 2-7 Angas Weir (Photo SA Department of Water Land and Biodiversity Conservation) 2-5 Figure 2-8 Example Farm Dams 2-5 Figure 2-9 Example Ambient Water Quality Data 2-6 Figure 3-1 Step 1 A Spatial Description of the Catchment is Developed 3-1 Figure 3-2 Step 2 – A Node-Link Network is Constructed 3-2 Figure 3-3 Step 3 Functional Units (land uses) are Defined 3-2 Figure 3-4 Step 4 Node Models are Selected 3-2 Figure 3-5 Step 5 – Selection of Link Models 3-3 Figure 3-6 Combined Node and Link Models Describing the Catchment 3-3 Figure 3-7 Step 6 Climatic Data Inputs Data 3-3 Figure 3-8 Step 7 Parameterisation and Calibration (Gauge AW425530) 3-4 Figure 3-9 Final Murraylands E2/WaterCast Model 3-4 Figure 4-1 3D View of pitfilled DEM 4-2 Figure 4-2 Murraylands Subcatchment Map 4-4 Figure 4-3 Murraylands Model Node-Link Network 4-5 Figure 4-4 Murraylands E2/WaterCast Model Land Use Map 4-6 Figure 4-5 Murraylands E2/WaterCast Calibration Catchments 4-15 Figure 4-6 RRL Calibration and Verification For Gauge AW426403 4-17 Figure 4-7 RRL Calibration of Daily Flows (Small Events) For Gauge AW426403 4-17 Figure 4-8 RRL Calibration of Daily Flows (Large Events) For Gauge AW426403 4-18 Figure 4-9 Hydrological Parameterisation of Murraylands E2/WaterCast Model 4-19 Figure 4-10 Stream Gauge Sites With Overlapping Record 4-21 Figure 4-11 Lower Angas Daily Flow Record 4-21 Figure 4-12 Lower Bremer Daily Flow Record 4-22 Figure 4-13 Cumulative Flow, Angas River 4-23 Figure 4-14 Cumulative Flow, Bremer River 4-23 Figure 4-15 Winter 2006 Angas River Flow 4-24 Figure 4-16 Winter 2006 Bremer River Flow 4-24 Figure 4-17 Angas River instream loss model calibration/verification 4-26 Figure 4-18 Bremer River instream loss model calibration/verification 4-27 Figure 5-1 Mean Annual Rainfall, 1957-2006 5-2 Figure 5-2 Mean Annual Areal Flows 5-3 Figure 5-3 Total Suspended Solids Areal Load Contributions 5-6 Figure 5-4 Total Nitrogen Areal Load Contributions 5-7 Figure 5-5 Total Phosphorus Areal Load Contributions 5-8 Figure 5-6 Predicted Annual Flows at Model Outlet 5-9 G:\ADMIN\B16618.G.TRW_MURRAYLANDS_E2\R.B16618.001.02.DOC LIST OF TABLES IV Figure 5-7 Predicted Annual Total Suspended Solids Loads at Model outlet 5-10 Figure 5-8 Predicted Annual Total Nitrogen Loads at Model Outlet 5-10 Figure 5-9 Predicted Mean Annual Total Phosphorus Loads at Model Outlet 5-11 Figure 5-10 Predicted vs Measured TN for the Finniss River GS 426504 5-11 Figure 5-11 Relative Land Use Loads 5-13 Figure 5-12 Modelled TN Concentration 5-14 Figure 5-13 Modelled TP Concentration 5-14 Figure 5-14 Existing vs Predevelopment TSS Loads 5-16 Figure 5-15 Existing vs Predevelopment TN Loads 5-16 Figure 5-16 Existing vs Predevelopment TP Loads 5-17 Figure 5-17 Nutrient Generation Rates (Extracted From Drewry et al 2006) 5-18 Figure 5-18 Farm Dams in Series, Mt Lofty Ranges, August 2007. 5-19 LIST OF TABLES Table 4-1 Functional Units of the Murraylands E2/WaterCast Model 4-8 Table 4-2 Flow Gauging Sites Used for Model Calibration 4-10 Table 4-3 Bird In Hand Wastewater Treatment Plant Characteristics 4-11 Table 4-4 Mt Barker Wastewater Treatment Plant Characteristics (irrigation data) 4-12 Table 4-5 Monthly STP Discharge 4-12 Table 4-6 Adopted E2/WaterCast STP Water Quality Characteristics 4-12 Table 4-7 EMC Parameterisation 4-13 Table 4-8 DWC Parameterisation 4-14 Table 4-9 Subcatchment Calibration Summary 4-16 Table 4-10 Subcatchment Calibrated Hydrological Parameters 4-16 Table 4-11 Adopted Hydrological Parameters 4-18 Table 4-12 Gauge Records for Angas and Bremer Rivers 4-20 Table 5-1 Comparison Between CSIRO and E2/WaterCast Calibration Performance 5-4 Table 5-2 Comparison Between CSIRO and E2/WaterCast Predicted Flows 5-4 Table 5-3 Relative Land Use Pollutant Loads 5-12 Table 5-4 Ecosystem Protection Guidelines (ANZECC) 5-14 Table 5-5 Constituent Generation Rates 5-18 G:\ADMIN\B16618.G.TRW_MURRAYLANDS_E2\R.B16618.001.02.DOC EXECUTIVE SUMMARY V EXECUTIVE SUMMARY The Murraylands E2/WaterCast catchment model extends form the South Australian - Victoria border to the outlet of the Murray River and encompasses approximately 68,000 km2. The landscape covered by the model ranges from arid lands in the north to low rainfall irrigation lands along the Murray River and moderate rainfall grazing and cropping lands in the Eastern Mount Lofty Ranges. The dominant land use in the model is grazing lands, which in turn dominated the total pollutant loads. The model boundary and subcatchments were generated using both automated pit filled DEM data and hand drawn subcatchments.