Assessment of Environmental Effects for the Selwyn River / Waikirikiri Near River Recharge Scheme, Hororata Flow Augmentation Scheme
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Auckland Tauranga Wellington Christchurch PATTLE DELAMORE PARTNERS LTD Assessment of Environmental Effects for the Selwyn River/Waikirikiri Near River Recharge Scheme, Hororata Flow Augmentation Scheme Environment Canterbury solutions for your environment Assessment of Environmental Effects for the Selwyn River / Waikirikiri Near River Recharge Scheme, Hororata Flow Augmentation Scheme • Prepared for Environment Canterbury • December 2019 PATTLE DELAMORE PARTNERS LTD Level 2, 134 Oxford Terrace Tel +64 3 345 7100 Fax +64 3 345 7101 Christchurch Central, Christchurch 8011 Website http://www.pdp.co.nz PO Box 389, Christchurch 8140, New Zealand Auckland Tauranga Wellington Christchurch C02424506R002_AEE_TAKE AND DISCHARGE.DOCX ii ENVIRONMENT CANTERBURY - ASSESSMENT OF ENVIRONMENTAL EFFECTS FOR THE SELWYN RIVER / WAIKIRIKIRI NEAR RIVER RECHARGE SCHEME, HORORATA FLOW AUGMENTATION SCHEME Executive Summary Environment Canterbury (ECan) has engaged Pattle Delamore Partners Ltd (PDP) to assist in the augmentation of shallow groundwater immediately adjacent to the Selwyn River/Waikirikiri to enhance flows in the river and nearby springs by using water from the Central Plains Water Trust (CPW) pipeline, which sources water from the Rakaia River. ECan is seeking additional consents to take and use water from the Rakaia River for the purposes of stream flow augmentation in the Hororata River and its tributaries via groundwater recharge adjacent to the Selwyn River. With the agreement of the consent holders, proposes to utilise water currently consent to Selwyn District Council (SDC) and CPW during off peak demand periods. The proposed augmentation scheme will involve discharging water supplied from the CPW scheme infrastructure and discharged into an infiltration basin up- gradient of the targeted Haldon Pastures Spring Field and Derretts Road Spring Field at flow rates up to 3.5 m³/s when the rated daily Selwyn River/Waikirikiri flow is measured below 1.5 m3/s at Whitecliffs recorder site. This Assessment of Environmental Effects report provides a description of the proposed activity and outlines the actual and potential adverse effects to the environment which may occur as a result of the water take and discharge for the operation of the scheme. Overall, the effects to the environment were found to be positive with controls and mitigation measures put in place to avoid any negative adverse effects such as inundation or mixing of waters. The proposed consenting mechanism enables water to be used without increasing allocation of water takes from the Rakaia River and does not compromise regional water storage strategies. An assessment of relevant statutory documents confirmed that the activity is consistent with the objectives and policies of the relevant plans. The primary plans of relevance are the Canterbury Land and Water Regional Plan which identified the resource consents required to authorise the proposed activity. C02424506R002_AEE_take and discharge.docx PATTLE DELAMORE PARTNERS LTD i i i ENVIRONMENT CANTERBURY - ASSESSMENT OF ENVIRONMENTAL EFFECTS FOR THE SELWYN RIVER / WAIKIRIKIRI NEAR RIVER RECHARGE SCHEME, HORORATA FLOW AUGMENTATION SCHEME Table of Contents SECTION PAGE Executive Summary ii 1. Introduction 1 1.1 Background 1 1.2 Applicant and Property Details 2 2. Description of the Activity 3 2.1 Overview 3 2.2 Targeted Augmentation 3 2.3 Discharge Structure 4 2.4 Water Source 5 2.5 Operation 6 3. Statutory Framework 8 3.1 Relevant Planning Framework 8 3.2 Approach to Securing Water Rights 9 3.3 Reason for Resource Consents 10 3.4 Other Resource Consents 13 3.5 Term of Consent 13 4. Consideration of Alternatives 15 5. Description of the Environment 16 5.1 Locality and Land Use 16 5.2 Surface Water Bodies 16 5.3 Flooding 18 5.4 Ecology 18 5.5 Existing Water Users 20 5.6 Topography 21 5.7 Surface Soils 21 5.8 Geology 22 5.9 Groundwater 22 5.10 Community Drinking Water Supplies 25 5.11 Cultural Setting 25 6. Assessment of Potential Effects 27 6.1 Positive Effects of Whole Scheme 27 6.2 Cultural Effects of Whole Scheme 28 6.3 Effects of Water Take (On Rakaia River Catchment) 31 6.4 Effects of Discharge (on Waikirikiri Selwyn River Catchment) 32 7. Management and Monitoring 41 7.1 Operational Monitoring Plan 41 C02424506R002_AEE_take and discharge.docx PATTLE DELAMORE PARTNERS LTD iv ENVIR ONMENT CANTERBURY - ASSESSMENT OF ENVIRONMENTAL EFFECTS FOR THE SELWYN RIVER / WAIKIRIKIRI NEAR RIVER RECHARGE SCHEME, HORORATA FLOW AUGMENTATION SCHEME 7.2 Additional Requirements 41 8. Consultation 42 9. Proposed Resource Consent Conditions 44 9.1 Subservient water take consent to CRC167218 (CPW) 44 9.2 Subservient water take consent to CRC153238 (SDC) 46 9.3 Subservient water take consent to CRC011996 (SDC) 49 9.4 Discharge Consent 51 10. Statutory Assessment 56 10.1 Resource Management Act 1991 56 10.2 Notification Assessment 56 10.3 Information Requirements 61 10.4 Section 104 Assessment 61 10.1 Section 105 – Matters Relevant to Discharge Applications 70 10.2 Section 107 – Restriction to Grant Certain Discharge Permits 71 10.3 Section 104B - Determination of applications for discretionary or non-complying activities 71 10.4 Statutory Assessment Conclusion 72 11. Conclusion 73 12. References 74 Table of Tables Table 1: Summary of the Application Details 2 Table 2: Consent locations and water takes 6 Table 3: Relevant SDP/LWRP Plans/Zones/Overlays 8 Table 4: Resource Consents Sought 10 Table 5: Assessment of Compliance with Rule 5.123 & Rule 5.191 11 Table 6: Fish Species known to occur in the Selwyn River/Waikirikiri 19 Table 7: Public Notification Assessment 56 Table 8: Limited Notification Assessment 59 Table 9: Section 105 Matters 71 C02424506R002_AEE_take and discharge.docx PATTLE DELAMORE PARTNERS LTD v ENVIRONMENT CANTERBURY - ASSESSMENT OF ENVIRONMENTAL EFFECTS FOR THE SELWYN RIVER / WAIKIRIKIRI NEAR RIVER REC HARGE SCHEME, HORORATA FLOW AUGMENTATION SCHEME Table 10: Section 107 Matters 71 Table 11: Restricted Discretionary Matters of Rule 5.123 and 5.191 E-2 Appendices Appendix A: Figures Appendix B: Selwyn River/Waikirikiri Near River Recharge Project: Operational Monitoring Plan Appendix C: Sales Purchase Agreement Appendix D: Central Plains Cultural Impact Assessment Appendix E: Restricted Discretionary Matters of Water Take Appendix F: Assessment of effects of discharges on adjacent forestry blocks Appendix G: Stantec details Appendix H: Additional Consultation details C02424506R002_AEE_take and discharge.docx PATTLE DELAMORE PARTNERS LTD 1 ENVIRONMENT CANTERBURY - ASSESSMENT OF ENVIRONMENTAL EFFECTS FOR THE SELWYN RIVER / WAIKIRIKIRI NEAR RIVER RECHARGE SCHEME, HORORATA FLOW AUGMENTATION SCHEME 1. Introduction 1.1 Background Environment Canterbury (ECan) has engaged Pattle Delamore Partners Ltd (PDP) to assist in the current investigation to augment flows in the Selwyn / Hororata River system as part of the Canterbury Water Management Strategy (CWMS), and assess the effects of associated activities to support Resource Consent Applications to ECan under the Land and Water Regional Plan. ECan has identified the opportunity to take water from the Central Plains Water Trust (CPW) Irrigation scheme pipeline, which sources water from the Rakaia River, and augment the shallow groundwater system immediately adjacent to the Selwyn River/Waikirikiri to enhance flows in that water body and nearby springs. This type of managed aquifer recharge (MAR) / targeted stream augmentation is known as Near River Recharge (NRR). The proposed augmentation scheme will involve discharging water supplied from the CPW irrigation scheme infrastructure into an infiltration basin adjacent to the river and up gradient of the springs at flow rates up to 3.5 cubic metres per second (m³/s) when the rated daily Selwyn River/Waikirikiri flow at the Whitecliffs recorder is below 1.5 m3/s. The CPW Irrigation Scheme is supplied from the Rakaia River and is authorised by resource consent CRC167218. SDC also has resource consent CRC153238 and CRC011996 to take water from the Rakaia River for its stockwater race distribution system. Recent land use changes that have led to the CPW irrigation scheme have also led to the reduced demand for the SDC Water Race network. Therefore, it is proposed to utilise “un-used” water from both these consented water takes, when they are not required for their respective consents, for the purposes of augmentation in the Selwyn River/Waikirikiri catchment to the north of the Rakaia River. As each of the three parent consents have differing durations of consent, ECan is subsequently applying for three separate water take consents such that the durations of the subservient consents can align. In order to augment flows in the shallow groundwater system it is proposed an infiltration basin is constructed and operated in Lot 3 DP 78682 with an overflow channel diverting water into the dry riverbed of Selwyn River/Waikirikiri. No mixing of waters with the natural Selwyn River flow will occur, as augmentation will only occur when the river is not naturally flowing in this reach. Resource Consents CRC194987, CRC194988, and SDC195880 have already been obtained by ECan and SDC to construct the works. This Assessment of Environmental Effects (AEE) has been prepared by PDP to support the resource consent application for the project associated with the augmentation in accordance with the Resource Management Act 1991 (RMA), C02424506R002_AEE_take and discharge.docx PATTLE DELAMORE PARTNERS LTD 2 ENVIRONMENT CANTERBURY - ASSESSMENT OF ENVIRONMENTAL