Paremata Residents Association Presentation to TGP Board of Inquiry - - PDF document

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Paremata Residents Association Presentation to TGP Board of Inquiry – 6 March 2012

• 1. My name is Russell Morrison and I am the Vice-President of the Paremata Residents

Association which covers an area of about 2,100 households encompassing Papakowhai, Paremata, Golden Gate, Mana and part of Camborne. I have lived in residences right next to the Pauatahanui Inlet and used the harbour in many different ways since the age of two when my family moved to Browns Bay in January 1950.

• 2. Our Association strongly supports the TGP and has been prepared to go to the

Environment Court on three occasions in the past to ensure, directly or indirectly, that TGP stayed on the books. We are asking, however, that the Board consider imposing conditions in a number of areas. Adverse Impacts on the Harbour

• 3. Our submission mentions our concerns about the harbour but does not go into much

detail, opting instead simply to endorse the recommendations of the Pauatahanui Inlet Community Trust (PICT) entirely. I would like to elaborate on our views here.

• Sedimentation
• 4. Quite a number of our members have lived next to the Porirua Harbour for many years.

We recall the controversy when the initial Whitby subdivision was pouring sediment out

• nto the beach opposite what is now Postgate Drive. Many still mention the promises about

retaining tidal flows when the highway was extended and the lagoons created between Porirua and Paremata. We remember the learned debates which took place when the National Roads Board proposed putting a 6 lane motorway on a causeway along the Dolly Varden beach and up through Camborne. So we became educated in a traditional wisdom which said that any reclamation or other reductions in the tidal prism (no matter how small) should be avoided because they will have a compounding effect on the rate of infill. Essentially, we were led to believe that the more the tidal compartment is reduced (i.e. the shallower the harbour is allowed to get), the faster it will infill.

• 5. As a result, when NZTA or other agencies have put forward projects which would reduce

the tidal prism or restrict tidal flows, this Association has asked for conditions requiring the agency to take equivalent measures to maintain the tidal prism. Up until now, such requests have never been accepted – the usual response being “the adverse effects of the works are expected to be less than minor”, or something along those lines. The cumulative impacts of adopting such a stance have become more and more apparent in recent years.

• 6. What we have learnt from the experts or from observation over the years is that there

are really three inter-related factors that determine the rate of infill (and thus the length of life) of our harbour: The amount of sediment or marine sand coming into the harbour;

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The rate at which the tidal prism is being reduced by that sedimentation or by works such as reclamations, seawalls, etc; The extent of restrictions which affect the tidal flow and flushing ability of the harbour. We believe that all of these factors need to be considered when addressing issues around sedimentation.

• 7. The draft Porirua Harbour and Catchment Strategy and Action Plan identifies excessive

sedimentation rates, pollution levels and degraded ecology as major issues affecting the

• harbour. Sediment rates over the past 35 years are said to have averaged about 6mm per

year in the Onepoto arm and 9mm per year in the Pauatahanui Inlet. The Strategy sets targets to reduce sediment inputs from tributary streams by 50% by 2021, and to reduce the sedimentation rate (averaged over the whole harbour) to 1mm per year by 2031. The Action Plan affords immediate priority (over the next 3 years) to reducing run-off from terrestrial sources by, for instance, developing and implementing a whole-of-catchment re-vegetation

• plan. The investigation of options to reduce or compensate for the effects of harbour

structures and other works on harbour dynamics is identified as medium priority (over the next 3-10 years).

• 8. As we understand it, the final Strategy is due to be launched in April and, regardless of

what happens with the TG Project, the “key stakeholders” are committed to its implementation.

• 9. There still seems to be considerable uncertainty as to the amount of sediment which is

likely to end up in the harbour as a result of constructing the TGP. Dr Murray Hicks in his Section 42A report thought that the sediment yield increases during relatively common events could be several (2-5 times) greater than had been estimated by NZTA’s experts. His updated statement of 20 February 2012 states that “there remains an approximately factor-

• f-two uncertainty on the baseline mean annual sediment yields and a larger uncertainty

factor still for event sediment yields”.

• 10. As I understand it, NZTA’s AEE forecasts that construction of the project will result in

about 50 mm of sediment accumulating in the harbour. And yet Transit’s marine ecology expert, Dr De Luca, does not see a need for any measures to mitigate or compensate for accumulation of sediment within the harbour (other than if there is a major Q10 rainfall event during construction) because “the contribution of the Project to the accumulation of sediment within the harbour is minimal compared to the baseline situation and has negligible additive adverse effects”. [Paragraph 55 of Rebuttal Evidence]

• 11. With respect, we strongly disagree with this assessment. If I have interpreted the

information correctly, an accumulation of 50mm is equivalent to 50 years of sedimentation at the normally expected “natural” rate of 1mm per year. I am happy to be corrected, but that suggests to me that the sediment deposited as a result of construction of the TGP will effectively reduce the natural life of the harbour by 50 years.

• 12. Regardless, my Association believes (in simple terms) that if constructing this project

deposits x tonnes of extra sediment into the harbour, then NZTA should be required to take

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measures that will have the effect of removing the equivalent of x tonnes of sediment from the harbour – not in 20 or 30 years’ time, but either before or as soon as possible after the deposition.

• 13. We are aware of Dr De Luca’s concern (shared by other experts) that remedial action to

remove sediment from ecologically sensitive habitats “is likely to cause more damage than benefit” [Paragraph 131 of her Evidence]. However this need not necessarily preclude removal of sediment from areas of “lesser ecological importance” – perhaps the deeper central muddy basins where most of the sediment is eventually expected to settle out. [Mr Roberts - Page 475/6 of Transcript]

• 14. Nor would we want to rule out the possible deepening or creation of new channels

within the harbour as a means of maintaining the tidal prism – notwithstanding the reported results of a recent modelling exercise by DHI Water and Environment Ltd which have been misrepresented by some local politicians as ruling out the viability of any dredging within the harbour. In fact the report merely purports to show that deepening of several existing channels would be unlikely to improve the flushing ability of the Inlet. It seems to us that, if the flushing ability cannot be improved, then early removal of any extra sediment being deposited in the harbour becomes even more important.

• 15. We also believe that the options should include the removal of some existing tidal

restrictions if that could be shown to have some benefits equivalent to sediment removal. For instance, the removal of the obstructions under the northern end of the rail bridge and replacement of the walkway on piles should be seriously considered. Our observations suggest that this work, carried out when the ferry jetty was installed, has had a major influence in reducing the channel width and tidal flow in that vicinity.

• 16. On the matter of tidal restrictions, we are also aware of correspondence and discussions

back in 1999/2000 relating to the possible effects of constructing the new Paremata Bridge

• n the infilling of the Inlet. At that time, one local “expert” - using the results of research on

inlet tidal stability by Hume and Herdendorf published in 1985 – assessed that the effect of the new bridge in reducing the cross-sectional area of the estuary’s inlet could be to create a reclamation 2 metres deep with an area of 14.5 hectares. Despite my best efforts, it proved impossible to get any expert agreement on this matter, but if removal of tidal restrictions around the estuary’s entrance had even a fraction of the benefits suggested by that analysis, they would certainly be significant. (Having said that, I am not sure that removal of the old bridge should be included as mitigation for this particular project because it has already been used for that purpose in gaining consents for building the second bridge - and at this stage anyhow, there is no guarantee that the bridge will even be demolished.)

• 17. We note that the Expert Conferencing Report on marine ecology (paragraph 20)

suggests some potential compensation including: Re-vegetation of stream margins in key catchments e.g. Duck Creek; Restoration of harbour margins to a more natural state e.g. de-reclamation and restoration of saltmarsh areas; and Seagrass restoration in suitable habitats.

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• 18. While not questioning the importance of such measures, we do not believe that they

should be included as mitigation for this particular project because: They have all been identified as “immediate priority” in the Harbour Strategy and presumably have been accepted as the responsibility of the Strategy’s key

• stakeholders. While the three Councils would no doubt welcome it, having NZTA pay

for work that is going to be done anyway will do nothing to improve outcomes for the harbour; and Reducing future sediment inputs and restoring habitats does nothing to directly mitigate or deal with the on-going and compounding effects of the extra sediment which is deposited in the harbour as a result of constructing the TGP. In other words, stopping future sediment from coming in will obviously slow the future rate of infill, but it will not remove the impact of allowing what has already come in to remain. While reducing future sediment rates is of prime importance, in this situation priority for mitigation should be given to maintaining (or preferably increasing) the existing tidal prism.

• Contamination
• 19. One of the benefits of TGP was always the belief that moving traffic further away from

the harbour would provide opportunities to reduce contaminant levels. We were surprised, therefore, to learn from the AEE that the project is expected to result in increased levels of Zinc, Copper and Total Petroleum Hydrocarbons in the Pauatahanui Inlet by 2031. Apparently this results from the overall increase of traffic volumes in the Inlet catchment and the relative ineffectiveness of current treatment methods.

• 20. We don’t claim to know a lot about such methods and our previous attempts to have

road run-off treated before discharge into the harbour have been of very limited value – special double sumps were installed to capture the worst of the contamination when Mana Esplanade was “upgraded” in 2005, but a seeming lack of agreement about who should maintain them has rendered them virtually worthless.

• 21. PICT asks in its submission that NZTA be required to “(a) continuously update

stormwater treatment methods and (b) install treatment measures on stormwater run-off from other roads in the catchment to offset the adverse effects”.

• 22. The Expert Conferencing Report (paragraph 20) seems to support PICT by suggesting

potential compensation could include: Treatment of other discharges to the harbour that may cause adverse effects on marine ecological values e.g. road runoff, urban stormwater. We can only agree.

• Conditions
• 23. PICT has recommended the inclusion of conditions requiring the applicants to

“undertake additional mitigating measures sufficient to ensure that any increases in

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sediment or contaminants entering the harbour as a result of the proposal are completely

• ffset by equivalent reductions”.
• 24. We imagine that estimating the amount of sediment and contamination attributable to

the Project could present some difficulties and it could be that a monitoring programme extending well beyond the construction period will be needed. PICT’s submission expects that “more modelling will be required if the most effective additional mitigation measures are to be assessed. It seems appropriate that this be funded by NZTA and carried out in collaboration with the Harbour Strategy team as a matter of relative urgency”. We agree and would be happy to be involved. The Effect of Tolls

• 25. Our submission explains our concerns about the possibility of tolls. We note that this

matter was also discussed in the traffic and transport Expert Conferencing Report which records: 15 It was acknowledged that the NZTA does not have any current proposals for the application of tolls to the Project, and therefore there was no requirement to consider the quantitative effect of tolls as part of the Project assessment. 16 Mr Wignall considers that sensitivity testing should have included a test of the effects of the Project were tolls to be applied. Mr Kelly considers that, given the NZTA position, such a test would be hypothetical and is not required as part of the assessment.

• 26. We are concerned that, despite NZTA’s current intentions, there is still a real possibility

that the Government or NZTA officers of the day will decide that the new road should be

• tolled. In our view, this would reduce the expected benefits considerably and impose (or

continue) significant adverse environmental effects.

• 27. We would like the Board to consider making reference to this issue in your decision and

(if you felt it appropriate) to require or recommend that, if tolls are used, the ability be maintained to remove such tolls at any time. It would be most unfortunate if a long-term tolling contract were entered into and could not be altered if subsequent traffic patterns showed this to be desirable. The Acknowledgement of Previous Commitments

• 28. Our submission outlines several commitments that were made at the time that the

Environment Court approved the conversion of Mana Esplanade into a peak hour T2 clearway operation back in 2000. Amongst other things we outline: (a) Transit’s “commitment to the local community” that Transit would “demolish the existing Paremata Bridge and remove the Clearways through Mana in conjunction with the opening of TGM, and following appropriate public process”; and (b) Transit’s advice that the funding for demolishing the bridge and removing the clearways “would be included in the cost of construction of the TGM as the de-

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commissioning of the existing bridge is a consequence of constructing the TG route and therefore the funding of it is related to that project”.

• 29. While our submission said that Transit’s “commitment” was (in essence) written into the

designations, in fact the condition concerned really only requires NZTA to consult the community (prior to completion of the TGP) and advise the PCC and GWRC of its intended response to that consultation. The actual wording of the conditions is:

• 59. Prior to the completion of the construction of Transmission Gully Motorway

Transit shall: 59.1 Consult with PCC, WRC, Paremata Residents Association Inc, Plimmerton Residents Association Inc, and Ngati Toa Rangatira in relation to its proposals for the Work following the construction of the Transmission Gully Motorway, including the following matters: (a) Ownership and control of the Work; (b) Options relating to the future of the existing Paremata Bridge; (c) The continuation of four laning of St Andrews Road between Acheron Road and James Street; (d) Measures (to the extent that they are legally available) to restrict or discourage heavy vehicle movements through the Work; (e) Other measures required to ensure an adequate level of service for the traffic volumes and traffic type expected to use the Work; (f) Provision of arrangements for cyclists; (g) Alteration of footpath widths; (h) Removal of traffic lights; (i) Changes to the operation of the clearway or HOV lanes; (j) Alteration of arrangements in relation to capacity; (k) Any changes to be sought to the designation in relation to those matters; and 59.2 Report on the outcomes of that consultation to PCC and WRC for the purposes of ensuring that the PCC and WRC are fully informed of the views of the public and those bodies, and of Transit’s intended response to that consultation.

• 30. From past and present experience, our Association has little reason to have a great deal
• f faith in NZTA’s ability or willingness to honour previous commitments, expectations or

even consent conditions. In this instance, it would seem to be in NZTA’s interest not to have to demolish the bridge or remove the clearways – and, instead, to pass that responsibility to future Porirua ratepayers.

• 31. Similarly, we are not at all confident about the PCC’s memory or judgement in such

matters – particularly when we read things like the transcript of Peter Bailey’s evidence to the Board. When questioned about the revocation process and handing over to PCC of the existing highway, he is recorded as saying (inter alia): In my experience, it’s normally gone a little bit past ... the time of the finishing of the construction of the project ...My experience, it can go on for three or four years afterwards, and bearing in mind the issues and expectations, I think that would be quite a useful area because then the community can see the effects of the reduction

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• f traffic and tailor the measures to suit what it really looks like rather than
• speculate. [pages 149/150 of the transcript]
• 32. We would like to remind NZTA and Mr Bailey that the major objective of the works on

SH1 between Paremata and Plimmerton was: To assist in ensuring that, during the interim period pending construction of the Inland Highway route, there is a sufficient level of service afforded in relation to the existing coastal highway route by enhancing traffic capacity between Plimmerton and Paremata.

• 33. At the time of the Environment Court hearing in August 2000, it was thought that the

TGM could be completed even as early as 2005/6, and a major advantage of the clearway

• ption put forward was its ability to be reversed when the TGM was constructed.
• 34. In fact, we will now be lucky if we see the TGP constructed by 2021. The local

community will have had to put up with four lanes of traffic through its centre for at least 16 years and the harbour will have suffered the additional adverse impacts of having two road bridges restricting the tidal flow for a similar period. We certainly don’t need yet another 3

• r 4 years three years of that or the uncertainty accompanying it.
• 35. We believe that the commitment (albeit confusingly qualified) given by Transit back in

2000 needs to be recognised, endorsed and spelt out more clearly in this Board’s decision, so that the decision as to demolition and removal of the clearways (at least) is not left with NZTA and there is no delay in implementation.

• 36. We have therefore recommended the inclusion of conditions requiring NZTA to

undertake all the steps necessary to allow demolition of the old Paremata Bridge and removal of the clearways at Mana by no later than 6 months after the TG route is opened, and to take such other actions as are necessary to restore the highway between Paremata and Plimmerton to a local road. Calculation of Benefit /Cost Ratio

• 37. Just one last thing. In case the benefit/cost ratio is likely to have any influence on your

decision, then I would like you to note the first paragraph on page 3 of our submission that mentions a letter from Transfund produced by Transit to the Environment Court in 2000. A copy of that letter is attached.

• 38. The Court was told at the time by Transit’s representative that the letter confirmed their

understanding that, because the works at Mana were “interim”, when the benefit/cost ratio for TG was ultimately worked out, it would be on the basis of using the levels of congestion which would exist if the Mana works had not been carried out.

• 39. As far as I can make out, this advice has not been followed in the determination of the

current BCR for this project. Thank you for the opportunity to provide these comments.