BEFORE THE ENVIRONMENTAL PROTECTION AUTHORITY. of an Application under Section 38 of the Act for Marine Consents by Trans-Tasman Resources Limited

Transcription

1 BEFORE THE ENVIRONMENTAL PROTECTION AUTHORITY IN THE MATTER of the Exclusive Economic Zone and Continental Shelf (Environmental Effects) Act 2012 AND IN THE MATTER of an Application under Section 38 of the Act for Marine Consents by Trans-Tasman Resources Limited JOINT STATEMENT OF EXPERTS IN THE FIELD OF EFFECTS ON WAVES AND SURFING Dated 25/3/2014

2 INTRODUCTION 1. Expert conferencing of the wave and surfing effects experts took place by telephone and videoconference on 20/3/ The conference was attended by 2.1. Dr Richard Gorman (TTR) 2.2. Dr Shaw Mead (TTR; for part of the meeting) 2.3. Dr Michael Huber (EPA) 2.4. Mr Miles Yeates (EPA) CODE OF CONDUCT 3. We confirm that we have read the Environment Court's Code of Conduct 2011 and agree to comply with it. We confirm that the issues addressed in this Joint Statement are within our area of expertise. SCOPE OF STATEMENT 4. In our conference we discussed the issues relevant to the Application which arise within our field of expertise. Prior to attending the conference we each read the relevant parts of the application, the evidence and independent reports prepared by the other expert(s) and circulated. 5. In relation to each issue we discussed points of agreement and disagreement in relation to: 5.1. Facts; 5.2. Assumptions; 5.3. Areas of uncertainty or lack of information; and 5.4. Expert opinions / conclusions. 6. In this Joint Statement we report the outcome of our discussions in relation to each issue by reference to points of agreement and disagreement relating to facts, assumptions, uncertainties and expert opinions / conclusions. We have noted where each of us is relying on the opinion or advice of other experts. Where we are not agreed in relation to any issue we have set out the nature and basis of that disagreement. LIST OF ISSUES 7. The view expressed in Submissions that, if permitted, mining activity could potentially affect the quality of surfing and surf breaks in Taranaki, both intermittently and permanently

3 2 8. Issues raised by the SKM Technical Reviews with respect to the application of grids of various spatial resolutions in the wave modelling studies 9. Issues raised in Submissions with respect to wave modelling studies 10. Concerns raised in the evidence of Mr Dougal Greer with respect to the effects of bathymetry modifications on sediment transport and bedforms in m water depth ISSUE 1: The view expressed in Submissions that, if permitted, mining activity could potentially affect the quality of surfing and surf breaks in Taranaki, both intermittently and permanently 11. We agree that the results reported in the evidence of Dr Shaw Mead, indicating only minor effects from mining activity on the quality of surfing and surf breaks in Taranaki, are soundly based. It was confirmed that the magnitude of predicted reductions in wave size (in the order of 0.1 m for a 3 m significant wave height) were proportional to the wave size. Thus, in smaller surfing conditions (e.g m waves), the reduction in wave size would be smaller than 0.1 m, and thus not affect wave quality for surfers. ISSUE 2: Issues raised by the SKM Technical Reviews with respect to application of grids of various spatial resolutions in the wave modelling studies 12. Dr Mead was absent from discussion of this issue. 13. The wave modelling studies employed three modelling grids: at 1 km resolution, used to provide boundary conditions for the other grids, at 500 m resolution, used to provide wave inputs for the hydrodynamic and sediment transport modelling, and at 100 m resolution, used to test the effects of pits and mounds and of vessels on wave conditions 14. We agreed that the modelling methods used, the spatial resolutions selected, and the choice of outputs reported from those simulations, were appropriate for the study.

4 3 ISSUE 3: Issues raised in Submissions with respect to wave modelling studies 15. Dr Mead was absent from discussion of this issue. 16. We discussed the following points that were raised in Submissions, and have been addressed in the Evidence in Chief of Dr Richard Gorman ( EiC ): Status of case 1 as a worst case scenario (raised by Taranaki Regional Council, addressed in par of EiC) Potential effects of changed currents and wave reflections from TTR's operations and infrastructure on Kupe platform (raised by Origin Energy, addressed in par. 84 of EiC) Inconsistency between Table 30 in the Impact Assessment and the corresponding Table 4-1 of the wave study report, and Table 5-2 of the coastal stability report, giving maximum changes in significant wave height observed in scenario-based wave model simulations. (raised by K. Pratt, addressed in par. 85 of EiC) Incorrect month given in report for scenario-based simulations (raised by K. Pratt, addressed in par. 86 of EiC) Representativeness of conditions selected from one month for scenario-based simulations (raised by K. Pratt, addressed in par. 87 of EiC) Use of empirical methods for nearshore and surfzone impacts, and relation to SWAN modelling (raised by K. Pratt, addressed in par. 88 of EiC) Extent of the grid area for nearshore wave modelling (raised by K. Pratt, addressed in par. 89 of EiC) Investigation of only one bathymetry modification in the one year simulation (raised by K. Pratt, addressed in par. 90 of EiC) Presentation of results from the one year simulation only as means and standard deviations of bathymetry-related differences, but not as maximum differences or confidence levels (raised by K. Pratt, addressed in par. 91 of EiC).

5 Possible fine-weather bias in environmental scenarios selected for the scenario-based study (raised by K. Pratt, addressed in par. 92 of EiC) Exclusion of tidal levels and currents from the scenario-based simulations (raised by K. Pratt, addressed in par. 93 of EiC) Inclusion of only the FPSO in the tests of vessel shadowing effects (raised by K. Pratt, addressed in par. 94 of EiC) The use of a constant K = 0.8 in estimating longshore sediment transport (raised by K. Pratt, addressed in par. 95 of EiC) Adequacy of the wave model verification (raised by K. Pratt, addressed in par. 95 of EiC) Design sea state for the FPSO: likelihood and consequences of exceedance (raised by Te Ohu Kai-Moana Trust Limited, addressed in par. 89 of EiC). 17. With respect to point 16.1 above, we agreed that the case1 bathymetry modification used in the simulations can be reasonably be considered as a worst case scenario with respect to the magnitude of impacts on wave conditions inshore from the mining areas. This conclusion is based on the fact that case 1 includes the maximum planned extent of seabed modification including the maximum expected pit depths and mound heights, does not include any allowance for pit infilling or mound deflation over the life of mine, and that modelling of six different scenarios confirmed the expectation that case 1 represents the worst case. 18. With respect to point above, we agreed that the level of agreement between modelled and measured wave conditions was reasonable for a study of this kind. 19. With respect to point above, we further agreed that the magnitudes of errors in comparing modelled and measured wave conditions when simulating historic wave conditions arise from a number of causes, including errors in the inputs (e.g. predicted wind fields, swell boundary conditions) to the model, as well as from any errors in how the model transforms wave conditions into the coast. 20. With respect to point above, we further agreed that the magnitudes of errors found in the verification study are not directly

6 5 applicable as an indication of errors arising in quantifying the difference between simulations with and without bathymetry modifications. This is because the errors will generally affect the predictions with and without bathymetry modification in a similar manner. 21. With respect to other points listed above, we agreed that these have been appropriately addressed by the Evidence in Chief of Dr Gorman. ISSUE 4: Concerns raised in the evidence of Mr Dougal Greer with respect to the effects of bathymetry modifications on sediment transport and bedforms in m water depth 22. Dr Mead was absent from discussion of this issue 23. We agreed that these concerns relate primarily to the evidence of Dr Terry Hume with regards to coastal stability, and are most appropriately addressed in relation to that evidence, with assistance, if required, of relevant results from the wave modelling study. Signed by: 25 th Dr Richard Gorman 23 rd Dr Shaw Mead 25 th Dr Michael Huber 25 th Mr Miles Yeates