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SUMMARY STATEMENT OF EVIDENCE FOR GRAEME JENNER

Introduction 1 The following summary of evidence supports an application by Fonterra Ltd for

resource consents to construct and operate a new wastewater pipeline and marine outfall at Studholme, South Canterbury. The pipeline route is shown on the drawing in Attachment A.

Construction management plan 2 Construction activities can result in adverse environmental effects unless properly

managed. A draft Construction Management Plan (CMP) has been prepared to support the consent application and to provide guidance on the content of the Contractor’s CMP. The Contractor’s CMP will identify how the Contractor will manage construction of the pipeline through best practice methods and compliance with relevant consent conditions.

3 Section 5.2 of the draft CMP identifies a number of potential effects for which, mitigation is required. The proposed mitigation method(s) are summarised in Table 5-1 of the AEE report (Volume 2) and discussed in my Statement of Evidence.

4 Consent conditions have been proposed in regard to the preparation of the Contractor’s CMP. The final consent conditions will be required to be included in a Project Consents Register appended to the CMP.

5 The overall construction period including the pipeline and marine outfall will be approximately 9 months.

Pipeline to coast 6 The pipeline is considered to be a permitted activity under the Waimate District Plan.

However, consent from Waimate District Council, and a number of consents from Environment Canterbury, will be required to enable the construction process.

7 The pipeline will be constructed in a covered trench, along a 2.5km long “corridor”, from the wastewater treatment plant site to an outfall assembly area near the coast (see Attachment A). This work will involve several local road crossings and maintenance of traffic flows and private access will be managed in accordance with a Temporary Traffic Management Plan prepared for District Council approval. The work will also be carried out in consultation with utility operators, in accordance with national guidelines.

8 The works will also involve several crossings of Waimate Creek which will likely be achieved by trenching through the dry bed with appropriate protection to ensure there is no risk of the pipe rupturing. A separate pipe bridge could also be constructed above flood flows. As either option would involve works through adjacent stopbanks, construction procedures have been agreed with Environment Canterbury’s River Engineers Section.

9 To meet weather “windows” and complete the work as quickly as possible, pipeline construction will need to be carried out with minimal restrictions. This is reasonable in the rural location but residents and landowners along the pipeline route will be advised in writing in advance of works commencing. Regular and timely communication between the Contractor and affected parties is considered key to a successful construction project.

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10 While soil types along the pipeline “corridor” are unlikely to release significant volumes of groundwater, any dewatering and subsequent discharge to local drains will be carried out in accordance with the latest Environment Canterbury erosion and sediment control guidelines.

Outfall assembly area 11 A temporary outfall assembly area will be installed to the west of the Waihao Stopbank

on flat pasture land owned by Mr Gary Rooney (see Attachment A). Mr Rooney’s house is the nearest residence and is located approximately 650m from the western end of the marine pipe launchway. While it is unlikely that construction traffic, noise, vibration and dust will have any more than minor effects on Mr Rooney, or any other neighbours, the Contractor will be required to initiate appropriate mitigation measures.

12 Significant volumes of petrol or diesel will not be stored onsite (subject to volume limits, storage of hazardous substances is permitted by the District Plan).The site is prone to flooding and the Contractor will be required to establish evacuation procedures.

13 A 3-4m high concrete surge chamber may be located close to the assembly area. The exact location would be determined during detailed design.

Construction through stopbanks 14 The pipeline will be trenched through several stopbanks including the Waihao

Stopbank. Works within stopbanks are authorised under the Environment Canterbury Flood Protection and Drainage Bylaw (2013), and the Environment Canterbury Rivers Engineering Section has provided a specification to be included in the CMP and adopted by the Contractor. Environment Canterbury requires that excavations within stopbanks be open for only a limited period to minimise the risk from floodwater intrusion.

Outfall construction 15 McConnell Dowell Constructions Ltd proposes that pipeline construction be separated

into three sections. The offshore section would be constructed first. A second section would then pass through the gravel beach. The third section would cross under the Waihao Arm and connect with the surge chamber.

16 Construction will require the installation of a 180m long temporary trestle over the Waihao Stopbank, the Waihao Arm and the gravel beach. A schematic of this trestle is shown in Attachment D of my Statement of Evidence. The pipeline will be installed from the trestle which will also provide safe access for heavy construction machinery between the assembly area and the beach.

17 Trenching through the Waihao Arm will need to occur in dry conditions requiring the temporary closure of one of the two channels in the Arm by bunding upstream and downstream of the construction works. The ecological values of the Wainono Lagoon and the Arm will be maintained by redirecting all flows through the remaining open channel. A Fish Recovery Plan will be implemented with advice from Te Runanga o Waihao, the Central South Island Fish and Game Council and the Department of Conservation. No works is proposed during the opening weekend of either the gamebird or trout fishing seasons.

18 Construction of the pipeline through the gravel beach will require the installation of sheet piling (also called a coffer dam), to provide a temporary, dry working

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environment. The extent of the sheet piling is shown on the McConnell Dowell schematic in Attachment D of my Statement of Evidence.

19 Dr Murray Hicks notes in his evidence, that the sheet piling will present a temporary barrier to littoral drift along the shoreline. Accordingly, the Contractor will need to relocate sufficient material during construction, from the south side of the coffer dam to the north side, to artificially retain natural gravel transport past the site. Adjacent beach material will be used for backfilling of the coffer dam to mitigate the likelihood of future failure.

20 The presence of the coffer dam will effectively restrict the public access along the beach barrier for up to 15 weeks during construction.

21 The location of the surge chamber and the depth of the pipeline through the Waihao Arm will be determined during detailed design, to account for the long-term effects of coastal erosion.

22 McConnell Dowell has proposed a “bottom pull” method to construct the marine section of the pipeline. The pipeline would be welded together and assembled with concrete weights along the launchway. The pipeline would then be winched through the trench and along the seabed into position.

23 The area immediately seaward of the shoreline is identified as an Area of Significant Natural Value (ASNV), in the Environment Canterbury Regional Coastal Environment Plan (see drawing in Attachment A). From discussions with the Department of Conservation, it appears that the role of the ASNV is to provide a “buffer” to coastal wetlands and the Wainono Lagoon. I understand that the works through the ASNV will require consent as a non-complying activity.

24 Installation of the pipeline will have minimal effects on the seabed. The proposed construction technique will minimise direct environmental effects which Mr Ross Sneddon from Cawthron describes as confined to some localised, temporary turbidity, the presence of a vessel and minor underwater noise and vibration.

Response to submissions 25 A number of submitters are concerned that the pipeline will endanger Waimate Creek

and the Waihao Arm. However, the implementation of the design features described in my Statement of Evidence, as well as the inclusion of procedures and controls prescribed by Environment Canterbury, provides a high degree of assurance about the long-term resilience of the proposed pipeline to the risk of damage and rupture.

26 The Applicant generally supports the mitigation proposed by key submitters such as Te Runanga o Waihao and the Central South Island Fish and Game Council. However, the suggestion from the latter to cease all instream works in the Waihao Arm in July/August is not supported as the proposed crossing will be achieved with no restriction on flows, upstream or downstream of the site.

27 The Contractor’s CMP will address all aspects of minimising nuisance to neighbours, and commit to early and on-going communication with potentially affected parties, prior to and throughout the pipeline construction process.

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Section 42A reports 28 I note that the reports prepared on behalf of Waimate District Council by Ms Patricia

Harte and the reports prepared by Mr Simon Woodlock and Dr Deepani Seneviratna from Environment Canterbury recommend that construction consents be granted subject to a set of consent conditions.

29 Most of the proposed consent conditions are acceptable to the applicant. However, the applicant does not support the recommendation of Mr Woodlock that there be no works in waterways during peak trout spawning season (July-August inclusive). Paragraph 102 of my Statement of Evidence states that the Applicant does not support the cessation of work in waterways during the first week of duckshooting season. This is incorrect and I wish to confirm that the Applicant would support this recommendation and has proposed such a restriction in Proposed Condition 2 (Consent to use land including the beds and banks of watercourses).

Conclusions 30 The construction of the wastewater pipeline can be carried out with effects that are

less then minor. The proposed mitigation that has been identified in the AEE report and draft CMP provides the basis for appropriate consent conditions and the development of the Contractor’s CMP.

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ATTACHMENT A

Drawing 2932873-GIS-01 showing proposed pipeline route corridor and associated activities