Lower Campaspe Valley Water Supply Protection Area Technical Report Final Date: February 2012 Document Number: 3269708 Document History and Distribution Version(s) Version Date Author(s) Notes A 1 Feb 2012 B Cossens Reviewed S Cowan L Richards Distribution Version Recipient(s) Date Notes Final 23 Feb 2012 i Table of Contents 1 INTRODUCTION ...................................................................................................... 5 1.1 PURPOSE ............................................................................................................ 5 1.2 BACKGROUND ...................................................................................................... 5 2 STRATEGIC CONTEXT ........................................................................................... 6 2.1 POLICY CONSIDERATIONS ..................................................................................... 6 2.2 DISCUSSION ........................................................................................................ 6 3 LOWER CAMPASPE VALLEY .............................................................................. 12 3.1 LOCATION .......................................................................................................... 12 3.2 BACKGROUND .................................................................................................... 12 3.3 BOUNDARY ........................................................................................................ 12 4 GROUNDWATER SYSTEM ................................................................................... 20 4.1 AQUIFERS .......................................................................................................... 20 4.2 MANAGEMENT ZONES ......................................................................................... 22 4.3 GROUNDWATER USE .......................................................................................... 23 5 GROUNDWATER SALINITY .................................................................................. 26 5.1 BACKGROUND .................................................................................................... 26 5.2 GROUNDWATER SALINITY IN THE LOWER CAMPASPE VALLEY WSPA ..................... 27 5.3 GROUNDWATER SALINITY RISK ............................................................................ 28 5.4 SALINITY SAMPLING OPTIONS .............................................................................. 29 6 GROUNDWATER INTERACTION WITH SURFACE WATER ................................ 31 6.1 SURFACE WATER MANAGEMENT .......................................................................... 31 6.2 INVESTIGATIONS ................................................................................................ 32 6.3 CONCLUSIONS ................................................................................................... 33 7 GROUNDWATER DEPENDENT ECOSYSTEMS .................................................. 35 7.1 CONTEXT ........................................................................................................... 35 7.2 BACKGROUND .................................................................................................... 35 7.3 CONSIDERATIONS .............................................................................................. 35 7.4 KNOWLEDGE OF GDES....................................................................................... 37 7.5 CONCLUSIONS ................................................................................................... 37 8 WATER BALANCE ................................................................................................ 39 8.1 APPROACH ........................................................................................................ 39 8.2 RESULTS ........................................................................................................... 40 8.3 DISCUSSION ...................................................................................................... 41 9 TRIGGER LEVELS ................................................................................................ 44 9.1 CONTEXT ........................................................................................................... 44 9.2 CONSIDERATIONS .............................................................................................. 44 9.3 PROPOSAL ......................................................................................................... 48 10 RESTRICTIONS .................................................................................................. 49 10.1 CONTEXT ....................................................................................................... 49 ii 10.2 BACKGROUND ................................................................................................. 49 10.3 DISCUSSION ................................................................................................... 49 10.4 RESTRICTION RATIONALE ................................................................................ 50 11 INTENSIVE GROUNDWATER PUMPING .......................................................... 53 11.1 BACKGROUND ................................................................................................. 53 11.2 DISCUSSION ................................................................................................... 53 12 GROUNDWATER TRADING .............................................................................. 56 12.1 BACKGROUND ................................................................................................. 56 12.2 ADVANTAGES AND LIMITATIONS OF TRADING ..................................................... 56 12.3 DISCUSSION ................................................................................................... 56 13 GROUNDWATER CARRYOVER ........................................................................ 59 13.1 CONTEXT ....................................................................................................... 59 13.2 ASSESSMENT ................................................................................................. 59 13.3 DISCUSSION ................................................................................................... 60 13.4 PROPOSAL ..................................................................................................... 61 14 MONITORING ..................................................................................................... 63 14.1 CONTEXT ....................................................................................................... 63 14.2 BACKGROUND ................................................................................................. 63 14.3 CONSIDERATIONS ........................................................................................... 63 15 RECOMMENDATIONS FOR FUTURE WORK ................................................... 70 16 REFERENCES .................................................................................................... 71 APPENDIX A ................................................................................................................ 73 iii List of Figures Figure 1 Victoria’s water entitlement framework .............................................................. 8 Figure 2 Lower Campaspe Valley WSPA ...................................................................... 13 Figure 3 Extent of Calivil Formation in the Lower Campaspe Valley WSPA and seasonal drawdown between August 2006 and February 2007 .................................................... 14 Figure 4 Groundwater flow ............................................................................................ 16 Figure 5 Groundwater salinity in the Lower Campaspe Valley ....................................... 18 Figure 6 Management Zones ........................................................................................ 21 Figure 7 Metered use in the Lower Campaspe Valley WSPA ........................................ 24 Figure 8 Campaspe River average monthly flow at Barnadown station 406201 ............ 31 Figure 9 Water balance inputs and outputs ................................................................... 39 Figure 10 Lower Campaspe Valley WSPA water balance results .................................. 40 Figure 11 water balance results for zones ..................................................................... 41 Figure 12 Modelled output for period 1983/84 to 2010/11 ............................................. 42 Figure 13 South to north section in ................................................................................ 45 Figure 14 Hydraulic gradient to New South Wales over time ......................................... 46 Figure 15 Trigger level and allocations for Elmore-Rochester, Bamawm and Echuca Zones ............................................................................................................................ 52 Figure 16 Trigger level and allocations for the Barnadown Zone ................................... 52 Figure 17 Interference caused by intensive groundwater pumping ................................ 53 Figure 18 Intensity of groundwater pumping .................................................................. 54 Figure 19 Intensity rule example ................................................................................... 55 List of tables Table 1 Number