Lake Rotorua Groundwater Study: Results of the 2004-2005 Field
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Lake Rotorua groundwater study: results of the 2004-2005 field programme Confidential R Reeves, P A White, S G Cameron, G Kilgour, U Morgenstern, Client Report 2005/66 C Daughney, W Esler and S Grant July 2005 Lake Rotorua groundwater study: results of the 2004-2005 field programme Prepared for ENVIRONMENT BAY OF PLENTY R Reeves P A White S G Cameron G Kilgour U Morgenstern C Daughney W Esler S Grant Institute of Geological & Nuclear Sciences Limited CONFIDENTIAL Client Report 2005/66 Job Numbers 520W2054 to 520W2060 inclusive July 2005 COMMERCIAL IN CONFIDENCE: This report has been prepared by the Institute of Geological & Nuclear Sciences Limited exclusively for and under contract to Environment Bay of Plenty. Unless otherwise agreed in writing, all liability of the Institute to any party other than Environment Bay of Plenty in respect of the report is expressly excluded. Confidential LIST OF CONTENTS Page EXECUTIVE SUMMARY............................................................................... vi 1.0 INTRODUCTION ...............................................................................................1 1.1 References................................................................................................3 2.0 GEOLOGY AND PIEZOMETER CONSTRUCTION OF THE NEW DRILL HOLES .........................................................................................4 2.1 Introduction..............................................................................................4 2.2 Dibley piezometer ...................................................................................4 2.2.1 Drilling.....................................................................................................4 2.2.2 Geology of Dibley Bore..........................................................................8 2.2.2.1 90-122 m aquifer .....................................................................................9 2.2.2.2 122-123 m..............................................................................................10 2.2.2.3 123-125 m..............................................................................................10 2.2.2.4 125-151.5 m...........................................................................................10 2.3 Jessie Martin Memorial Park Piezometers...........................................11 2.3.1 Introduction............................................................................................11 2.3.2 Summary of D3 .....................................................................................16 2.3.2.1 Drilling...................................................................................................16 2.3.3 Summary of DP-2..................................................................................17 2.3.3.1 Drilling...................................................................................................17 2.3.4 Geology of the Jessie Martin Memorial Park bores ............................18 2.4 References..............................................................................................23 3.0 PUMP TEST RESULTS...................................................................................24 3.1 Results of pump test on Dibley bore (DP-1)........................................24 3.1.1 Introduction............................................................................................24 3.1.2 Pump test results....................................................................................25 3.2 Results of pump test on JMM Park bore (DP-2) .................................31 3.2.1 Introduction............................................................................................31 3.2.2 Pump test results....................................................................................33 3.2.3 Conclusions ...........................................................................................37 3.2.4 Mamaku Township pump test ..............................................................37 3.2.5 References..............................................................................................38 4.0 LAKE ROTORUA CATCHMENT BORE SUMMARY............................39 4.1 Introduction............................................................................................39 4.2 Methods .................................................................................................39 4.2.1 Bore locating..........................................................................................40 4.2.2 Measuring water levels .........................................................................41 4.2.3 Bore survey............................................................................................41 © Institute of Geological & Lake Rotorua groundwater study: results Nuclear Sciences Ltd i of the 2004-2005 field programme Confidential Page 4.3 Results....................................................................................................42 4.4 Limitations.............................................................................................44 4.5 References..............................................................................................44 5.0 GROUNDWATER QUALITY AND WATER DATING ...........................45 5.1 Introduction............................................................................................45 5.2 Methods .................................................................................................45 5.2.1 Site selection..........................................................................................45 5.2.2 Sampling/analyses.................................................................................47 5.2.3 Re-sampling...........................................................................................49 5.3 Results....................................................................................................49 5.4 References..............................................................................................53 6.0 GROUNDWATER CATCHMENT................................................................54 6.1 Introduction............................................................................................54 6.2 Review ...................................................................................................54 6.3 The field programme.............................................................................56 6.3.1 Nature and location of water discharge................................................56 6.3.1.1 Results....................................................................................................57 6.3.2 Measurement of water discharge..........................................................57 6.3.3 Combined list of lake-side sites............................................................58 6.3.4 Surface water flow rates........................................................................58 6.3.5 Stream losses/gains to/from groundwater ............................................62 6.3.6 Rotorua rainfall recharge lysimeter installation...................................62 6.3.6.1 Introduction............................................................................................62 6.3.6.2 Materials and methods ..........................................................................62 6.4 Summary................................................................................................68 6.5 References..............................................................................................69 LIST OF APPENDICES Appendix 1.1 Scope of work for the field programme (Note that the contract is not reproduced in full) .............................................................................70 Appendix 3. Pump test data supplied to GNS for the Mamaku Township bores ......75 Appendix 4.1 New bores found and the survey results .................................................89 Appendix 4.2. Data used for the piezometric map..........................................................90 Appendix 5.1 Laboratory result reports and methods................................................. 100 © Institute of Geological & Lake Rotorua groundwater study: results Nuclear Sciences Ltd ii of the 2004-2005 field programme Confidential Page Appendix 6.1 Description of Lake Rotorua springs, seeps and wetlands identified in the lake-edge survey........................................................... 124 Appendix 6.2 Flow measurements made by Environment Bay of Plenty in December 2004 and February 2005 ....................................................... 158 LIST OF TABLES Table 2.1 Piezometer construction summary of piezometer DP-1 .......................7 Table 2.2 Piezometer construction summary of piezometer D3...........................17 Table 2.3 Piezometer construction summary of piezometer DP-2 .......................18 Table 3.1 Summary of pumping and observation bore details .............................25 Table 3.2 Bore location.........................................................................................25 Table 3.3 Summary of aquifer transmissivity and storativity...............................26 Table 3.4 Summary of pumping and observation bore details .............................32 Table 3.5 Bore location.........................................................................................33 Table 3.6 Summary of aquifer transmissivity and