Kaeo Bridge Project Assessment of Acoustic Effects New Zealand Transport Agency Reference: 254914 Revision: 4 16 December 2019

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Document prepared by: Aurecon New Zealand Limited Level 4, 139 Carlton Gore Road Newmarket Auckland 1023 PO Box 9762 Newmarket Auckland 1149 New Zealand

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Report title Assessment of Acoustic Effects

Document ID Project number 254914

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Client New Zealand Transport Agency

Client contact Jane Price Client reference

Rev Date Revision details/status Author Reviewer Verifier Approver (if required) A. Liberona 1 6 December 2017 Draft for client review J. Grimes F. Parr R. Wareing 2 17 July 2019 Draft for Client Review J. Ngo H. Miller -

3 25 September 2019 Draft for Client Review J. Ngo H. Miller -

4 16 December 2019 Minor Amendments J. Ngo H. Miller -

Current revision 4

Approval

Author signature Approver signature

Name J. Ngo Name

Title Acoustic Engineer Title

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Contents

1 Executive Summary...... 6

2 Introduction ...... 7 2.1 Project Background ...... 7 2.2 Purpose of this Report ...... 8

3 Site Description ...... 8 3.1 Existing noise environment ...... 9 Measurement details ...... 9 Long-term noise measurements ...... 10 Short-term noise measurements ...... 10 Summary of results ...... 11

4 Construction Noise and Vibration ...... 12 4.1 Construction noise ...... 12 Criteria ...... 12 Assessment ...... 13 4.2 Construction Vibration ...... 16 Criteria ...... 16 Assessment ...... 16

5 Operational Noise and Vibration ...... 19 5.1 Operational noise...... 19 Criteria ...... 19 Protected Premises and Facilities ...... 19 Assessment ...... 20 5.2 Operational vibration ...... 24 Criteria ...... 24 Assessment ...... 24

6 Recommendations...... 26 6.1 Construction noise and vibration ...... 26 Management strategy ...... 26 Construction Noise and Vibration Management Plan ...... 26 General good practice ...... 27 Site specific mitigation ...... 27 6.2 Operational noise and vibration ...... 28

7 Conclusions ...... 29 7.1 Construction Noise and Vibration ...... 29 7.2 Operational Noise ...... 29

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Appendices

Appendix A Relevant Standards, Guidelines, and Rules

Far North District Plan – Rural Environment Site zoning Construction Noise Construction Vibration

Standards and Guidelines NZS 6803:1999 BS5228-1 BS5228-2 DIN4150-3

Appendix B Operational Noise Contours

Appendix C Construction Noise Contours

Appendix D Construction Vibration Contours

Appendix E List of equipment used for noise assessment Figures

Figure 1 Proposed works Figure 2 Project location Figure 3 Noise measurement locations Figure 4 MP2 - View from monitoring station towards Kaeo Bridge Figure 5 MP4 – Monitoring location Figure 6 Far North District Plan (Map 21) and proposed road alignment

Tables

Table 1 Details of long term noise logger Table 2 Details of hand-held sound level meter Table 3 Noise logger measurement results – MP1, 12th to 18th September 2017 Table 4 Short-term noise measurements results, 12th September 2017 Table 5 Construction noise limits for all properties surrounding the Project

Table 6 Required stand-off distance to achieve 70 dB LAeq Table 7 Predicted noise levels at PPFs during construction activities relating to the main alignment and bridge works Table 8 List of PPFs exceeding morning and daytime noise criteria for specific construction activities. Table 9 Vibration limits for buildings around the construction site Table 10 Vibration levels at PPFs due to piling or stone column construction activities Table 11 Vibration levels at PPFs due to dynamic compaction Table 12 NZS 6806:2010 noise criteria Table 13 Modelling parameters

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Table 14 Road traffic details Table 15 Comparison of measured and predicted (modelled) noise levels Table 16 Noise categories (As specified in NZS 6806:2010 for an altered road) Table 17 Predicted free-field noise levels at PPFs Table 18 Distance between proposed alignments and PPFs Table 19 Hierarchy of controls for the Project Table 20 Construction noise limits for all properties surrounding the Kaeo bridge replacement Table 21 NZS6803-1999 Noise Guidelines for residential receivers (values taken from Table 2 in NZS6803-1999) Table 22 Transient vibration guidelines for cosmetic damage (replicated from Table B.2 from BS 5228- 2:2009) Table 23 Subjective evaluation of vibration (replicated from Table B.1 from BS 5228-2:2009) Table 24 Vibration guidelines for short-term vibration on structures (replicated from Table 1 from DIN4150-3: 1992-02) Table 25 Acoustic Data used in Construction Assessment Table 26 List of construction activities and cumulative noise levels

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1 Executive Summary

Aurecon has been engaged by the New Zealand Transport Agency (Transport Agency) to provide an assessment of noise and vibration effects for the proposed SH10 Kaeo Bridge Project. This report provides an assessment of both the operational and construction noise and vibration effects of the project. New Zealand Standard 6806:2010 is an industry accepted benchmark for assessment of reasonable effects under Section 16 of the Resource Management Act 1991 (RMA). Therefore, assessment of road traffic noise in accordance with the standard represents the Best Practicable Option (BPO) for assessing operational road traffic noise and has been applied to the Project. Computational noise modelling for the existing and proposed road alignment has been conducted to predict road traffic noise emissions to the surrounding environment. An assessment of the results has been undertaken in accordance with NZS6806:2010. Results have shown that the change in noise levels between the Do Nothing and Do Minimum scenarios at all Protected Premises and Facilities (PPFs) are expected to be 3 dB LAeq(24hr) or less. The noise modelling has shown that the proposed changes to the road alignment are not expected to cause an increase in noise levels above the stipulated thresholds to trigger an assessment in accordance with Section 1.5.2 of NZS6806:2010. Consequently, further assessment of acoustic mitigation is not required in accordance with NZS6806:2010.

The assessment of construction noise and vibration has been completed respect to Morning and Daytime periods as construction will only occur during these specified times of the day. The predictions indicate daytime noise limits may be exceeded at 8 Whangaroa Road. Whilst morning period noise limits are exceeded at numerous PPFs for vegetation clearance, bulk earthworks, road surfacing, bridge construction and bridge demolition.

The vibration criteria may be exceeded at times at 8 and 10 Whangaroa Road if extensive dynamic compaction is required.

During construction, we consider that with appropriate equipment selection, appropriate scheduling and noise mitigation measures, noise emissions from the site can generally comply with the applicable construction noise limits during the morning period and daytime period. With appropriate scheduling, liaison and communication with the occupants of the PPF’s, it is considered that the construction noise and vibration effects would be reasonable. A Condition of Consent requiring preparation and implementation of a Construction Noise and Vibration Management Plan is considered the Best Practicable Option for mitigating any noise effects from this project.

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2 Introduction

2.1 Project Background

State Highway 10 (SH10) is an important link in the Northland State Highway network and is part of the Paihia to Kaitaia section of the Twin Coast Discovery Route. The one lane bridge located along SH10, at the intersection with Whangaroa Road crossing the Kaeo River (asset reference Bridge 448) has been identified by the Transport Agency to have a number of risks associated with resilience and driver safety. The Project proposes to resolve these risks by realigning the road geometry and replacing the bridge with a new two-lane bridge, as depicted in Figure 1. In summary, the key elements of the Project are as follows: Realignment of SH10 through the construction of a new section of state highway across rural land; Construction of a two-lane road bridge over the Kaeo River and demolition of the existing single lane bridge; Construction of a new roundabout at the intersection of SH10 with Whangaroa Road; Construction of cross culverts under SH10 and earthworks to improve resilience during flooding; and Provision of access onto SH10 to properties directly impacted by the new alignment Improved State Highway capacity, safety and resilience improvements through enhanced vertical and horizontal alignment, increased sight distances on approach to the proposed bridge and safety barriers along the length of the alignment. A full description of the Project, including its components and construction, is contained in the Assessment of Environmental Effects (AEE) for the Project.

Figure 1 Proposed works

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2.2 Purpose of this Report

This report is one of several technical specialist reports that has been prepared to inform the Project AEE. The particular focus of this report is an assessment of the acoustic effects that the Project has with respect to the construction and operation of the Project. This assessment has considered all noise sensitive locations within 200 metres of the existing and proposed road alignment in accordance with NZS 6806:2010. These noise sensitive locations are known as Protected Premises and Facilities (PPFs) and include existing houses, schools, Marae and various other land uses defined in the Standard. This assessment is based on drawings prepared as of 31 May 2019. A modification was made to the alignment on 14 June 2019 resulting in the roundabout at the intersection of SH10 and Whangaroa Road being moved east of the position modelled in this assessment. A qualitative assessment has deemed the design change to be insignificant with respect to the subject operational and construction acoustic assessment. Should further changes to the design and location of the roundabout be made, a review of the predicted operational and construction acoustics is recommended.

3 Site Description

The site of the Project is predominantly rural in nature, located approximately 2.5 km north-west of Kaeo township along the Kaeo River, as depicted in Figure 2. Dwellings are dispersed throughout the locality, including along the ridgeline above SH10 to the east and several adjacent to the proposed works area. Hills to the south west are planted as pine fores, the Kaeo Rugby Club located approximately 240m north of the Kaeo Bridge along Whangaroa Road and a quarry is located off SH10 to the south east at 232 SH10, Whangaroa.

Figure 2 Project location

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3.1 Existing noise environment Baseline noise monitoring was undertaken between 12th September 2017 and 18th September 2017 adjacent to the Project extents.

Measurement details Noise measurements were carried out in general accordance with the New Zealand Standard 6801:2008 “Acoustics – Measurement of environmental sound”. Unattended (long term) and attended (short term) noise measurements were conducted at locations depicted at Figure 3. This included a long-term noise logger installed approximately 37m directly east of the dwelling at 339 SH10, setback approximately 100m from SH10 (MP1). Attended noise monitoring was also conducted in the surrounding area at locations MP1 through MP4.

Figure 3 Noise measurement locations The meteorological conditions were suitable for short term environmental noise monitoring with no rain and wind speeds below 5m/s. During long term monitoring some periods of rain and high wind speeds above 5m/s were identified, with the data collected during these periods of poor weather excluded from the results. The equipment used for the long-term noise measurements is described in Table 1, and details of the sound level meter used for short term noise measurements are included in Table 2.

Table 1 Details of long term noise logger

Equipment Details Noise Logger ARL Ngara Noise Logger Instrument Serial Number 87805F Microphone Serial Number 317088 Last Calibration Date 26/07/2017

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Table 2 Details of hand-held sound level meter

Equipment Details Sound Level Meter Bruel & Kjaer 2250 - Type 1 Instrument Serial Number 2653913 Microphone Type Bruel & Kjaer 4189 Microphone Serial Number 2643633 Last Calibration Date 13/07/2017

Long-term noise measurements Unattended noise logging was undertaken continuously from 10:15am 12/09/2017 through to 10:30am 18/09/2017. The equipment was calibrated prior to and after the measurements. A wind shield was used during the entire measurement period. The noise logger was located on a raised bank of land, approximately 1m higher than the road level in free field conditions. The results of the long-term noise logging are presented below in Table 3.

Table 3 Noise logger measurement results – MP1, 12th to 18th September 2017

dBA DATE Day (0700-2200) Night (2200-0700) 24 hrs

(2) (2) Leq L90 Leq L90 Leq Tues 12/09/17 (1) (1) 45 29 (1) Wed 13/09/17 52 40 46 32 50 Thu 14/09/17 52 38 47 31 51 Fri 15/09/17 (1) (1) 46 32 (1) Sat 16/09/17 51 38 43 25 49 Sun 17/09/17 (1) (1) 47 31 (1) Mon 18/09/17 53 41 48 31 (1) Average 52 39 46 31 50 (1) Not full 24 hour data due to weather conditions and measurement configuration, therefore excluded from the calculation of the average;

The L90 values presented in Table 3 are arithmetic averages calculated for two specific extended time reference periods (0700 – 2200 and 2200 – 0700) on consecutive dates for the duration of the survey.

Presented levels therefore do not represent the absolute lowest L90 levels likely to occur in the existing acoustic environment over shorter time reference periods.

Short-term noise measurements Attended noise measurements were undertaken from 10:37am to 12:43pm on 12th September 2017 at the same location as the noise logger (MP1) and at locations MP2 through MP4 shown in Figure 3. These measurements were conducted for 15 minute periods at each MP. Shorter measurements were taken at MP2 to identify three specific events of road traffic as described in Table 4.

Table 4 Short-term noise measurements results, 12th September 2017

Measurement Measurement Measurement Leq, L90, Position Comments date time duration dBA dBA

MP1 Birdsong and insects noise were 12/09/2017 10:37 15:00 51 41 heard. Approaching vehicles from (339 SH10) both directions are audible.

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Measurement Measurement Measurement Leq, L90, Position Comments date time duration dBA dBA MP2 Double truck over the bridge, idling (adjacent 12/09/2017 11:09 3:00 63 53 noise from the truck dominated as Kaeo it waited to cross the bridge. bridge 4 cars passed by, 2 over bridge, 2 eastern 12/09/2017 11:14 1:34 58 44 directly to the left of monitoring bridge location. abutment, refer Total of 7 cars passed by, no 12/09/2017 11:25 1:57 58 53 Figure trucks. 4) Noise monitoring location approximately at 37m east from SH10 with hills on all three sides MP3 from north, east and south. Road 12/09/2017 11:42 15:00 49 37 (258 SH10) view shielded from site by tall trees. Noise from chickens and Guinea fowls have been excluded from the data. Noise monitoring location MP4 approximately at 18m south from SH10. Not shielded location (253 SH10, 12/09/2017 12:28 15:00 63 43 refer outside property No. 253. Traffic Figure 5) noise is the dominant noise source at this location.

At the time of noise measurements, the dominant noise source in the area was road traffic travelling along SH10. The change in speed of vehicles as they approach the bridge due to the single lane crossing was noticeable. Engine noise from HGV’s idling whilst waiting to cross the bridge was prominent, and their movement over the bridge caused vibrations and clattering at bridge joints. The measurements were conducted prior to cicada season hence were not affected by cicada noise.

Figure 4 MP2 - View from monitoring station towards Figure 5 MP4 – Monitoring location Kaeo Bridge

Summary of results It is considered that the monitoring locations are representative of ambient noise levels for the nearest

PPFs. The background levels during the daytime period ranged between 37-43 LA90 dB, and between

25 – 32 LA90 dB during the night time period. Long-term and short-term monitoring at MP1 show similar results where daytime ambient noise levels are consistently 51-53 LAeq dB; Short-term results at MP4 show the highest noise level due to the proximity to SH10.

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4 Construction Noise and Vibration

Predictions of the construction noise and vibration have been undertaken for this project. The noise levels at PPFs within 200 m of the work areas have been predicted. In addition, the noise and vibration effects associated with the demolition and removal of the existing bridge have also been assessed. It has been assumed that the construction and demolition works will occur over a period of greater than 18 weeks and are therefore considered “long-duration” under NZS6803:1984 and NZS6803:1999. These assessments are presented in this section.

4.1 Construction noise

Criteria The Far North District Plan specifies noise limit criteria for construction noise, based upon the criteria outlined in NZS6803:1984 “The Measurement and Assessment of Noise from Construction, Maintenance and Demolition Work”.

The Construction noise standard NZS6802:1984 was superseded in 1999. In the revised standard the key noise descriptor was updated from L10 to Leq. In order to assess the effects of construction noise in accordance with the most up to date standards, we have used the 1999 version of the standard consistent with the most modern methodology. We consider that the most recent version of the standard is appropriate to assess construction noise effects for the project. These construction noise limits for the project are summarised in Table 5.

Table 5 Construction noise limits for all properties surrounding the Project

Duration of work Typical duration Short-term duration Long-term duration Activity Time Period (dBA) (dBA) (dBA) Leq Lmax Leq Lmax Leq Lmax 0630-0730 60 75 65 75 55 75 0730-1800 75 90 80 95 70 85 Weekdays 1800-2000 70 85 75 90 65 80 2000-0630 45 75 45 75 45 75 0630-0730 45 75 45 75 45 75 0730-1800 75 90 80 95 70 85 Saturdays 1800-2000 45 75 45 75 45 75 2000-0630 45 75 45 75 45 75 0630-0730 45 75 45 75 45 75 Sundays 0730-1800 55 85 55 85 55 85 and public holidays 1800-2000 45 75 45 75 45 75 2000-0630 45 75 45 75 45 75

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Assessment

Noise sources and construction activities Based on the information provided by contractor Fulton Hogan and Aurecon’s experience of similar projects, noise sources and sound power levels have been assumed for the proposed construction activities. A list of these noise sources is provided in Appendix E. Proposed construction activities are planned to be undertaken between 0700 – 1800. This time period spans over both the morning and daytime periods and will invoke two sets of noise criteria from NZ6803:1999.

Construction activities The noise resulting from each major activity being undertaken during construction has been predicted. The activities, equipment used, and the required stand-off distances are presented in Table 6. Further information regarding data input into the noise model is included in Table 25 and Table 26.

Table 6 Required stand-off distance to achieve 70 dB LAeq

Stand-off distance (metres) Activity Equipment necessary to achieve 70 dB LAeq Excavator (16t) Use of laydown site and yards Truck with hiab 35m Mobile generator Asphalt paver and tipper truck Dump truck (23t) Road surfacing Road Roller 55m Dump truck (23t) Vibratory roller (12t) Excavator (16t) Dump truck (23t) Bulk Earthworks 50m Bulldozer (20t) Vibratory roller (12t) Pulveriser on excavator Excavator loading rubble onto dump truck Hand-held hydraulic breaker Hand held petrol concrete circular saw Bridge Demolition 90m Gas cutter Angle grinder (steel) Mobile generator Truck with hiab Mobile generator Truck with hiab Concrete pump and mixer truck Gas cutter Angle grinder (steel) Bridge Construction Tracked mobile crane (55t) 44m Portable hand-held welder Excavator (16t) Dump truck (23t) Screw pile rig Sheet pile rig Petrol Chain Saw Vegetation Clearance Excavator (16t) 55m Dump truck (23t)

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Construction activity predicted noise levels The noise from construction activities relating to construction of the main alignment, bridge construction and demolition and activity at the proposed construction yard and equipment laydowns areas were predicted at each PPF using the methodology described in BS5228-1. The resulting noise levels are presented in Table 7, and contour maps showing the predicted noise levels and location of the PPF’s are presented in the Appendix B. Where exceedances to the day time standards are predicted, these are highlighted.

Table 8 summaries the PPFs that exceed the morning and daytime noise limits for the listed construction activities, based on the predictions from Table 7. These exceedances have been highlighted in Table 7, dark orange highlighting exceedances of the daytime period and yellow exceedances of the morning period.

Table 7 Predicted noise levels at PPFs during construction activities relating to the main alignment and bridge works

Yard and Vegetation Bulk Road Bridge Bridge Address Laydown Clearance Earthworks Surfacing Construction Demolition dB LAeq dB LAeq dB LAeq dB LAeq dB LAeq dB LAeq 401 SH10 36 40 43 43 38 45 421 SH10 34 38 41 41 36 44 402 (No. 1) SH10 34 38 41 41 37 44 402 (No. 2) SH10 35 38 42 42 37 43 402 (No. 3) SH10 34 38 41 41 37 44 40 Whangaroa 50 54 55 55 49 57 Road 407 SH10 35 39 42 42 37 45 409 SH10 34 38 42 42 37 44 339 SH10 48 49 62 62 49 56 393 SH10 38 41 47 47 40 48 8 Whangaroa Road 51 74 68 68 62 66 286 SH10 45 59 56 56 52 58 10 Whangaroa 54 68 64 65 59 69 Road 253 SH10 41 55 54 54 47 53 18 Waikoura Road 49 57 56 56 51 60 258 SH10 43 59 57 57 49 52 156 Dip Road 35 43 42 43 39 45 232 SH10 37 48 47 47 42 50 Pahuhu 1A SH10 41 54 52 53 43 55

Table 8 List of PPFs exceeding morning and daytime noise criteria for specific construction activities.

PPFs Exceeding NZS6803 Criteria Construction Activity Morning (0630 – 0730) Daytime (0730 – 1800)

55 dBLAeq 70 dBLAeq Vegetation Clearance 8 Whangaroa Road 8 Whangaroa Road 286 SH10 10 Whangaroa Road 253 SH10 258 SH10 Bulk Earthworks 8 Whangaroa Road - 339 SH10 286 SH10

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PPFs Exceeding NZS6803 Criteria Construction Activity Morning (0630 – 0730) Daytime (0730 – 1800)

55 dBLAeq 70 dBLAeq 10 Whangaroa Road 258 SH10 Road Surfacing 8 Whangaroa Road - 286 SH10 10 Whangaroa Road 258 SH10 Bridge Construction 8 Whangaroa Road - 10 Whangaroa Road Bridge Demolition 40 Whangaroa Road - 8 Whangaroa Road 286 SH10 10 Whangaroa Road

Table 7 and 8 above shows that noise levels from construction activities are predicted to comply with the daytime noise limits except at one location when vegetation clearance is being undertaken along the eastern side of SH10. Whilst a number of PPFs exceed the morning noise limit of LAeq 55 dBA for vegetation clearance, bulk earthworks, road surfacing, bridge construction and bridge demolition.

At 8 Whangaroa Road, the predicted noise level of 74dBA during vegetation clearing at the eastern side of SH10 exceeds the daytime period construction noise limit of 70dBA, however is less than the Lmax criteria of 85dBA. Vegetation clearance is a temporary activity to be undertaken during the daytime, within a relatively short period of time during the broader construction programme.

The Best Practical Option (BPO) to mitigate against the exceedance in discussed in Recommendations, Section 6 of the report.

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4.2 Construction Vibration There are three main sources of vibration expected during construction: Ground improvements required for the construction of the new bridge. This could include piling or stone column insertion; Dynamic compaction required along the road alignment; Demolition of the existing bridge. The vibrations caused by these activities have been assessed in this section.

Criteria The Far North District Plan does not include specific limits for vibration from construction activities, only limits relating to blasting which is not proposed to be used for the Project. For this assessment, the construction vibration criteria specified in Standards BS5228-2 and DIN4150-3 have been utilised to develop the project vibration criteria specified in Table 9. In addition, similar vibration criteria are also specified in the NZ Transport Agency guidance document for managing construction noise and vibration1. Table 9 Vibration limits for buildings around the construction site

Limit description Peak Particle Velocity Limit Annoyance criteria – 1 mm/s ppv notification required Potential cosmetic damage – 5 mm/s ppv precondition surveys required

Assessment

Piling or stone column installation There are a range of different piling methodologies that may be used in the development of the bridge foundations. The predicted vibration levels from each of these are described in this section. Typically, the vibration levels for rotary bored piling are negligible. Table D.6 of BS 5228-2 provides typical vibration levels measured around rotary bored piling works. For rotary piling works in soft earth above rock the peak vibration levels (ppv) were approximately 0.5 mm/s at 5 m. As no receivers are within 5 m of the bridge site the predicted vibration levels due to rotary bored piles are below the 1 mm/s notification threshold at all the identified receivers. Installation of piles using a percussive driver can produce peak vibration levels. Vibratory piling, sheet piling, and stone column insertion can produce long duration vibration levels. The vibration levels due to these piling works can be predicted using the equations presented in Table E.1 of BS 5228-2. The predicted vibration levels at the PPFs due to ground improvement activities are presented in Table 10. Based on the predicted levels set out at Table 10, the vibration criteria set out at Table 8 for annoyance will be exceeded at one receiver only, at 8 Whangaroa Road. The predicted vibration levels at 8 Whangaroa Road are less than the limits in Table 8 relating to Potential cosmetic damage. It is therefore recommended that specific communication with occupants of Whangaroa Road is undertaken prior to the commencement of vibratory piling activities.

Table 10 Vibration levels at PPFs due to piling or stone column construction activities

Percussive piling Vibratory piling Stone column insertion Address mm/s mm/s mm/s 401 SH10 0.0 0.1 0.0 421 SH10 0.0 0.1 0.0

1 NZ Transport Agency. State highway construction and maintenance noise and vibration guide. Version 1.0 / August 2013 Project number 254914 File 254914-REP-KB-1.2 Kaeo_Acoustics_v1.4.docx, 16 December 2019 Revision 4 16

Percussive piling Vibratory piling Stone column insertion Address mm/s mm/s mm/s 402 (No. 1) SH10 0.0 0.1 0.0 402 (No. 2) SH10 0.0 0.1 0.0 402 (No. 3) SH10 0.0 0.1 0.0 40 Whangaroa Road 0.0 0.3 0.0 407 SH10 0.0 0.1 0.0 409 SH10 0.0 0.1 0.0 339 SH10 0.0 0.3 0.0 393 SH10 0.0 0.1 0.0 8 Whangaroa Road 0.1 1.1 0.2 286 SH10 0.0 0.4 0.0 10 Whangaroa Road 0.1 0.9 0.1 Lot 1 Waikoura Road 0.1 0.5 0.1 18 Waikoura Road 0.0 0.2 0.0 258 SH10 0.0 0.3 0.0 156 Dip Road 0.0 0.3 0.0 232 SH10 0.0 0.1 0.0 Pahuhu 1A SH10 0.0 0.1 0.0

Dynamic compaction Vibration levels due to dynamic compaction can be predicted using the equations provided in Table E.1 of BS 5228-2. Dynamic compaction can cause high vibration levels, especially at start up and shut down. Start up and shut down of this equipment should be performed as far as practical from nearby receivers to minimise vibration effects. The predicted vibration levels at the PPFs due to dynamic compaction are presented in Table 11. As exceedance to annoyance criteria set out at Table 11 may be exceeded at 8 Whangaroa Road and 10 Whangaroa Road, if dynamic compaction is required adjacent to those properties, communication with occupants will be required prior to the commencement of dynamic compaction works.

Table 11 Vibration levels at PPFs due to dynamic compaction

Vibration level Address mm/s 401 SH10 0.1 421 SH10 0.0 402 (No. 1) SH10 0.0 402 (No. 2) SH10 0.0 402 (No. 3) SH10 0.0 40 Whangaroa Road 0.3 407 SH10 0.1 409 SH10 0.0 339 SH10 0.7 393 SH10 0.1 8 Whangaroa Road 1.8 286 SH10 0.4 10 Whangaroa Road 1.0

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Vibration level Address mm/s 253 SH10 0.2 Lot 1 Waikoura Road 0.9 18 Waikoura Road 0.3 258 SH10 0.4 156 Dip Road 0.1 232 SH10 0.1 Pahuhu 1A SH10 0.2

Bridge demolition Ground vibration from the demolition works required to remove the existing bridge are unlikely to be perceptible at any of the adjacent receivers. The main vibration sources associated with the bridge demolition are the hydraulic breaker or pieces of concrete or steel being dropped. This assessment assumed no explosives will be utilised in the demolition. No notification or precondition surveys would be required for these works.

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5 Operational Noise and Vibration

5.1 Operational noise

Criteria The operative Far North District Plan does not contain any specific road traffic noise rules. The Transport Agency has released its “Guide to assessing road-traffic noise using NZS 6806:2010 for state highway asset improvement projects (Version 1.0, October 2011)” (Transport Agency Guide). The Agency Guide describes how NZS 6806:2010 is to be implemented. In addition, some Agency specific processes are described, such as the use of an Agency internal matrix of project discipline feedback when determining the BPO for noise mitigation. The New Zealand Standard 6806:2010 provides criteria and an assessment method for road-traffic noise for new and altered roads. Following review of all relevant documentation, it is considered that the methodology and provisions of NZS 6806:2010 should be applied to the operational traffic noise design for the Project. The outcome would result in the best practicable noise mitigation. The Kaeo bridge replacement project involves alterations to the existing SH10. Whilst the road is to be constructed on greenfield land, noise from the road will affect PPFs that already receive noise from the existing SH10 alignment. The proposed road is also an alteration of the existing SH10 alignment and, once completed, existing SH10 traffic will use the new SH10 alignment. Section 1.5.2 of NZS6806:2010 sets out the limited types of roading projects that the standard applies to. This is clarified in C1.5.2, which is reproduced below: “… C1.5.2 Section 1.5.2 (a) means this Standard does not apply where alterations to an existing road are predicted to increase the do-minimum noise environment compared with the do-nothing noise environment, by less than 3 dB LAeq(24h). For a change of exactly 3 dB LAeq(24h), the do-nothing noise environment for consideration would therefore be 61 dB LAeq(24h) since the most stringent external noise criterion is 64 LAeq(24h). For a change greater than 3 dB LAeq(24h) a lower do-nothing noise environment may be relevant if the do-minimum noise environment is 64 LAeq(24h) or more. …“ Section 6.1.2 of NZS6806:2010 sets out noise criteria for New and Altered roads. The noise criteria for altered roads are shown in Table 12. Table 12 NZS 6806:2010 noise criteria

Category Criterion Altered roads

Primary free field external A 64 dB L noise criterion Aeq(24h)

Secondary free field external B 67 dB L noise criterion Aeq(24h)

C Internal noise criterion 40 dB LAeq(24h)

Protected Premises and Facilities NZS 6806:2010 specifies the noise sensitive locations where road-traffic noise from the project should be assessed. These are known as Protected Premises and Facilities (PPFs), and include existing houses, schools, Marae and various other locations defined in the Standard. The distance from the road within which properties are considered to be PPFs is set in the standard as: Urban areas – 100 metres from the edge of the nearside traffic lane; Rural areas – 200 metres from the edge of the nearside traffic lane.

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The extents of rural and urban areas are defined by Statistics New Zealand2. Under this definition, the Project is in a rural area and therefore the 200m distance is applicable. PPFs in excess of 200m from the edge of the nearside traffic lane do not require assessment.

Assessment Road traffic noise emissions from the operation of the existing and proposed future SH10 Kaeo bridge alignment has been modelled using the Calculation of Road Traffic Noise (CRTN) algorithm, which is implemented in the software package SoundPLAN v7.4. The parameters used in SoundPLAN are listed in Table 13 below. We note that any settings not listed were left as default.

Table 13 Modelling parameters

Parameter Setting/Source Software SoundPlan v7.4 Algorithm CoRTN 1988

Parameter LAEQ,24h Ground Absorption 1.0 Road Absorption 0 Receiver Height 1.5 m Noise Contour Grid 1.5 m height, 1 m resolution Receiver positions Free-field Reflection Order 3

The topographical contours immediately adjacent to the road alignment have been imported directly from the projects geospatial data. Topographical contours outside the range provided in the project data were sourced from LINZ online data service3. Project alignment data was provided as part of the project’s geospatial data. Building footprints and other structures were traced from aerial photography.

Road surface and traffic data Noise emission adjustments are required to account for New Zealand road surfaces and conditions. The Transport Agency Guide to State Highway Road Surface Noise (Version 1.0, January 2014) provides road surface corrections for various road surface types applicable to New Zealand conditions, these corrections have been utilised in this road traffic noise model. Table 14 below summarises the road details used for calculations. The Design Year is defined in NZS6806:2010 as a point in time that is not less than 10 years but not more than 20 years after the opening of a new road, or the opening of alterations to an altered road, to the public. For the purposes of this project the design year has been defined as 2030. The following scenarios, consistent with the Standard, were modelled: Existing: Existing road conditions and layout, 2018 traffic volumes; Do Nothing: The project not constructed; the existing road with estimated 2030 traffic volumes; Do Minimum: The project constructed; estimated 2030 traffic volumes and no noise mitigation.

2 New Zealand: An urban/rural profile, Statistics New Zealand 3 www.data.linz.govt.nz Project number 254914 File 254914-REP-KB-1.2 Kaeo_Acoustics_v1.4.docx, 16 December 2019 Revision 4 20

Table 14 Road traffic details Existing, 2018 Do Nothing and Do minimum, 2030

Road Surface Surface Speed AADT HV Road Speed AADT HV Road section Surface Surface (km/h) (vpd) (%) correction (km/h) (vpd) (%) correction factor factor SH10 West side of Chipseal 100 3270 7.5 2.9 Chipseal 100 4941 7.5 2.9 bridge SH10 South side of Chipseal 100 3834 7.5 2.9 Chipseal 100 5794 7.5 2.9 bridge Whangaroa Chipseal 100 910 7.5 2.9 Chipseal 100 1375 7.5 2.9 Road (1) Information advised by Aurecon transport team.

The CRTN algorithm gives results in terms of the LA10(18h). To convert this to LAeq(24h) a –3 dB adjustment has been made. This adjustment has been implemented in the software in conjunction with the road surface adjustment detailed in Table 14. For operational road traffic noise assessments, road safety barriers are modelled if they deemed to provide adequate noise attenuation against road traffic noise. The safety barriers used on the project include: Aluminium parapet on the bridge structure Steel Guardrail system on the SH10 No safety barriers were modelled as the prescribed safety barriers do not provide any road traffic noise attenuation. These safety barriers are not contiguous and do not possess the required density to assist in noise attenuation.

Existing road traffic noise A comparison of the measured noise levels (as described at section 3.1) with the results of the computer noise modelling using monitored traffic volumes is provided in Table 15. NZS 6806:2010 requires modelled results to be within ±2 dB of measurements. The CRTN method used in these predictions has previously been shown to provide the required accuracy under controlled conditions close to state highways.

Table 15 Comparison of measured and predicted (modelled) noise levels

Difference between Measured noise level Predicted (modelled) measured and Measurement location (free field) noise level (free field) predicted dBA dBA dBA

MP1 – 399 SH10 50 dB Leq(24hr) 52 dB Leq (24hr) +2

Predicted operational noise levels

A comparison of predicted traffic noise levels between the Do Nothing and the Do Minimum are presented in

Table 17. The cells are colour coded according to the NZS 6806:2010 categories presented in Table 16. Noise levels are predicted free-field noise levels and have been rounded to the nearest decibel.

Table 16 Noise categories (As specified in NZS 6806:2010 for an altered road) Category Free-field noise level at assessment position, dBA Colour Code

Category A ≤ 64 Leq(24hr)

Category B ≤ 67 Leq(24hr)

Category C > 67 Leq(24hr)

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Table 17 Predicted free-field noise levels at PPFs

Change in noise LAeq (24hr), dB level, (dB) PPF Address

Existing Do Do Minimum – Do Do Nothing 2018 Minimum Nothing 1 10 Whangaroa Rd 51 54 54 1 2 156 Dip Road 54 55 55 0 3 18 Waikoura Rd 45 47 43 -4 4 232 SH10 61 63 63 0 5 253 SH10 62 64 64 1 6 256 SH10 40 41 41 0 7 258 SH10 52 54 54 0 8 339 SH10 54 55 56 1 9 393 SH10 56 58 58 0 10 8 Whangaroa Rd 51 52 55 3 11 40 Whangaroa Rd 56 58 58 0 12 402 SH10 58 60 60 0 13 407 SH10 60 62 62 0 14 409 SH10 61 63 63 0 15 421 SH10 52 54 54 0 16 Lot 1 Waikoura Rd 50 52 47 -5 17 Pahuhu 1A SH10 46 48 49 1

The predicted noise levels at the identified PPFs are Classified in the following Categories for the Do Nothing Scenario: Category A – 17 The Do Minimum scenario is predicted to result in an increase in the noise levels over the Do Nothing scenario at the properties listed below: 10 Whangaroa Rd (Increase of 1 dB) 8 Whangaroa Rd (Increase of 3 dB) 253 SH10 (Increase of 1 dB) Pahuhu 1A SH10 (Increase of 1 dB) 339 SH10 (Increase of 1 dB)

The Do Minimum scenario is predicted to result in a decrease in the noise levels over the Do Nothing scenario at the properties listed below: Lot 1 Waikoura Rd (Decrease of 5 dB) 18 Waikoura Rd (Decrease of 4 dB)

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NZS6806:2010 only applies to limited roading projects. Section C1.5.2 states when the standard applies, the relevant section is reproduced below: 1.5.2 Subject to 1.5.4, an altered road means an existing road that is subject to alterations of the horizontal or vertical alignment where at any assessment position at any one or more PPF: (a) The do-minimum noise environment would be greater than or equal to 64 dB LAeq(24h) and, if no specific noise mitigation was undertaken, the alterations would increase road- traffic noise at that assessment position by 3 dB LAeq(24h) or more at the design year, when compared with the do-nothing noise environment; or (b) The do-minimum noise environment is greater than or equal to 68 dB LAeq(24h) and, if no specific noise mitigation was undertaken, the alterations would increase road-traffic noise at that assessment position by 1 dB LAeq(24h) or more at the design year, when compared with the do-nothing noise environment. C1.5.2 Section 1.5.2 (a) means this Standard does not apply where alterations to an existing road are predicted to increase the do-minimum noise environment compared with the do-nothing noise environment, by less than 3 dB LAeq(24h). For a change of exactly 3 dB LAeq(24h), the do-nothing noise environment for consideration would therefore be 61 dB LAeq(24h) since the most stringent external noise criterion is 64 LAeq(24h). For a change greater than 3 dB LAeq(24h) a lower do- nothing noise environment may be relevant if the do-minimum noise environment is 64 LAeq(24h) or more. The predicted noise levels summarised in

Table 17 indicate that none of the PPFs are subject to an increase in noise levels of more than 3 dB

LAeq(24hr) between the Do Nothing and the Do Minimum scenarios. On this basis, none of the thresholds of Section 1.5.2 are exceeded and the project is not classified as an altered road, therefore the standard does not apply to this project. No further assessment and mitigation of operational road traffic noise is required for this project.

Other noise sources Some specific road structures have the potential to generate significant noise. The following noise sources have resulted in high noise emissions in previous projects: Bridge joint noise – due to interaction between the tyres and the bridge joints; Rumble strips – the current preferred design does not incorporate any “rumble strips”. Road traffic noise approaching and leaving roundabouts. The noise levels at PPFs due to these systems has not been predicted as it depends on the selection and design of the preferred system. Bridge joint noise will be mitigated via appropriate detailing of the structure and is not predicted to cause a significant variation in the Do Minimum noise level. Road traffic noise approaching and departing the roundabout has not been modelled in the computational model. The CoRTN assessment method for traffic noise assumes constant speed and does not take into account noise generated from acceleration and deacceleration from vehicles. From previous project experience, noise from acceleration / braking near roundabouts can vary based on a number of factors such as driver behaviour, approach speed, queuing conditions etc. The transition from the current arrangement of a T-intersection to a roundabout is likely to lead to more even traffic flow in all directions. On this basis, noise from vehicles specifically accelerating and decelerating is likely to be similar to the existing condition and the inclusion of the roundabout arrangement is not expected to lead to additional noise impacts.

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NZTA suggests that the promotion of steady speed and gradual acceleration is explored within the proximity of roundabouts and intersections This may include signage that encourages early reduction of speed and signages that deter heavy vehicles from engine braking. Furthermore, the sign posted speed being gradually increased to 100 kmph could also be explored to ensure gradual acceleration to the design speed limit and to limit harsh acceleration by vehicles.

5.2 Operational vibration

Criteria Currently, there is no applicable New Zealand Standards for vibration induced by road-traffic. However, road-traffic vibration for new and altered roads is assessed based on the Norwegian Standard NS 8176E:2005. Road-traffic vibration in New Zealand looks to comply with the Class C levels set out in the NS 8176E:2005.

Assessment The change in distance between the alignment and the PPFs is presented in Table 18. The PPF located at 8 Whangaroa Road will be approximately 36 m closer to the road alignment in the Do Minimum situation. All other PPFs either remain the same distance from the alignment or are further away from the alignment in the Do Minimum situation. Due to the small changes in separation distance, no perceptible change in road traffic vibration will occur between the Do Nothing and the Do Minimum situation. In addition, the separation distances will result in very low (imperceptible) vibration levels at all PPFs.

Table 18 Distance between proposed alignments and PPFs

PPF Distance to Do Nothing Distance to Do Minimum Change in separation Alignment Alignment distance (m) 401 SH10 87 m 87 m 0 421 SH10 212 m 212 m 0 402 SH10 227 m 227 m 0 40 Whangaroa Road 17 m 17 m 0 407 SH10 105 m 105 m 0 409 SH10 143 m 143 m 0 339 SH10 107 m 107 m 0 393 SH10 113 m 113 m 0 8 Whangaroa Road 97 m 61 m -36 286 SH10 176 m 176 m 0 10 Whangaroa Road 103 m 103 m 0 Lot 1 Waikoura Road 70 m 70 m 0 18 Waikoura Road 230 m 230 m 0 258 SH10 107 m 107 m 0 156 Dip Road 227 m 227 m 0 232 SH10 23 m 23 m 0 Pahuhu 1A SH10 117 m 117 m 0 Project number 254914 File 254914-REP-KB-1.2 Kaeo_Acoustics_v1.4.docx, 16 December 2019 Revision 4 24

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6 Recommendations

6.1 Construction noise and vibration

Management strategy Noise and vibration effects will be managed using a standard hierarchy of controls as specified in Table 19. Mitigation of vibration from construction activities is typically limited to scheduling of operations and the notification of nearby receptors prior to the commencement of the works being the source of the vibration.

For both construction noise and vibration, exceedance of the day-time and annoyance criteria are predicted to potentially occur at times. Notification will be required as a minimum for the PPFs as a measure to mitigate the noise and vibration, this will be discussed further in this section. Furthermore, the methodology and selection of equipment should be taken into great consideration when looking to reduce construction noise and vibration affects.

Table 19 Hierarchy of controls for the Project

Ranking Control Description Schedule activities which are likely to cause disruption outside of sensitive times – this includes ensuring high noise or vibration activities are undertaken during the day wherever practicable. Construction activities such as vegetation clearance, bulk 1 Scheduling earthworks, road surfacing, bridge construction and bridge demolition. should be restricted to be undertaken only during the daytime period (0730 – 1800) to avoid exceeding the morning period noise limit Utilise alternative equipment or processes that result in lower 2 Alternative methodologies noise levels – this includes using low noise/vibration piling equipment and saws Enclosures, portable screens and/or mufflers are effective solutions for mitigating the noise impacts of stationary or isolated 3 Mitigation at source works. Portable screens are typically practical around localised or small high noise activities (e.g. concrete cutting). Notification of affected Notification of noise and vibration impacts on the identified 4 receivers affected receivers is effective at mitigating most adverse impacts. In rare circumstances, it may be necessary provide alternative Alteration to accommodation for residents for a period of time to allow high 5 residents/commercial noise or vibration activities to be undertaken. This will be avoided activities where alternative mitigation options are available. Installation of physical mitigation at receiver (e.g. new glazing) is effective at mitigating ongoing noise levels, but is typically 6 Mitigation at receiver impractical for construction activities causing adverse effects over a short, temporary period and will be avoided.

Construction Noise and Vibration Management Plan Prior to the initial works a Construction Noise and Vibration Management Plan (CNVMP) will be developed as a sub plan to the Project Construction Environmental Management Plan (CEMP). The development of a CNVMP is considered the best practicable option to control the potential impacts associated with construction activities. This document will include the following: Hours of operation, including times and days when construction activities causing noise and/or vibration would occur; The construction noise and vibration standards for the Project. Identification of affected houses and other sensitive locations where noise and vibration criteria apply;

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Mitigation options to be implemented during construction, including alternative strategies where full compliance with the relevant noise and/ or vibration criteria cannot be achieved; Methods and frequency for monitoring and reporting on construction noise and vibration; Procedures for maintaining contact with stakeholders, notifying of proposed construction activities and handling noise and vibration complaints, with reference to a complaints management process set out in the Project Stakeholder Management Plan; Construction equipment operator training procedures and expected construction site behaviours; and Contact numbers for key construction staff, staff responsible for noise assessment and council officers.

General good practice The following good practice guidelines should be followed for all construction/demolition works on the worksite, this list is recommended to be incorporated in the CNVMP: No amplified music or use of radios; Locate skip bins away from noise sensitive receivers. Materials shall be lowered into bins and not dropped /thrown from height; Place stationary equipment (generators, pumps etc.) as far as practical from sensitive receivers; Do not leave vehicles idling unnecessarily; Only use designated access routes; Place materials into trucks (avoid dropping materials from a height); Ensure equipment is well maintained and serviced; Avoid dropping tools and equipment; Avoid dragging materials along the ground; Avoid shouting across site; When arriving at work drive slowly and carefully; Do not slam doors.

Site specific mitigation

The following site-specific measures are recommended to be implemented to mitigate potential noise and vibration effects during construction. Scheduling of vegetation clearance, bulk earthworks, road surfacing, bridge construction and bridge demolition. should be restricted to be undertaken only during the daytime period (0730 – 1800) to avoid exceeding the morning period noise criteria. Communication should be provided to the residents of 8 and 10 Whangaroa Road prior to the following works being undertaken: Vegetation Clearance Dynamic compaction The communication should include the times and dates where the specified works are anticipated to be undertaken and highlight any scheduled days off (Saturdays, Sundays, Public Holidays, rostered days off etc). The communication should include project contact details for the residents to raise any concerns or queries during the works. Communication with the resident is considered to be the BPO to mitigate against the construction noise. These are due to the following reasons: Vegetation clearance is a relatively short construction activity in relation to the whole construction programme.

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The exact location of the vegetation clearance is unknown. The assessment assumes worse case scenario in terms of proximity. The actual location of vegetation clearance may occur further away from the property and consequently have a lower noise level. If dynamic compaction is being performed immediately adjacent to 8 Whangaroa Rd or 10 Whangaroa Road, the construction vibration annoyance criteria as been predicted to be exceeded, and communication advising the potential impacts should also be provided to the residents prior to the construction activity occurring.

6.2 Operational noise and vibration No specific mitigation is recommended for the operational noise due to the predicted noise and vibration levels meeting the required standards. During detailed design, appropriate detailing and selection of bridge joints will be required to mitigate potential bridge joint noise.

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7 Conclusions

7.1 Construction Noise and Vibration Noise and vibration due to construction of the new alignment and the demolition of the existing bridge has been assessed against the Far North District Plan noise limits updated with the LAeq noise descriptor and international standards vibration criteria. One property is predicted to be exposed to noise levels greater than the applicable construction noise limits. Two properties may experience vibration levels greater than the recommended vibration limits relating to annoyance specified in Section 4.2 of this report. These effects will be managed with communication with occupiers before construction activities are undertaken and the implementation of a CNVMP. With the implementation of the proposed mitigation strategies described in this report, the environmental impacts from noise and vibration are considered to be reasonable. Scheduling of vegetation clearance, bulk earthworks, road surfacing, bridge construction and bridge demolition. should be restricted to be undertaken only during the daytime period (0730 – 1800) to avoid exceeding the morning period noise criteria. Liaison with the residents of 8 and 10 Whangaroa Road prior to the works being undertaken would be the BPO, as exceedances of the criteria are not extensive and only occur at the aforementioned residences. A Condition of Consent requiring preparation and implementation of a CNVMP is considered the Best Practicable Option for mitigating any noise effects from this project.

7.2 Operational Noise The traffic noise levels from the Kaeo bridge realignment works have been assessed following the methodology described in NZS 6806:2010. No PPF is subjected to a change in road traffic noise of greater than 3 dB LAeq between the Do Nothing and Do Minimum situations. The predicted noise levels summarised in

Table 17 indicate that none of the PPFs are subject to an increase in noise levels of more than 3 dB

LAeq(24hr) between the Do Nothing and the Do Minimum scenarios.. On this basis, none of the thresholds of Section 1.5.2 are exceeded and the project is not classified as an altered road, therefore the standard does not apply to this project

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Appendix A Relevant Standards, Guidelines, and Rules Far North District Plan – Rural Environment

Site zoning Under the Far North District Plan, the relevant areas around the project site are zoned “Rural Production” and “Recreational Activities” as shown in Figure 4. There is a small area zoned “Minerals”.

Figure 6 Far North District Plan (Map 21) and proposed road alignment

Construction Noise The Far North District Plan criteria “Chapter 8 - Section 8.6.5.1.7 – Noise” states that construction noise is required to meet the following noise level criteria: “…Construction noise shall meet the limits recommended in, and shall be measured and assessed in accordance with, NZS 6803P:1984 ‘The Measurement and Assessment of Noise from Construction, Maintenance and Demolition Work.’.” “..If construction work is of more than 18 weeks’ duration the limits may be lowered by 5 dBA for the duration of the construction...”

As the construction duration exceeds 18 weeks, the lower noise limits apply. The applicable construction noise limits for the project are summarised in Table 20.

Table 20 Construction noise limits for all properties surrounding the Kaeo bridge replacement

Maximum noise level (dBA) Time of week Time period L10 L95 Lmax 6:30am – 7:30am 55 40 65 7:30am – 6:00pm 70 55 85 Weekdays 6:00am – 8:00pm 65 50 80 8:00pm – 6:30am ** ** ** 6:30am – 7:30am ** ** ** 7:30am – 6:00pm 70 55 85 Saturdays 6:00am – 8:00pm ** ** ** 8:00pm – 6:30am ** ** ** 6:30am – 7:30am ** ** **

Sundays and 7:30am – 6:00pm ** ** ** Public Holidays 6:00am – 8:00pm ** ** ** 8:00pm – 6:30am ** ** ** ** At these times, the relevant provisions of NZS 6802 shall apply. This may mean that no noisy construction work can take place during these hours.

Construction Vibration The Far North District Plan does not specify any vibration limits for construction. Standards and Guidelines

NZS 6803:1999 Noise from construction activities is typically governed by NZS 6803:1999 “Acoustics – Construction noise”. This standard provides construction noise limits that depend on the duration of the activity and the corresponding duration of exposure. These criteria are presented in Table 21. The Far North District Plan references NZS6803:1984 which has been superseded by NZS 6803:1999. The LA10 limits provided in NZS6803:1984 are the same in value as the LAeq limits provided in NZS 6803:1999.

Table 21 NZS6803-1999 Noise Guidelines for residential receivers (values taken from Table 2 in NZS6803-1999)

Short-term duration (up to 14 Long-term duration (more Typical duration (more than 14 days), than 20 weeks), days but less than 20 weeks), dBA Time period dBA dBA

Leq LFmax Leq LFmax Leq LFmax

Weekdays 0630-0730 60 75 65 75 55 75 0730-1800 75 90 80 95 70 85 1800-2000 70 85 75 90 65 80 2000-0630 45 75 45 75 45 75 Saturdays 0630-0730 45 75 45 75 45 75 0730-1800 75 90 80 95 70 85

Short-term duration (up to 14 Long-term duration (more Typical duration (more than 14 days), than 20 weeks), days but less than 20 weeks), dBA Time period dBA dBA

Leq LFmax Leq LFmax Leq LFmax

1800-2000 45 75 45 75 45 75 2000-0630 45 75 45 75 45 75 Sundays and Public Holidays 0630-0730 45 75 45 75 45 75 0730-1800 55 85 55 85 55 85 1800-2000 45 75 45 75 45 75 2000-0630 45 75 45 75 45 75

BS5228-1 Guidance for evaluating and mitigating noise and vibration from construction sites is presented in BS 5228-1:2009 “Code of practice for noise and vibration control on construction and open sites. Part 1 – Noise”. This standard contains an extensive list of reference noise levels for a range of different equipment and methods for predicting noise emissions from construction sites. This standard is referenced extensively throughout NZS 6803 as a method for predicting the noise levels from construction activities and has been used for all construction noise level predictions presented in this report.

BS5228-2 Guidance for evaluating and mitigating vibration from construction activities is presented in BS 5228-2:2009 “Code of practice for noise and vibration control on construction and open sites. Part 2 – Vibration”. This standard provides a set of equations for predicting the ground vibration due to a wide range of site activities. The criteria provided in this standard, which utilises the measurement Peak Particle Velocity (PPV), is replicated in Table 22. The guidance on effects of vibration levels based on human perception is replicated in Table 23.

Table 22 Transient vibration guidelines for cosmetic damage (replicated from Table B.2 from BS 5228-2:2009)

Vibration level at the foundations in Peak Particle Velocity, Type of building PPV 4 Hz to 15 Hz 15 Hz and above Reinforced or framed structures 50 mm/s at 4 Hz and above 50 mm/s at 4 Hz and above Industrial and heavy commercial buildings

Unreinforced or light framed structures 15 mm/s at 4 Hz increasing to 20 mm/s at 4 Hz increasing to 50 Residential or light commercial buildings 20 mm/s at 15 Hz mm/s at 15 Hz

Table 23 Subjective evaluation of vibration (replicated from Table B.1 from BS 5228-2:2009)

Vibration level Effect (component ppv) Vibration might be just perceptible in the most sensitive situations for vibration frequencies 0.14 mm/s associated with construction and maintenance. At lower frequencies, people are less sensitive to vibration. 0.3 mm/s Vibration might just be perceptible in residential environments. It is likely that vibration of this level in residential environments will cause complaint, but can be 1.0 mm/s tolerated if prior warning and explanation has been given to residents. 10.0 mm/s Vibration is likely to be intolerable for any more than a very brief exposure to this level.

DIN4150-3 The German Standard DIN4150-3 (1999) “Structural vibration – Part 3: Effects of Vibration on Structures” provides guidance criteria for assessing the impacts of ground vibration from construction activities on structures. The vibration criteria are presented in Table 24.

Table 24 Vibration guidelines for short-term vibration on structures (replicated from Table 1 from DIN4150-3: 1992-02)

Type of building Vibration level at the foundations in Peak Particle Velocity, PPV (mm/s) 1 Hz to 10 Hz 10 Hz to 50 Hz 50 Hz to 100 Hz Buildings used for commercial purposes, industrial 20 20 to 40 40 to 50 buildings, and buildings of similar design Dwellings and buildings of similar design and/or 5 5 to 15 15 to 20 occupancy Structures that, because of their particular sensitivity to vibration, cannot be classified under lines 1 and 2 and 3 3 to 8 8 to 10 are of great intrinsic value (e.g. listed buildings under preservation order)

Appendix B Operational Noise Contours

Appendix C Construction Noise Contours

Appendix D Construction Vibration Contours

Appendix E List of equipment used for noise assessment

Table 25 Acoustic Data used in Construction Assessment

A weighted Sound Pressure Level at Equipment Size Reference 10 m (dBA Leq) Excavator 22t 76 BS 5228-1 C.2.5 Dump truck 23t 78 BS 5228-1 C.4.2 Sheet pile rig 52t 88 BS 5228-1 C.3.8 Bored Piling Rig 110t 83 BS 5228-1 C.3.14 Mobile generator - 73 BS 5228-1 C.3.32 Vibratory roller 12t 84 BS 5228-1 C.5.24 Truck with hiab 6t 77 BS 5228-1 C.4.53 Tracked mobile crane 55t 70 BS 5228-1 C.3.29 Concrete pump and mixer truck 26t 75 BS 5228-1 C.4.28 Petrol powered circular saw 9kg/300mm 91 BS 5228-1 C.4.70 Air Compressor 7m3/min 72 BS 5228-1 D.7.26 Road Roller - 80 BS 5228-1 D.3.114 Bulldozer 20t 81 BS 5228-1 C.2.14 Loading rubble into dump truck - 85 BS 5228-1 C.1.10 Hand-held hydraulic breaker 20kg 93 BS 5228-1 C.1.7 Hand-held petrol concrete saw 9.2kg 87 BS 5228-1 C.5.36 Gas cutter - 79 BS 5228-1 C.1.18 Angle grinder 4.7kg 80 BS 5228-1 C.4.93 Portable hand-held welder - 73 BS 5228-1 C.3.31

Table 26 List of construction activities and cumulative noise levels

Sound Pressure Activity Equipment Number Duty Cycle Level at 10m. dB LAeq Excavator (16t) 1 Occasional (50%) Use of laydown site Truck with hiab 2 Continuous (100%) 81 and yards Mobile generator 1 Continuous (100%) Asphalt paver and 1 Continuous (100%) tipper truck Dump truck (23t) 1 Continuous (100%) Road surfacing 86 Road Roller 1 Continuous (100%) Dump truck (23t) 1 Continuous (100%) Vibratory roller (12t) 1 Occasional (50%) Excavator (16t) 2 Continuous (100%) Dump truck (23t) 2 Continuous (100%) Bulk Earthworks 86 Bulldozer (20t) 1 Continuous (100%) Vibratory roller (12t) 1 Infrequent (25%) Pulveriser on excavator 1 Continuous (100%) Excavator loading 1 Continuous (100%) rubble onto dump truck Hand-held hydraulic 1 Occasional (50%) breaker Hand held petrol Bridge Demolition 1 Occasional (50%) 92 concrete circular saw Gas cutter 1 Occasional (50%) Angle grinder (steel) 1 Occasional (50%) Mobile generator 1 Continuous (100%) Truck with hiab 1 Occasional (50%) Mobile generator 1 Continuous (100%) Truck with hiab 1 Continuous (100%) Concrete pump and 1 Infrequent (25%) mixer truck Gas cutter 1 Infrequent (25%) Angle grinder (steel) 1 Infrequent (25%) Tracked mobile crane Bridge Construction 1 Continuous (100%) 84 (55t) Portable hand-held 1 Infrequent (25%) welder Excavator (16t) 1 Infrequent (25%) Dump truck (23t) 1 Infrequent (25%) Screw pile rig 1 Infrequent (25%) Sheet pile rig 1 Rarely (10%) Petrol Chain Saw 1 Continuous (100%) Vegetation Clearance Excavator (16t) 1 Continuous (100%) 87 Dump truck (23t) 1 Continuous (100%)

Document prepared by

Aurecon New Zealand Limited Level 4, 139 Carlton Gore Road Newmarket Auckland 1023 PO Box 9762 Newmarket Auckland 1149 New Zealand

T +64 9 520 6019 F +64 9 524 7815 E [email protected] W aurecongroup.com

Aurecon offices are located in: Angola, Australia, Botswana, China, Ghana, Hong Kong, Indonesia, Kenya, Lesotho, Macau, Mozambique, Namibia, New Zealand, Nigeria, Philippines, Qatar, Singapore, South Africa, Swaziland, Tanzania, Thailand, Uganda, United Arab Emirates, Vietnam.

Kaeo Replacement Bridge Project

Assessment of Natural Character, Landscape and Visual Effects

Prepared for Aurecon Ltd and the NZ Transport Agency

December 2019

Document Information

Project: Kaeo Bridge Replacement Project

Title: Assessment of Natural Character, Landscape and Visual Effects

Prepared for: Aurecon Ltd and the NZ Transport Agency

Prepared by: Wayfinder Landscape Planning and Strategy Ltd

Cover Photo: Existing Kaeo Bridge, August 2017

Revision History

Rev Date Author Reviewer 1 15.07.2019 S Bray M McBain 2 17.12.2019 S Bray C Cunningham

Contents

Introduction 1

Landscape Context 3 Historical and Cultural Context 6

Planning Context 6

Proposal 7 Landscape Development Proposal 7 Potential Effects 9

Natural Character Effects 9 Landscape Effects 11

Visual Effects 12 Construction Effects 13 Urban Design Considerations 14 Conclusion and Recommendations 14

Appendix 1: Author Credentials Appendix 2: Landscape Concept Plan

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Introduction

The New Zealand Transport Agency is seeking to replace the existing Kaeo River bridge with a new double-lane structure and an altered road alignment, in order to meet modern road safety standards.

Wayfinder Landscape Planning and Strategy Ltd (Wayfinder) has been commissioned to provide an assessment of the natural character, landscape and visual effects, and to provide input into the urban design elements of the proposal. Wayfinder was also involved in the review of previous design options which were ultimately ruled out for environmental and budget reasons.

This assessment provides an overview of the landscape context, including a brief summary of the important cultural and historical connections to the area. As a detailed planning assessment is provided by Aurecon, only a brief outline of the policies relevant to landscape are covered, however a broader understanding of the relevant legislation, regional and territorial policy was considered in the preparation of this report.

Overall it is concluded that the natural character, landscape and visual effects will be all low or less, except during construction where there will be a heightened presence of the road and within the landscape. In considering the project overall and the landscape mitigation that is to be incorporated, there will be a number of positive outcomes.

Methodology

Five site and locality visits have been undertaken in August 2017, October 2017, September 2018, June 2019 and December 2019. The purpose of these visits was to assess the location of the site and the proposed works, iteratively review the design options, review the surrounding viewing catchment, engage with key stakeholders (including mana whenua partners) and note the potential landscape and visual effects that might arise from the proposal. The assessment was undertaken from publicly accessible land only, this largely being the road reserve areas.

An assessment of the proposal was then undertaken using knowledge gained on the site and locality visits (using photographs as a reference), in addition to online tools such as Google Maps, Google Street View and the Far North District Council online GIS portal. The assessment is also informed by the ecological effects report prepared by Bioresearchers, the archaeological assessment prepared by Geometria, and feedback provided through two hui held with mana whenua. This report describes the outcomes of the assessment.

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Scale of Effects

The New Zealand Institute of Landscape Architects Best Practice Note on Landscape Assessment promotes the use of a 7-scale assessment rating1. In more recent times, the wording used in this assessment has been a topic of discussion, and emerging best practice guidance suggests the replacement of more emotive words such as ‘extreme’ and ‘negligible’ with more neutral terms (‘very-high’ and ‘very-low’), with more even graduations across the scale. This assessment has adopted this latter approach.

The avoidance of RMA terminology within the assessment is deliberate – as the focus is on providing a detailed analysis of individual effects that will inform a broader planning judgement (which is provided as part of the overall conclusion). Neverthelss, by way of guidance, it is generally accepted that ‘minor’ sits at level 3 on the seven point scale, as demonstrated in the following table:

Effect Level 1 2 3 4 5 6 7

NZILA Negligible Very-Low Low Moderate High Very-High Extreme Existing

This Low- Moderate- Very-Low Low Moderate High Very-High Assessment Moderate High

RMA Less than Minor Minor More than Minor Significant

In regard to landscape effects, a very-high rating represents a situation where a proposal would result in direct, extensive change to landform or land-cover, and would result in changing the character of a place. A very-low rating represents a situation where a proposal would have only a small impact on landform or land-cover (such as temporary works), and relates to works that are in character with the existing landscape, or the same as a type of activity that already exists.

In terms of visual effects, a very-high rating represents a situation where a proposal would become the key, dominating element in the primary view from a particular viewpoint, likely in the foreground, making the appreciation of other aspects of the view difficult to achieve. A very-low rating represents a situation where a proposal might be partially visible from a particular viewpoint, but it would be subservient to other aspects of the view and likely partially (or largely) obscured by foreground elements.

1 https://nzila.co.nz/media/uploads/2017_01/nzila_ldas_v3.pdf (page 8)

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Landscape Context

The existing Kaeo Bridge crosses the Kaeo River in a rural landscape, approximately 3km downstream (northwest) of Kaeo, in eastern Northland. It is currently a single-lane bridge on State Highway 10 (SH10), a key arterial route that connects a number of small Northland communities such as Kaeo, Taipa and Mangonui with Kerikeri in the south and Kaitaia (Awapuni) in the north. The highway is a key part of the Northland tourist path, known as the ‘Twin Coast Discovery Route’. Immediately east of the bridge is an intersection between SH10 and Whangaroa Road that sits below a large escarpment cutting in the hillside.

The Kaeo River takes a meandering route, approaching Kaeo from the south. After passing the township it widens across the floodplain, before flowing underneath the Kaeo Bridge and towards the Whangaroa Inlet. From the town to the inlet the river is contained by flood-control banks to help reduce flood risks on neighbouring properties. Nevertheless, much of the Kaeo area experiences regular flooding which can lead to road and bridge closures. As a result, erosion is greatly evident along both banks of the main water channel, particularly in areas that lack riparian vegetation.

The river has likely defined much of the topography of the area. The floodplain forms a fertile valley floor that largely supports cattle farming and a variety of exotic amenity trees. The valley is surrounded by hills that contain vast tracks of native bush and commercial pine forests.

The stretch of river just upstream of the bridge to the harbour inlet is tidal and brackish, and as such supports mangrove growth and some pohutukawa on the riparian margins (including a prominent cluster in close proximity to the existing bridge, Figure 1), increasing its visual prominence through this part of the landscape.

On the eastern side of the valley, the existing SH10 is sandwiched between the river and a peninsula of hills that run in close proximity and parallel to it. These hills stop abruptly just north of the existing bridge to give way to flat pastoral farmland. A sizeable escarpment has been formed to accommodate the existing road and intersection, and at some time in the past this has been graffitied with the words ‘NO MINING’ creating somewhat of a local landmark

Figure 1: Pohutukawa and riparian planting upstream of bridge, eastern side

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Figure 2: Escarpment above existing intersection

(Figure 2). A selection of exotic scrubby plants have established across the escarpment, which gives it a weathered and somewhat natural appearance, despite it being a modified feature. Above the escarpment are four dwellings, although these are orientated to the north away from the bridge and road.

Closer to Kaeo, a property is located at 253 SH10. This contains a private residence in a somewhat unique octagonal shaped dwelling, and the remnants of a restaurant facility together with various outdoor attractions and developments (such as mini golf, ponds, walkways with an arched bridge, and canoeing facilities). The general character of the property is under- maintained and overgrown, largely with various exotic trees and weeds. Immediately south of this property is a small-lot stand of densely spaced eucalyptus trees, which are understood to have been planted for commercial harvest.

To the west of the bridge, SH10 traverses open pastoral land (Figure 3), elevated slightly out of the floodplain. Most of the houses on this side of the valley are located along the hillsides above the flood zone, with the exception of a couple of dwellings situated on the valley plain. A handful of these dwellings are within close proximity of the bridge (less than 2km), and would have a view of the existing bridge as part of the distant landscape. Those closest to the bridge (approximately 1km) are shrouded by amenity and shelter vegetation.

The settlement of Kaeo has a population of approximately 500 people. The main centre is built on the flood plain of the river, although many residential properties are located on higher ground in the surrounding hills. Whangaroa, approximately 5km to the northeast of the bridge location, is a well-known fishing hub located along the shores of Whangaroa Harbour.

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Figure 3: Pastoral landscape on western side of bridge

Distributed between Kaeo and Whangaroa are a number of commercial or community operated properties. The Kaeo Rugby Club is located a few hundred metres north of the bridge, on Whangaroa Road, and a small quarry is located to the south, with access from SH10.

A small parcel of Department of Conservation (DoC) land is located immediately south of the bridge, on the left bank (western side) of the Kaeo River (Figure 4). It is highly modified, consisting largely of mud flats that are devoid of vegetation. Other DoC owned parcels are located further downstream, and around tidal areas of the Whangaroa Inlet.

In close proximity to the bridge are a variety of infrastructure elements, including road signs, advertising placards and various electricity lines. A power pole sits high on the hill above the escarpment, with the lines dramatically decreasing in height as they cross the river. A single street light illuminates the intersection. Open stormwater drainage channels run along both verges of the road, converging with a concrete drain that directs runoff into the river.

Figure 4: Department of Conservation Land on western side

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Historical and Cultural Context

Whangaroa is a significant focus for mana whenua, as their cultural history in this area is inextricably linked to their kaitiakitanga of the coastal waterways. It is understood that iwi have concerns about the degradation of Whangaroa waterways, including the reduction of water quality in the Kaeo River.

The archaeological report indicates that the area around Kaeo has had a rich history, particularly in Māori times. It identifies a large number of significant archaeological sites around the mouth of the Kaeo River, and a campsite located near to the existing bridge (on the western side)2. Discussion with mana whenua indicate that there may have been a waka landing site in this location. The remains of a small village and urupā are located on the eastern side of SH10, immediately north of the Pahuhu Creek.

It is understood that Kaeo is named after the freshwater shellfish that inhabit the river and surrounding streams. The shellfish resembles a large pipi, and is unique to this area. Historically the shellfish was collected from the river between Kaeo and the Whangaroa Inlet, however it is no longer found in the river.

The large conical hill near Kaeo (just south of the Police Station) is the former pā of Ngāti Uru. The defensive terraces of the pā are still clearly visible when approaching Kaeo from the south.

Flooding in this area has always been a common occurrence. In the 1960’s, ongoing concerns about flooding instigated changes to the main street (Leigh Street) in Kaeo, and it was raised approximately one metre to mitigate the effects of floods. It is understood that the town motto, ‘Small Town, Big Spirit’ derives from the town regularly pulling together around flooding events.

Planning Context

A full planning and policy analysis has been prepared by Aurecon. It is important to note that from a landscape and visual effects perspective, the existing bridge and highway are not located within any identified outstanding natural landscapes or features (ONLF). Ohakiri (St Paul’s) is the nearest ONLF, located east of Whangaroa, and not visible from the site area.

Areas of significant natural character are noted around the Whangaroa Inlet and coastline, but not in close proximity to the site. The ecology report notes that the Kaeo River is ‘highly mobile and flood prone’, with ‘little or no salt marsh habitat within the road designation on the western bank’, and ‘patchy distribution on the eastern bank’3.

As the Kaeo River is tidal in the proximity of the bridge, the provisions set out in the New Zealand Coastal Policy Statement 2010 (NZCPS) will apply. In particular, Policy 13 requires the preservation of the natural character of the coastal environment.

2 Archaeological Assessment of the Proposed SH10 Kaeo Bridge Project prepared by Geometria. Page 13.

3 Kaeo Bridge Ecological Assessment prepared by Bioresearchers, October 2017. s4.4

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Proposal

It is understood that the existing Kaeo Bridge is unfit for purpose and needs to be replaced. In addition to being a single-lane bridge on a main state highway, the eastern approach to the bridge presents various road-safety issues. Further, the bridge is located within, and effects the flood channel within the river area.

The proposed alignment and bridge location are set out in the Aurecon technical drawings in Appendix B of the Assessment of Environmental Effects. Briefly the proposal includes the following:

Construction of a new bridge of approximately 60m in length, located approximately 30m south of the existing bridge on a slightly skewed crossing angle.

Realignment of SH10, approximately 250m west of the existing bridge to align with the new bridge, including realignment of the road embankment.

Construction of a new roundabout intersection with Whangaroa Road.

Removal of the existing Kaeo Bridge, with the exception of the eastern side abutment.

Removal of part of the existing SH10 on the western side of the existing bridge.

Realignment of flood protection banks, and lowering of some areas of the flood plain to improve flood water capacity (including widening of the river immediately upstream and downstream of the new bridge).

Some resurfacing and replacement line work.

The construction of the road and new bridge is anticipated to take 12-18 months, with a significant period of this being required for natural settling of the proposed embankments. For obvious reasons, the existing bridge will not be removed until the new road is operational.

The plans are described as preliminary alignment concepts, and provide an overview of the route, height and earthworks (bulk and scale). As is common practice for Transport Agency projects of this type, the final alignments and earthwork contours are subject to detailed design following the consenting/designation process, and these will be done in the context of the recommendations set out in this (and other specialist) reports, and any particular conditions determined through the consenting/designation process.

It is understood that the Transport Agency have engaged with mana whenua to consider painting the ‘No Mining’ escarpment rock face with a Māori patterned design. This is being considered as a separate project, and the direction and outcome of this project is unknown at this time.

Landscape Development Proposal

A landscape concept plan has been developed to support the recommendations outlined in this report. The plan was prepared in consultation with mana whenua, following hui held with representatives of each iwi in October 2017 and again in December 2019. The plan also incorporates the recommendations of the project ecologists (Bioresearchers), and makes reference to the archaeological findings outlined in the archaeological report. Further detailing

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work in regard to landscape outcomes is anticipated through further engagement with mana whenua.

The main aspects of the landscape concept plan are as follows:

Concentrated native planting around the proposed new intersection between SH10 and Whangaroa Road, including a combination of low planting to allow for road visibility and taller tree species (including kowhai, as specifically requested by mana whenua). Also some taller tree planting on the western side of the new bridge to create a link to the forest on the adjacent hillslope (species to be confirmed).

The establishment of riparian/road-edge planting to enhance amenity and increase potential avifauna habitat on the eastern side of the river, upstream and downstream of the new bridge and provide enhanced stormwater outcomes.

The establishment of riparian planting to enhance fernbird and other avifauna habitat, particularly on the western side of the river, from the new bridge to downstream from existing bridge. Within the flood channel planting is designed to be frangible so as not to restrict flood water capacity and flow.

Removal of the existing bridge and its western abutment, but retention of the eastern abutment to avoid potential damage to the existing stand of pohutukawa in this area. It is envisaged that this abutment would be used by local people for fishing (as suggested by mana whenua).

Removal of part of the existing SH10 embankment to the west of the existing bridge, and its conversion to farm use. This includes the removal of the chipseal surface of the old road and partial replacement with a gravel track.

Fencing both sides of the road on the western side of the bridge.

Grass planting along the banks of SH10 from the new bridge westward to the connection with the existing alignment.

Provision of a relocated stock-race, as requested by the neighbouring landowner.

Rehabilitation of all construction areas and old road alignments to pasture.

A preliminary plant species table has been prepared that identifies the desired planting in each of the planting areas shown on the plan. This list has been prepared in consultation with mana whenua and the project ecologists, but will be subject to further refinement during the detailed design stage.

It is anticipated that this plan will form the basis of a more detailed landscape plan that will be prepared in conjunction with the appointed construction contractor and mana whenua. This will be prepared in accordance with the recommendations set out in section 7.5 of the Ecologists report4.

4 Assessment of Ecological Values: Northland Bridges Kaeo Bridge Replacement, Option 5. Bioresearches, September 2019. Section 7.5

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Potential Effects

The following section provides an assessment of the potential natural character, landscape and visual effects of the proposal. The effects have been assessed based on the elements contained within the landscape plan being incorporated into the proposal.

Natural Character Effects

Replacement of the existing bridge will require works within the river environment, and may potentially impact natural character values. As identified, this will require consideration of the project under the provisions of the NZCPS. It is understood that the Northland Regional Council defines the Coastal Marine Area (CMA) as extending up the Kaeo River to approximately the location of the existing bridge.

Natural character is not defined in the RMA, however the NZCPS indicates (Policy 13(2)) that ‘natural character is not the same as natural features and landscape or amenity values’ and as well as including ‘natural elements, processes and patterns’, also includes ‘experiential attributes, including the sounds and smell of the sea; and their context or setting’. Commonly, an assessment of natural character considers abiotic values (such as landform and habitat), biotic values (flora and fauna) and experiential values (appreciation).

The Kaeo River is the largest freshwater source into the Whangaroa harbour, and consequentially is a significant river in the immediate region. Immediately upstream of the project a small tributary, the Pahuhu Creek, flows through an existing culvert into the river.

The river is highly modified from its natural state. A combination of factors will have contributed to the change in the patterns and processes of the river over time. Deforestation to accommodate productive farming and other human activity, including a decline in vegetation on the river banks, is likely to have contributed to a build-up in sediment in the river channel. Runoff from properties, especially modified farmland areas, is likely to have contributed to a reduction in water quality. Tidal processes also have an effect on the river, especially in the event of extremely high tides.

The abiotic values of the river in the vicinity of the site are consistent with many similar rivers in the Northland region. Banks of the river are highly eroded, and the water channel is contained by man-made flood control systems.

Overall the abiotic values of the river are considered to be low.

An analysis of the flora evident within the lower reaches of the river suggests that its biotic values increase towards the coast. Around the bridge, riparian vegetation consists of both native and exotic plants, and is patchy. Downstream, the density of mangroves increases, as does the overall width of the river system. Bird and fish life appears to increase near the inlet, although there is evidence of some wading birds in close proximity to the bridge, and a stand of mature pohutukawa just to the north (it is unknown whether these were planted or naturally seeded).

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The ecological report outlines for the Kaeo River5:

‘The Kaeo River and the Kaeo River Riparian Zone within the proposed alignment have high ecological value for fish migration, ... and as habitat for the ‘at risk’ fernberd which is nesting in the vicinity.’

It goes on to note that the eastern bank riparian vegetation is narrower and that weed species are more prevalent, and this side of the river having a moderate ecological value. Fernbird have been recorded on both sides of the river, within the riparian vegetation, alongside a small number of other native and exotic species.

Overall it is considered that the biotic values of the river near the new bridge are moderate, increasing to high on the western side.

Whilst the river has been clearly modified, the more densely planted areas retain a degree of experiential value by their very contrast to the open pastoral landscape through which the river passes. From the bridge itself, a snapshot view is afforded downstream, where biotic values are highest, creating a brief but significant connection to the coast. The value is somewhat eroded by the presence of weed species and eroded banks in close proximity to the crossing. Overall, it is considered that the experiential value of the river, in the vicinity of the bridge, is moderate, increasing to high near the coast.

Combining this analysis, it is considered that the immediate vicinity of the proposed bridge has a moderate degree of natural character. The values increase towards the coast, where natural character value is most significant (as reflected by Regional policy).

The proposed planting of the riparian edges of the modified channel will potentially enhance natural character from its existing state. Where possible, existing native vegetation (particularly the stand of pohutukawa adjacent to the existing bridge) will be retained, and pest and weed maintenance will occur on the eastern bank.

The proposed planting has been outlined in the landscape concept plan, with a strong focus of native planting around the new SH10/Whangaroa Road intersection, new bridge, and the riparian margins of the river between the new bridge and the existing bridge. This planting would include the establishment of additional vegetation as recommended in the ecological report6, and the inclusion of tree and shrub species that are found naturally around this environment (where possible). It is anticipated that plants will take between 5 and 10 years to become fully established.

The retention of the eastern abutment of the existing bridge for the purposes of providing a fishing platform is consistent with Policy 18 of the NZCPS in providing opportunities for people to connect with the coast. It is considered that this abutment, nestled amongst existing and enhanced native riparian habitat, will increase the experiential value of this part of the river.

5 Assessment of Ecological Values: Northland Bridges Kaeo Bridge Replacement, Option 5. Bioresearches, September 2019. Section 3.5.6.

6 Assessment of Ecological Values: Northland Bridges Kaeo Bridge Replacement, Option 5. Bioresearches, September 2019. Section 7.5

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Whilst the abutment will result in a concrete structure being left on the river bank, this will provide stability around the existing pohutukawa. The remainder of the old bridge will be fully removed, such that the effect will appear simply be a widening and relocating of an existing built structure in the river environment.

With these measures undertaken, it is considered that the potential adverse effects on natural character resulting from the proposal are likely to be low. Indeed, other than the river widening (which will naturalise over time), it is more likely the proposal will create positive effects in the vicinity of the project area over the longer term as plants become established and natural habitat is enhanced.

It is considered the level of natural character effects are in accordance with the requirements of the NZCPS.

Landscape Effects

By its very nature of this being a ‘replacement bridge’ project (rather than construction of an entirely new road), the existing bridge and roads (including the intersection) are already significant elements of the existing landscape. To the west of the existing bridge, the already elevated road creates a notable division across the farmland floodplains, although from an experiential perspective this provides the traveller with enhanced views across the valley.

In addition, the escarpment to the east, various road signs and a lighting pole are existing features that contribute to the overall landscape context.

In this regard, the realignment of the road and bridge does not introduce any new elements to the landscape, and the works are on a scale that is comparable to the level of existing infrastructure. Any potential landscape effects will be mitigated by the removal of the previous bridge, road and embankment – with only the eastern side abutment remaining – however, this will become a relatively small feature that can be used by people for fishing and the retention of the eastern side abutment ensures better protection of the existing stand of pohutukawa in this location.

The existing escarpment feature on the eastern side of the road will need to be enlarged slightly to accommodate the new roundabout. In addition, some areas of vegetation will need to be removed in order to construct the approaches to the roundabout and bridge, including some patchy riparian vegetation on the eastern side of the river. However, whilst there are some native species amongst this vegetation, including on the hillside where the escarpment will be enlarged, most of it is compromised by exotic weed species. Replacement tree planting on the eastern side of the road, including ongoing maintenance in accordance with standard NZTA planting specifications7, will result in an overall improved planting habitat.

Further tree vegetation planting is incorporated at the base of the embankment on the western side of the proposed bridge, which will assist in creating an eco-link from the forested area on

7 P39 Standard Specification for Highway Landscape Treatments

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the adjacent hillside and the river. The extent of this planting is restricted by flood capacity requirements.

Overall, it is considered that the potential landscape effects of the proposal will be generally positive, once plants have become established. The road will remain one of the most modified elements of the landscape, but hydroseeding the banks rather than planting them will help the road better integrate into the surrounding pastural landscape than if they were fully planted, even if only marginally.

The proposed planting around the new bridge, including the establishment of salt marsh and enhanced riparian vegetation will make a measurable difference to the quality of the landscape in this area. The planting will provide better habitat for fernbirds and other birdlife, as well as enhancing an ecological connection between the river and forestry on the adjacent hillsides. In addition, the planting provides an opportunity for cultural connections, which might also be further enhanced as engagement with mana whenua progresses.

Visual Effects

The visual catchment of the proposal is remarkably limited. It is noted that the nearest property to the proposal that contains a dwelling will need to be purchased to complete the proposal, this being the northern extent of 339 SH10, approximately 500m west of the existing bridge. As this property forms part of the project area, the potential effects on these residence have not been considered as part of this report. It is envisaged that through the property purchase process a more detailed assessment of effects will be carried out, and appropriate mitigation agreed with the landowner.

253 SH10, the former restaurant located on the eastern side of the river, is located approximately 700m south of the existing bridge. A large stand of eucalypts on this property, together with riparian vegetation, would effectively screen the proposal from this property. It is possible that parts of the new bridge will be visible, but this would be in the same view, and of the same scale, as the existing bridge. It is therefore concluded that effects on this property will be very-low.

An analysis of the topography and vegetation surrounding the four elevated properties to the east of the proposal (three located at 10 Whangaroa Road and one at 18 Leacock Road) suggests that none will have any views of the bridge. Whilst some views of the road across the floodplain may be possible, it would be difficult from such a viewing angle to see any notable difference between the existing road and that proposed. It is therefore considered the potential visual effects on these properties will be very-low.

A collection of dwellings is located near the western end of the project, including 393, 401, 402 (containing several dwellings), 409 and 421 SH10. Each property is elevated to a varying degree above the floodplain, and therefore most (if not all) will have views across the existing road towards the existing bridge. However, only those located on the northern side of SH10 (principally the dwellings located at 402) will have any opportunity to see the new bridge structure. From this location the new bridge, located over one kilometre away, will be in a similar position in the landscape as the existing bridge. From this perspective, even though the proposed new bridge will be slightly wider than the existing bridge, it will be seen in the context

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of the hillside backdrop. The proposed vegetation planting along the river, north of the bridge, will visually enhance the presence of the river in the view, contributing to an increase in visual amenity. It is therefore considered that the visual effects on the collection of properties to the west of the proposal will be very-low.

A property located at 175 SH10, a few hundred metres north of the Sanford Seafood facility, may have a snapshot view of the bridge directly to the north. However, the view would be restricted by landforms either side of the river (the valley narrows considerably just south of the proposed bridge) and would be compromised by intervening vegetation, including riparian vegetation along the river. It is considered that the visual effects of the proposal on this property will be very-low.

No other properties are considered to be visually affected by the proposal.

Overall it is considered that the potential visual effects of the proposal will be very-low.

Construction Effects

Due to the underlying geomorphology, it is understood that the construction methodology will require a settling period for the new road and bridge embankments. During this time the existing road will need to remain operational to one side, and parts of the project area will resemble an abandoned construction site for several months. This is not unusual for a roading project such as this, however it will have an impact on how people appreciate the landscape during the construction period. In addition, the works within the river area will expose a the area of construction to the surrounding narrow catchment.

Unfortunately, there is little that can be done to mitigate the construction effects. Planting cannot be effectively undertaken until the bulk earthworks are fully completed, and even if it were done sooner the plants would not establish in time to provide any notable reduction in construction effects.

At a more operational level, measures to screen the construction yard through selection of location, the use of natural coloured temporary screens and/or painting temporary buildings in darker colours would be consistent with best practice. All construction yards and set down areas should be re-contoured to match surrounding natural landforms and rehabilitated either with planting in accordance with the landscape concept plan, or grassed.

Overall, the road is likely to have an increased presence in the landscape during its construction, and create increased visual effects for those properties who have a view over it. It is likely that, with adequate signage that sets out realistic project timeframes, local people will accept such effects as a means to an end. Nevertheless, it is considered that the landscape and visual effects of the construction will be moderate, for a period of at least 18 months.

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Urban Design Considerations

The Transport Agency manages urban design considerations through a number of methods, however designs are principally driven by the agency’s ‘Bridging the Gap’ document8. These guidelines set out an array of urban design objectives, although not all are relevant to every project.

Objective 1 in the Bridging the Gap guidelines seeks a design response to the landscape context. This includes considering the overall alignment of the project, but also how any proposed mitigation responds to the surrounding landscape. The landscape concept plan has been developed to achieve this outcome, and has been done in consultation with mana whenua who have a long association with the environment in which the road will be located. As a result, the project also responds to Objective 7, respecting cultural heritage values, and Objective 8, design with nature.

The existing bridge has very little (if any) provision for safe cycling, being narrow, single-lane and flanked by a sharp, blind corner. The new proposed bridge will be significantly wider, with side shoulders up to 1.5m in width and very long sightlines. This represents a significant improvement for cyclists – the overall improved road environment will enhance motorist visibility. Given the location of the road in a rural environment, some distance from any settlement or natural feature, it is not considered that providing a separate cycle-pedestrian bridge is necessary in this location.

The elevated level of the bridge means that it will provide opportunity for road users to have a view over the landscape and the river they are passing. Steel rail type barriers are proposed, similar to those used on the recently completed Taipa Bridge, which will enable outward views from the bridge. Potentially bridge supports will be painted, although this is subject to ongoing consultation with mana whenua.

Crime Prevention through Environmental Design (CPTED) is an important consideration, and all Transport Agency projects are required to be assessed for public safety. A full CPTED analysis will be undertaken during the detailed design stage, to ensure that the project meets the safety objectives of the Transport Agency and the Ministry of Justice. However, in anticipation of this review, low planting has been proposed around the intersections to allow for increased visibility, this also important for visibility of walkers or hitchhikers.

Overall, it is considered that the project achieves appropriate urban design outcomes.

Conclusion and Recommendations

The landscape concept plan provides a list of the landscape and ecological mitigation recommendations that have been incorporated into the proposal. As identified, it was developed in consultation with mana whenua and the project ecologists with the objective to

8 https://www.nzta.govt.nz/resources/bridging-the-gap/

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integrate mitigation measures into the overall proposal. The key outcomes the plan seeks are outlined as follows:

Enhanced riparian and saltmarsh habitat (particularly focussed on fernbird) around the proposed new bridge, and downstream to the existing bridge, including enhanced eco- links to existing vegetation on the adjacent hillside landforms.

Removal of the existing bridge, but retention of the eastern abutment to ensure protection of the existing stand of pohutukawa and to provide a fishing platform. It is considered that the landscape proposals set out in this plan will result in positive natural character and landscape outcomes for the project overall. Overall, the project is considered to have:

Low adverse effects on natural character – although more likely to be positive over the longer term. It is considered that the effects are consistent with the requirements of the NZCPS in protecting (or enhancing) natural character, and in providing public access to the coast.

Positive landscape effects, albiet with enhanced adverse landscape effects across the western elevated portion of the road.

Very-low visual effects.

Moderate landscape and visual effects, and low natural character effects, during the 18 month construction period. These conclusions are based on the proposal being developed in accordance with the landscape concept plan.

Shannon Bray NZILA Registered Landscape Architect

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Appendix 1: Author Credentials

This report was principally prepared by Shannon Bray, Principal Landscape Architect and Director of Wayfinder Landscape Planning and Strategy Ltd.

Shannon Bray | Curriculum Vitae and Experience

Background:

Bachelor Landscape Architecture (with Honours), Lincoln University 1996

Bachelor Forestry Science, Canterbury University 1994

NZILA Registered Landscape Architect

NZILA National President 2015 to 2018

RMLA Member

2016 to present – Director, Landscape Architect, Wayfinder Landscape Planning & Strategy Ltd

2012 to 2016 – Senior Principal, Landscape Architect, Boffa Miskell Ltd

2004 to 2012 – Landscape Architect, Shannon Bray Landscape Architect Ltd

1997 to 2004 – Various Management and Strategy Roles in England, UK

Project Experience:

Spark 4G Development, Nationwide (Spark) Landscape and Visual Effects Assessment and Advice: Kawau Island, Gisborne, Hāwea, Gore, Queenstown

SH20/SH20A/SH20B Corridors, Auckland (NZTA) Options Assessment, Urban Design and Landscape Framework (UDLF), Preliminary Lansdcape Assessment

Northern Corridor, Auckland (NZTA) UDLF, Board of Inquiry

Southern Corridor, Auckland (NZTA) UDLF, Project Design, Tendering, Hearing, Compliance

SH16/18, Auckland (NZTA) Preliminary Landscape Assessment, Long List Options Assessment, Short List Options Assessment

SH29, Tauranga (NZTA) Preliminary Landscape Assessment, Long List Options Assessment

SH3 Awakino, Waikato (Downer) Bid Project Design

He Ara Ktahi – Manawatū Shared Path River Bridge (Palmerston North City Council) s42a reporting, Council Hearing

Waterview, Auckland (NZTA) Effects Assessment Northern Interchange Design Changes

Appendix 1: Author Credentials Page 1- 1

Waterview Shared Use Path, Auckland (AT) Effects Assessment, Project Design, Hearing

Puhoi to Warkworth, Auckland (Ferrovial) Bid Project Design, Interactive Sessions

Waikato Expressway, Cambridge (Council) Effects Assessment

Penlink, Auckland (AT) Effects Assessment, Project Design, Open Days, Council Hearing

Glenvar Ridge Road, Auckland (AT) Effects Assessment, Submitter Mtgs, Design, Hearing

Transmission Gully, Wellington (NZTA) Effects Assessment, Submitter Meetings, Project Design

Westmere Coastal Walkway, Auckland (Council) Effects Assessment, Council Hearing

Orakei Basin Coastal Walkway, Auckland (Council) Effects Assessment, Council Hearing

Wainui Interchange, Orewa (AT/NZTA) Effects Assessment, Council Hearing

iWay, Hastings (Council) Project Development and Strategy

Ultra-Fast Broadband Rollout, National (Chorus) Project Design, Effects Assessment, Meetings

ONFL Unitary Plan Submissions, Auckland (Spark/Vector) Expert Conferencing, Hearing

Puke Coal, Huntly (Puke Coal) Effects Assessment, Project Design, Hearing

Howick Pump Station, Auckland (Watercare) Effects Assessment, Project Design

Mangatangi Coal Mine, Pokeno (Council) Effects Assessment, Hearing

Waverley Wind Farm (Council) Commissioner

10+ Wind Farms (Meridian Energy, Council, Community) Effects Assessments and Hearings Professional Development

2018 – New Zealand Institute of Landscape Architects, Auckland Conference

2018 – GIS Training

2017 – Australian Institute of Landscape Architects, Sydney Conference

2017 – New Zealand Institute of Landscape Architects, Wellington Conference

2017 – Judge, Asia Pacific Landscape Architecture Awards

2017 – Project Director NZILA Code of Practice for Landscape Assessment

2016 – Making Good Decisions

2016 – Australian Institute of Landscape Architects, Canberra Conference

2016 – Judge, Australian Institute of Landscape Architects National Awards

Appendix 1: Author Credentials Page 1- 2

Appendix 2: Landscape Concept Plan

Refer next page - best printed at A3 Landscape.

Appendix 2: Landscape Concept Plan Page 2- 1

www.wayfinder.nz

SH10 Kaeo Bridge Project 21 June 2019

Revision: 1 Integrated Transport Assessment Reference: 254914 NZ Transport Agency

Project 254914 File Kaeo Northland Bridges Traffic Impact Assessment Finaldocx.docx Revision 1

Document control record

Document prepared by: Aurecon New Zealand Limited Level 4 139 Carlton Gore Road Newmarket, Auckland 1023 PO Box 9762 Newmarket Auckland 1149 New Zealand

T +64 9 520 6019 F +64 9 524 7815 E [email protected] W aurecongroup.com

Document control

Report title Integrated Transport Assessment

Document ID 254914-3000-REP-NN-0009 Project number 254914

File path P:\200000-BST\252852 - Northland Bridges\03 Project Delivery\Traffic Impact Assessment Client NZ Transport Agency Client contact Deepak Rama

Rev Date Revision details/status Author Reviewer Verifier Approver (if required) 0 15 December 2017 Draft for internal review R Inman P De Wet

1 20 June 2019 Updated Draft for internal J Chauke P De Wet R Inman review

Current revision 1

Approval

Author signature Approver signature

Name J Chauke Name R Inman

Title Traffic Engineer Title Principal Traffic Engineer

Project 254914 File Kaeo Northland Bridges Traffic Impact Assessment Finaldocx.docx Revision 1

Contents

1 Description of the project 3 1.1 Project background 3 1.2 Purpose of this report 4 2 Existing transport environment and data 5 2.1 State highway network 5 2.2 Local road access 5 2.3 Private property access 6 2.4 Existing and historic traffic volumes 6 2.5 Crash data 8 3 Proposal requirements 11 3.1 Proposal 11 3.2 Design standards 11 4 Design review 13 4.1 Safe system 13 5 Traffic impacts 15 5.1 Traffic movements 15 5.2 Network impact 16 5.3 Safety 16 6 Construction management 18 6.1 Construction strategy 18 6.2 Construction traffic management plan 18 7 Assessment of project effects 20 7.1 Traffic generation 20 7.2 Signage 20 7.3 Safety 20 7.4 Vulnerable road users 21 7.5 Local road and private access 21 7.6 Resilience 21 7.7 Construction traffic 21 8 Conclusions 22

Appendices

Appendix A CAS Data

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Figures Figure 1: Project location - regional context 3 Figure 2:Proposed SH10 alignment and bridge 4 Figure 3: State Highway count site (NZ Transport Agency TMS database) 6 Figure 4: AADT growth trends - NZ Transport Agency count site 01000029 7 Figure 5: Average hourly traffic flow profile (NZ Transport Agency count site 01000029) 7 Figure 6: Crash Diagram - SH10 from Martin Road to Pupuke Mangapa Road 9 Figure 7: Crash Diagram – SH10 Kaeo Bridge project extent 10 Figure 8: Level of service and service flow rates 16

Tables Table 1: Baseline Average Annual Daily Traffic (AADT) 8 Table 2: AADT 2015, 2030 and 2048 15

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1 Description of the project

1.1 Project background State Highway 10 (SH10) is an important link in the Northland State Highway network and is part of the Paihia to Kaitaia section of the Twin Coast Discovery Route. A single-lane bridge is located on SH10, at the intersection with Whangaroa Road crossing the Kaeo River (asset reference Bridge 448) as shown in Error! Reference source not found.. This bridge and intersection has been identified by the NZ Transport Agency (Transport Agency) as having several driver safety and transport network resilience risks. This project is aimed at resolving the road network constraint by replacing the single-lane bridge with a two-lane bridge and upgrading the SH10 / Whangaroa Road intersection with a roundabout as depicted in Figure 2. The proposed upgrades will also include construction of culverts, to improve flood resilience and removal of and upgrade of access-ways for properties that will be directly impacted by the proposed realignment. Project objectives include improved SH10 capacity, driver safety and road network resilience, through increased bridge capacity, enhanced vertical and horizontal alignment, increased sight distances on approach to the proposed bridge and provision of safety barriers within the project extents. A full description of the Project, including its components and construction, is contained in the Assessment of Environmental Effects1 (AEE) for the Project.

Figure 1: Project location - regional context

1 Kaeo Bridge Project, Assessment of Environmental Effects; Aurecon NZ Limited, July 2019

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1.2 Purpose of this report This report is one of several technical specialist reports that has been prepared to inform the Project AEE. The focus of this report is an assessment of the effects that the project has to transport modes along the section of SH10 around the Kaeo Bridge and the SH10 / Whangaroa Road intersection. This includes consideration of the existing transport environment, the predicted increase in traffic flows along SH10 and effects of the Project including traffic operation, safety of users, active modes of transport (walking and cycling), signage and construction traffic effects. The extent of the project covers about 1.0 km, including the existing one-lane bridge over the Kaeo River and several access connections including: Proposed roundabout at Whangaroa Road / SH10 Private properties access ways An approximate alignment of the proposal is shown in Error! Reference source not found., along with the existing SH10 alignment and the local road network.

Figure 2:Proposed SH10 alignment and bridge

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2 Existing transport environment and data

2.1 State highway network

2.1.1 State Highway 1 and State Highway 10 inter-dependencies SH1 is the primary arterial road link between districts and regions in New Zealand’s North Island. In the Northland region, SH10 branches off SH1 at Pakaraka, providing road connectivity to towns to the east including Kerikeri, Kaeo, and Taipa, then connecting with SH1 at Awanui via several one-lane bridges. SH1 takes a more central route from Pakaraka, through to Mangamuka, Kaitaia and Awanui. SH1 and SH10 play complementary north-south principal arterial roles, with either state highway able to act as an alternative route to the other in case of an event necessitating closure of the road. The dependency on SH10 to provide connectivity to Northland is critical when SH1 is closed and therefore SH10 provides a critical role in the resilience of the Far North state highway network.

2.1.2 State Highway 10 SH10 is part of the Twin Coast Discovery Highway tourist route connecting the Bay of Islands with Doubtless Bay. SH10 traverses a range of environments, from low lying areas that are subject to flooding such as at Kaeo, to areas prone to land slips. There are therefore several locations in the network that are susceptible to closure due to heavy rain events. Closures also occur at the single-lane bridges such as at Kaeo following crash events, causing disruption and significant detours for local communities. Closures result in lengthy periods of isolation and high social and economic costs to local community and businesses. There are currently no footpaths or cycle routes along SH10 at Kaeo, or in the broader locality. The Twin Coast Cycle Trail runs in an east/west direction, some 65km to the south east and south west of the Kaeo Bridge from Opua near Paihia, to Mungungu Mission Station west of Horeke. No new walking and cycling schemes are known to have been identified in the local area. Whangaroa College and Kaeo Primary School are located approximately 3.4 km south east of the SH10 Kaeo Bridge. Whangaroa College has three school bus routes that cross the single-lane bridge from Kaeo, Otangaroa and Pupuke. The Bridge is also used by the Intercity buses travelling between Kerikeri and Kaikohe. No public bus stops are located at the Kaeo bridge.

2.2 Local road access Within the Project extents, the only local road access onto SH10 is Whangaroa Road (Secondary road), as depicted at Error! Reference source not found.. Whangaroa Road is accessed via an intersection adjacent to the eastern approach to the SH10 Kaeo Bridge. Whangaroa Road provides access to Whangaroa Harbour, which is used by residents, tourists, commercial deliveries and boat users. Use of the road is greatest during the peak summer holiday period.

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Whangaroa Road is a sealed road which currently ties into SH10 via a STOP controlled ‘T’ intersection that gives way to the 90° bend on SH10. The traffic exiting from Whangaroa Road in a southerly direction can do so at speed as there is little deflection, allowing vehicles to exit in a straight line. Similarly, traffic heading north on SH10 entering Whangaroa Road can do so at speed, but visibility to the left towards the one lane bridge is restricted due to the 90-degree bend and vertical elevation of the road. Visibility is available in all directions for traffic exiting Whangaroa Road, albeit the visual depth of field to oncoming traffic beyond the one lane bridge to the east can be obscured.

2.3 Private property access To the east and south of the bridge, there are 5 formalised property accesses. To the west of the bridge there are 6 accesses to the neighbouring farms, 2 to the north and 4 to the south. There are two property accesses onto SH10 within the project extent that will be changed as part of the project. The proposed alignment will tie into the existing access.

2.4 Existing and historic traffic volumes Traffic data has been sourced from the NZ Transport Agency Traffic Management System (TMS) database for the two count sites closest to the project site as shown in Figure 3. Although the count sites are several kilometres away from the project site, the data from the site provide historic growth trends and daily flow profiles along the corridor, that informed the traffic growth estimates and the assessment of the potential traffic impact of the project. TMS site “01000029” is a permanent monitoring site with almost 350 days (per year) of data on average. The historic growth trends from TMS site “01000029” are shown in Figure 4 and the flow profiles are shown in Figure 5.

Figure 3: State Highway count site (NZ Transport Agency TMS database)

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Figure 4: AADT growth trends - NZ Transport Agency count site 01000029

Figure 5: Average hourly traffic flow profile (NZ Transport Agency count site 01000029)

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The data shows that traffic on the site has been growing at an average rate of 7% per annum (pa) over the period between 2014 and 2018. Heavy commercial vehicle composition ranged between 7.1% and 7.6% in the period under review. Heavy vehicle growth fluctuated between years but has on average grown by about 7.1% pa (about the same average growth rate as light vehicles). Highest traffic peak occurs between 5 and 6 pm, with traffic volumes reaching about 9% of daily traffic in 2018. The growth rate is relatively high, which is understandable considering the low traffic volume environment in the area historically. However, this high growth rate is not considered sustainable over a long-term period. A lower growth rate is proposed for future traffic estimates, as discussed in Section 5. The TMS data was supplemented with Local volumes sourced from NZ Transport Agency Crash Analysis System (CAS), as shown in Table 1. The data shows the traffic flows on the relevant section of SH10 are low and Whangaroa Road has very low traffic flow. Congestion and queuing of vehicles waiting to cross the single lane bridge and Whangaroa Road intersection is expected, however it will most likely be minimal due to the low volumes.

Table 1: Baseline Average Annual Daily Traffic (AADT)

HCVs AADT Count Site Reference Road Section %HCV HCV 2015 2018 2018 2018 01000060 SH10 (1.1km north of 8.4 198 1,805 2,351 (NZ Transport Agency) Salvation Road) 01000029 (NZTA SH10 (1km south of 7.6 356 3,857 4,704 (NZ Transport Agency) Takou Bay Road) SH10 (1.5km west of CAS Database 7.6* 248* 2,669 3,270** Whangaroa Road) SH10 (1km south of CAS Database 7.6* 291* 3,130 3,834** Whangaroa Road)

CAS Database Whangaroa Road 7.6* 69* 743 910**

Source: NZ Transport Agency *%HCVs not provided, assumed to be the same as NZ Transport Agency count site “01000029” **2018 volumes on local road count sites unavailable, estimated using historic average growth rates, applied to the 2015 traffic volumes.

2.5 Crash data The KiwiRAP (New Zealand Road Assessment Programme) analyses the road safety of the state highway network. The latest issue of the KiwiRAP regional results is 2012. The objectives are to reduce deaths and injuries by systematically assessing risk and identifying safety shortcomings. There are two measures of risk:

Collective Risk – total number of fatal and serious injury crashes per kilometre over a section of road Personal Risk – measure of risk to each individual, taking in to account traffic volumes The Collective Risk on SH10 is Medium (0.10) meaning there are a medium number of people “killed and seriously injured” (KSI) along this stretch of corridor, and the Personal Risk is Medium-High (7.8) suggesting there are a relatively high number of KSI crashes per vehicle on this corridor.

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2.5.1 Broader transport network A search of the NZ Transport Agency CAS data has been undertaken for a 5-year period (01 June 2014 to 17 June 2019) for the surrounding road network. The data represents all reported crashes within this period and search area. The data relevant to the broader Project area is summarised in Figure 6. The data is summarised below with full data print outs provided in Appendix A. A total of 23 crashes occurred in the broader area including: 2 serious injury crashes; 5 minor injury crashes; and 16 non-injury crashes.

Main driver / vehicle risk factors involved “lost control on a bend” (52%) and rear end /obstruction (26%). Weather and surface conditions were not major risk factors, for over 56% of the crashes occurred under fine weather conditions and over 56% under dry surface conditions. 44% of the crashes occurred under dark natural light conditions, 35% when overcast and 22% under bright sun conditions.

Project site

Figure 6: Crash Diagram - SH10 from Martin Road to Pupuke Mangapa Road It is noted that crash analysis data for the period between 2012 and 2016 had a higher number of road crashes (29). This comprised of 1 fatal, 1 serious injury, 5 minor injury and 22 non-injury crashes.

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2.5.2 Local transport network Within 1km of the Project site, NZ Transport Agency CAS data for a 5-year period (01 June 2014 to 17 June 2019), recorded a total of 15 crashes. This included 1 serious injury, 2 minor injury and 12 non- injury crashes. The following provides further details on the recorded crashes: 2 crashes (both non-injury) were recorded on the bridge, both classified as rear end / obstruction in dark or overcast natural light conditions A vehicle failed to give-way at the SH10 / Whangaroa Road intersection Vehicle or driver contributing factors comprised of: Rear-end / obstruction – 20% Loss of control on curve / Head on collision – 53% Loss of control on straight / Head on collision – 20% Crossing / Turning – 7% Weekend crash rates were similar to the weekday average 53% of the crashes occurred under natural light conditions recorded as overcast, 25% when dark and 7% under bright light condition

47% of the crashes occurred when the weather conditions were fine, 27% with light rain, 13% when there was mist and fog and 7% during heavy rain

In the period 2012 to 2016 there were 12 crashes in the local area, comprising of 1 fatal, 1 serious injury, 1 minor injury and 9 non-injury crashes. The contributing factors have mainly remained the same in the revised analysis period when compared to the previous period.

Project site

Figure 7: Crash Diagram – SH10 Kaeo Bridge project extent

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3 Proposal requirements

3.1 Proposal The Project objectives and detailed description are provided within the project’s Assessment of Environmental Effects (AEE), and generally seek to improve the safety and resilience of SH10 at the Kaeo Bridge. The Project will remove both the vertical and horizontal alignment challenges of the existing Whangaroa Road, SH10 intersection and one lane Kaeo river bridge. An indicative drawing of the proposal is provided at Figure 2. The proposed alignment of SH10 provides a rounded curvature, removing the existing 90º angle intersection of Whangaroia Road and SH10. A roundabout is proposed, to the east of the river to connect SH10 with Whangaroa Road. The roundabout removes the requirement for a new side road intersection to connect with Whangaroa Road and removes the need for new access connections with private properties. It is anticipated that the roundabout will encourage vehicles to reduce speed through the intersection and minimise loss of control crashes, improving safety and reducing the risk of fatal or serious injury crashes. There are no known new developments planned for in the local area and Far North District Council (FNDC) has no planned works on the surrounding local road network in its Ten-Year Plan.

One of the existing direct private property access onto SH10 to the west will be removed as part of the SH10 removal works on approach to the bridge. That property will be accessed from the existing SH10. Two other private property access onto SH10 on the western side will remain at the project extents. As the proposed intersection of SH10 and Whangaroa Road will be located further south, one existing access-way currently on SH10 will be realigned.

3.2 Design standards There are several design requirements set out in the NZ Transport Agency Appendices to Principal’s Requirements App 1. These include: The treatment of design vehicles shall be in accordance with the principles in Chapter 5 of the Austroads Guide to Road Design Part 4, Intersections and Crossings ̽ General, with the following additions and exceptions: The design vehicle for intersection turning movements shall be the 18 m 4 axle semi-trailer as defined in the LTNZ Road and Traffic Guidelines ͆RTS 18 New Zealand On-road Tracking Curves for Heavy Motor Vehicles͇ 2007, with a dimension of 9.4m from king pin to rear axis of trailer; The swept path of the design vehicle for any movement shall not encroach into opposing traffic lanes or into adjacent left side shoulders. The tracking path (wheel path) of the design vehicle for any movement shall not encroach within 0.5m of a face of kerb or lip of channel; The Contractor shall ensure all infrastructure, such as signs and posts, shall not encroach within 1.0m of the vehicle body swept path; Provision shall be made to allow for over dimensional vehicles along the state highway lengths. The required clearance envelope is to accommodate a vehicle envelope 6m high by a 10m wide with an allowance for a possible off-centre load and for tracking variation where the geometry requires;

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Design Speed of 80km/h on state highways and 50km/h on local roads; Sight distances shall be based on the Austroads Guide to Road Design using normal design domain values for all parameters unless otherwise stated. The values stated in Table 3.2 of AGRD Part 4a shall be taken as minimum requirements; Reaction times shall be: 2.0 seconds for the state highways; 2.0 seconds for all local roads and local intersections; Coefficient of longitudinal deceleration for the car stopping sight distance shall be 0.36. Increase lateral offset to roadside features including barriers on the inside of horizontal curves for all standard object heights. The roundabout design is based on a 60km/h speed environment using a R=12m central island and a 7.6m wide circulating carriageway. Other design criteria, as specified in project specifications, include minimum turning lane widths of 3.5m, alignments of splitter islands, 2% minimum carriageway cross fall and maximum 4% cross fall, kerbing, verges, clearances and access way treatment.

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4 Design review

4.1 Safe system There are several considerations that are required for the design of a new road, using the guiding Safe System philosophy. These include:

1. People make mistakes – People make mistakes and some crashes are inevitable. 2. People are vulnerable – Our bodies have a limited ability to withstand crash forces without being seriously injured or killed. 3. We need to share responsibility – System designers and people who use the roads must all share responsibility for creating a road system where crash forces do not result in death or serious injury. 4. We need to strengthen all parts of the system – We need to improve the safety of all parts of the system – roads and roadsides, speeds, vehicles, and road use so that if one part fails, other parts will still protect the people involved.

The Safe System approach in New Zealand has four pillars that underpin the above principles: Safe roads – that are predictable and forgiving of mistakes. They are self-explaining in that their design encourages safe travel speeds. Safe speeds – travel speeds suit the function and level of safety of the road. People understand and comply with the speed limits and drive to the conditions. Safe vehicles – that prevent crashes and protect road users, including pedestrians and cyclists, in the event of a crash. Safe road use – road users that are skilled and competent, alert and unimpaired. They comply with road rules, take steps to improve safety, and demand and expect safety improvements (Ministry of Transport 2010).

The proposed design has been assessed considering the above principles for vehicle users and drivers. The following findings are noted:

The proposed design of the bridge is to the appropriate lane width and shoulder for a corridor of this nature. A 3.5m lane with a 1.5m shoulder width is proposed which exceeds the minimum lane width2 being 3.25m and shoulder 1.2m. The shoulder width provided is an improvement on the existing section of SH10, and the additional width could be used by cyclists. The SH10 eastbound approach to the roundabout has good sight distance a suitable threshold and backdrop created by the bridge and hillside to provide good conspicuity. The adopted design speed of 80km/h requires 114 of Stopping Sight Distance (SSD), however the design generally provides >180m (100km/h) with a minimum of 120m to a 0.2m object height. Sight distance to the roundabout limit line meet the Approach Sight Distance (ASD) requirement of 114m to the pavement. The SH10 westbound approach has unobstructed sight distance of >151m (90km/h) exceeding the extent of works. The existing southbound approach on Whangaroa Rd goes through an existing R=200m curve with a design speed of 70km/h prior to the start of works. This existing curve has SSD restricted to approximately 60m (50km/h) due to existing vegetation. However; from the end of this curve, the start of works, 114m (80km/h) of ASD is provided to the roundabout limit line. The deflection on the three entry legs in the concept design is between R=70 and 80m which exceeds the desired value of ≤55m. The intention is to increase the deflection during detailed design by

2 https://www.nzta.govt.nz/assets/resources/road-traffic-standards/docs/rts-15.pdf

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optimising the roundabout location and the potential use of concrete aprons for heavy vehicle tracking. Barriers will be installed on both sides of the bridge to promote loss of control vehicles being confined to the road. Barriers are also proposed along both sides of the carriageway within the project extent. This provides an improved level of safety by absorbing some vehicle impact and retaining vehicles within the road corridor if an incident occurs. Austroads standard require the minimum cross fall of 2%, and even 2% should only be prescribed for concrete pavements where levels and surface finish are tightly controlled3. The project design is 3%, exceeding the standard, which is the preferred cross fall for this road. Minimising visibility obstructions and collision hazards such as trees and power/telephone-wire poles should be carefully considered. There are existing power lines cutting across the fields to the west of Kaeo River and on both sides of SH10 south of the bridge, of which the wires are unlikely to be the correct height for the new proposed alignment and elevation of the road. During detailed design, investigation of these poles and lines location should be completed to ensure height clearances and sight distances are appropriate.

The design alignment of the road and associated operating speed includes:

460m radius (L=59m) curve at the western end – operating speed of approximately 80kph 600m radius curve (L=69m) at the southern end – operating speed of approximately 80kph Based on the NZTA Safer Journeys Risk Assessment Tool (MegaMaps) the existing mean operating speed of the 32km segment of SH10 between Kaeo and Mangonui is between 85 & 89km/h. The existing mean operating speed of the 4.9km segment of Whangaroa Rd between SH10 and Lewer Rd is between 60 and 64km/h.

3 Austroads: Guide to Road Design Part 3: Geometric Design 2016: 39

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5 Traffic impacts

5.1 Traffic movements A review of the historical growth trends on the State Highway traffic monitoring site “01000029” established an average annual traffic growth of approximately 7% per annum, over the period between 2014 and 2018. This growth is off a low traffic volume baseline and is unlikely to be sustained over a long-term period. The dominant economic sectors in the region are also cyclical in nature. A revised growth rate of 3.5% is therefore proposed for estimating future traffic growth in the area. This revised rate is 50% of the average growth observed. This approach is considered a more pragmatic approach to the current rapid growth and expected low growth over a long-term horizon. The anticipated traffic volumes are shown below at Table 2.

Table 2: AADT 2015, 2030 and 2048

2018 HCVs Baseline AADT 2030 AADT 2048 AADT Road Section %HCV HCV 2015 2018 HCV Total HCV Total s TMC 0100060 SH10 (1.1km north of 8.4 198 1,805 2,351 299 3,553 556 6,599 Salvation Road) TMC 0100029 SH10 (1km south of Takou 7.6 356 3,857 4,704 538 7,108 999 13,203 Bay Road) SH10 (1.5km west of - 248 2,669 3,270 375 4,941 697 9,177 Whangaroa Road) SH10 (1km south of - 291 3,130 3,834 440 5,794 818 10,762 Whangaroa Road)

Whangaroa Road - 69 743 910 105 1,375 194 2,555

The 2030 AADT traffic volumes shown in Table 2 show the annualised percentage growth of 3.5% growth in both light vehicles and heavy commercial vehicles, compounded on the 2018 volumes. The 2030 and 2048 volumes along the SH10 corridor are estimated at approximately 7,100 and 13,200 vehicles per day respectively. Based on observed flow profiles, the PM peak volumes are estimated at approximately 650 and 1,200 vehicles per an hour for 2030 and 2048 design years respectively (about 9% of the daily total). Using the LOS guide in Austroads Traffic Studies and Analysis guide, as shown in Figure 8, it is expected that the corridor would operate at level of service A (LOS A) in 2030 and reducing to LOS C in 2048. It is, therefore, concluded that the project will provide sufficient capacity to allow the network to accommodate significant growth in the future, while maintaining acceptable level of service and improved vehicle and driver safety.

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Figure 8: Level of service and service flow rates Source: Austroads 2013 Part 3: Traffic Studies and Analysis

5.2 Network impact The new road alignment will support significant traffic growth on the state highway. Most local traffic will either continue along SH10 to their destination or onto Whangaroa Road via an improved intersection. Several properties will maintain direct access to the state highway network. It is noted though that there could be higher through traffic volumes and vehicle speeds through the corridor, following the implementation of the project. However, the improved visibility from their properties, at the Whangaroa Road intersection and removal of the existing conflict point on a right-angle turn on approach to the Bridge are a positive benefit to the local network and users, which improves on the existing conditions.

5.3 Safety Several safety improvements are proposed, which includes: introduction of safety barriers along the length of the new alignment and bridge to prevent vehicles leaving the corridor in a ‘loss of control’ event, which is a major contributing factor to road crashes in the study area as illustrated in the crash data. The safety barriers ensure that a proportion of vehicle momentum is absorbed, reducing the severity of the collision and prevent vehicles colliding with neighbouring physical objects including trees, ditches, fences, buildings etc. a straightened carriageway alignment that provides improved sight distances for forward visibility and turning movements at the intersection with Whangaroa Road; increased carriageway shoulder width which will provide an area for driver error, a safer pull-over area in the event of a break down or traffic incident, and a safer space for cyclists and other slow- moving traffic to use;

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Construction of a new intersection with Whangaroa Road will provide improved sight distances, managed vehicle speeds with the roundabout and reduced general speed for all vehicle movements; Construction of a two-lane bridge will provide increased capacity for vehicles and no delay for through- traffic, which minimises the potential for risky driving behaviour, potential head-on collisions and maintains the ability for one lane to remain open if an accident occurs, therefore improving road network resilience in the area; Implementation of new signage along the road carriageway will provide clearer directions for visitors, reducing the potential for risky manoeuvres on the corridor, and the roundabout will allow for safe manoeuvring including U-turns; New lighting of the roundabout at the Whangaroa Road intersection will provide a clear signal for road users in times of darkness of the approaching intersection hazard. This will also provide clearer directions for visitors, reducing the potential for risky manoeuvres on the corridor. Most of the crashes recorded in the area were during periods of low light levels and overcast conditions; The project is expected to improve overall safety for drivers along the section of SH10, with a reduction in loss of control crashes and Killed and Serious Injury collisions (KSI). The current KiwiRAP rating is two stars through this section of SH10. The aspiration for this corridor is to be 3 stars for the whole length. The current proposals will bring the corridor up to 3 stars in this section but will be unlikely to raise it to a 4-star rating. To reach a 4-star rating, the road lanes would typically have to be separated, with only minor deficiencies. Undivided roads are to be straight with good overtaking provision, good delineation and safe roadsides, with low traffic volumes. The new proposal meets some but not all of these requirements. The improved capacity, safety features and alignment of the SH10, within the project extents could result in some crash migration to other sections of the corridor. The immediate neighbouring sections of SH10 are relatively straight but forward visibility on bends and some gradients further along the corridor, particularly to the south and southeast, could be improved. The traffic speeds environment varies along the SH10 corridor based on the topography, adjacent land uses and traffic control. As such there needs to be better management of speed progression between high and low speed environments. The posted speed limits should provide guided progression as the drivers transition between the various sections of the corridor that have varying operational speeds. For the sections of the corridors within the immediate project extents, speed-progression (step-down) should be considered as part of the detailed design. There is a need to review the operational, design and posted speeds along the project corridor, given the considerable changes in the traffic speed environment along the corridor and a high number of “loss of control” type crashes, especially on curves.

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6 Construction management

6.1 Construction strategy A two-lane concrete road bridge is proposed to be constructed over the Kaeo River. The bridge will require both temporary construction and permanent works within the Kaeo River. Kaeo Bridge will be constructed offline. To facilitate safe and efficient construction practices, a temporary “clip on” pedestrian bridge is proposed on the southern side of the existing bridge. Temporary slim line piles will be installed in alignment with the road bridge piles. The temporary pedestrian bridge will avoid alternative measures such as contractors walking along SH10 to access all areas of the construction site. Construction of the bridge will be undertaken progressively in horizontal sections from both the eastern and western embankment. To gain construction efficiencies, safety and environmental management, temporary staging will be built across the Kaeo River. Temporary slim line piles will be installed within the riparian management zone and main channel to support the temporary staging. The western embankment will be constructed offline to SH10. To construct the realigned section of SH10 including intersection with Whangaroa Road to the north east, a temporary road diversion will be constructed. The road diversion will enable the continuation of traffic flows along the state highway whilst works are undertaken within that area. Accessways to the site off SH10, controlled by temporary traffic signals or similar and measures to manage construction traffic, including the proposed road diversions, will be described within the Project Construction Traffic Management Plan (CTMP) that will be submitted to the roading authority prior to commencement of construction. It will be necessary for earthworks machinery to travel along and cross SH10 to access the construction site, main construction yard and to import and export fill. Access ways controlled by temporary traffic signals and/or stop/go control or similar to the site off SH10 will be required. Peak construction traffic movements from the site will occur during the importation of fill for construction of the embankments. Measures to manage construction traffic, including the proposed road diversion, will be described within the Project Construction Traffic Management Plan (CTMP) that will be submitted to the road controlling authority prior to commencement of construction. It is recommended that the CTMP is required as a condition of resource consent. The CTMP will be a sub plan to the Construction Environmental Management Plan (CEMP) and is further discussed below.

6.2 Construction Traffic Management Plan During construction, a CEMP will be implemented. The CEMP is the overarching management plan which identifies the principles and provides the framework of methods to be applied in order to manage the potential environmental effects of the project during construction. It is recommended that a CTMP is implemented as a subplan to the CEMP. The CTMP will provide the following information: Details of the methods for avoiding, remedying or mitigating the effects of construction on the safe and efficient operation of Whangaroa Road and SH10; Details on the numbers, frequencies, routes, duration and timing of peak construction traffic movements to and from the site; Details of temporary road diversions proposed during construction;

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The location of the site construction yard, equipment laydown areas and site access locations off SH10 Details of the measures to be implemented to maintain emergency service vehicles access along the SH10 carriageway during construction.

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7 Assessment of project effects

7.1 Traffic generation No additional traffic is being generated by the proposed new bridge and road alignment. Traffic from general population growth in the region and growth of tourism will increase demand on the network. These traffic volume increases have been accounted for in the 3.5% pa general traffic growth between 2018 and 2048 shown in Section 5. The new alignment provides sufficient capacity for the projected increase in traffic flow, contributing to the long-term sustainability and capability of the region.

7.2 Signage New signage is proposed to give drivers warning of the approaching intersection with Whangaroa Road. During detailed design, the location of signage should be reviewed to ensure that their location provides sufficient time for vehicles to react and maintain sight lines. The existing signs at the current Whangaroa Road intersection will need to be removed as part of the Project and new signs introduced on approach to the new intersection warning of the approaching bend and intersection. It is recommended that during the detailed design stage, signage is used to support a speed limit progression from a high to low traffic speed environment (speed limit step-down) from the highway to the roundabout.

7.3 Safety The proposal will result in an improvement to general vehicle safety along SH10 at the Kaeo Bridge by incorporating a number of safety improvements, which is set out in Section 5.3 and includes the following: Removal of a 90o corner along SH10 on approach to the one lane bridge at the intersection, removing a turning movement where visibility is restricted by both the intersection arrangement and the single lane bridge. Removal of a one lane bridge and construction of a two-lane bridge. This improves the safety by reducing the likelihood of head-on collisions, reducing queuing and driver frustration, which reduces the likelihood of unsafe overtaking manoeuvres and minor collisions at the end of the bridge where visibility is restricted. The introduction of safety barriers on both sides of SH10 which will help reduce the severity of crashes and minimise loss of control crashes. Lighting at the SH10 and Whangaroa Road intersection improves the visual prominence of the intersection for drivers on approach, highlighting the hazard and warning drivers to be cautious or reduce speed, raising awareness of potential vulnerable users and illuminating waiting vehicles which may not be clearly visible without street lighting. All the crashes recorded in the vicinity were during periods of low light level.

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7.4 Vulnerable road users The proposed shoulder width will be wider than what currently exists, providing improvements to cyclist safety. However, the project does not provide specific facilities for horse riding, walking and cycling such as a separate shared path. There is a growth trend towards cycle tourism across New Zealand with the national cycle network growing. There may, therefore, be opportunities to consider provision of higher quality shared paths or cycling facilities along the SH10 corridor in the future. Local school bus routes use SH10 for Whangaroa College and Kaeo Primary School, which may have school bus stops. During detailed design, consultation with the schools should progress to ensure that provision of bus stops, pick up and drop off areas, if required to serve the local community are incorporated within the design to achieve safe outcomes. Horse riders, as well as slow moving vehicles such as tractors may wish to use this corridor, being in a rural area and the restricted width and shoulder may cause safety issues.

7.5 Local road and private access As the new bridge alignment is very similar to existing, local access will remain largely the same as existing. Local road access onto Whangaroa Road from SH10 will be improved through the construction of the roundabout intersection including lighting and compliant sight distances. All lighting will meet the Far North District Council Engineering Standards 2009 Section 3.3.2 (NZS 6701) and as set out in Austroads4. A Safety audit of the intersection is to be undertaken during the Preliminary and Detailed design of the project.

7.6 Resilience The introduction of a two-lane bridge at Kaeo will improve the resilience of the network in the event of a collision. 4 collisions were recorded at the intersection with Whangaroa Road and 2 head-on collisions on the bridge, each of which are likely to have resulted in a road closure. The improvements to safety listed in section 7.3 are expected to reduce the frequency of collisions. The increased shoulder width and two-lane bridge will provide space in the event of a collision, to provide temporary traffic management past the event, to maintain access along the corridor.

7.7 Construction traffic Construction will generally be undertaken offline. Traffic will result in a temporary increase of vehicles crossing SH10. However, the traffic flows along SH10 are of a volume to consider that the number of construction vehicles will not cause issues to the capacity of SH10. It is recommended that a CTMP will form part of the conditions of consent for this development to safely and efficiently manage access. All construction activities will be managed under this plan including all temporary traffic management and diversions through the project and access to the site.

4 Austroads Guide to Traffic Engineering Practice, Part 12: Roadway Lighting

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8 Conclusions Based on our analysis, the proposal is an improvement to the existing bridge and intersection design. The proposed two-lane bridge, safety barriers, traffic lanes and shoulders, alignment, intersection design and lighting will bring safety benefits to the corridor and vehicle users. There are further details listed below that should be considered in the detailed design, including: Power line and poles be investigated to ensure visibility, clearance from the corridor and heights are appropriate; Review speed progression on approach to the project site and the new SH10 / Whangaroa Road roundabout. A CTMP to be implemented during construction to manage temporary effects of construction traffic.

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Appendices

Appendix A CAS Data

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