Aupouri Peninsula Water Resources
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/I OUPUCATE :<; AUPOURI PENINSI!ILA {:/ -..../ WATER RESOURCES i ASSESSMENT ; / -- .. _'-. -/-- . · .. / -- - "- .....,- ',' -··,-:_ --·· hORTHLAnD ~--. - I REGIOnAL COUR,CIL CARING FOR NORTHLAND AND ITS ENVIRONMENT \ 3 I , u I ,·,_ AUPOURIPENrnN~LA WATER RESOURCES ASSESSMENT 1991 nORTHLAnD RECiiOnAL counciL CARING FOR NORTHLAND AND ITS ENVIRONMENT Quay Street, Private Bag 9021, Whangarei Phone (09) 4384639 Fax (09) 4380012 192 Commerce Street, Kaitaia Phone (09) 4081415 Fax (09) 4380012 l I !_I Table of Contents Page Acknowledgements List of Figures List of Tables List of Appendices 1.0 Introduction I 1.1 Background to report I 1.2 Objectives I 1.3 Investigations carried out 3 1.4 Limitations 4 1 2.0 Features of the study area 5 ' 2.I General description and relief 5 2.2 Surface drainage 5 .) t 2.3 Geology 5 2.4 Soils, vegetation and landuse 7 i 1> 3.0 Climate 10 3.I General IO 3.2 Evapotranspiration 10 ·'{ . 3.3 Rainfall 11 3.3.1 Rainfall stations 11 3.3.2 Rainfall during investigation 13 3.3.3 Long term rainfall patterns 13 4.0 Groundwater investigation 24 t 4.1 Introduction 24 i. 4.2 Geological maps and Geophysical and hydrological investigation i reports 24 ! 4.3 Bore log data 25 .. 4.4 Investigation drilling programme 25 L~ 4.4.1 Purpose of drilling programme 25 4.4.2 Choice oflocation for investigation drilling sites 25 4.5 Geophysical surveys 29 L 4.6 Pumping tests 29 4.7 Groundwater level monitoring 29 i 5.0 Groundwater Resources 31 5.1 Introduction 31 5.2 Sweetwaters to W aihopo 31 5.2.1 Groundwater bearing strata - type and distribution 31 5.2.2 Geological crossections 34 j. ;' 5.2.3 Groundwater flow and storage 39 t,. 5.2.4 Recharge and discharge of groundwater 43 5.2.5 Bore yields 44 5.2.6 Bore construction 44 ''' 5.3 Sweetwaters to Ahipara 45 5.3.1 Topography and geology 45 i .. Hydrogeology I 5.3.2 45 '. 5.3.3 Bore yields 45 I . 5.4 Waihopo- North 46 5.4.1 Introduction 46 ! 5.4.2 Hydrogeology 46 l ' 5.4.2.1 Unconsolidated material 46 I , 5.4.2.2 Hard rock 47 I' . 5.5 Karikari 47 5.5.1 Introduction 47 !I 5.5.2 Topography and geology 47 I. 5.5.3 Hydrogeology and groundwater availability 48 5.5.4 Bore yields 48 ! 5.6 Possible causes for groundwater level falls 49 5.. 6.1 Impacts of variation in rainfall 49 5.6.2 Impacts of Afforestation 49 5.6.3 Impact of Irrigation development 59 5.7 Saltwater intrusion 59 Groundwater quality 60 I 5.8 ' ' .. 6.0 Lakes and wetlands 65 6.1 Introduction 65 I 6.2 Lake levels and water balance 67 6.3 Lake water quality 73 6.3.1 Faecal Bacteria 74 6.3.2 Phytoplankton blooms 74 6.3.3 Water clarity 76 6.3.4 plant nutrients 77 6.3.5 Temperature and dissolved oxygen 78 6.3.6 Major ions 78 i :i· I 6.3.7 Lake water quality and suitability for various uses 81 \ j 6.4 Aquatic plants 82 I. 6.5 Freshwater fish 85 I 6.6 Bird life 89 I' 6.7 Lake modification 89 I : 6.8 Management options 88 I ' . 7.0 Biological values of the freshwater wetlands within the Te Paki and Aupouri ecological regions 91 7.1 Summary 91 7.2 Introduction 91 7.3 Methods 95 .-. 7.3.1 Fieldwork 95 7.3.2 Ranking of sites 95 7.4 Wetland types recorded 96 7.5 Biological values 97 7.6 Loss of wetlands 102 7.7 Conclusions 103 8.0 Streamflow 105 8.1 Introduction 105 8.2 Streamflow gauging sites 105 8.3 Selwyn swamp llO 8.4 Stream water quality 113 8.4.1 Results of sampling 113 8.4.2 Suitability of the stream for various uses 113 8.4.3 Wastes disposal l14 1 . 9.0 Consumptive water use and effluent discharges 115 9.1 Introduction 115 'o!- 9.2 Domestic water supplies 115 9.3 Farm water supplies 115 [ 9.4 Irrigation 115 9.5 Commercial uses 116 9.6 Industry l16 9.7 Public water supplies l16 9.8 Allocation of the water resource to consumptive users l17 9.9 Water supply shortages 117 9.10 Discharges 118 10.0 Summary of findings 120 i 10.1 Groundwater availability 120 10.2 Groundwater quality 120 10.3 Saltwater intrusion into groundwater 120 f 10.4 Impacts of afforestation on groundwater levels 120 10.5 Impacts of irrigation use on groundwater levels 121 10.6 Abandoned flowing artesian wells 121 ' "' 10.7 Wildlife habitat value 121 10.8 Impacts of farming and afforestation 121 (·' 10.9 Introduced species 122 i 10.10 Taking water from or discharging waste to lakes 122 10.ll Stream flow and quality 122 ~ 10.12 Existing water supplies 122 L 10.13 Potential water demand 122 10.14 Wastes discharges 123 1 10.15 Continued resource monitoring 123 10.16 Management plan 123 :1 ' References 124 ~ i. Appendix 1 128 Appendix2 144 Appendix3 153 l Appendix4 161 l' t ' I' ,, __ L·: I' Acknowledgements This report was largely prepared by NRC staff, particularly Tony Phipps, George Skuse and Dwane Kokich. I . The following people and organisations contributed material for inclusion in this report and their assistance is gratefully acknowledged: I Department of Conservation Biological values of freshwater wetlands f GCNZ Groundwater investigations ' Local W elldrillers Bore logs and subsurface geology I i Stephen Mcintosh Geophysical investigations I . The assistance of the many farmers and landowners who provided access onto their properties for groundwater investigations is also gratefully appreciated. [ ;, I I . r • I ,i. i ' List of Figures Page 1.1 Area of investigation: Aupouri and Karikari peninsulas 2 2.1 Surface geology 6 2.2 Vegetationllanduse 8 3.1 Rainfall 12 3.2 Cumulative departure curves for selected rainfall sites 14 3.3 5 year running mean at selected rainfall sites 20 4.1 Location of bore holes, piezometers and pumping tests 28 4.2 Location of geophysical survey sites 30 5.1 Sub area boundaries 32 5.2 Shell bed interceptions 33 5.3 Local rock basement levels 35 5.4 Ngatiki crossection 36 5.5 Hukatere - Houhora crossection 37 5.6 Big Flat crossection 38 5.7 Waipapakauri- Awanui crossection 40 5.8 Groundwater potential (m.a.m.s.L) Hukatere-Pukenui 41 5.9 Simplified conceptual groundwater flow system 42 5.10 Groundwater level measurements for selected boreholes 50 6.1 Location oflake sampling sites 66 6.2 Lake water levels 68 6.3 Bathymetry and crossection for selected lakes 69 6.4 Dissolved Oxygen and temperature profiles for selected lakes 79 7.1 Location of freshwater wetlands 92 8.1 Location of stream gauging sites 107 8.2 Selwyn swamp flow during 'wet' and 'dry' years 111 ~: 8.3 Selwyn swamp flow from November 1990 to March 1991 112 r-· ' . ' List of Tables '' ~ Page Ll Investigations carried out 3 3.1 Potential Evapotranspiration 10 3.2 Pan Evaporation 1986 - 1990 11 3.3 Location of rainfall stations 11 3.4 Waiharara1986- 1990 13 4.1 Summary of bores tested 26 5.1 Bore water quality results 62 6.1 Location and dimensions oflakes on the Aupouri and Karikari penisulas 65 6.2 Species code used by Tarmer et al., (1986) 83 ! -, 6.3 Aquatic plants surveyed by Tanner et al., (1986) on the 1 ! Aupouri peninsula 84 ( _, 6.4 Lake location and surrounding land use 89 1 -· 8.1 Location of gauging sites on the Aupouri and Karikari peninsulas 106 9.1 Existing consumptive water use for the Aupuri and Karikari peninsulas 117 9.2 Discharge water permits in the Aupouri and Karikari peninsulas 119 ',-' I' . List of Appendices Page Appendix 1 Selection of bore logs with location map 128 Appendix2 Bore hole construction logs for 9 drilled investigation sites 144 Appendix3 Physical and chemical results of lake sampling on the Aupouri and Karikari peninsulas 153 Appendix4 Criteria for, and ranking of, wetlands of special biological interest 161 ~- i t' j ' . I' I \ ' ''- ' 1 AUPOURI PENINSULA- WATER RESOURCES ASSESSMENT 1 INTRODUCTION 1.1 Background to Report This final report details the findings of the Northland Regional Council (NRC) (and previously Northland Catchment Commission (NCC)), investigation into the nature, quantity, quality and use of the water resources of the Aupouri and Karikari Peninsulas. The region covered by this report includes the Aupouri and Karikari Peninsulas as well as the area north of the Kaitaia - Ahipara road and west of the Awanui River. The area is shown in Fig 1.1. In the early to mid 1980's both the NCC and the Mangonui County Council (MCC) were faced with making decisions on water rights and planning consents for proposed developments on the Aupouri and Karikara Peninsulas. These included the subdivision of farmland for orcharding and vegetable growing, development of forestry, possible forest processing industries, tourist resorts and such things as the kauri gum mining proposal. It was known that the main source of water supply on the peninsulas was groundwater. However, at that time there was little information available on the water resources of the area and there were concerns about the sustainability of the ground water resource. In particular concerns were expressed about the impact the substantial plantings of exotic forest on the sand country of Aupouri peninsula might have on the quantity of ,._ ground water available and that there may not be enough water available to meet both existing farm water supply needs and the extra demands and use for irrigation and other proposed developments.