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PATTLE DELAMORE PARTNERS LTD
Assessment of Environmental Effects for the Selwyn River/Waikirikiri Near River Recharge Scheme, Hororata Flow Augmentation Scheme
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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
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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.
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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
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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
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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
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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),
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Canterbury Land and Water Regional Plan (LWRP) and other relevant statutory and regulatory documents. The report is structured as follows:
• Section 1 – Introduction;
• Section 2 – A description of the proposed activity;
• Section 3 – A statutory planning overview;
• Section 4 – Consideration of alternatives;
• Section 5 – A description of the existing environment;
• Section 6 – An assessment of the potential effects on the environment;
• Section 7 – Management and monitoring proposed for the activity;
• Section 8 – Consultation undertaken;
• Section 9 – Proposed Resource consent conditions;
• Section 10 – An assessment against relevant national and regional plans;
• Section 11 – Conclusions. 1.2 Applicant and Property Details Table 1 below supplies the relevant applicant details, parent consent numbers and land parcels involved in this consent application.
Table 1: Summary of the Application Details
Applicant Environment Canterbury
Land Parcel ID 3511989
Appellation Lot 3 DP 78682
Map Reference NZTM: 1519355 5179708
Landowners Canterbury Regional Council from 9 May 2019 Previously owned by Selwyn Forestry No. 1 Limited
Diversion Consent CRC167220
Parent Consents to CRC153238, CRC011996 and CRC167218 take water
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2. Description of the Activity 2.1 Overview ECan proposes to operate an infiltration basin system constructed in accordance with Resource Consents CRC194987, CRC194988, and SDC195880 with an associated overflow channel in the Selwyn River/Waikirikiri during dry periods and when water is available from the unused water rights in current consents CRC153238, CRC011996 and CRC167218 to augment groundwater and spring flows discharging to the Hororata River. The augmentation will benefit the environment in the following ways:
• Enhance reliability of spring flows feeding the Hororata River;
• Enhance mudfish habitat in downstream springs;
• Enhance shallow groundwater and connected surface water of the down- gradient Selwyn River system;
• Creation of a lizard refuge in bunding of excess excavated material around the infiltration basin;
• Enhancement of native flora and seed sources through planting around the perimeter of the recharge basin, and plantation clearings following forestry harvest. The associated works and operation for the activity are described below. 2.2 Targeted Augmentation The augmentation scheme will involve discharging water supplied from the CPW scheme infrastructure into an infiltration basin up-gradient of Haldon Pastures Spring Field and Derretts Road Spring Field at flow rates up to 3.5 m³/s. Additional to the infiltration basin, there will be an overflow channel into the dry riverbed of Selwyn River/Waikirikiri which will allow water in excess of the infiltration basin capacity to infiltrate into the groundwater system via the riverbed gravels. The main CPW trunk supply pipeline crosses the Upper Selwyn River/Waikirikiri between Hawkins Road and Bealey Road, near Hororata Township, close to where the river naturally recharges a number of springs in the vicinity of Haldon Road. These provide a significant proportion of the low flow to the Hororata River and middle reaches of the Selwyn River/Waikirikiri. The proposed infiltration basin site is located on the true right bank of the Upper Selwyn River/Waikirikiri active riverbed, approximately 2.8 km upstream of the Bealey Road Bridge. The Haldon Pasture Spring field and the Bealey Stream and its tributaries are located almost directly downgradient of the proposed re-charge site and its estimated reach. Most of the Haldon Pasture Springs are located on Haldon Pastures Station, which is owned by the Grigg Family. The Derretts River /
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Mill Stream Spring field is located further to the west of the Haldon Springs area, and is believed to be located more cross gradient to the proposed infiltration basin site and reach. The system will be controlled to ensure that excessive discharges will not occur. There will be number of operational triggers in place that will require discharges to ground to cease. The proposed triggers to cease augmentation are:
• Water levels in the BX22/0184 at the head of the main tributary of Bealey Stream (to avoid excessive spring flows flooding downstream farmland);
• Flow present in the Selwyn River/Waikirikiri adjacent to the site (assessed when flows at Whitecliffs recorder site greater than 1.5 m³/s) to avoid mixing of waters in the Selwyn Waikirikiri;
• The depth of groundwater beneath the infiltration basin (to avoid excessive mounding of groundwater table in close vicinity to the site). The purpose of the proposed augmentation is to increase water levels in the shallow groundwater system to enhance the flow and quality of the nearby streams, rivers and ultimately, Te Waihora/Lake Ellesmere. The recharged water is intended to increase shallow groundwater levels downgradient of the recharge site with the shallow groundwater expected to emerge above ground level in a number of springs down-gradient of the proposed recharge site. During dry years, flows in many of the waterways within the Te Waihora/Lake Ellesmere catchment are typically reduced and, in some cases, streams dry up completely. Reduced flows result in less dilution of any nutrients present in the streams and can also reduce the habitat of native aquatic species (in particular the threatened Canterbury Mudfish) within the catchment. Figure 1, Appendix A shows the general location of the site and the Selwyn River/Waikirikiri in relation to Te Waihora/Lake Ellesmere and the major surface water ways of the Central Canterbury Plains, including the CPW canal and pipeline infrastructure. The tributaries to Selwyn River/Waikirikiri are shown in Figure 2, Appendix A and the proposed infiltration basin location is shown adjacent to the Selwyn River/Waikirikiri. The site is located within a forestry block and the proposed infiltration basin is shown in Figure 3, Appendix A. 2.3 Discharge Structure
Resource Consents CRC194987, CRC194988, and SDC195880 have been obtained to construct an infiltration basin of approximately 200 m in length and 70 m in width will be installed at Lot 3 DP 78682. The floor will be excavated to a depth of 1.5 m below ground level at the western end and 0.5 m at the eastern end. The basin will have a weir constructed from gabion baskets or similar at its eastern end and will be approximately 0.5 m above the basin floor. The weir will allow a small volume of water to be stored in the basin to encourage infiltration to occur and to mitigate surges of water being released to the riverbed. When the basin reaches capacity, the weir will allow excess water to flow down the dry
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ENVIRONMENT CANTERBURY - ASSESSMENT OF ENVIRONMENTAL EFFECTS FOR THE SELWYN RIVER / WAIKIRIKIRI NEAR RIVER R ECHARGE SCHEME, HORORATA FLOW AUGMENTATION SCHEME riverbed and infiltrate via the gravels in the bed. An overflow channel will be excavated to direct flow down the dry riverbed. The water source will be provided via the installation of a tee connection on the CPW Stage 2 glass fibre reinforced plastics (GRP) pipeline. The pipeline at the proposed point of the tee connection is 1.6 m below existing ground level. Approximately 30 m of 1.2 m diameter pipework will be installed from the connection point to the valves at the basin. This will discharge to a concrete chamber to dissipate excess water prior to entry into the basin. Water will be discharged into the chamber via 10 control valves. From the basin, four culverts will be installed to connect the basin to discharge flows to the riverbed when the basins infiltration capacity is exceeded. Further detail can be found in Appendix H regarding the concept report and proposed construction details undertaken by Stantec (Stantec, 2017). The forested area currently covering the majority of the infiltration basin site will be felled; no woody vegetation or waste will be discarded into the river during the removal of the plantation. Some other riparian vegetation such as gorse and broom will also be removed from the dry riverbed prior to connecting the discharge to a flood channel of the river. It is anticipated that a volume of up to 25,000 m³ of riverbed gravels and soils will be excavated to construct the basin. It anticipated that over 1 m of disturbed material will be maintained between the bottom of the basin excavation and seasonal high-water table. The infiltration basin is currently over 200 metres from the flowing surface water of Selwyn River/Waikirikiri. Minor excavation works with the removal of vegetation and shaping of the return channel to the water course may encroach within 20 m of the low flow channel of the river. Excess excavated material will be used to form a bund around the infiltration basin and control building to act as a noise attenuation barrier for the noise from the control valves as well as forming lizard habitat on the landward extent of the floodway within the current forested area. The construction works will be undertaken at low flows in the Selwyn River/Waikirikiri and are expected to be several hundred metres from the nearest water body. A dust plan and erosion and sediment control plan (ESCP) will be used to avoid any detrimental runoff from entering the river during the earthworks excavation and construction period. The building housing main equipment and electrical components will be built on the landward side of the basin adjacent to the natural floodplain terrace. 2.4 Water Source ECan has identified the unused portion of existing water consents from the Rakaia River for the recharge of the Haldon Pasture Spring field and the Bealey Stream as an effective way to enhance flows in the shallow groundwater system near Selwyn River/Waikirikiri. This includes historical SDC stock water takes within the Selwyn/Waikirikiri Catchment. Table 2 shows the consents which have unused water rights that can be repurposed to the project.
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Table 2: Consent locations and water takes
Consent Consent / Consented Annual Expiry Date Holder Locations flow rates Volume (m³) (m3/s)
CPW CRC167218 33.5 N/A 25 July 2047
SDC CRC153238 0.732 23,084,352 21 November (Early’s Intake) 2031
SDC CRC011996 0.5 15,768,000 4 February 2025 (Headworks Road)
The operation of the scheme will only be possible when the CPW scheme is operating below maximum capacity. CPW’s Consent CRC167218, is limited in operation at low flows in the Rakaia River in accordance with the water allocation and constraints of the National Water Conservation (Rakaia River) Order 1988 (NWCO). However, SDC’s consents CRC153238 and CRC011996 are not restricted by these constraints and ECan seeks to utilise this water when it is not being used by SDC, and when CPW water is not available to be used. The point of take will be from the CPW irrigation pipeline as it passes the site. Water will be diverted to this point from the Rakaia River via CPW infrastructure. The takes will be monitored by a certified electro-magnetic flow meter at the irrigation off take and the existing CPW and SDC off take points. Flows will be monitored in accordance with the accuracies required for the Resource Management (Measurement and Reporting of Water Takes) Regulations (2010). 2.5 Operation The system is designed to augment groundwater levels when they are naturally low. Pipeline capacity to deliver water is primarily available during the irrigation off season from approximately May to August as well as at the beginning and end of the irrigation season (September – November, and March/April). During wet years when the springs flow naturally, this being a result of high river flows and groundwater levels, the system will not be required to be operated. The implementation of this system will enhance the habitat of the affected channel by reducing the length of the dry period the fish need to survive. Water will be diverted from the main CPW GRP pipeline via the tee and controlled with an isolation valve. The water will enter the system through 10 controlled valves which act to dissipate the energy of the water caused by the high pipeline pressure. These valves are estimated to emit up to 89 dB of sound each (99 dB in total) due to the high pressure drop and large amount of energy dissipation. The valves will be housed in a building designed with sufficient
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ENVIRONMENT CANTERBURY - ASSESSMENT OF ENVIRONMENTAL EFF ECTS FOR THE SELWYN RIVER / WAIKIRIKIRI NEAR RIVER RECHARGE SCHEME, HORORATA FLOW AUGMENTATION SCHEME attenuation measures to ensure noise from the valves is not at an unacceptable level for neighbours, riverbed users and wildlife. It is proposed to operate the scheme to avoid discharging the flows from the CPW scheme directly into local groundwater or to flow in the adjacent Selwyn/Waikirikiri River. Flow into the basin will cease once the water table monitoring sites indicate the groundwater levels are less than 1 m below ground level at the discharge site ( i.e. 1m of the ground surface ) as measured at in the proposed monitoring bore adjacent to the infiltration basin) or surface water flow in Selwyn River/Waikirikiri are measured above 1.5 m³/s at the water level recorder site at Whitecliffs, approximately 13 km upstream of the discharge site. It is intended that the scheme may still be operated if no natural flow is observed in the Selwyn River/Waikirikiri adjacent to the infiltration basin. In order to avoid potential downstream flooding effects, it is not intended to operate the scheme if significant water is flowing naturally from the downstream springs. This will be initially set to cease scheme discharges when groundwater levels are less than 1 m below ground level downstream at BX22/0184 (adjacent to the head of the Haldon Pastures Spring Field). It is acknowledged that there are several significant uncertainties relating to the characteristics of the springs and the existing ecological habitat. These uncertainties are principally related to the limited understanding in the groundwater flow system and the length in time since the springs have flowed. To overcome these uncertainties, the scheme commissioning will be staged and monitored for water quality and water level at different flow rates. The system will be operated and monitored at infiltration basin capacity and stepped flow rate increases as CPW water availability allows. Starting at small flow rates and building up in conjunction with monitoring will ensure risks of adverse effects to the existing eco-systems are identified and minimised. The commissioning for the system will be carried out as outlined in the report, Selwyn River/Waikirikiri Near River Recharge Project: Operational Monitoring Plan (OMP), which is found in Appendix B (PDP, 2018). During commissioning and operation, level 1 monitoring specified in the OMP (Appendix B) will be carried out to maintain effective control of the system and ensure adverse effects are effectively mitigated and controlled. The OMP also includes level 2 and 3 monitoring options which may potentially be implemented additionally to the necessary level 1 monitoring. However, these are to improve the understanding of the environment and for general scientific understanding and this monitoring is not essential for the operation of the scheme.
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3. Statutory Framework The planning document relevant to this consent application are as follows:
• Resource Management Act 1991
• National Water Conservation (Rakaia River) Order 1988
• National Policy Statement Freshwater Management 2014 (Revised 2017) (NPSFM)
• Land and Water Regional Plan (LWRP)
• Plan Change 7 – Notified Version (PC 7-NV) to the LWRP There is no RMA direction of the precedence the NWCO may take other than a Water Conservation Order being prevailing over a national environmental standard where the Water Conservation Order is more stringent and vice versa. In this case, the NWCO is considered to prevail over other planning documents. 3.1 Relevant Planning Framework Table 3 provides a description of statutory planning zones and any overlays that apply for the relevant planning documents within Canterbury.
Table 3: Relevant SDP/LWRP Plans/Zones/Overlays
District Plan Selwyn District Plan
Zone Outer Plains
Overlays • Waterbody Generalisation and/or key features • Wāhi Taonga Management Area
Regional Plan Land and Water Regional Plan
• Rakaia-Selwyn Groundwater Allocation Zone,
• Selwyn-Waihora Surface Water Allocation Zone,
• Semi/Unconfined Aquifer
• Phosphorus Sediment Risk Area (Spring fields),
Overlays • Rivers where Damming is prohibited and/or key features • Selwyn Waikirikiri Surface Water Catchment • Irrigation Zone Area (CPW)
• Water Quality Classification = Hill-fed Lower River (Selwyn/Waikirikiri Main Channel)
• Water Quality Classification = Spring –fed Plains (Selwyn/Waikirikiri Secondary Channels)
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E NVIRONMENT CANTERBURY - ASSESSMENT OF ENVIRONMENTAL EFFECTS FOR THE SELWYN RIVER / WAIKIRIKIRI NEAR RIVER RECHARGE SCHEME, HORORATA FLOW AUGMENTATION SCHEME
3.2 Approach to Securing Water Rights The reason ECan is applying to share water with the CPW and SDC is to maximise the use of an existing authorised allocation of water and not further contribute to new water being taken from the Rakaia River. This approach enables other prospective users to access Rakaia River water at times when it is available for allocation and avoid locking up further new water when there is an opportunity to better use an authorised volume. As the remaining “unallocated” water for Rakaia River is only available during winter months, this approach is in line with the Water Storage strategy in the Canterbury Regional Policy that seeks to maximise the efficient allocation of water and encourage use of water storage. As illustrated above, ECan has identified a number of existing consents which represent an opportunity to water share an existing authorised volume. An agreement has been reached with CPW and SDC to enable this and water will be taken by ECan up to the existing authorised limits of the CPW and SDC consents. Consent conditions are proposed to avoid either rate or volume limits being exceeded, in conjunction with the CPW and SDC consents. The current CPW infrastructure and take consent will limit instantaneous take limits not being exceed. Annual volumetric take limits are included in the take consent conditions to ensure limits are adhered to. It is considered only appropriate to assess this on an annual basis as the instantaneous take limits will be already protected by the parent take and diversion consents, and the intricacies of the storages in the CPW irrigation network will not allow relevant comparisons of instantaneous and even daily limits. Monitoring of the discharges will also be undertaken on a continuous instantaneous basis to ensure that adverse effects of the discharges are appropriately mitigated and avoided. The effects, as directed by the restricted discretionary matters of Rule 5.123 1 are assessed in Section 6.3 of the AEE. In summary, no additional allocation is required over and above already authorised allocations and effects downstream on the Rakaia River are considered less than minor. Furthermore, Clause 9(4) of the NWCO states: Resource consents under the Act may be granted and general authorisations may be made in respect of any part of the waters specified in this clause for all or any of the following purposes: (a) research into, and enhancement of, fisheries and wildlife habitats: A legal opinion has been provided which considers that the NWCO enables decision makers to grant water for the purpose of fishery and wildlife habitat, which this application is for. While this mechanism may be used, it is anticipated that the applicant will still be required to demonstrate that adverse effects as result of the take are acceptable, regardless of the benefits of the purpose.
1 Acknowledging the overall activity status is discretionary.
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The mechanism for water sharing is made possible through Rule 5.133 of the LWRP, Rule 5.191 of PC 7-NV and provisions of the NWCO. See section 3.3 below for an assessment of compliance with Rule 5.123. 3.3 Reason for Resource Consents ECan is applying for resource consents for works associated with targeted augmentation and biodiversity enhancement of the Haldon Pasture Spring field and Derretts River/ Mill Stream Spring field as shown in Figure 2 (Appendix A).
Activity Status A justification for the activity status of each rule is illustrated in Table 4 below.
Table 4: Resource Consents Sought
Provision Activity Activity Status
Section 5: Region-wide rules
Rule 5.123 The taking and use of surface water Restricted from a river or lake is a restricted Discretionary discretionary activity, subject to conditions (see Table 5 below).
Section 11: Selwyn Te Waihora Sub-region Rules
11.5.43 The discharge of water into water or Discretionary onto or into land for the purpose of (Duration greater than augmenting groundwater or surface Five years) water to increase stream flows in the Selwyn Te Waihora sub-region that does not meet one or more of the conditions of Rule 11.5.42.
Plan Change 7 to the LWRP
5.191 The take of surface water for managed Restricted aquifer recharge, the associated use Discretionary and discharge of that water and entrained contaminants into water or into or onto land, the use of land for the excavation and deposition of material to construct the managed aquifer recharge system, and the discharge of construction-phase stormwater into or onto land where it may enter water subject to conditions (see Table 5 below)
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Important to facilitating the water sharing proposed, the activity must be able to comply with conditions of Rule 5.123 of the LWRP and Rule 5.191 of PC 7 --NV. This assessment is provided in Table 5 below.
Table 5: Assessment of Compliance with Rule 5.123 & Rule 5.191
Rule 5.123 of the LWRP Comments
1. … the take, in addition to all existing Section 12 (Central Canterbury consented takes, does not result in Alpine Rivers) of the LWRP makes any exceedance of any this condition (1) applicable instead environmental flow or allocation of Condition 2. For allocation limit or rate of take or seasonal or limits, Section 12 directs applicants annual volume limits set in to the NWCO. Sections 6 to 15 for that surface The NWCO sets out the provisions waterbody; and relating to allocation limits and minimum flows that have already been applied to the CPW and SDC parent consents. Therefore, as this proposal will share water with existing consent holders, there will be no change to the allocation status of the Rakaia River and the granting of this consent will not cause any over- allocation.
2. …if no limits are set in Sections 6 to N/A as the Condition 1 of Rule 15 for that surface waterbody, the 5.123 takes precedence in the take, both singularly and in addition gateway to determine allocation. to all existing consented takes meets a flow regime with a minimum flow of 50% of the 7-day mean annual low flow (7DMALF) as estimated by the CRC and an allocation limit of 20% of the 7DMALF; and
3. … the take is not from a wetland, The take is not from any of these Hāpua or a high naturalness river or identified water bodies. high naturalness lake that is listed in Sections 6 to 15.
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Table 5: Assessment of Compliance with Rule 5.123 & Rule 5.191
Rule 5.191of Plan Change 7 Comments
1. The take and use of water, in As per Rule 5.123(1) above. Also, of combination with all other takes, pertinence is the ability to grant complies with the provisions of any consent for enhancement of, fisheries relevant Water Conservation Order; and wildlife habitats as described in and Section 3.2 above.
2. … the take, in addition to all existing As per Rule 5.123(1) above. consented takes, does not result in an exceedance of any environmental flow or allocation limit, or rate of take, or seasonal or annual volume limit set in Sections 6 to 15 of this Plan for that surface water body; and
3. The take is not from a high As per Rule 5.123(3) above. naturalness river or high naturalness lake listed in Sections 6 to 15, or from a wetland (excluding an artificial wetland); and
4. The application demonstrates the See Sections 6.4.1, 6.4.2 and 6.4.3 proposal will either reduce the and Appendix B of this AEE. concentration of contaminants, or increase the volume of water, in the receiving groundwater aquifer;
5. The application demonstrates the See Sections 6.4.1 and Appendix B proposal will not reduce the quality of this AEE. of human and animal drinking water at any existing drinking water supply source within 1 kilometre of the point of discharge; and where there are no existing drinking water supply sources within 1 kilometre of the proposal the application demonstrates there will be no degradation in groundwater quality further than 1 kilometre beyond the discharge point; and
6. The point of discharge is not: The discharge location meets these requirements. The discharge is via a. directly into the bed of a river or an infiltration basin and flows will lake, an artificial watercourse or a
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Table 5: Assessment of Compliance with Rule 5.123 & Rule 5.191 wetland, excluding an artificial only discharge to the bed of the wetland; or Selwyn River when flows are not present. b. onto or into contaminated or potentially contaminated land; or c. within 50 m of an existing bore used for water abstraction; or 7. within a Community Drinking- water Protection Zone as set out in Schedule 1; and
8. A Managed Aquifer Recharge Plan is A Managed Aquifer Recharge Plan prepared in accordance with (MARP) has been prepared and is Schedule 32 and is submitted with included in the OMP in Appendix B. the application for resource consent
In strict accordance with Rule 5.123 and 5.191, the application complies with the conditions. Overall, consent is sought from ECan as a Discretionary Activity. For the avoidance of doubt, ECan is seeking consent under the above rules and any other rules which may apply to the activity, even if not specifically noted.
Restricted Discretionary Matters of Rules 5.123 and 5.191 Although the overall status of the application is discretionary, the Restricted Discretionary matters of Rule 5.123 and 5.191 have been used to guide the assessment of effects for the water sharing. A response to those matters is provided in Appendix E. 3.4 Other Resource Consents Resource Consents CRC194987, CRC194988, and SDC195880 have already been obtained by ECan and SDC to construct the works. CPW holds Consent CRC167220 for the diversion structure and its operation. 3.5 Term of Consent As provided for by section 123 (RMA), ECan can apply for a term of up to 35 years. However, in regard to the proposed water take consents, the proposed durations must align with the parent consents. The proposed durations for the subservient water take consents are as follows:
• Consent subservient to CRC167218 25 July 2047.
• Consent subservient to CRC153238 21 November 2031.
• Consent subservient to CRC011996 4 February 2025.
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In regard to the discharge permit, it is proposed to align the duration with the parent water take consent that is authorised for the longest duration. In this case, aligning the discharge consent duration with CRC167218 (expiring on 25 July 2047) is proposed. As each parent consent expires, ECan will be required to also apply for a replacement subservient consent. Policy 4.11 of the LWRP promotes limiting the duration of any resource consent granted to a period not exceeding five years past the expected notification date of any plan change that will introduce water quality or water quantity provisions into the LWRP. However, the policy also allows for longer resource consent duration for discharge permits where appropriate. It is considered that this discharge will not impact nitrogen loss from the land, and that this activity is proposed to help meet water quality and water quantity provisions in this area, and therefore a twenty-eight-year duration is appropriate in this circumstance. This duration is sought owing to the value of the infrastructure and to ensure that the system can be commissioned within the time this consent is active such that any additions or alterations to the system can be made. This also takes into account the chance of encountering a number of varying seasons where the construction and full commissioning of the infrastructure is not achievable.
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4. Consideration of Alternatives Schedule 4, Section 6(1)(a) states that: ‘if it is likely that the activity will result in any significant adverse effect on the environment”, then the application must include “a description of any possible alternative locations or methods for undertaking the activity’. The take and discharge of water from the Rakaia River to the Selwyn River/Waikirikiri does not have significant effects, however, it is considered prudent to comment on alternative options because ECan has been looking into flow augmentation solutions in the Selwyn River/Waikirikiri catchment since 2011. While many alternatives have been investigated, including the use of stock water races and pipelines, they have not been feasible due to high infrastructure costs, cultural issues relating to the direct mixing of waters, and water treatment requirements such as primary treatment wetlands. Stock water race diversion flow rates were also determined to be limited to 0.05-0.1 m3/s, which is considered too low for the proposed project to have a significant improvement effect in the spring flows. The proposed infiltration basin was chosen as the favourable option for the following reasons:
• The close proximity of the infiltration basin site to the CPW pipeline;
• Minimal infrastructure requirements, with a relatively shallow basin needed to intersect highly permeable aquifer layers;
• Filtration through groundwater and gravels provides acclimatisation time for CPW water, to mitigate any risks of mixing waters from different catchments, rather than shorter duration acclimatisation time through a wetland;
• Proximity to significant Canterbury mudfish habitat in Haldon Pastures and Derretts River Spring systems. The proposed water sources were selected to provide efficient use of existing infrastructure and the benefits offered by the strategic location of the CPW pipeline to the area of high ecological value at the spring fed tributaries of the Hororata River.
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5. Description of the Environment 5.1 Locality and Land Use The proposed infiltration basin site is approximately 4.3 km from the Township of Hororata and has been recently been purchased by ECan. The surrounding land- use is predominantly agricultural pasture and forestry within the immediate vicinity of the infiltration basin site. There are also a number of lifestyle blocks located around the western edge of the forestry block. This area is classified as a rural Outer Plains Zone by the SDC and ECan classify the area as the Rakaia-Selwyn Groundwater Allocation, Selwyn-Waihora Surface Water Allocation, and Semi-Confined or Unconfined Aquifers zones. ECan also consider the area as a Phosphorus Sediment Risk Area (Spring fields), and Irrigation Scheme Area. The infiltration basin site is located approximately 1.5 km upstream of the intersection between Bealey Road and Selwyn River/Waikirikiri. Figure 1 (Appendix A) shows the location of this area. Several lifestyle blocks with residential dwellings are located on the edge of the forestry block and at the northern end of Haldon Road downgradient of the infiltration basin site. The residential dwellings have private water supply bores and below ground wastewater disposal systems. There are no records of the site on the Listed Land Use Register as a contaminated site. 5.2 Surface Water Bodies
Rakaia River The Rakaia River is a large alpine sourced river located to the south of the Selwyn/Waikirikiri catchment area. This is the principal water source for the CPW irrigation scheme and the SDC stockwater race systems. Flow has been measured by NIWA at the Fighting Hill Flow Recorder site in the Rakaia Gorge upstream of State Highway 77 since 1978. This flow measurement site is located approximately 10 km upstream of the CPW intake with an upstream catchment area of 2,600 km2. Downstream of the flow recorder site, the contributing catchment is limited to such an extent that the only surface water inflow of any significance is the discharge of the Rangitata Diversion Race through the High Bank power station. These flows are typically 30-35 m3/s, and the power station is located approximately opposite the CPW intake and return channel from in-front of the intake fish screen. Review of daily flow records indicates a median daily flow of 158 m3/s between 1978 and 2019 at NIWA’s Fighting Hill Site. Minimum flows typically occur between February – July, and vary between 52 and 66 m3/s during these months.
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In 1988, the NWCO set an allocation limit for the Rakaia River which limited the amount of water that could be granted for consumptive purposes other than those activities listed in s9(4) of the NWCO. Under the NWCO, a maximum of 70 m3/s may be allocated at any one time. Water is currently allocated in 23 separate bands with minimum flows ranging from 129 -202 m3/s. This excludes SDC’s take consents for their water races, which are outside the scope of the NWCO.
Selwyn River/Waikirikiri The Selwyn River/Waikirikiri is an alluvial plain river that is subject to large flow fluctuations and is used frequently for water abstraction (Larned, et al., 2008) . The river originates in the Canterbury foothills above Whitecliffs and crosses the Canterbury Plains before discharging into Te Waihora/Lake Ellesmere (Larned, et al., 2008). The river is fed by rainwater recharge in the upper reaches and springs in the lower reaches, where ephemeral / intermittent tributaries are more common (Kerr & Swaffield, 2007). The principal hill country tributary catchments are the Hawkins River (105 km 2), Waianiwaniwa River (150 km2), Upper Selwyn River/Waikirikiri (275 km2) and the Hororata River (134 km2). The confluence of the Upper Selwyn River/Waikirikiri and Hororata River is located approximately 13 km upstream of the SH1 Bridge, 38 km upstream of Te Waihora/Lake Ellesmere. The Hawkins and Waianiwaniwa rivers join the Selwyn River/Waikirikiri approximately 0.9 km upstream and 4.1 km downstream of the Hororata River confluence. Base flows from these hill country catchments are lost to deep gravel aquifer formations as the Selwyn River/Waikirikiri emerges from the foothills upstream of the site. The flows in the Selwyn River/Waikirikiri are highly ephemeral and it dries for extended periods of time between the foothills to approximately 3-4 km downstream of SH1; this includes the area of riverbed adjacent to the site. The riverbed adjacent to the proposed discharge site has limited recreational use owing to its proximity to major roads. Recreational four wheel driving is undertaken on the riverbed and is largely accessed from Hawkins Road approximately 1km from the site. Gravel extraction is undertaken upstream of the site at Hawkins Road.
Haldon Pastures and Derretts River/ Mill Stream Spring fields The Haldon Pasture Spring field, which feeds the Bealey Stream and ultimately the Hororata River, are located almost directly downgradient of the proposed infiltration basin site and reach. Most of the Haldon Pasture Springs are located on Haldon Pastures Station, which has been owned by the Grigg Family for nearly 100 years. The Derretts River/ Mill Stream Spring field also feeds the Hororata River and is located further to the west of the Haldon Springs area, and is believed to be located more cross gradient to the proposed infiltration basin site and reach. However, these springs are also considered a part of the targeted
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Hororata River The spring-fed Hororata River is a major tributary to the Selwyn River/Waikirikiri. The confluence of the Hororata River is located approximately 11 km downstream of the proposed discharge location. The Hororata River originates from tributaries on the south facing slopes of Harper Hills and western Malvern Hills, before flowing along the Canterbury Plains for approximately 40 km to the Selwyn River/Waikirikiri confluence. The Hororata River is intermittent in the lower reaches, with permanent flow limited to the upper 10 km of the watercourse. Approximately 50-60% of the river flow at the confluence with the Selwyn/Waikirikiri River is thought to account to spring flow from Haldon Pastures and Derretts River Spring fields. 5.3 Flooding The SDP Map identifies land nearby the riverbank, downstream of the confluence of Hororata River and Selwyn River/Waikirikiri, as a lower plains flood hazard area. Upstream of the confluence no flood hazard zones are identified in the plan from the Selwyn River/Waikirikiri spilling from its normal course during high rainfall. The plantation and infiltration basin site are considered part of the flood plain in large floods and the proposed basin will be in the flood plain. Stantec (ref to Appendix H) have shown that the any additional flood risk created by infiltration basin and placement of excess excavated material within the greater floodplain is minor (Stantec, 2018). It is understood that this area was not flooded during the July 2017 flood event, which was estimated as a 10-20 year AEP flood event. The infiltration basin site is largely protected from floodwaters by the upstream pine plantation in the vicinity of Hawkins Road, as the thickly planted floodway berm limits velocities and flows spilled over the floodway berm on the true right berm of the floodway. 5.4 Ecology
Selwyn River/Waikirikiri The Selwyn River/Waikirikiri is home to a wide range of fish and macroinvertebrate species (Table 6), of which the abundance and diversity are directly related to flow permanence (Davey & Kelly, 2007). The Selwyn River/Waikirikiri in the vicinity of the proposed infiltration basin site is intermittent; therefore, aquatic habitat in the area is temporary.
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Table 6: Fish Species known to occur in the Selwyn River/Waikirikiri
Scientific name Common name Threat Status Catchment
Selwyn River, Anguilla australis Shortfin eel Not Threatened Hororata River tributaries
Selwyn River, Anguilla At Risk - Longfin eel Hororata River dieffenbachii Declining tributaries
Galaxias At Risk - Inanga Selwyn River maculatus Declining
Selwyn River, Canterbury At Risk - Galaxias vulgaris Hororata River galaxias Declining tributaries
Threatened – Geotria australis Lamprey Nationally Selwyn River Vulnerable
Selwyn River, Gobiomorphus Upland bully Not Threatened Hororata River breviceps tributaries
Gobiomorphus Common bully Not Threatened Selwyn River cotidianus
Gobiomorphus Giant bully Not Threatened Selwyn River gobioides
Selwyn River, Threatened – Hororata River, Neochanna Canterbury Nationally Hororata River burrowsius mudfish Critical tributaries
Retropinna Common smelt Not Threatened Selwyn River retropinna
Selwyn River, Introduced and Hororata River, Salmo trutta Brown trout naturalised Hororata River tributaries
The dry riverbed in the vicinity of the proposed site has the potential to be used as breeding habitat for a number of bird species (L. Drummond, pers. observation). No formal surveys have been completed for the Selwyn River (Gray & Harding, 2007); however, the shallow coastal lagoon and associated
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Haldon Pastures Spring field In the Haldon Pastures Spring field, Bealey Stream is a known habitat for the threatened Canterbury mudfish (Neochanna burrowsius). The Canterbury mudfish is confined to the Canterbury Plains and is amongst New Zealand’s most threatened freshwater species. The Canterbury mudfish is classified as a threatened, nationally critical species, according to the Conservation Status of New Zealand Freshwater Fish (Dunn, et al., 2017), due to very high ongoing or predicted population decline.
Hororata River The Hororata River has recorded fish presence from the springs to the confluence with the Selwyn River/Waikirikiri (Table 4). The Hororata River can provide a refuge for fish passage upstream from the drying Selwyn River/Waikirikiri during drying periods. 5.5 Existing Water Users The proposed activity may discharge overflowing water from the basin into the Selwyn River/Waikirikiri bed in which water is expected to take up to 3 km in distance to infiltrate through the riverbed. Water users within a 2 km distance of the basin and the 3 km stretch down the river have been identified on the ECan GIS database. There are 30 active or altered bores within 2 km of the activity area and four bores which are currently proposed to be drilled or altered. The uses for the above bores are as follows:
• Domestic supply (14 bores, 11 – 36 m bgl)
• Irrigation (8 bores, 32.9 – 130 m bgl)
• Domestic and stock water (8 bores, 24 – 37.3 m bgl)
• Groundwater Quality (2 bores, 35 – 40 m bgl)
• Stock supply (2 bores, 15.2 – 30 m bgl) There are also fifteen bores that are buried, abandoned, unused, unlawfully established or have no information and expired consents within 2 km of the proposed activity area.
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There is only one documented surface water take within the 2 km area. This took water from Selwyn River/Waikirikiri at Bealey Road Bridge under consent permit s14 CRC980186 and has since been terminated. No public water supplies are located within five kilometres of the proposed discharge. 5.6 Topography The topography of the site consists of relatively flat paleo river terraces. Plains surround the river infiltration basin site and downstream flow area. Land elevation at the infiltration basin site is at approximately 180 m above mean sea level and elevation gradually descends towards the coast and Te Waihora/Lake Ellesmere which guides water flow direction. Shallow channels exist towards the Selwyn River/Waikirikiri and deeper channels formed from incised spring discharges are common throughout the Te Waihora/Lake Ellesmere catchment. A surface topographic catchment divide between the Bealey Stream and Derretts Rivers catchments has been interpolated from ground surface contours based on Lidar data from ECan’s online database. The divide is roughly north – south in orientation and extends from approximately the infiltration basin site to the Hororata River, between the Bealey Stream and Derretts River. The surface contours and the extent of the catchment are also displayed in Figure 2 (Appendix A). 5.7 Surface Soils The Manaaki Whenua/Landcare Research database identifies the recharge area as predominantly Lismore shallow silt loam with the soil types immediately downstream consisting of a mixture of Mayfield, Struan, Waterton, Waimakariri and Rakaia moderately deep silt loams and Willowby shallow silt loams. Soil information from Landcare Research’s S-Map online GIS database indicates that soils around the infiltration basin site are well draining sandy loams with PAW60 values (PAW between 0 and 0.6 m bgl) ranging between 26 and 46 mm. The soils in the vicinity of the Haldon Pastures Springs field system generally varies between imperfectly to poorly draining with PAW60 values ranging between 87 and 138 mm, although there are areas of moderately well-drained silty loam soils with PAW60 values that range between 80 and 88 mm. These poorer draining soils form the surface confining layer where the springs emerge in discontinuities in the lower permeability soils. Based on the available soil information, the soils around the Derretts and Haldon Pastures Springs fields are expected to generally have lower permeabilities and poorer drainage characteristics than the soils around the infiltration basin site. It is considered likely that these lower permeability soils act as an aquitard causing localised semi-confined and artesian aquifer conditions in the vicinity where the springs emerge to the surface.
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5.8 Geology The 1:250,000 geological map for the Christchurch area and surrounding Canterbury Plains indicates that the strata beneath the infiltration basin site consists predominantly of Unweathered Holocene river deposits and Pleistocene river alluvium (GNS Science, 2014). These alluvial deposits form alluvial fans which are typical of the Canterbury Plains and are related to glacial and interglacial climatic periods that occurred in the inland valleys and mountains during the late Quaternary period. These structures influence the flow paths and travel between unconfined aquifers for groundwater within this area. The proposed infiltration basin site is located on gravels of the Springston Formation that are described by Vincent (2005) as being well rounded and well sorted fluvial gravel with sand and silt, derived from the degradation of older gravels.
Fault Traces The main extent of the Greendale fault trace (shown in Figure 5, Appendix A) runs through the area and is orientated roughly east – west for the majority of its surface expression. West of the Selwyn River/Waikirikiri, the Greendale fault trace changes direction between the Hororata and Selwyn River/Waikirikiri, becoming roughly subparallel to both rivers. The fault trace extent has been mapped up to the Haldon Pastures Spring field. There are no known faults located in the vicinity of the infiltration basin.
Surface Strata Stantec (2017) undertook a site inspection of the proposed infiltration basin in 2017 and provided descriptions of the strata at the site based on an open pit west of the proposed basin, a test pit located just north of the proposed basin and the exposed riverbed. The site observations indicated that the near surface strata consisted of around 0.5 m to 1.5 m of silt and silty gravel overlying more permeable sandy gravel. Bore logs nearby the site can also be assessed for an indication of expected surface strata. Bore BX22/0140 (30 m deep) adjacent to Struie Road indicates sandy gravel and clayey, silty gravel from ground level to around 10 m below ground level (m bgl) with interbedded less permeable claybound gravel and more permeable sandy gravels to depths greater than 25 m bgl. Bore L35/0550 (33 m deep) indicates water-bearing sandy gravel with clay from ground level to around 22 m bgl. This is underlain by water bearing sandy gravel to the base of the bore at 33 m bgl. Copies of these borelogs are provided in the OMP, Appendix B. 5.9 Groundwater Vincent (2005) undertook a relatively extensive assessment of the hydrogeology of the area. This study indicated at least three aquifers beneath the
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Waikirikiri/Selwyn River denoted as Aquifer 1, Aquifer 2 and Aquifer 3 with increasing depth (Vincent, 2005). Aquifer 1 is described as being unconfined and extends to a depth of around 30 m bgl (Vincent, 2005). Vincent (2005) noted that Aquifer 1 is more distinguishable near rivers and suggested the possibility that Aquifer 1 may not be present between Waikirikiri/Selwyn River and Greendale.
Groundwater Flow Path There are likely to be preferential groundwater flow paths within the strata described in Section 5.8 above. This is due to the Selwyn River/Waikirikiri catchment and alluvial fan location within a depression between two larger alpine river alluvial fans (Rakaia River and the Waimakariri River). A meltwater channel is likely to have formed from the Rakaia Glacier (Vincent, 2005). This means there is likely to be significant heterogeneity within the strata from buried paleo channels and varying permeability in strata. Vincent (2005) also produced a piezometric contour map for Aquifer 1 which shows that groundwater flow generally mimics the flow in the Waikirikiri/Selwyn and Hororata Rivers which is shown in Figure 5, Appendix A. The piezometric contour map shows that shallow groundwater flow between the Selwyn River/Waikirikiri and Hororata River is in a southerly direction, with flow heading from the Selwyn River/Waikirikiri toward the Hororata River. Based on this, the discharged water to ground at the infiltration basin site is expected to follow this similar flow pattern. It can be seen from this information that the targeted area for augmentation is the Haldon Pastures Spring Fields.
Transmissivity ECan’s online GIS database (Canterbury Maps) indicates that the closest bores with transmissivity information to the infiltration basin site are bores L35/0550 (screened between 29.9 and 32.9 m bgl, approximately 1 km to the west) and L36/0626 (8.2 m deep, approximately 3 km to the west) with reported transmissivities of 3,000 m²/day and 2,000 m³/day based on a step-drawdown tests in each bore respectively. The OMP (Appendix B) discusses calculated transmissivities and expected basin behaviour in detail.
Groundwater Levels The Stantec Report (2017) included in Appendix H reported that groundwater levels from a test pit near the recharge site are between 1.9 and 3.2 m bgl. A strong connection with the Selwyn River/Waikirikiri was noted. These observations are consistent with the information available from borelogs in the surrounding area with a more permeable layer of shallow gravels overlying lower permeability gravels. PDP measurements taken at bores nearby the spring heads between February and March (2018) indicate that it is common for groundwater levels to be
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ENVIRONMENT CANTERBURY - ASSESSMENT OF ENVIRONMENTAL EFFECTS FOR THE SELWYN RIVER / WAIKIRIKIRI NEAR RIVER RECHARGE SCHEME, HORORATA FLOW AUGMENTATION SCHEME between 0.61 - 4.35 m below ground level while the Haldon Pastures Springs are active with no overflowing or flooding noted. The OMP (Appendix B) assesses groundwater levels in the area that have been measured by ECan as part of their state of the environment monitoring and data collected by Vincent (2005). Groundwater level data in the area is available for shallow, and intermediate/deep bores which can be considered representative of the three aquifers. This data is summarised in the OMP.
Groundwater Quality The OMP, Appendix B shows the measured data for most key water quality parameters for a number of monitored bores and spring L36/1961 which are shown in Figure 7, Appendix A. Measurements were compared against both the Drinking-water Standards for New Zealand (2005) (Revised 2008) (DWSNZ) and also the ANZECC (2000) guidelines. These standards are relevant as groundwater will be recharging surface water in the spring habitats and therefore needs to be of a sufficient standard to sustain the life supporting capacity of the water. The groundwater quality results indicated that the shallow groundwater is generally good quality, with the exception of exceedances of dissolved oxygen (DO), E. coli, nitrate-nitrogen (Nitrate-N), iron and pH of the various maximum acceptable values (MAV’s) and guideline values (GV’s) required specified for drinking water in the NZDWS and ANZECC guidelines. These exceedances are detailed below:
• DO saturations have been outside the ANZECC range of 98% to 105% for the majority of the samples collected. In general, DO saturation in groundwater is much lower than surface water due to minimal aeration of the water through the groundwater system. Once the water in the shallow groundwater system emerges above ground level; natural aeration of the water flowing in the Derretts River and Haldon Pastures spring fields is likely to increase DO saturation. This demonstrates that shallow aquifers are influenced by surface activities.
• E. coli has been tested for samples from 2 bores (L35/0205, 28 m deep) and L35/0581, 7.7 m deep). Bore L35/0205 has detections greater than the MAV of <1 MPN/100 ml on 5 out of 49 samples with a maximum concentration of 19 MPN/100 ml (April 2004). E. coli has only been tested once from L35/0581 and was recorded at 14 MPN/100 ml (October 2005). Bores L35/0205 and L35/0581 are located north of the Waikirikiri/Selwyn River and near the Hororata Township respectively. These results show that the shallow groundwater activities are affected by surface activities and conditions.
• Nitrate-N concentrations have been recorded below the short term DWSNZ MAV of 11.3 mg/L but have exceeded the ANZECC guideline of 2.4 mg/L for the 95 % protection of aquatic species for the majority of the samples collected (i.e., only 5 samples from a total of 78 in all bores
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within 2 km of the infiltration basin site have been recorded with concentrations of 2.4 mg/L or less). The maximum recorded Nitrate-N concentration was 10.6 mg/L in 2005 in bore L36/0075 (28 m deep). This bore is located on the north side of the Waikirikiri/Selwyn River. This shows that groundwater quality in the area has been significantly affected by land uses in the vicinity.
• The DWSNZ GV (0.2 mg/L) and the ANZECC guideline (0.3 mg/L) for iron were exceeded once by bore L35/0161 (9 m deep) in 1979 measuring 0.46 mg/L. None of the 51 other samples tested for iron have exceeded the guidelines. This shows iron is not a major concern.
• Measurements of pH were outside the DWSNZ GV range (7.0 - 8.5) and the ANZECC guidelines range (7.2 – 7.8) for pH on 124 and 211 occasions respectively. However, this is not unusual for shallow groundwater receiving recharge from rainfall in New Zealand, as percolation of the rainfall through soils into the groundwater system alters pH. In addition to the ECan groundwater results discussed above, Vincent (2005) monitored 29 bores, including Spring L36/1961 as part of his thesis. Vincent’s groundwater quality assessment included an analysis of the general quality of groundwater, stable isotopic analysis, as well as comparing the chemical characteristics of the groundwater and surface water using Stiff diagrams and Piper plot analysis. Vincent (2005) determined that groundwater in the Haldon Pastures and Derretts/Mill Stream springs was most likely sourced from the Upper Selwyn River/Waikirikiri. This is discussed further in the OMP (Appendix B). 5.10 Community Drinking Water Supplies The nearest Community Drinking Water Protection Zone (CDWPZ) is over 8 km upstream of the infiltration basin site. This supply is a surface water abstraction point in Glentunnel. The nearest downstream CDWPZ’s are:
• Te Pirita drinking water supply bore L36/1313, 13.9 km south-west
• Barhill drinking water supply bore L36/0640, 17.9 km south-west
• Dunsandel drinking water supply bore L36/0640, 20.2 km south-east
• Burnham military camp supply bores M36/2694, M36/577, M36/3924 and M36/2693, 24.3 km east These community drinking water supplies and the CDWPZs are shown in Figure 8, Appendix A in relation to the proposed infiltration basin site and the springs. 5.11 Cultural Setting In most of Te Waipounamu (the South Island), Ngāi Tahu is the local iwi and within this iwi there are a number of tribal councils. The Papatipu Rūnanga for
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ENVIRONMENT CANTERBURY - ASSESSMENT OF ENVIRONMENTAL EFFECTS FOR THE SELWYN RIVER / WAIKIRIKIRI NEAR RIVER RECHARGE SCHEME, HORORATA FLOW AUGMENTATION SCHEME the Hororata and Selwyn River/Waikirikiri area are Ngā Tangata o Te Taumutu Rūnanga (the people of Taumutu Rūnanga) and Ngāi Tūāhuriri Rūnanga. The takiwā (territory) of Te Taumutu Rūnanga centres on Taumutu and the waters of Waihora (Ellesmere), while the takiwā of Ngāi Tūāhuriri Rūnanga centres on Tuahiwi near Kaiapoi. Te Waihora/Lake Ellesmere is of great significance to Papatipu Rūnanga. The Hororata River and Selwyn River/Waikirikiri are inside of the Te Waihora/Lake Ellesmere catchment and therefore contribute to the Te Waihora/Lake Ellesmere water quality and volume. As well as this, these rivers have been identified by Papatipu Rūnanga as sensitive areas and a historical travel route. There is a Wāhi Taonga site oven near Derretts Road (Pt Lot 1 DP 3012, C36 in the SDP); this site is also identified as of archaeological significance by ECan. There are no identified silent files documented on Canterbury Maps in the immediate area surrounding the proposed activity. Canterbury mudfish are the most threatened of New Zealand's mudfish species and are considered a Taonga species. Taonga species are plants and animals of special cultural significance and importance to Ngāi Tahu. The Mahaanui Iwi Management Plan and Te Waihora Joint Management Plan can be considered as relevant documentation which outlines the values of Ngā Tangata o Te Taumutu Rūnanga. A particular area of relevance is in the preservation and protection of Te Waihora/Lake Ellesmere as water from the Selwyn River/Waikirikiri flows into this protected water body. There are cultural issues associated with the unnatural mixing of water between and within catchments. In general, the unnatural mixing of water from different sources is deemed culturally inappropriate due to the varying perspectives of different hapū to unnatural mixing of waters in their takiwā and the protection of water quality, quantity and indigenous biodiversity (Mahaanui Kurataiao Ltd, 2013). The unnatural mixing of waters may be acceptable where it involves waters that:
• already mix naturally within the same catchment;
• are of same type (e.g., rain fed to rain fed); or
• are filtered through natural processes, such as natural or constructed wetlands and riparian margins.
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6. Assessment of Potential Effects An assessment of environmental effects is required to determine any potential adverse effects the proposed activity may have to the surrounding environment. For the purposes of this assessment the following matters have been considered:
• Positive effects
• Cultural effects
• Effects to water quality
• Effects to groundwater levels and spring flows
• Effects to groundwater quantity
• Effects on riverbed erosion
• Effects on adjacent land uses
• Effects to community drinking water supplies
• Material disturbance/sedimentation effects
• Ecological effects
• Noise effects
• Effect of change of take location on the Rakaia River. 6.1 Positive Effects of Whole Scheme The proposed project has the unique opportunity to enhance natural habitat for the Canterbury mudfish and contribute to the population recovery of this species. Canterbury mudfish are the most threatened of New Zealand's mudfish species, with a conservation status of ‘Threatened’ (Nationally Critical) under the New Zealand Threat Classification System (Goodman, et al., 2013). Canterbury mudfish are found in a limited number of waterways in the Canterbury Plains, between the Ashley River (in the north) and the Waitaki River (in the South). The primary factors that affect Canterbury mudfish survival are the degradation and removal of habitat and predation. Canterbury mudfish frequent habitats that are subject to summer drying and although they are adapted to seasonally stagnant habitats, they are not well adapted to complete or extended drying, with multiple extended dry years historically resulting in high Canterbury mudfish mortality. This project aims to stabilise the hydrology of Bealey Stream and the Haldon Pastures Spring field, an area of known high quality mudfish habitat, in an effort to enhance Canterbury mudfish habitat and reduce the number of multiple dry years. ECan and the Department of Conservation (DOC) are also implementing a unique solution to Canterbury mudfish predation at this location; an electric barrier within Bealey Stream that will deter upstream migration of trout (and potentially eels) from the Hororata and Selwyn River/Waikirikiri, when connected. The
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ENVIRONMENT CANTERBURY - ASSESSMENT OF ENVIRONMENTAL EFFECTS FOR THE SELWYN RIVER / WAIKIRIKIRI NEAR RIVER RECHARGE SCHEME, HORORATA FLOW AUGMENTATION SCHEME proposed flow augmentation will work together with the predator exclusion barrier, to provide high quality refugia habitat for the Canterbury mudfish. 6.2 Cultural Effects of Whole Scheme Dyanna Jolly Consulting (2005) carried out a cultural impact assessment on Ngāi Tahu values for the Central Plains Water Enhancement Scheme. This assessment discussed the idea of discharging from the irrigation scheme and is therefore relevant to the proposed activity. This consultation process identified five areas of concern regarding potential or actual effects on cultural values; these are listed below (Dyanna Jolly Consulting, 2005):
• Effects related to water abstractions
• Effects related to mixing of waters
• Effects related to the use of water on the Central Plains The above areas of concern have been assessed in this section against the mitigation controls and operational procedures proposed for the augmentation activity to ensure there are no adverse effects on Ngāi Tahu values. The Waianiwaniwa Storage Reservoir was not established as a result of this consultation process and the construction of the canal is not related to the proposed augmentation activity, therefore is not discussed. The Cultural Impact Analysis carried out for the CPW scheme can be found in Appendix D.
Effects Related to Water Abstractions The extraction of water from the Rakaia River and Waimakariri River was outlined as a major concern to iwi during the consenting phase of the CPW pipeline development in 2005. Ngāi Tahu policies on surface water abstraction focus on advocating for appropriate flow regimes on rivers, promoting best practice and efficient use of water, recognising and providing for the relationships between surface water and groundwater, and monitoring the cumulative effects of water abstractions on land, water and biodiversity. The proposed activity does not involve any new water take rights, and instead proposes the use of existing water rights. This is due to no more water being taken beyond than what has already been allocated and assessed for any potential effects prior to the granting of such CPW and SDC consents. Furthermore, the use of unused existing water consent rights in off peak season will recharge groundwater levels with the target of increasing water quality and maintaining biodiversity, in particular the endangered Canterbury mudfish (Mahinga kai), which otherwise would be unused or allocated to irrigation.
Effects Related to Mixing of Waters The CPW Enhancement Scheme area provides irrigation water to three large river catchments and originally proposed to mix water from the Waimakariri and Rakaia Rivers in a storage reservoir. This was a large issue adversely affecting
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ENVIRONMENT CANTERBURY - ASSESSMENT OF ENVIRONMENTAL EFFECTS FOR THE SELWYN RIVER / WAIKIRIKIRI NEAR RIVER RECHARGE SCHEME, HORORATA FLOW AUGMENTATION SCHEME resources and values of significance to Ngāi Tahu due to the transfers and mixing of water within and between catchments. Ngāi Tahu has traditionally opposed mixing waters from different environments with two main contributors which make waters incompatible, these are:
• Specific uses or associations associated with water (e.g., food, bathing, ceremonial, spiritual) that needed to be kept separate;
• Distinctive characteristics of waters (e.g., source, topography, temperature, pH, flow) that result in unique ecosystems, where those ecosystems may be compromised upon mixing with other waters. The resulting CPW system resultantly does not mix water from the Rakaia and Waimakariri Rivers, with no connection between the water sources along the pipeline, therefore observing iwi values. The allowance of glacial waters from the Waimakariri or Rakaia Rivers to enter Te Waihora via the Waikirikiri or any other waterway could result in a change to the seawater-freshwater ratio of the lake. The environment of this lake, including its lakeshore vegetation and habitat, is a result of the salt-to-water balance. For Ngāi Tahu, disruption of this balance through inputs of glacial water is unacceptable. Many Rūnanga representatives raised concerns regarding biosecurity risks in regard to the mixing of waters during the CPW consent hearings. These included potential for the transfer of pest species (e.g., aquatic weed, pest fish) as a result of mixing of waters between rivers. Such concerns can be considered of particular importance with an example of validation being the spread of the species Didymosphenia geminate (Didymo), an invasive alga that has significantly altered several South Island Rivers. Ngāi Tahu policy focuses on avoiding the unnatural mixing of waters from different waterbodies (e.g., direct flow augmentation, tributary transfers, out of catchment transfers) where such mixing will adversely affect the mauri, integrity, biodiversity, or cultural associations of the waterway. It has been stated that under no circumstances shall glacial waters (e.g., the Waimakariri and Rakaia River water) directly enter Te Waihora. As mentioned in Section 5.11, mixing of water from different catchments may be considered appropriate only when water is filtered through natural processes, such as natural or constructed wetlands and riparian margins. While the proposed activity does not involve a wetland or riparian margin, the application of water to ground surface (such as with irrigation practices) do not result in the direct mixing of waters from different catchments. This is because the soils, gravels and plant root uptake effectively filter the water (similar to processes in which wetlands filter water). The purpose of the proposed augmentation is targeted at sustaining ecology, in particular the endangered Canterbury mudfish, in the Selwyn River/Waikirikiri
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ENVIRONMENT CANTERBURY - ASSESSMENT OF ENVIRONMENTAL EFFECTS FOR THE SELWYN RIVER / WAIKIRIKIRI NE AR RIVER RECHARGE SCHEME, HORORATA FLOW AUGMENTATION SCHEME area. It is also proposed that targeted flow increases in the catchment will also benefit the species which inhabit Te Waihora/Lake Ellesmere. Mitigation measures to avoid entry of unwanted species from other catchments have been proposed as well as the monitoring of water level and quality during commissioning and operational phases to ensure no adverse effects occur. Based on the considerations above, the effects from the unnatural mixing of waters have been assessed against iwi values, and adverse effects to the environment as a result of mixing are expected to be minor. Commissioning monitoring will confirm if mild negative adverse effects are occurring and will cease augmentation if this is observed; however, effects to the ecology and biodiversity are expected to be positive for the habitat of the Canterbury mudfish in the springs and for the overall ecology in Te Waihora/Lake Ellesmere.
Effects Related to the Use of Water on the Central Plains A particular area of concern for the use of water on the Central Plains was the effects on Te Waihora/Lake Ellesmere and lower catchments areas. While some consider the lake as “technically dead”, local Kaitiaki Rūnanga have stated that they do not believe the lake is dead. However, they have also stated that water quality and water quantity are both at unacceptably low levels in the Te Waihora catchment. This is attributed to groundwater abstractions, changes in land use, land drainage and the management of Te Waihora/Lake Ellesmere water levels. It is believed that the CPW scheme has relieved pressure on the quantity of the groundwater resources in the project area which in turn will potentially result in recharged groundwater resources below State Highway One with time. However, the preservation of species and their habitat within the upper catchment is of importance to prevent the further degradation of the catchment quality, quantity and ecology. The recharge of groundwater localised to the Haldon Spring fields and Derretts Spring fields will contribute to the sustained habitat for Canterbury mudfish, reducing the length of dry periods which cause large counts of fish death.
Summary of Effects to on Cultural Values The cultural values outlined above are established to protect the native and unique species in waterways while preventing the degradation of the unique environmental conditions which sustain them, such as changes in water quality or introduction of predator species or toxic alga. The value of improving or sustaining the quality of an environment is also outlined in the Mahaanui Iwi Management Plan and Te Waihora Joint Management Plan. It is considered that the proposed augmentation activity is consistent with these values as filtration of the glacial water via the shallow geological formations results in the prevention of potentially harmful species entering the Canterbury mudfish environment. The augmentation will boost the water levels in the Haldon Pastures and Derretts River Spring fields improving the quality of the Canterbury mudfish habitat and helping maintain the population of the
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ENVIRONMENT CANTERBURY - ASSESSMENT OF ENVIRONMENTAL EFFECTS FOR THE SELWYN RIVER / WAIKIRIKIRI NEAR RIVER RECHARGE SCHEME, HORORATA FLOW AUGMENTATION SCHEME endangered species. Therefore, this approach can be considered consistent with the values of Papatipu Rūnanga. 6.3 Effects of Water Take (On Rakaia River Catchment)
Effects on Water Allocation No changes to existing allocated water is proposed. ECan is seeking the best use of allocated water but a change in the location of the takes is proposed. When using SDC water from Early’s Site and Headworks Road, the effects of the change in location of the take from downstream to further upstream are expected to be less than minor. The quantity being taken from Rakaia River is not changing overall. Additionally, the quantity of water taken from the SDC consents in comparison to the overall base flow of the river is minimal. In addition to this, it is more likely excess water from the CPW scheme will be used most of the time, with water from the SDC consents only being used when there is no availability from the CPW scheme. Of the two SDC take sites, it is more likely Early’s site excess water allocation will be used than the Headworks Rd site. This is due to reduced stockwater use from this consent as a direct result from installation of the CPW scheme. Availability of water from the Headworks site is less likely, but consent is still sought on the occasion that there is availability.
Effects on Flow Regime While the take location of CRC011996 (0.5 m3/s) is over 32 kms downstream of the CPW/proposed take location proposed under this consent, the magnitude of the take is 0.3-0.7% of the minimum flow limits for the 23 allocation bands in the Rakaia River. Consent CRC153238 (0.732 m3/s) is located approximately seven kilometres downstream from the CPW take. This take is a similar proportion of the low flow limit in the river and is equivalent to less than seven times the average bed width of the river upstream of the parent take. Highbank Power Station discharges over 30 m3/s in the vicinity of the CPW take location. Minimum flows with the inclusion of the 30 m3/s from the Highbank Power Station are anticipated to be between 80 -100 m3/s. The relocation of both takes to the CPW intake are considered minor changes to the overall flow regime in the Rakaia River.
Effects on Instream Ecology and Habitat As discussed above, the changes in the flow regime supporting instream ecology and habitat is considered minor. Therefore, effects on instream ecology and habitat are expected to be minor.
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Effects on Water Quality Limits The minor changes in the flow regime are not expected to cause any significant changes in water quality in the Rakaia River.
Effects to Groundwater Levels and Spring Flows The minor changes in the flow regime from the relocated SDC takes are only expected to have minor impacts on downstream groundwater levels and spring flows.
Effects on Other Users As the abstraction limit is set upstream of the proposed relocated point of take, and the magnitude of the relocated takes compared with the minimum take limits is minor, relocation of the proposed takes is not expected to affect other water users. 6.4 Effects of Discharge (on Waikirikiri Selwyn River Catchment)
Effects on Water Quality As there is a strong hydraulic connection between groundwater from aquifer 1 and surface water in the area the effects to water quality can be assessed as a whole. As there will be no direct mixing of waters in the Selwyn River/Waikirikiri there are no anticipated adverse effects to surface water quality of the river. This is because the riverbed will be dry during the augmentation such that no direct surface mixing of waters can occur if water re-emerges in the in the Selwyn River/Waikirikiri. Surface water that is discharged to groundwater will be filtered through gravels and sediments. The discharge of good quality water to the groundwater system at the infiltration basin is expected to assist in dilution of nutrients in the shallow aquifer downgradient of the basin. Water quality of the Haldon Pastures and Derretts Spring systems receiving environments are not anticipated to be negatively affected by the scheme, as the mixing of source water will be filtered through the shallow geological formations in the groundwater system and the quality of the source water. It is also considered that the water quality of the source water (from the Rakaia River) and receiving water (i.e. in the springs) is of similar quality (OMP, Appendix B). Suspended sediment is naturally higher from the alpine sourced Rakaia River; however, a primary settling basin is located at the intake from the Rakaia River before the CPW pipeline which is designed to remove suspended sediment before the water is piped to farms. Therefore, by the time it reaches the infiltration basin the level of sediment from the source water is not expected to be any greater than what is naturally discharged and filtered by the aquifers under the Selwyn River/Waikirikiri.
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The land area surrounding the Haldon Pastures Spring field is irrigated and has been marked as a phosphorus sediment risk area by ECan. Water quality data from ECan’s surface water site database shows that Dissolved Reactive Phosphorus (DRP) levels in the upper Rakaia River are generally lower than levels measured in the Selwyn River/Waikirikiri (see OMP, Appendix B). Based on the above information it is considered that the effects to water quality will be less than minor and increased water flow will help to dilute phosphorus concentrations in the Selwyn/Waihora catchment. This dilution may have a positive effect, helping to achieve the area’s water quality outcomes. Available groundwater quality data indicates that the groundwater in the area is of relatively good quality (see Section 5.9.4), although elevated Nitrate-N concentrations in bores less than 30 m deep have been detected on the northern side of the Selwyn River/Waikirikiri. The OMP outlines that a number of shallow domestic water supply bores exist in close proximity to the Selwyn River/Waikirikiri. The infiltration basin is located outside the normal zone of influence that would be controlled for public water supply bores (as defined in the LWRP). The closest bore is located approximately 700 m down gradient and 700 m across the piezometric contour, with the nearest bore directly downgradient in excess of 2 km from the proposed infiltration basin. Therefore, while the exact subterranean flow paths are not known for certain, it is considered unlikely that the water quality in the downstream bores will be adversely affected by discharges from the infiltration basin. The water quality of these bores is expected to be influenced by climatic events and surface water conditions (i.e. they would be considered an “unsecure” water supply source. It is proposed to verify the climatic and surface water effects on these bores during construction, scheme commissioning and operation to ensure that no adverse effects are occurring. The commissioning details are found in the OMP (Appendix B). The OMP includes controls to ensure any adverse effects are controlled. Due to the ponding of water in the infiltration basin to create a hydraulic driving head, there is potential for birds to use the pond as habitat, creating a potential microbe contaminant source to groundwater. It is proposed water will only be discharged through the basin when groundwater levels are below the base of the recharge area to ensure a zone of soil aquifer treatment and that water will not remain in the infiltration basin when the scheme is not operating. This is expected to limit contamination risks to groundwater via birdlife in the infiltration basin, and the risk of contaminants entering the aquifer is considered lower than the risks of contaminants in floodwaters and normal river flows discharging to the aquifer through the river gravels. It has been found with ECan’s MAR basin at Lagmhor to the west of Tinwald that there has been no sign of contaminated surface waters affecting the downstream aquifer through the infiltration basin. It was noted that E. coli counts found in
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ENVIRONMENT CANTERBURY - ASSESSMENT OF ENVIRONMENTAL EFFECTS FOR THE SELWYN RIVER / WAIKIRIKIRI NEAR RIVER RECHARGE SCHEME, HORORATA FLOW AUGMENTATION SCHEME the shallow aquifer more than 50 m from the site were considered “unlikely” to have been sourced from the infiltration basin discharge. Notwithstanding, the proposal includes measures to monitor any adverse effects that may occur and an adaptive OMP to ensure potential adverse effects are controlled. Potential mounding (discussed in Section 6.4.3) may increase flushing of nutrients in the shallow groundwater system into the Hororata and Selwyn Rivers/ Waikirikiri. The additional flow in surface waterways and the shallow groundwater aquifer can be considered as a positive effect as it will result in more dilution of any residual contaminants, which will be favourable for the habitats of aquatic species in the downstream waterways. It should be noted that the Selwyn River/Waikirikiri will contain elevated levels of microbial contaminants when it is in flood, which has had no reported adverse effects on water quality in the shallow domestic water supply bores adjacent to the river (OMP, Appendix B). This will be assessed during commissioning and scheme operation to understand the background water quality of the shallow aquifer that is recharged from the river. Another potential contaminant source may be septic tanks and old offal pits, although as previously mentioned, the proposed discharge is not expected to increase groundwater levels above natural maximum fluctuations. Therefore, it is not expected that there will be any change in groundwater contamination risks beyond what currently occurs in wet years. Based on the above information it is considered that the negative effects to groundwater quality are most likely to be less than minor. It is expected that groundwater quality should improve as a result of nutrient dilution, however monitoring of water quality during the commissioning phase is required to confirm this.
Effects to Groundwater Levels and Spring Flows The objective of the augmentation is to increase groundwater levels and spring flows in a controlled manner, these being outlined in the OMP (Appendix B). Discharge will only occur into the Selwyn River/Waikirikiri system when there is no flow at Hawkins Road, upstream from the infiltration basin site, based on a flow reading of less than 1.5 m3/s at the Whitecliffs recorder (68001). Flow rates discharged to the Selwyn River/Waikirikiri bed are unknown until commissioning occurs, however the expected extent of surface water flow in the Selwyn River/Waikirikiri from the overflow channel is estimated to be potentially up to 10 m wide and 3 km long. This extent has been determined by losses observed in gauging runs. Discharge to the infiltration basin will also cause an increase in groundwater levels, which is predicted to cause an increase in flow in the springs at Haldon Pastures Spring field. The current understanding is that the Derretts River Spring
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ENVIRONMENT CANTERBURY - ASSESSMENT OF ENVIRONMENTAL EFFECTS FOR THE SELWYN RIVER / WAIKIRIKIRI NEAR RIVER RECHARGE SCHEME, HORORATA FLOW AUGMENTATION SCHEME field is influenced from flows in the Upper Selwyn River/Waikirikiri upstream of the proposed infiltration basin site, and this scheme should not influence surface water flows at this site; however, there is some uncertainty in this assumption. Therefore, it is considered that any effects to surface water level at Derretts Road Springs will be minor. It should be noted that increasing water level at these springs will only enhance Canterbury mudfish habitat at this location, which is considered a positive effect. The predicted increase in flow in the Haldon Pastures Springs will cause an increase in depth and velocity of water in the Hororata River, which could result in erosion of the river banks. However, the increase in flow is expected to be significantly less than what will occur under naturally high flow conditions in the river (i.e., flood flows). The Haldon Pastures Spring field flow increase should also enhance aquatic habitat in the Hororata River, due to an increase in flow permanence in dry years. The location of the springs in relation to surface water is shown in Figure 9 (Appendix A). There is potential that increased flows as a result of the proposed augmentation may result in surface flooding around the properties immediately downgradient of the infiltration basin and the properties surrounding the Derretts River and Haldon Pastures Spring fields. This potential is greater if groundwater levels are already elevated or there is significant increase in flow in the Selwyn River/Waikirikiri adjacent to the springs during any augmentation. This is likely to cause flooding of surrounding pastoral land and cause disruption to local landowners. It is proposed that such effects will be controlled by ceasing the discharge of water when groundwater levels exceed the 1 m below ground level trigger in a bore adjacent to the site and near the Haldon Springs system that causes significant spring flows. Details of these trigger levels and flows are discussed in the OMP, Appendix B. These controls are anticipated to provide sufficient protection from excess flows causing flooding of downstream land, therefore mitigating any adverse effects from flooding. Stantec has indicated that due to the placement of the infiltration basin on the southern embankment, the weir, culverts and return channel may be exposed to floodwater in a high intensity flood event. It has been indicated that these can be readily replaced if they are damaged in a flood event. The forestry plantation upstream of the basin will help to act as a protective barrier to this equipment and reduce the severity of flood flow as well as diverting water around the basin. Additionally, basin embankments may impede flood flow. However, given the scale of the Selwyn River flood channel beyond the forested area in comparison to the basin this is likely have a minor effect.
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Effects to Groundwater Quantity While the target of the activity is to increase groundwater levels such that the springs are recharged, any negative effects from the increase in groundwater quantity should be mitigated. It is predicted that the proposed discharge to ground at the infiltration basin will increase groundwater levels within Aquifer 1. It is unlikely that the discharge will have any significant effect on groundwater levels in the deeper semi-confined aquifers beneath due to the strata and groundwater behaviour observed (i.e., Aquifers 2 and 3). As a result of the proposed discharge to ground, there is potential for effects on groundwater levels near the infiltration basin and also around the springs in the Derretts and Bealey Stream to become elevated due to mounding effects of discharge. The main effects that potential mounding may have on the surrounding environment are: • Inundation of domestic onsite wastewater disposal fields; • Flushing of nutrients in shallow groundwater (Section 6.3); • Restriction of discharge rates beneath the infiltration basin; • Increased spring flow causing surface flooding where the groundwater table intercepts topographical depressions (i.e., springs, old surface channels) (Section 6.4.2). The effects of each of these matters are discussed in further detail below or have been previously discussed in Section 6.3 or Section 6.4.2. Inundation of domestic onsite wastewater disposal fields There is potential for inundation of domestic onsite wastewater disposal fields downgradient of the infiltration basin as a result of the augmentation. The nearby wastewater disposal fields are shown in relation to the activity in Figure 10, Appendix A. However, the purpose of the augmentation project is not to increase groundwater levels above their natural regime but maintain them at a suitable level when otherwise groundwater levels are typically lower. This ensures sufficient flow and water quality within the downgradient spring and river systems. Observations of groundwater levels in the vicinity of the spring heads indicate groundwater levels well above the base are required to raise spring flows and that the shallow groundwater levels are confined by the low permeability soils, therefore well designed wastewater disposal fields discharging to the shallow surface soils should not be discharging directly to the shallow groundwater aquifer when the springs are operating. The proposed discharge is not expected to increase shallow groundwater levels above the natural maximum groundwater levels. As inundation of wastewater disposal fields may occur during wet winters, it is considered that the effects of
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ENVIRONMENT CANTERBURY - ASSESSMENT OF ENVIR ONMENTAL EFFECTS FOR THE SELWYN RIVER / WAIKIRIKIRI NEAR RIVER RECHARGE SCHEME, HORORATA FLOW AUGMENTATION SCHEME any inundation of wastewater disposal fields, beyond any natural groundwater fluctuations in the area, will be less than minor. The scheme includes controls in place to cease discharges when groundwater reaches one metre below ground level at the Haldon Pastures Spring Field and at the infiltration basin monitoring site. Natural groundwater levels at the Haldon Pastures Spring Field have been recorded at levels between 0.61 – 2.45 m below ground level in BX22/0184 (Measured in February – June 2018 by PDP) while flow has been present in Selwyn River/Waikirikiri. No inundation was noted at the higher groundwater levels. Given the above information it is considered that no adverse effects will occur in terms of inundation using the proposed 1 m below ground level trigger values for the cessation of augmented flow. The proposed discharge will result in localised mounding at both the infiltration basin and also in springs located downgradient of the infiltration basin. Potential mounding effects as a result of discharge at these locations were modelled in the OMP (Appendix B) using a simplistic Theis mounding assessment (Theis, 1935). Mounding assessments were undertaken for both the Derretts River Spring system and the Haldon Pastures Springs System, due to the uncertainty regarding whether or not discharged water will emerge in both areas. This shows that there could be potential adverse effects caused by groundwater mounding at down gradient locations. However, as such effects will be controlled by ceasing discharges when groundwater levels are high, the proposed discharge is not anticipated to adversely affect any wastewater disposal fields. Spring flows were been observed to be very stable in the first six months of 2018, with the water level at the downstream culvert no more than 50% of the culvert height (approximately 0.5-0.6 m3/s) after the initial fresh flows in the Selwyn River/Waikirikiri in January and February 2018. This suggests there is further limitation in the recharge mechanism that naturally limits excessive flows in the downstream spring field. This observation supports the hypothesis that recharge is also limited by riverbed conductivity and mounding under the riverbed limit s recharge at higher flowrates. The mounding assessments do not take into account any attenuation of augmented water, which may lessen the mounding effect. For this reason, the proposed monitoring during commissioning of the infiltration basin to quantify any potential effects on the wastewater disposal field has been proposed. The OMP (Appendix B) proposes detailed Level 1 environmental monitoring during the commissioning phase as the best method for quantifying the mounding effects from the discharge at the basin and also in the overflow channel. There is currently little evidence to suggest increased recharge flows through the riverbed increases downstream spring flows dramatically. It is therefore considered that the effects from mounding in the springs are minor. Consultation has taken place with surrounding property owners regarding the activity.
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Restriction of discharge rates beneath the infiltration basin The overflow channel allows for any excess water restricted by localised mounding beneath the infiltration basin. Therefore, any effects from restriction in flows are mitigated.
Effects on Riverbed Erosion Erosion is a natural geomorphic process which occurs in all channels as adjustments of channel size and shape are made to convey the discharge and sediment supplied from the stream catchment. The most major factor contributing to erosion of a braided river is likely hydraulic/gravitational forces. The climate and geology of the Canterbury plains allows braided rivers to form ever-changing and highly dynamic ‘braided’ channels across a wide gravelly riverbed. Bank erosion is occurring on the periphery of the forest on the true right bank; both upstream of the site immediately downstream of Hawkins Road and approximately 1-2km downstream of the site. This bank erosion will continue to occur as a natural morphological process. Examination of Lidar levels shows that the true right bank levels are considerably lower than the opposite bank in these locations, hence the river is currently eroding at these locations. The proposed maximum discharge of 3.5 m3/s is well below any erosive flow and will occur when there are no other flows in the riverbed. Therefore, the proposed discharges are not likely to accentuate any existing bank erosion that may be occurring.
Effects on Flooding As discussed in the Stantec concept report part B, flood levels have been estimated at RL185.2m for the 25 year return period flood event and RL185.4m for the 500 year return period flood events. Water from these flood events would reach approximately half way across the forested area under current river conditions. Observations from a flood in July 2017, estimated to be approximately a 10-20 year return period flood event, was that water did not reach the forested section. This indicates that the predicted water levels discussed immediately above may be conservative. With the basin in place the proposed southern embankment, weir, culverts and return channel would be potentially exposed to floodwater. The basin embankments could have an impact on flood levels in the river as they will act as a small impediment to flood flow. However, their impact is anticipated to be minor given the significant width of the Selwyn River flood channel beyond the forested area (this being 600 m river fairway versus 200 m forested area). Maintaining a heavily vegetated berm upstream site will be important to prevent flows being directed towards the infiltration basin site. Any erosive effects will be controlled by the flowrate that can spill through the thick vegetation upstream. The effect of the reduction in floodway area has been discussed with ECan River Engineers and is considered to be only a minor effect.
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Effects on Adjacent Downstream Land Uses Concern has been raised as a result of consultation on the effects of forestry trees below the infiltration basin. Guidance from Forestry Consultant Mr Stephen Brailsford (Appendix F) states that soils are Lismore Stoney Silt Loam which are amongst the most free draining in Canterbury. Initial judgements are that if the water table is going to fluctuate more readily to 1 m then this would only enhance the growing environment for the pine trees. The best pine growth in Canterbury is on the sand country to the east of the city around Bottle Lake where the water table is high and fluctuates with the tide. The fresh water is continually moving towards the coast, however the rising and falling of the tide also raises the fresh water movement through these very free draining soils. Effectively the trees are getting a ground-based watering twice a day. For this reason, it is considered that the forestry blocks downstream are unlikely to have effects that are less than minor and may be positively affected.
Effects to Community Drinking Water Supplies As outlined in Section 5.10 the nearest CDWPZ to the proposed activity is 8 km upstream and the nearest downstream CDWPZ is bore L36/1313, which is 13.9 km south-west from the infiltration basin site. Given the distance of the community drinking water supplies to the proposed activity, the southerly groundwater flow path, and the likely effect of the flow augmentation improving groundwater quality through nutrient dilution, the effects to community drinking water supplies can be considered less than minor.
Ecological Effects Any effects to ecology are considered less than minor, or any effects which may be more than minor are positive effects as per the intended target of the flow augmentation. Aquatic Macroinvertebrates The addition of flow to this reach of the river may create habitat for aquatic macroinvertebrates, dependant on the length of flow presence. Although not connected to the upstream or downstream perennial reaches, aquatic macroinvertebrates may colonise the flowing channel through aerial dispersal/oviposition, or inundation of dry substrata, which can trigger hatching in desiccation-resistant eggs and cysts of aquatic invertebrates, and terminate diapause and aestivation (Brock, Nielsen, Shiel, Green, & Langley, 2003) (Tronstad, Tronstad, & Benke, 2005). Colonisation and drying/desiccation are natural cycles of the Selwyn River/Waikirikiri and aquatic invertebrates provide a valuable food source for terrestrial predators residing in the floodplain (Greenwood & McIntosh, 2010).
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Fish Bealey Stream is a known habitat for the threatened Canterbury mudfish. The increase in flow within Bealey Stream is expected to provide additional habitat for the Canterbury mudfish, particularly during periods when groundwater levels in the area and flow in Bealey Stream are lowest (i.e., late summer/early autumn). This additional habitat is considered to be a positive effect, as it will alleviate stressors on the Canterbury mudfish caused by low flows in their habitat. However, the increase in flow may also encourage native eels and introduced fish species such as trout to enter the Haldon Pastures Springs from the Hororata River. These fish species are known predators of the Canterbury mudfish and understood to be eradicated (or excluded at present) from Bealey Stream in 2015-17 after a prolonged drought in the area, which caused Haldon Spring field, including Bealey Stream to dry. The expected increase in flow to the Haldon Pastures and Derretts River Springs, which feed the Hororata River, should increase the flow permanence in the lower reaches of the Hororata River, which will increase fish habitat for both native and introduced fish species. Migratory passage of predatory fish to Bealey Stream will not be enhanced until flows connect to the Lower Selwyn River/Waikirikiri, downstream of SH1. As the scheme is anticipated to be primarily used under dry winter conditions, it is unlikely that the Hororata River will be connected to the Lower Selwyn River/Waikirikiri, as the confluence is located approximately 13 km upstream from SH1.
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7. Management and Monitoring
7.1 Operational Monitoring Plan The OMP (Appendix B) outlines the monitoring regime and management of the scheme commissioning. Monitoring in the OMP includes the chemical analysis of water for quality control, groundwater level monitoring in the area to avoid inundation around the site, and ecological monitoring to ensure the activity is achieving its purpose while avoiding adverse effects throughout commissioning and operation. Figures 11 and 12 (Appendix A) show the monitoring locations for surface water, groundwater and rainfall which have been proposed for use in the OMP (Appendix B). 7.2 Additional Requirements Under Rule 11.5.45 of the LWRP a drainage management plan (DMP) is to be prepared if the activity is within a Cultural Landscape/Values Management Area and submitted for approval, prior to any work on the riverbed, identifying the following:
• The frequency, extent and characteristics of the works to be authorised by the Plan; and
• The identification and avoidance or mitigation of all effects on mahinga kai, wāhi tapu and wāhi taonga. There are no cultural landscapes identified in this area on ECan’s GIS database therefore at this stage no DMP has been prepared, however this will be prepared if required.
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8. Consultation Preliminary consultation has been undertaken by ECan (Brett Painter) with a number of stakeholders including the Selwyn Waihora Zone Committee, Te Taumutu and Te Ngāi Tūāhuriri Rūnanga, DOC, CPW and some local landowners, in particular landowners of property around the Haldon Springs system who may be potentially affected (i.e., John Grigg).
Department of Conservation
Additional consultation with landowners adjacent to the Haldon Springs system has also been conducted in relation to an effort to preserve the Canterbury mudfish habitat within Haldon Pastures Springs system. While the proposed augmentation is expected to result in increased flows and enhanced Canterbury mudfish habitat in Haldon Pastures Springs system, increased flows may allow introduced fish species such as trout to enter the river system from the Hororata River. To mitigate the effects of trout entering the Haldon Pastures Springs, DOC and ECan is installing an electric barrier in Bealey Stream, upstream of the confluence with the Hororata River. The Bealey Stream is not an identified trout spawning area and Fish and Game have indicated they have no objection to the installation. DOC has raised concerns relating to effects on the downstream habitat and lifecycle of the Canterbury Mudfish in Hororata River tributaries. Although, as outlined in the application, this is not anticipated (with a more stable flow regime a goal of the scheme) ECan propose to appoint Dr Leanne O’Brien to provide a monitoring plan to be implemented during commissioning of the work. This will be agreed with DOC and submitted for approval prior to commencement of the Commissioning. Provision is also included in Condition 7(d), and 14 of the Discharge Consent to ensure that any unanticipated adverse effects are appropriately monitored, and remedial measures undertaken. Environment Canterbury Rivers A meeting was held with ECan River Engineering and details on the main points of the meeting and identifies requirements can be found in the OMP, Appendix B. In summary the proposed project was determined to have a very minor impact on the wider Selwyn River/Waikirikiri system. Neighbouring Property owners It is expected that consultation with the stakeholders mentioned above will be ongoing throughout the consenting process and any augmentation activities. Initial consultation has been undertaken with both infiltration basin neighbours (Edward Howard and Tony Scarlett).
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Central Plains Water Trust CPW has requested suitable protection for their infrastructure, ecological enhancement works and effects on downstream groundwater levels. This is provided for in the proposed OMP, but further protection against unforeseen effects is provided in Conditions 7(e) and Condition 8 in the proposed Discharge Consent Conditions.
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9. Proposed Resource Consent Conditions Proposed conditions for each consent are provided below. 9.1 Subservient water take consent to CRC167218 (CPW)
RMA Authorisation Environment TBC Client Name Number Canterbury
Rakaia River Intake and Consent Location State Issued - Active Headworks, DARFIELD
To to take water from the Rakaia River
Commencement TBC Date
Expiry Date 25 July 2047
1. Water may be taken in accordance with parent consent CRC167218 at Surface water abstraction point (SWAP) Rakaia River, at map reference NZTopo50 BX21 9846 7598 when surplus water is available from the consent take limits. 2. Water diverted and taken under this consent in combination with Central Plains Water Scheme consent CRC167218 shall not exceed 33,500 litres per second and shall not be diverted unless the take limits in these consents are not yet reached. 3. Water shall only be used for discharge to the area of land shown on attached plan CRCXXXXXX, which forms part of this consent. 4. The consent holder shall, before the first exercise of this consent, install an easily accessible straight pipe(s), with no fittings or obstructions that may create turbulent flow conditions, of a length at least 15 times the diameter of the pipe, as part of the pump outlet plumbing or within the mainline distribution system. 5. The consent holder shall before the first exercise of this consent: a. i. install a water meter(s) that has an international accreditation or equivalent New Zealand calibration endorsement, and has pulse output, suitable for use with an electronic recording device, which will measure the rate and the volume of water taken to within an accuracy of plus or minus five percent as part of the pump outlet plumbing, or within the mainline distribution
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system, at a location(s) that will ensure the total take of water is measured; and ii. install a tamper-proof electronic recording device such as a data logger(s) that shall time stamp a pulse from the flow meter at least once every 15 minutes, and have the capacity to hold at least one season’s data of water taken as specified in clauses (b)(i) and (b)(ii), or which is telemetered, as specified in clause (b)(iii). b. The recording device(s) shall: i. be set to wrap the data from the measuring device(s) such that the oldest data will be automatically overwritten by the newest data (i.e. cyclic recording); and ii. store the entire season’s data in each 12 month period from 1 July to 30 June in the following year, which the consent holder shall then download and store in a commonly used format and provide to the Canterbury Regional Council upon request in a form and to a standard specified in writing by the Canterbury Regional Council; or [and] iii. shall be connected to a telemetry system which collects and stores all of the data continuously with an independent network provider who will make that data available in a commonly used format at all times to the Canterbury Regional Council and the consent holder. No data in the recording device(s) shall be deliberately changed or deleted. c. The water meter and recording device(s) shall be accessible to the Canterbury Regional Council at all times for inspection and/or data retrieval. d. The water meter and recording device(s) shall be installed and maintained throughout the duration of the consent in accordance with the manufacturer’s instructions. All practicable measures shall be taken to ensure that the water meter and recording device(s) are fully functional at all times. 6. Within one month of the installation of the measuring or recording device(s), or any subsequent replacement measuring or recording device(s), and at five-yearly intervals thereafter, and at any time when requested by the Canterbury Regional Council, the consent holder shall provide a certificate to the Canterbury Regional Council, Attention Regional Leader - Monitoring and Compliance, signed by a suitably qualified person certifying, and demonstrating by means of a clear diagram, that:
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a. The measuring and recording device(s) has/have been installed in accordance with the manufacturer’s specifications; and b. Data from the recording device(s) can be readily accessed and/or retrieved in accordance with clauses (b) and (c) of condition 5. 7. The Canterbury Regional Council, Attention Regional Leader - Monitoring and Compliance, shall be informed within five days of first exercise of this consent by the consent holder. 8. The consent holder shall take all practicable steps to: a. Ensure that the volume of water used for the discharge does not exceed that required for the soil to reach field capacity; and b. Avoid leakage from pipes and structures. 9. The Canterbury Regional Council may, once per year, on any of the last five working days of May or November, serve notice of its intention to review the conditions of this consent for the purposes of dealing with any adverse effect on the environment which may arise from the exercise of the consent. 10. If this consent is not exercised before 30 September 2022 then it shall lapse in accordance with section 125 of the Resource Management Act. 9.2 Subservient water take consent to CRC153238 (SDC)
RMA Authorisation Environment TBC Client Name Number Canterbury
Rakaia River Intake and Consent Location State Issued - Active Headworks, DARFIELD
To to take water from the Rakaia River
Commencement TBC Date
Expiry Date 21 November 2031
1. Water may be taken in accordance with parent consent CRC153238, at Surface water abstraction point (SWAP) Rakaia River, at map reference NZTopo50 BX21 9846 7598 when surplus water is available from the consent take limits. 2. Water diverted and taken under this consent in combination with Selwyn District Council consent CRC153238 shall not exceed 732 litres per second and shall not be diverted unless the take limits in these consents are not yet reached.
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3. Water shall only be used for discharge to the area of land shown on attached plan CRCXXXXXX, which forms part of this consent. 4. The consent holder shall, before the first exercise of this consent, install an easily accessible straight pipe(s), with no fittings or obstructions that may create turbulent flow conditions, of a length at least 15 times the diameter of the pipe, as part of the pump outlet plumbing or within the mainline distribution system. 5. The consent holder shall before the first exercise of this consent: a. i. install a water meter(s) that has an international accreditation or equivalent New Zealand calibration endorsement, and has pulse output, suitable for use with an electronic recording device, which will measure the rate and the volume of water taken to within an accuracy of plus or minus five percent as part of the pump outlet plumbing, or within the mainline distribution system, at a location(s) that will ensure the total take of water is measured; and ii. install a tamper-proof electronic recording device such as a data logger(s) that shall time stamp a pulse from the flow meter at least once every 15 minutes, and have the capacity to hold at least one season’s data of water taken as specified in clauses (b)(i) and (b)(ii), or which is telemetered, as specified in clause (b)(iii). b. The recording device(s) shall: i. be set to wrap the data from the measuring device(s) such that the oldest data will be automatically overwritten by the newest data (i.e., cyclic recording); and ii. store the entire season’s data in each 12 month period from 1 July to 30 June in the following year, which the consent holder shall then download and store in a commonly used format and provide to the Canterbury Regional Council upon request in a form and to a standard specified in writing by the Canterbury Regional Council; or [and] iii. shall be connected to a telemetry system which collects and stores all of the data continuously with an independent network provider who will make that data available in a commonly used format at all times to the Canterbury Regional Council and the consent holder. No data in the recording device(s) shall be deliberately changed or deleted.
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c. The water meter and recording device(s) shall be accessible to the Canterbury Regional Council at all times for inspection and/or data retrieval. d. The water meter and recording device(s) shall be installed and maintained throughout the duration of the consent in accordance with the manufacturer’s instructions. All practicable measures shall be taken to ensure that the water meter and recording device(s) are fully functional at all times. 6. Within one month of the installation of the measuring or recording device(s), or any subsequent replacement measuring or recording device(s), and at five-yearly intervals thereafter, and at any time when requested by the Canterbury Regional Council, the consent holder shall provide a certificate to the Canterbury Regional Council, Attention Regional Leader - Monitoring and Compliance, signed by a suitably qualified person certifying, and demonstrating by means of a clear diagram, that: a. The measuring and recording device(s) has/have been installed in accordance with the manufacturer’s specifications; and b. Data from the recording device(s) can be readily accessed and/or retrieved in accordance with clauses (b) and (c) of condition 5. 7. The Canterbury Regional Council, Attention Regional Leader - Monitoring and Compliance, shall be informed within five days of first exercise of this consent by the consent holder. 8. The consent holder shall take all practicable steps to: a. Ensure that the volume of water used for the discharge does not exceed that required for the soil to reach field capacity; and b. Avoid leakage from pipes and structures. 9. The Canterbury Regional Council may, once per year, on any of the last five working days of May or November, serve notice of its intention to review the conditions of this consent for the purposes of dealing with any adverse effect on the environment which may arise from the exercise of the consent. 10. If this consent is not exercised before 30 September 2022 then it shall lapse in accordance with section 125 of the Resource Management Act.
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9.3 Subservient water take consent to CRC011996 (SDC)
RMA Authorisation Environment TBC Client Name Number Canterbury
Rakaia River Intake and Consent Location State Issued - Active Headworks, DARFIELD
To to take water from the Rakaia River
Commencement TBC Date
Expiry Date 4 February 2025
1. Water may be taken in accordance with parent consent CRC011996 at Surface water abstraction point (SWAP) Rakaia River, at map reference NZTopo50 BX21 9846 7598 when surplus water is available from the consent take limits. 2. Water diverted and taken under this consent in combination with Selwyn District Council consent CRC011996 shall not exceed 500 litres per second and shall not be diverted unless the take limits in these consents are not yet reached. 3. Water shall only be used for discharge to the area of land shown on attached plan CRCXXXXXX, which forms part of this consent. 4. The consent holder shall, before the first exercise of this consent, install an easily accessible straight pipe(s), with no fittings or obstructions that may create turbulent flow conditions, of a length at least 15 times the diameter of the pipe, as part of the pump outlet plumbing or within the mainline distribution system. 5. The consent holder shall before the first exercise of this consent: a. i. install a water meter(s) that has an international accreditation or equivalent New Zealand calibration endorsement, and has pulse output, suitable for use with an electronic recording device, which will measure the rate and the volume of water taken to within an accuracy of plus or minus five percent as part of the pump outlet plumbing, or within the mainline distribution system, at a location(s) that will ensure the total take of water is measured; and ii. install a tamper-proof electronic recording device such as a data logger(s) that shall time stamp a pulse from the flow meter at
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least once every 15 minutes, and have the capacity to hold at least one season’s data of water taken as specified in clauses (b)(i) and (b)(ii), or which is telemetered, as specified in clause (b)(iii). b. The recording device(s) shall: i. be set to wrap the data from the measuring device(s) such that the oldest data will be automatically overwritten by the newest data (i.e., cyclic recording); and ii. store the entire season’s data in each 12 month period from 1 July to 30 June in the following year, which the consent holder shall then download and store in a commonly used format and provide to the Canterbury Regional Council upon request in a form and to a standard specified in writing by the Canterbury Regional Council; or [and] iii. shall be connected to a telemetry system which collects and stores all of the data continuously with an independent network provider who will make that data available in a commonly used format at all times to the Canterbury Regional Council and the consent holder. No data in the recording device(s) shall be deliberately changed or deleted. c. The water meter and recording device(s) shall be accessible to the Canterbury Regional Council at all times for inspection and/or data retrieval. d. The water meter and recording device(s) shall be installed and maintained throughout the duration of the consent in accordance with the manufacturer’s instructions. All practicable measures shall be taken to ensure that the water meter and recording device(s) are fully functional at all times. 6. Within one month of the installation of the measuring or recording device(s), or any subsequent replacement measuring or recording device(s), and at five-yearly intervals thereafter, and at any time when requested by the Canterbury Regional Council, the consent holder shall provide a certificate to the Canterbury Regional Council, Attention Regional Leader - Monitoring and Compliance, signed by a suitably qualified person certifying, and demonstrating by means of a clear diagram, that: a. The measuring and recording device(s) has/have been installed in accordance with the manufacturer’s specifications; and b. Data from the recording device(s) can be readily accessed and/or retrieved in accordance with clauses (b) and (c) of condition 5.
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7. The Canterbury Regional Council, Attention Regional Leader - Monitoring and Compliance, shall be informed within five days of first exercise of this consent by the consent holder. 8. The consent holder shall take all practicable steps to: a. Ensure that the volume of water used for the discharge does not exceed that required for the soil to reach field capacity; and b. Avoid leakage from pipes and structures. 9. The Canterbury Regional Council may, once per year, on any of the last five working days of May or November, serve notice of its intention to review the conditions of this consent for the purposes of dealing with any adverse effect on the environment which may arise from the exercise of the consent. 10. If this consent is not exercised before 30 September 2022 then it shall lapse in accordance with section 125 of the Resource Management Act. 9.4 Discharge Consent
(RED as required by Department of Conservation) A consent authorising discharge of water from the CPW pipeline GRP offtake tee to ground. It is proposed that the following conditions should be utilised for the discharge of water onto or into land for the purpose of augmenting: Limits 1. The discharge shall be limited: a. to the discharge of water taken from the Central Water Plains pipeline, as shown on Plan CRCXXXXXX, which forms part of this consent; b. to a rate not exceeding 116,800 cubic metres per week; and c. to an annual volume within 13% of the annual volume taken under resource consent CRCXXXXXX, CRCXXXXXX, and CRCXXXXXX Advisory Notes: (a) The discharge is specified in cubic metres of water per week to account for differences in the travel time between the Rakaia River and the Take Location and various operational states of the irrigation scheme. (b) The accuracy of flow measurement of the respective surface and pipe flow measurement structures are +/- 8 % and +/-5% respectively. 2. The discharges authorised in condition (1) shall only occur: a. on legal parcel, Lot 3 DP 78682, into the infiltration basin and the Selwyn River/Waikirikiri overflow channel, at or about map references
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NZ Topo 50: BX22 1935 7971, as shown on Plan CRCXXXXXXA which forms part of this consent; b. via an offtake pipe fitted with an isolation valve and control valves; and c. onto the concrete chamber and into the infiltration basin with overflow entering the bed of Selwyn River/Waikirikiri through the discharge culverts. Prior to commencement of discharge 3. On completion of the commissioning of the infiltration basin, infrastructure and valve assembly and a minimum of 10 working days prior to the first exercise of this consent the applicant shall submit an updated Operational Monitoring Plan (OMP) that outlines the results from the scheme commissioning and verifies the proposed discharge regime to the Canterbury Regional Council Attn: Regional Leader – Monitoring and Compliance. This Plan shall be approved by the Project Ecologist, a suitably qualified person with Canterbury mudfish expertise. 4. The Canterbury Regional Council, Attn: Regional Leader – monitoring and compliance, shall be informed (in writing) within two days of the first exercise of this consent. 5. A suitably qualified person shall confirm no nesting birds shall be disturbed with any discharge of water to the bed of the river between 1 September to 31 January. Operation and monitoring 6. The discharge shall be controlled in accordance with the Operational and Monitoring included with the consent application and initial operation shall cease immediately if: a. water table monitoring sites in Plan CRCXXXXXXX indicate the groundwater levels are above one metre below ground level at the discharge site; or b. surface water recordings in Selwyn River/Waikirikiri are measured above 1.5 cubic metres per second at the water level recorder site at Whitecliffs as shown in Plan CRCXXXXXXX; or c. flow is observed in the Selwyn River/Waikirikiri adjacent to the infiltration basin which is not from the overflow channel; or d. Requested by the Project Ecologist due to potential negative effects on Canterbury mudfish. 7. The discharge shall not: a. flood land or property owned or occupied by another person; or
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b. cause erosion to the bed and banks of the Selwyn River/Waikirikiri. c. adversely affect the operation of any onsite wastewater system downstream of the discharge. d. Adversely affect the downstream Canterbury Mudfish population, as determined by the Project Ecologist. e. Adversely affect the Central Plains Irrigation scheme including but not limited to effects on their constructed infrastructure, constructed ecological enhancement works and any effects on increased ground water levels that are shown to affect compliance with Consent CRC165680 Schedule 2 Condition (i). 8. The OMP that outlines the scheme operation and verifies the effects of the discharge regime shall be maintained for the duration of the consent in order to mitigate adverse effects of the discharge. 9. Any changes to the OMP shall be approved by the Project Ecologist and notified to the Canterbury Regional Council Attn: Regional Leader – Monitoring and Compliance complete with the reasons for the recommended changes. 10. Water quality monitoring and sampling of the discharge undertaken in accordance with the conditions of this consent shall be undertaken in accordance with the OMP. 11. The discharge shall be sampled at the point of entry to the infiltration basin. 12. Monitoring undertaken to control the operation of the system shall include but not limited to: a. groundwater levels in bores shall be measured; b. the extent of flow in Selwyn River/Waikirikiri at Whitecliffs and adjacent to the infiltration basin; and c. the discharge rate at the time of operation. d. As included in the OMP updated following commissioning of the scheme 13. Sampling and monitoring shall be undertaken by a suitably qualified and experienced person. 14. The consent holder shall ensure: a. Water quality sampling results are reviewed and compared to the Australian and New Zealand Guidelines for Fresh and Marine Water Quality, by a suitably qualified person; b. If the water quality sampling shows an exceedance of the recommended triggers as a result of the scheme discharge greater
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than the guidelines for 95 % protection of aquatic species, The person reviewing the results in accordance with clause (a) shall make recommendations for remedial actions to maintain water quality in the Selwyn River/Waikirikiri for those results the consent holder is able to influence, such as dissolved oxygen, turbidity; total suspend solids; c. The effects on the downstream habitat of the Canterbury Mudfish are inspected and reviewed by the Project Ecologist, whom shall be a suitable expert in the knowledge of the species habitat requirements and lifecycle. d. in consultation with the Department of Conservation and the reviewer these actions are implemented as far as practicable; e. the reasons for not implementing any actions are included in the yearly report in conditions (13). 15. The consent holder shall provide an annual report to the Canterbury Regional Council Attn: Regional Leader – Monitoring and Compliance by 1 October each year. The report be approved by the Project Ecologist and shall detail the result of the sampling carried out in the previous calendar year, including: a. The laboratory analysis results; b. Results of any groundwater monitoring; c. The extent of the discharge on the day of sampling; d. The discharge rate at the time of sampling; e. An interpretation of trends including comparisons to previous years’ monitoring; and f. Documentation of trigger values and the action taken to address exceedances, including what actions were undertaken and when those actions were implemented. g. Any updates to the OMP required to ensure adverse effects do not occur as result of the discharge. Administration 16. The Canterbury Regional Council may, once per year, on any of the last five working days of May or October, serve notice of its intention to review the conditions of this consent for the purposes of: a. Dealing with any adverse effects which may arise from the exercise of the consent and which it is appropriate to deal with at a later stage; or b. Requiring the adoption of the best practicable option to remove or reduce any adverse effect on the environment
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17. If this consent is not exercised before XX Month 20XX it shall lapse in accordance with section 125 of the Resource Management Act 1991.
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10. Statutory Assessment 10.1 Resource Management Act 1991 The RMA is the fundamental piece of legislation in New Zealand which sets restrictions on land use and development, discharges, water use and waste disposal to ensure adverse effects of activities on the environment are appropriately managed. This section of the AEE sets out the statutory framework against which this application is to be assessed under the RMA. 10.2 Notification Assessment
Sections 95A, 95C & 95D - Public Notification Under section 95A ‘Public notification of consent applications’, the consent authority is to decide (in accordance with sections 95C and 95D) whether public notification of the activity is required. Under the provisions of the amended RMA there is now no presumption in favour of notification (Section 95A). The requirement for the Council to be “satisfied” that the effects “will be minor” before proceeding on a non-notified basis has been removed. Public notification is considered in accordance with the following steps in Table 7.
Table 7: Public Notification Assessment
Section Comments Step 1 – Mandatory public notification in certain circumstances is required if: 95A(3)(a) The applicant has requested that the To be limited notified application not be publicly notified. only to identified affected parties, where formal consent has not been provided 95A(3)(b) Required under section 95C being: ECan will attempt to provide any information 95C The consent authority has requested requested under s92(1) further information under section on time or as otherwise 92(1), but applicant: agreed with the 95C(2)(a) does not provide the information regulatory arm of ECan. before the deadline concerned; or 95C(2)(b) refuses to provide the information;
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Table 7: Public Notification Assessment
Section Comments 95C(4) This section applies despite any rule or national environmental standard that precludes public or limited notification of the application. 95A(3)(c) The application is made jointly with The application is not an application to exchange made jointly with an recreation reserve land under application to exchange section 15AA of the Reserves Act recreation reserve land 1977. under section 15AA of the Reserves Act 1977. The activity does not require public notification under Step 1 2. Step 2 – if public notification isn’t required in step 1, it may be precluded if: 95A(5)(a) the application is for a resource The activity is not subject consent for 1 or more activities, and to a rule or NES that each activity is subject to a rule or precludes limited national environmental standard notification. that precludes public notification 95A(5)(b)(i) a controlled activity The activity is not for a controlled activity under the district plan. 95A(5)(b)(ii) a restricted discretionary or The activity is not a discretionary activity, but only if the subdivision of land or a activity is a subdivision of land or a residential activity. residential activity 95A(5)(b)(iii) a restricted discretionary, The activity is not a discretionary, or non-complying boundary activity. activity, but only if the activity is a boundary activity: 95A(5)(b)(iv) a prescribed activity (as per The activity is not an s360H(1)(a)(i) activity prescribed under s360H(1)(a)(ii) which prescribes particular activities or classes of
2 Provided information requested under s92(1) is provided on time (or as otherwise agreed with CRC), or is not refused to.
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Table 7: Public Notification Assessment
Section Comments activities, or the methods or criteria. The activity is not precluded from public notification. Step 3 – If not precluded by step 2, public notification in certain circumstances is required if: 95A(8)(a) the application is for a resource The activity is not subject consent for 1 or more activities, and to a rule or NES that any of those activities is subject to a requires public rule or national environmental notification. standard that requires public notification: 95A(8)(b) the consent authority decides, in The activity is not accordance with s95D, that the considered to have activity will have or is likely to have adverse effects on the adverse effects on the environment environment that are that are more than minor. more than minor. The activity does not trigger public notification under Step 3. Step 4 – If not required by Step 3, public notification, is required if: 95A(9)(a) Special circumstances exist in Special circumstances are relation to the application that not considered to exist. warrant the application being publicly notified. 95A(9)(b) If the answer is no, determine See Table 8 below. whether to give limited notification of the application under s95B.
The activity does not trigger public notification under Step 4.
On the basis of the preceding assessment in Table 7, it is considered that the proposal does not require public notification under section 95B for the reasons given.
Sections 95B & 95E - Limited Notification Under section 95B ‘Limited notification of the consent application’, the consent authority is then to decide (in accordance with sections 95E to 95G) whether there are any affected persons in relation to the activity. The threshold for identifying affected persons is more rigorous, whereby the consent authority must decide that a person is affected if the activity’s adverse effects are minor or
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Table 8: Limited Notification Assessment Section Step 1 – Limited notification of Comments certain affected groups and affected persons is required if: 95B(2)(a) There are any affected protected There are affected customary rights groups. protected customary rights groups. 95B(2)(b) There are any affected customary There are no affected marine title groups (in the case of an customary marine title application for a resource consent for groups relevant to this an accommodated activity). application. 95B(3)(a/b) any person has a statutory There are no statutory acknowledgement (made in acknowledgements in the accordance with an Act specified in nearby region. Schedule 11) made on the land or adjacent land and is considered an affected person under section 95E. The activity does trigger limited notification under Step 1. Step 2 – if limited notification isn’t required in step 1, it may be precluded in certain circumstances if: 95B(6)(a) the application is for a resource The activity is not subject consent for 1 or more activities, and to a rule or NES that each activity is subject to a rule or precludes limited national environmental standard that notification. precludes limited notification the application is for a resource consent for either or both of the following, but no other, activities: 95B(6)(b)(i) a controlled activity that requires The activity is not [solely] consent under a district plan (other a controlled activity than a subdivision of land); under the district plan. 95B(6)(b)(ii) a prescribed activity (as per The activity is not an s360H(1)(a)(ii) activity prescribed under s360H(1)(a)(ii) which limits who is considered affected. The activity is not precluded from limited notification.
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Table 8: Limited Notification Assessment Step 3 – If not precluded by step 2, limited notification of certain other affected persons is required if: 95B(7)(a) In the case of a boundary activity, an The activity is not a owner of an allotment with an boundary activity. infringed boundary and is considered an affected person under section 95E. 95B(7)(b) In the case of any activity prescribed The activity is not under section 360H(1)(b), a prescribed under section prescribed person in respect of the 360H(1)(b). proposed activity and is considered an affected person under section 95E; 95B(8) In the case of any other activity, a The potential adverse person is considered an affected effects on any person are person in accordance with section considered to be minor. 95E. The activity does trigger limited notification under Step 3. Step 4 – Further notification if:
95B(10) Special circumstances exist in Special circumstances are relation to the application that not considered to exist in warrant notification of the relation to the application to any other persons not application that warrant already determined to be eligible for notification of the limited notification under this section application to any other (excluding persons assessed under persons not already section 95E as not being affected determined to be eligible persons). for limited notification. The activity does not trigger limited notification under Step 4.
On the basis of the preceding assessment in Table 8, it is considered that the proposal requires limited notification under section 95B for the reasons given.
Section 95 Summary Having regard to the assessment undertaken within the AEE in support of this application, it is considered that there are potentially adversely affected parties and the proposal can be processed on a limited notification basis. The following parties have been identified as being potentially affected as a result of the proposed activity:
• John Maurice and Audrey Hilary Grigg (land owners at Haldon Pastures Spring Field and owner of monitoring bore BX22/0184)
• Grant and Jeanie Sanford (land owners near Haldon Pastures Spring Field)
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• Martin Carmalt Welsford, Petrie Hugh Kerr and Prudence Gaye Kerr (land owners near Haldon Pastures Spring Field)
• Kylie Jane and Richard Leo Hussey (owners of bore BX22/0140 close to the infiltration basin)
• Margaret Mary Kirk, William Anthony Scarlett and Jean Therese Scarlett (adjacent neighbours to the site)
• Department of Conservation
• Iwi - Te Taumutu Rūnanga Formal letters have been sent to these identified parties and verbal correspondence has already been undertaken with John Grigg regarding the augmentation. Landowners in the area have also received letters from ECan informing them of the intended activities to be undertaken, although they have not been identified as potentially being affected by the activity. 10.3 Information Requirements
Section 88 - Making an application Section 88(2) states that a resource consent application must: a) be made in the prescribed form and manner; and b) in the case of a fast-track application, include the prescribed information relating to the activity (if any); and c) in the case of any other application or a fast-track application where there are no prescribed information requirements relating to the activity, include the information relating to the activity, including an assessment of the activity’s effects on the environment, that is required by Schedule 4. This AEE is considered to fulfil the section 88 requirements above.
Schedule 4 - Information required in application for resource consent Schedule 4 sets out the information to be included within a resource consent application. All the information specified is considered to have been provided for within this AEE. 10.4 Section 104 Assessment
National Policy Statement on Freshwater Management 2014 (Revised 2017) The National Policy Statement on Freshwater Management 2012 (Amended 2017) (NPS-FM) was built on the provisions that fresh water is essential to New Zealand’s economic, environmental, cultural and social well-being. The main objective of relevance to the proposed activity is Objective B1:
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• To safeguard the life-supporting capacity, ecosystem processes and indigenous species including their associated ecosystems of fresh water, in sustainably managing the taking, using, damming, or diverting of fresh water. Policy B7 requires regional councils when considering any application, that the consent authority must have regard to the following matters:
• The extent to which the change would adversely affect safeguarding the life-supporting capacity of fresh water and of any associated ecosystem; and
• The extent to which it is feasible and dependable that any adverse effect on the life supporting capacity of fresh water and of any associated ecosystem resulting from the change would be avoided. The purpose of the proposed activity is to support the safeguarding of the life- supporting capacity of fresh water and associated ecosystem for the Haldon Pastures Spring field and Derretts Road Spring field and is therefore considered consistent with the relevant objectives and policies of the NPS-FM.
Canterbury Regional Policy Statement The Canterbury Regional Policy Statement 2013 (CRPS) (revised 2017) gives an overview of the significant management issues facing the region, including the issues of resource management significance to Ngāi Tahu. It is considered that the regional and district plans give effect to the CRPS and therefore the objectives and policies of the CRPS can be addressed by evaluating the relevant lower order documents such as the LWRP and SDP.
Canterbury Land and Water Regional Plan The LWRP identifies the resource management outcomes for land and water resources in Canterbury to achieve the purpose of the RMA and give effect to the CRPS. The LWRP is considered of primary relevance to the proposed activity and therefore the activity should be assessed against the objectives, policies and rules of the LWRP for consistency. Objectives and Policies The objectives and policies of the LWRP of primary relevance to the proposed activity are outlined and assessed against the activity below. Objective 3.1 seeks that land and water are managed as integrated natural resources to recognise and enable Ngāi Tahu culture, traditions, customary uses and relationships with land and water. Objective 3.2 seeks that water management applies the ethic of ki uta ki tai – from the mountains to the sea – and land and water are managed as integrated natural resources recognising the connectivity between surface water and groundwater, and between fresh water, land and the coast.
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Objective 3.6 seeks that water is recognised as essential to all life and is respected for its intrinsic values. Objective 3.8 seeks that the quality and quantity of water in fresh water bodies and their catchments is managed to safeguard the life-supporting capacity of ecosystems and ecosystem processes, including ensuring sufficient flow and quality of water to support the habitat and feeding, breeding, migratory and other behavioural requirements of indigenous species, nesting birds and, where appropriate, trout and salmon. Objective 3.17 seeks that the significant indigenous biodiversity values of rivers, wetlands and hāpua are protected. Objective 3.21 seeks that the diversion of water, erection, placement or failure of structures, the removal of gravel or other alteration of the bed of a lake or river or the removal of vegetation or natural defences against water does not exacerbate the risk of flooding or erosion of land or damage to structures. Region Wide General Policies Policy 4.86 states that activities that occur in the beds or margins of lakes, rivers, wetlands, hāpua, coastal lakes and, lagoons are managed or undertaken so that: (a) the character and channel characteristics of rivers including the variable channel characteristics of braided rivers are preserved; (b) sites and areas of significant indigenous biodiversity values or of cultural significance to Ngāi Tahu are protected; and (c) existing lawful access to the bed of the lake, river, wetland, hāpua, coastal lake, or lagoon for recreational, customary use, water intakes or supplies or flood control purposes, is not precluded, except where necessary to protect public health and safety. Policy 4.92A enables catchment restoration activities that protect springheads, establish or enhance riparian margins, create restore or enhance wetlands, and remove nuisance macrophytes and fine sediment from waterways. Selwyn Te-Waihora - Sub region policies Lake, Catchment and Flow Restoration Policy 11.4.21 seeks to enable catchment restoration activities that protect springheads, protect, establish or enhance plant riparian margins, create, restore or enhance wetlands and target removal of macrophytes or fine sediment from waterways. Policy 11.4.22 seeks to enable managed aquifer recharge and targeted stream augmentation to assist with improvements to lowland stream flows and their ecological and cultural health where, by design, construction, and operation of any project:
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(a) Adverse effects on cultural values, including those associated with unnatural mixing of water, are remedied or mitigated; and (b) Adverse effects on the availability, quality and safety of human drinking water are avoided; and (c) Adverse effects on fish passage are avoided or mitigated; and (e) There is no net loss of significant indigenous vegetation or significant habitats of indigenous biodiversity; and (f) Adverse effects on people, property and drainage systems from raised groundwater levels and higher flows are avoided, remedied or mitigated. Assessment of Objectives and Policies This application is considered consistent with the objectives and policies of the LWRP given the following:
• The targeted augmentation is to enhance ecology, water quality and quantity within the Selwyn/ Te Waihora catchment. The protection and improvement of this area is of great significance to Ngāi Tahu culture;
• The proposed activity recognises the intrinsic values of the Canterbury mudfish and their habitat as well as the importance of water quality and quantity in the Rakaia and Selwyn/Te Waihora catchments. It is considered that this activity is consistent with the above objectives as the targeted augmentation is set to improve the ecological habitat in the spring field areas while avoiding adverse effects to other wildlife such as birds;
• To avoid mixing of waters the project has been designed so that surface water that is lost to groundwater will be filtered through gravels and sediments, which will acclimatise this water with existing groundwater; and
• The proposed activity will not prevent fish passage, but will enhance habitat for fish through increased flow permanence. Proposed Plan Change 7 Policy 4.99 seeks to improve the quality and/or quantity of groundwater, and any hydraulically connected surface water body, by providing for managed aquifer recharge where: a. alternative mitigations, in addition to managed aquifer recharge, have or will be implemented to improve water quality and quantity in the receiving water body; b. adverse effects will be minimised for any take from a surface water catchment where the environmental flow and water allocation limits are exceeded;
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c. adverse effects on sites and values of importance to Ngāi Tahu, including effects associated with unnatural mixing of water, are avoided as far as practicable; d. adverse effects on the availability, quality and safety of human and animal drinking water are avoided; e. adverse effects of taking surface water on ecosystems and ecosystem services of that surface water body are minimised; f. there is no net loss, including through inundation, of significant indigenous vegetation, significant habitats of indigenous fauna, and existing wetlands; and g. adverse effects on people and property from raised groundwater levels and higher surface water flows are as a first priority avoided, and where avoidance is impracticable, effects are minimised. Policy 4.100 requires that when considering applications to take surface water for managed aquifer recharge where the rate of take and/or volume of water sought for abstraction from that surface water body will, in combination with other takes, exceed the environmental flow and/or allocation limit in Sections 6 to 15 of this Plan: a. restrict any further over-allocation of surface water to proposals which demonstrate the environmental benefits of the managed aquifer recharge to the receiving waterbody outweigh any adverse effects; and b. if the applicant holds an existing water permit that authorises the take and use of surface water for irrigation and proposes to use a portion of that water for managed aquifer recharge, require that there is no net increase in the total rate of take or volume of water compared with that authorised under the existing permit. Assessment of Objectives and Policies This application is considered consistent with the objectives and policies of the LWRP given the following:
• Adverse effects on the Rakaia River are minimised by using water already authorised to be abstracted (water sharing).
• Adverse effects on Ngāi Tahu have been considered and are considered acceptable.
• There are no drinking water supplies in the area and stock drinking water will be enhanced.
• Ecosystems will be enhanced in the Selwyn Catchment and effects on the Rakaia catchment are within the range of already authorised abstraction.
• There will be no net loss of ecosystem habitat.
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• Adverse effects on downstream neighbouring properties are considered acceptable.
• There will be no net increase of rate or volume from the irrigation use water and will not result on more allocation being taken from the Rakaia River.
Other Matters Te Rūnanga o Ngāi Tahu Freshwater Policy Statement 1999 The focus of the Freshwater Policy Statement is the management of freshwater resources within the rohe of Ngāi Tahu. It outlines the environmental outcomes sought by Ngāi Tahu and the means but which Ngāi Tahu is seeking to work with resource management agencies to achieve these outcomes. The objectives and policies of the policy statement seeks to protect water of significance to Ngāi Tahu; restore, maintain and protect the mauri of freshwater resources, maintain mahinga kai populations and promote collaborative freshwater management. This application is considered consistent with this policy statement given that the recharge at the Haldon Pastures Spring fields will enhance habitat in Bealey Stream for the threatened Canterbury mudfish, a taonga species to Ngāi Tahu. Collaborative freshwater management has been a part of this project, with stakeholder consultation with landowners and DOC ongoing, in an effort to improve habitat for Canterbury mudfish. Mahaanui Iwi Management Plan The Mahaanui Iwi Management Plan (MIMP) was released in March 2013 and reflects values and policies in regard to natural resource management for many areas within Canterbury. Those chapters primarily relevant to this application are Chapters 5.3 – Wai Māori (freshwater) and Chapter 6.11 – Te Waihora. Chapter 5.3 – Wai Māori (freshwater) This Chapter intends to guide freshwater management in a manner consistent with Ngāi Tahu cultural values and interests. Objectives and policies in this chapter relevant to the proposed water use and discharge activity in the bed of a river application include: Objective 1 states that water management effectively provides for the taonga status of water, the Treaty partner status of Ngāi Tahu, the importance of water to cultural well-being, and the specific rights and interests of tangata whenua in water. Objective 3 states that water and land are managed as interrelated resources embracing the practice of Ki Uta Ki Tai, which recognises the connection between land, groundwater, surface water and coastal waters.
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Issue WM3.1 seeks to protect and sustain freshwater resources so as to protect instream values and uses including indigenous flora and fauna. Issue WM6.7 seeks to ensure that the relationship between water quality and water quantity is recognised and is put in place to ensure that over-allocation does not result in a decline in water quality. Issue WM8.6 recognises aquifers as wāhi taonga Issue WM12.8 seeks to require that all river works activity, are undertaken in a manner that protects the bed and margins of the waterway from disturbance. This application is considered consistent with the objectives and issues of Chapter 5.3 of the MIMP given that:
• Mixing of waters is recognised as culturally inappropriate due to the varying perspectives of different hapū to unnatural mixing of waters in their takiwā and the protection of water quality, quantity and indigenous biodiversity (Mahaanui Kurataiao Ltd, 2013). To avoid mixing of waters the project has been designed so that surface water that is lost to groundwater will be filtered through gravels and sediments, which will acclimatise it with existing groundwater. This methodology incorporated the principals of Ki Uta Ki Tai, as the connection between land groundwater and surface water is an integral part of the project;
• The near river recharge will sustain freshwater resources by enhancing habitat for the threatened Canterbury mudfish, a taonga species, through increased flow permanence in Bealey Stream during extended dry periods;
• Water quality is not expected to be adversely impacted by the project, as water will be sourced from the already allocated CPW scheme. Increased flow in the downgradient spring systems is not anticipated to cause a decline in water quality, as water quality of the source water (Rakaia River) is similar to that of the receiving waterbodies (see OMP, Appendix B). An improvement in water quality downstream is expected, through the dilution of contaminant levels through increased flow and groundwater levels; and
• The infiltration basin will require minor bed works for the overflow channel, this work will however be conducted under dry conditions and bank stabilisation will be completed to reduce erosion potential. Chapter 6.11 – Te Waihora This chapter addresses issues of particular significance in the catchment of Te Waihora. The following objectives and policies are relevant to this application: Objective 5 states that land and water use in the catchment respects the boundaries, availability and limits of our freshwater resources and the need to protect soil and water resources for future generations.
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Objective 6 recognises the relationship between land use, groundwater, surface water and Te Waihora. Objective 8 seeks that the cultural health of lowland waterways is restored through the restoration of water quality and quantity and riparian margins. Issue TW7.5 seeks to improve flow and water quality in waterways in the Te Waihora catchment and to protect water quality in aquifers and aquifer recharge. This application is considered consistent with the objectives and issues of Chapter 6.11 of the MIMP given that the near river recharge will increase flows to the Haldon Pastures Spring field, improving water quality and enhancing habitat for the threatened Canterbury mudfish, a taonga species. Te Waihora Joint Management Plan The Te Waihora Joint Management Plan (TWJMP) was prepared by Te Rūnanga o Ngāi Tahu with advice from the Te Waihora Management Board (local Papatipu Rūnanga representatives) and the Canterbury Conservancy of DOC to guide long- term objectives and detailed policies and methods for effective integrated management of the natural resources within the area. Objectives and policies relevant to this application include the following: Chapter 4 - Wildlife Habitat and Biodiversity Objective 1 seeks that the indigenous plant and animal communities of Te Waihora and the ecological processes that ensure their survival, are restored and protected to maintain and improve indigenous wetland biodiversity. Objective 3 seeks that the habitats and wider needs of threatened species, taonga species and other species of importance to Ngāi Tahu are protected. Policy 4.1.3 seeks to restore habitats and indigenous vegetation through threat removal, natural regeneration, and the re-establishment of indigenous vegetation and species. Policy 4.2.1 seeks to protect and improve the freshwater ecosystem and habitats of Te Waihora. Policy 4.2.3 seeks to recognise the link between water quantity and water quality, and the maintenance of surface water and spring flows to protect conservation values, particularly wildlife habitat, biodiversity and mauri. Policy 4.2.4 seeks to improve water quality in waterways (including stream, rivers, springs and drains) and lake-edge habitats. Policy 4.3.4 seeks to take special measures to protect threatened plant and animal species, and to protect taonga species and other species of importance to Ngāi Tahu and ensure that the habitats and wider needs of all these species are protected within the TWJMP Area.
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This application is considered consistent with the objectives and policies outlined in the TWJMP given that:
• The flow augmentation will enhance and stabilise habitat for the threatened Canterbury mudfish (a taonga species), with predicted improvements in ecological health and functioning of the stream; and
• The flow augmentation will increase flow in the Haldon Pastures and Derretts/Mill Stream Spring fields, which will create a dilution effect of potential contaminants downstream, ultimately adding to a cumulative improvement of water quality and habitat in the Te Waihora catchment. Canterbury Water Management Strategy The CWMS was notified in November 2009 and updated in 2010. It was developed to help manage Canterbury’s water resources, as they are deemed vitally important to the region and to the nation. Lakes, rivers, streams and aquifers are used for hydro electricity generation, agricultural production and drinking water, as well as for a range of customary and recreational uses. The desired outcome of the CWMS is: “To enable present and future generations to gain the greatest social, economic, recreational and cultural benefit from out water resources within an environmentally sustainable framework.” This vision includes the outcome that ecosystems, habitats and landscapes will be protected, and progressively restored, and indigenous biodiversity will show significant improvement. In achieving this vision there are fundamental principles that have been developed to underpin the strategy. These include setting priorities for the use of water. Targets for water use efficiency and ecosystem health/biodiversity are relevant to this application. This application is considered consistent with the CWMS given that increased flow permanence will enhance habitat for the threatened indigenous Canterbury mudfish, a taonga species. This Near River Recharge initiative is part of a wider CWMS Selwyn Waihora Zone Committee initiative to increase flows in lowland, spring-fed streams that contribute flow to Te Waihora/Lake Ellesmere. It is therefore directly in alignment with the visions of the CWMS. The Resource Management (Measurement and Reporting of Water Takes) Regulations 2010 The Resource Management (Measurement and Reporting of Water Takes) Regulations 2010 (MRWT) are relevant to this application. Section 4(1) applies to water permits that allow fresh water to be taken at a rate of 5 L/s or more, for consumptive purposes.
• Section 5(1) stipulates that the rate (in L/s) at which fresh water may be taken under a water permit must be specified;
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ENVIRONMENT CANTERBURY - ASSESSMENT OF ENVIRONMENTAL EFFECTS FOR THE SELWYN R I V E R / WAIKIRIKIRI NEAR RIVER RECHARGE SCHEME, HORORATA FLOW AUGMENTATION SCHEME
• Section 6(1) requires that the permit holder must take continuous measurements of the water taken;
• Section 6(2) requires consents holders to keep records of the volume taken (either in m3/day or m3/week);
• Section 6(5) specifies the form of these records;
• Section 6(6) details the manner in which they are kept, including accuracy to within ±5% for full pipe takes, design standard and location of the meter;
• Section 8 requires annual records to be provided to ECan covering all water taken for the water year (from 1 July to 30 June); The proposed consent conditions are consistent with section 5 to 8 of the MRWT and will continue to do so.
Overall Summary After considering all those matters relevant under Part 2 and section 104, granting the resource consents with appropriate conditions would promote the purpose of the RMA and would constitute sustainable management of natural and physical resources for the following reasons:
• It allows the use of natural and physical resources in a way which enable people and the community to provide for their social, cultural and economic wellbeing;
• It sustains the potential of natural and physical resources (excluding minerals) to meet the reasonably foreseeable needs of future generations;
• It safeguards the life-supporting capacity of air, water and soil, ensures that adverse effects are appropriately avoided, remedied or mitigated;
• It is demonstrably consistent with the relevant planning documents, including the water take provisions in the LWRP. 10.1 Section 105 – Matters Relevant to Discharge Applications In addition to the section 104 matters which a consent authority must have regard to, s105(1) sets out additional matters, listed in Table 9, which must be considered when considering discharge applications.
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Table 9: Section 105 Matters Section 105 Matters Comments (a) the nature of the discharge and the sensitivity of the See section 5 receiving environment to adverse effects; and (b) client's reasons for the proposed choice; and See section 1.1 and 2.2. (c) any possible alternative methods of discharge, including discharge into any other receiving See section 4 environment
In summary, in each case it is concluded the adverse effects of the discharge would be less than minor and the proposed method of managing the effects of the discharge is the Best Possible Option (BPO). 10.2 Section 107 – Restriction to Grant Certain Discharge Permits Section 107 of the RMA specifies certain circumstances in which the consent authority shall not grant a discharge permit if after reasonable mixing, the contaminant or water discharged (either by itself or in combination with the same, similar, or other contaminants or water), is likely to give rise to all or any of the following effects in the receiving waters detailed in Table 10.
Table 10: Section 107 Matters Section 107 Matters Comments (a) The production of any conspicuous oil or grease See section 6. films, scums or foams, or floatable or suspended The discharge is materials. water from the (b) Any conspicuous change in the colour or visual Rakaia River and clarity. filtered through (c) Any emission of objectionable odour. permeable river (d) The rendering of fresh water unsuitable for gravel therefore consumption by farm animals. will not cause (e) Any significant adverse effects on aquatic life. any of the outlined effects.
In summary, none of those section 107 circumstances are present in any of the proposed discharges. 10.3 Section 104B - Determination of applications for discretionary or non-complying activities After considering an application for a resource consent for a discretionary activity or non-complying activity, a consent authority— (a) may grant or refuse the application; and (b) if it grants the application, may impose conditions under section 108.
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ENVIRONMENT CANTERBURY - ASSES SMENT OF ENVIRONMENTAL EFFECTS FOR THE SELWYN RIVER / WAIKIRIKIRI NEAR RIVER RECHARGE SCHEME, HORORATA FLOW AUGMENTATION SCHEME
In accordance with section 104B, ECan requests:
• the consent be granted; and
• conditions be imposed (in accordance with section 108) that are fair and reasonable. 10.4 Statutory Assessment Conclusion The Near River Recharge activity is proposed to improve Canterbury mudfish habitat and the surrounding spring environments, which in turn has significant and demonstrable positive effects in terms of sustaining the social and economic wellbeing of the community. Any adverse effects are less than minor with appropriate mitigation and appropriate management through the proposed consent conditions. After considering all those matters relevant under Part 2 and s104, it is considered granting the resource consents will promote the purpose of the RMA and constitute sustainable management of natural and physical resources.
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11. Conclusion The augmentation of groundwater during dry periods to enhance the endangered Canterbury mudfish habitat, dilute groundwater nutrient levels and contribute to overall water quantity in the Selwyn/Te Waihora catchment is considered a positive activity for the surrounding environment. It is considered that the proposed activity meets the objectives and policies of relevant high order and lower order statutory documents. Any permitted activity conditions in regional and district rules that are not met by the activity have been addressed within this resource consent application and have measures put in place to minimise adverse effects to the environment and community. It is considered that negative adverse effects to the environment from the excavation and construction of the infiltration basin are less than minor. The effects to the environment from the proposed discharge of water to augment water levels are considered to be positive with measures in place to control operation in such a way that negative adverse effects to the environment will be less than minor.
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12. References
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ENVIRONMENT CANTERBURY - ASSESSMENT OF ENVIRONMENTAL EFFECTS FOR THE SELWYN RIVE R / WAIKIRIKIRI NEAR RIVER RECHARGE SCHEME, HORORATA FLOW AUGMENTATION SCHEME
Larned, S. T., Hicks, D. M., Schmidt, J., Davey, A. A., Dey, K., Scarsbrook, M., . . . Woods, R. A. (2008). The Selwyn River of New Zealand: A benchmark system for alluvial plain rivers. Rivers Research and Applications, 1-21. Mahaanui Kurataiao Ltd. (2013, February). Mahaanui Iwi Management Plan. Christchurch , New Zealand: Te Taumutu Rūnanga. Manaaki Whenua - Landcare Research. (2018). Pallic Soils. Lincoln, Canterbury, New Zealand. Ministry of Health. (2008, October 02). Drinking-water Standards for New Zealand 2005 (Revised 2008). Wellington: Ministry of Health. National Institute on Deafness and Other Communication Disorders (NIDCD). (2017, February 7). Noise-Induced Hearing Loss. Bethesda, USA. O'Donnell, C. J., & Moore, S. M. (1983). The wildlife and conservation of braided river systems in Canterbury. Fauna Survey Unit Report 33. Wellington: Wildlife Service, Department of Internal Affairs. Stantec. (2017). Selwyn River Discharge Letter Report prepared for Central Plains Water Ltd 14 July 2014. Stantec. (2018). Selwyn River Discharge Letter Report to Central Plains Water dated 18 March 2018. Theis, C. V. (1935). The relation between the lowering of the piezometric surface and the rate and duration of discharge of a well using groundwater storage. Am. Geophys. Union Trans (cited by Vincent, 2005), 519-524. Thorley, M., & Ettema, M. (2007). Review of water allocation limits for the South Canterbury Region, Report No. U07/09. Christchurch: Environment Canterbury. Tronstad, L. M., Tronstad, B. P., & Benke, A. C. (2005). Invertebrate seedbanks: rehydration of soil from an unregulated river floodplain in the south- eastern U.S. Freshwater Biology, 646-655. Vincent, C. N. (2005). Hydrogeology of the Upper Selwyn Catchment. Canterbury. Waihora Ellesmere Trust. (2017). Te Waihora/ Lake Ellesmere State of the Lake 2017. Christchurch: Waihora Ellesmere Trust.
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