Medstone Dairy Limited Resource Consent Application To Renew Consent CRC084945.2 To Take and Use Groundwater Assessment of Environmental Effects November 2018 TABLE OF CONTENTS 1.0 INTRODUCTION ................................................................................................................................................. 3 2.0 DESCRIPTION OF THE AFFECTED ENVIRONMENT ...................................................................................... 3 2.1 Cultural and Ecological Values of the Hurunui River and Surrounds .............................................. 3 2.2 Flow and Allocation Regime ................................................................................................................ 4 2.3 Waitohi River ......................................................................................................................................... 4 2.4 Groundwater .......................................................................................................................................... 5 2.5 Water Quality ......................................................................................................................................... 5 2.6 Biodiversity and Dryland Habitat ......................................................................................................... 8 3.0 PLANNING MATTERS ....................................................................................................................................... 8 3.1 Resource Management Act 1991 (the Act) .......................................................................................... 8 3.2 Hurunui Waiau River Regional Plan (HWRRP) ................................................................................... 9 3.3 Land Water Regional Plan (LWRP) ...................................................................................................... 9 3.4 Case Law ................................................................................................................................................ 9 3.5 Duration Sought .................................................................................................................................. 10 4.0 ASSESSMENT OF ACTUAL AND POTENTIAL EFFECTS ............................................................................ 10 4.1 Effects of an Inefficient Take and Reasonable Need........................................................................ 11 4.2 Effects of Take on Hurunui River and Waitohi River Flows ............................................................ 11 4.3 Effects on Tangata Whenua Values ................................................................................................... 12 5.0 PROPOSED CONSENT CONDITIONS ............................................................................................................ 14 6.0 OVERALL ASSESSMENT AGAINST RELEVANT PLANNING DOCUMENTS .............................................. 14 6.1 Hurunui and Waiau River Regional Plan ........................................................................................... 14 6.2 Regional Policy Statement ................................................................................................................. 15 6.3 National Policy Statements, Environmental Standards, Regulations............................................. 16 6.4 Resource Management Act - Part 2 ................................................................................................... 17 APPENDICES Appendix 1 Resource Consent CRC084945.2 Appendix 2 Consent Location Map Appendix 3 Bore Logs Appendix 4 Flow Meter Data Appendix 5 Irrigated Area Appendix 6 IrriCalc Appendix 7 Stream Depletion Assessment 2 Bowden Environmental Assessment of Environmental Effects Groundwater Abstraction November 2018 1.0 INTRODUCTION Medstone Dairy Limited currently holds consent CRC084945.2 (Appendix 1) located on Medbury Road, Medbury, in North Canterbury (Appendix 2). The consent expires on 26 May 2019 and Medstone applies for a replacement at the same rates and volume, i.e. no changes to the current consent. 2.0 DESCRIPTION OF THE AFFECTED ENVIRONMENT The applicant’s property is located within the Hurunui River Catchment. The Hurunui River drains numerous tributary rivers and lakes. Below the Mandamus recorder site it broadens out into a wide braided river and crosses the Amuri Plains. It then narrows into a single channel where it passes through the Lowry Peaks Gorge, before widening out again and crossing the “Domett Plains” before finally discharging to the sea. The Hurunui River is characterised by rapid changes in flow and floods at any time of the year, but particularly in winter and spring. Flow data, recorded at the Mandamus recorder site, shows a mean flow of 53 cumecs, a seven day MALF of 16.8 cumecs, a lowest recorded flow of 7.8 cumecs and a highest recorded flow of 1,140 cumecs. The main tributaries of the river below the Mandamus recorder site are the Mandamus River, Waitohi River, Dry Stream, Pahau River, Waikari River and Kaiwara River. A good summary description of the catchment is contained in the HWRRP. 2.1 Cultural and Ecological Values of the Hurunui River and Surrounds The Hurunui River has statutory acknowledgement pursuant to Section 206 of the Ngai Tahu Claims Settlement Act 1998, Schedule 20 for Hoka kura (Lake Sumner) and Schedule 21 for the Hurunui River. There is a strong cosmological link with regards to the formation of the lakes of the Te Wai Pounamu, and it is believed that the lakes were dug by the chief Rakaihautu. The Hurunui River is a traditional route to the west coast (via the lakes and upper river). Below the confluence with the Mandamus River to the coast the river has medium value for Te Ngai Tuahuriri Rūnanga, otherwise it has high value. Mauri of the river includes the capacity of the river to renew groundwater flow and surface water stocks; maintaining mahinga kai species and freshwater habitats, including fish passage for migratory fish species; flow variability including floods so that the river “cleanses” itself; continuity of flow from the source to the sea; and naturalness of water quality. Wahi tapu and urupa sites are found in the area. Waters of the Hurunui were used for rituals. Maori Gully is a section of the greenstone trail to the west coast. Nohanga (settlement) were located at points along the length of the river. Traditionally the Hurunui River was an important tuna (eel) and inanga fishery. This is not so important now as a result of the modified nature of the river, and the depleted fish stocks. 3 Ecological values of the Hurunui River are also influenced to some extent by anthropogenic factors. During times of low flow periphyton biomass can increase to nuisance levels, probably as a result of increased water temperatures and an increase in nutrients such as dissolved organic nitrogen (DIN) and dissolved organic phosphorus (DRP). Drainage from both the Balmoral Scheme and the Waiau Irrigation Scheme carry contaminants into the Hurunui mainstem. These contaminants affect water quality from the confluence with the Pahau River to the sea. During summer and autumn “algal blooms” come to dominate the riverbed, and comprise filamentous green algae and thick mats of mucilaginous algae. This growth smothers macroinvertebrate habitat, decreases dissolved oxygen concentration (as a result of a breakdown of the algae) and as a consequence decreases the abundance of fish life through a loss of habitat and food. Abstractions draw the river down faster and hold it lower for longer, and therefore exacerbate the frequency and duration of nuisance algal growth. NIWA freshwater fish database has been searched for fish species present in the Hurunui River. Results gave a list of 14 different species and include; Brown trout, Upland Bully, Longfinned eel, Canterbury galaxies, Torrentfish, Chinook Salmon, Common Smelt, Yelloweyed Mullet, Koaro, Shortfinned eels, Perch, Alpine Galaxias and unidentified galaxiid and salmonid. Fish species found between the Lowry Peaks gorge downstream to the coastal marine boundary include; Upland bully, Canterbury galaxies, Long and shortfinned eels, Common bully, Stockell Smelt and Yellow eyed mullet. The Hurunui River has medium value habitat for resident brown trout and migratory sea-run brown trout and Chinook salmon. However, it provides only low value habitat for rainbow trout, hence why they are generally not present. Tributaries of the Hurunui River are listed as having low value habitat for salmonid species. 2.2 Flow and Allocation Regime Floods and freshes play a very important role in maintaining the form, character and habitats associated with the Hurunui River. It is important that abstractions do not reduce the frequency and magnitude of freshes and floods, to ensure removal of vegetation that has colonised gravel bars, prevent nuisance growth of periphyton and provide for salmonid migration. Reports commissioned by Environment Canterbury indicate that the minimum flow set for the river during the 1980s is inadequate for aquatic ecosystems and flow variability, and further complicated by two different flow regimes, one for Balmoral Scheme irrigators, and one for other abstractors. Therefore, to protect the values of the river and to rationalise the flow regime, the HWRRP has set a new flow and allocation regime. This new regime separates the main stem of the Hurunui River into three areas with separate flow and allocation regimes in Table 1: Environmental