FINAL PROJECT REPORT Development of Source models for the ACT and Region December 2017 Document history Revision: Revision no. 06a Author/s Danielle Udy Ying Quek Tony Sheedy Tony Weber Checked Tony Weber Approved David Barratt Distribution: Revision no. 06a Issue date 15/12/2017 Issued to Stewart Chapman, Ross Knee ACT Government Description: Final report Citation: Alluvium 2017, Development of Source models for the ACT and Region, prepared for ACT Government Environment Planning & Sustainability Development Directorate, Canberra 2017. Acknowledgements: We would like to acknowledge and thank the following people for their input to the model development: Stewart Chapman (ACT Government) Ross Knee (ACT Government) Andrew Davidson (DPI Water) Tim Purves (Icon Water) Danswell Starrs (ACT Government) Ref: R01_ACTModelSetupReport_v6 Contents 1 Introduction 7 1.1 ACT Water Resources 7 Surface water resources in ACT 7 Groundwater resources in ACT 7 1.2 Topography and Physiography 8 1.3 Geology 9 1.4 Hydrogeology 10 Hydrogeological Landscapes of the ACT 10 Depth to Watertable 10 Groundwater Dependent Ecosystems 10 1.5 Relevant water management strategies and plans 13 Murray-Darling Basin Plan and SDL 13 The Basin Plan requirements for Water Resources Plans (WRPs) 14 ACT and Region Catchment Strategy 15 ACT Water Strategy 2014-2044 15 Environmental Flow Guidelines 15 ACT Water Management Area 16 1.6 Source model 16 Source catchment modelling 16 Source water resource management modelling 16 2 Previous work 18 2.1 Groundwater and Surface Water Connection 18 2.2 Existing Models 18 Icon Water REALM model 19 IQQM Model 19 3 Data Availability 21 3.1 GIS data sets 21 LiDAR data 21 Land Use data 23 Existing IQQM catchments 23 Groundwater data 23 3.2 Time series data 23 Flow time series 23 Climate data 23 Water quality and sewage discharge from ACT treatment plants 24 4 Model Conceptualisation 26 4.1 Source Catchment Model Conceptualisation 26 Model build process and quality assurance 27 Catchment Delineation 27 Groundwater 27 Limitation of model outside of ACT water management areas 32 4.2 Water Resource Model Conceptualisation 35 Model build process and quality assurance 35 Catchment Delineation 35 Incorporating existing IQQM model conceptualisation 39 5 Source Catchment Modelling 40 ACT Source Model Development i 5.1 Model Build 40 Catchment delineation 40 Functional Units 40 Storages/Lakes and Sewage Treatment Plants 45 Link and storage routing 46 5.2 Hydrology calibration and validation (Catchment model) 47 Statistical Performance 48 Hydrology Calibration 49 Hydrology Validation 50 5.3 Water Quality validation (Catchment model) 51 6 Water Resource Modelling 56 6.1 Upper Murrumbidgee catchments 56 6.2 Rainfall-runoff modelling in the ACT 57 6.3 ACT net take 57 6.4 Gross take 57 Icon Water Diversions 57 Non-Icon Water diversions 57 Water Transfers 58 6.5 STP Flow returns 59 Lower Molonglo Water Quality Control Centre (LMWQCC) 59 Queanbeyan Sewage Treatment Plant (QSTP) 59 Modelling LMWQCC outflow 59 Modelling QSTP outflow 64 Total STP returns 65 6.6 Source Model Structure 66 Time series inputs 67 Streamflow routing 67 Loss Function 68 Representation of lakes 68 Dams and lakes climate inputs 69 Water supply points 69 ACT net take 70 6.7 Water resource model calibration results 70 80th - 90th percentile flow of each WMA within the ACT border 70 7 Recommendations and Limitations 72 7.1 Catchment Model limitations and recommendations 72 7.2 Water resource model limitations and recommendations 73 8 References 75 Appendix 1 Environmental Flow Guidelines 76 Appendix 2 Gauged Flow Metadata 81 Appendix 3 Source Water Resource working map 84 Appendix 4 Source water resource model logs 86 Appendix 5 Water Resource Model Calibration result for 4100670 95 Appendix 6 Water resource flow balance table 98 Appendix 7 Source water resource model results 103 ACT Source Model Development ii Appendix 8 Catchment areas within each WMA and within ACT border 111 Appendix 9: Catchment Model – Hydrology calibration plots 114 Appendix 10: Catchment Model – Hydrology validation plots 126 Appendix 11: Catchment Model – Water Quality validation plots 128 Appendix 12: Land use mapping 139 Appendix 13: Gudgenby and Naas Inflow derivation 141 Figures Figure 1. Topography and Physiography 8 Figure 2. Geological units and structures in the ACT 9 Figure 3. Depth to groundwater 11 Figure 4. Groundwater Dependent Ecosystems (from the BOM GDE Atlas) 12 Figure 5. Water management of ACT at different spatial levels (Source: ACT Government, 2014). 13 Figure 6. Proportion of SDL in GL/year allocated for water courses, runoff dams (dam or reservoir that collects surface water flowing overland), commercial plantation (areas of commercial perennial woody plants), and groundwater within the ACT. 13 Figure 7 Existing IQQM model schematic (Source: Gilmore, 2008) 20 Figure 8: High resolution LiDAR sections available in the Upper Murrumbidgee 21 Figure 9: DEM (20m) developed from LiDAR and SRTM data across Upper Murrumbidgee 22 Figure 10. SIMHYD (left) and GR4J (right) conceptual model. Refer to eWater 2017 for more information. 26 Figure 11: Upper Murrumbidgee catchment delineation and ACT water management areas 28 Figure 12. Groundwatermmanagement unit boundaries 29 Figure 13. Baseflow 30 Figure 14. Groundwater Units and Average Annual Baseflow Contributions to Streams 34 Figure 15. Delineated Source water resource management model boundary of the Upper Murrumbidgee region. 37 Figure 16. Delineated Source water resource management model boundary with the associated flow gauges within the ACT water management areas. 38 Figure 17: Screenshot of Upper Murrumbidgee Source Catchment model 40 Figure 18: Upper Murrumbidgee Land Use 42 Figure 19: Storages, lakes and sewage treatment plants applied in Upper Murrumbidgee model 46 Figure 20: Hydrology calibration and validation gauge locations (410XXXb shows the rainfall runoff parameters applied to regions that have not been calibrated) 47 Figure 21: ACT WQ zones -adapted from GHD report 52 Figure 22. Calculated annual total non-Icon licensed gross take of current scenario from 2009/10 to 2013/14. 58 Figure 23. Calculated annual total non-Icon licensed demand for the current and SDL scenario from 1895/96 to 2008/09. 58 Figure 24. Historical gauged outflow from LMWQCC from 01/01/1999 to 31/12/2016. 59 Figure 25. Annual minima of the rolling 90-day average water use in the ACT. 61 Figure 26. Modelled LMWQCC baseflow time series from 1999 to 2016. 61 Figure 27. Modelled LMWQCC baseflow time series from 2014 to 2016. 62 Figure 28. Flow duration curves of the observed and simulated baseflow returns of LMWQCC. 62 Figure 29. Simulated and observed outflows of LMWQCC from 2006 to 2016. 63 Figure 30. Cumulative flows of simulated and observed outflows of LMWQCC from 2006 to 2016. 64 Figure 31. The annual LMWQCC outflow from 2006 to 2016. 64 Figure 32. Time series plot of QSTP outflows from 2008 to 2016. 65 Figure 33. Gauged outflows of LMWQCC and QSTP from 01/07/2015 to 01/12/2016. 65 Figure 34. Source water resource model structure 66 Figure 35. Level-volume rating curve of Lake Tuggeranong using bathymetry and water level data at gauge 410779. 69 Figure 36. Water resource working map. 85 Figure 37. Flow Duration Curve of gauged flow and modelled flow calibrated at gauge 410067. 96 Figure 38. Cumulative curves of gauged flow and modelled flow calibrated at gauge 410067. 97 ACT Source Model Development iii Figure 39. Time series of gauged flow and modelled flow calibrated at gauge 410067 97 Figure 40. Calibration results downstream flow recorded at 410050. 104 Figure 41. Calibration results for downstream flow recorded at 410731. 105 Figure 42. Calibration results for downstream flow recorded at 410761. 106 Figure 43. Calibration results for downstream flow recorded at 410738. 107 Figure 44. Calibration results for downstream flow recorded at 410729. 108 Figure 45. Calibration results for downstream flow recorded at 410741. 109 Figure 46. Calibration results for downstream flow recorded at 410777. 110 Figure 47: Time series 115 Figure 48: Baseflow time series 115 Figure 49: Flow duration curve 115 Figure 50: Time series 116 Figure 51: Baseflow 116 Figure 52: Flow Duration Curve 116 Figure 53: Time series 117 Figure 54: Baseflow 117 Figure 55: Flow Duration Curve 117 Figure 56: Time series 118 Figure 57: Baseflow 118 Figure 58: Flow Duration Curve 118 Figure 59: Time series 119 Figure 60: Baseflow 119 Figure 61: Flow Duration Curve 119 Figure 62: Time series 120 Figure 63: Baseflow 120 Figure 64:Flow Duration Curve 120 Figure 65: Time series 121 Figure 66: Baseflow 121 Figure 67: Flow Duration Curve 121 Figure 68: Time series 122 Figure 69: Baseflow 122 Figure 70: Flow Duration Curve 122 Figure 71: Time series comparison 123 Figure 72: Baseflow time series comparison 123 Figure 73: Flow duration curves 123 Figure 74: Time series 124 Figure 75: Baseflow time series 124 Figure 76: Flow duration curve 124 Figure 77: Time series comparison 125 Figure 78: Baseflow comparison 125 Figure 79: Flow duration curve 125 Figure 80: Murrumbidgee at Lobbs Hole flow duration curve 127 Figure 81: Murrumbidgee at Mt McDonald flow duration curve 127 Figure 82: Murrumbidgee at Halls Crossing flow duration curve 127 Figure 83: Modelled and observed total nitrogen concentration with modelled flow overlayed. 129 Figure 84: Modelled and observed total nitrogen (y axis zoom) 129 Figure 85: Modelled and observed total phosphorus concentration with modelled flow overlayed. 129 Figure 86: Modelled and observed total suspended solids concentration with modelled flow overlayed. 130 Figure 87: Modelled and observed salinity (assuming 0.6 conversion) concentration with modelled flow overlayed. 130 Figure 88: Modelled and observed total nitrogen concentration with modelled flow overlayed. 130 Figure 89: Modelled and observed total phosphorus concentration with modelled flow overlayed. 131 Figure 90: Modelled and observed total suspended solids concentration with modelled flow overlayed 131 Figure 91: Modelled and observed salinity (assuming 0.6 conversion) concentration with modelled flow overlayed.