Noise Effects Assessment · PDF fileRec9 Wilson Parks Peak Station . ... This document may not...

RUATANIWHA WATER STORAGE SCHEME

Noise Effects Assessment

Rp001 R07 2011549W

FINAL

May 2013

Level 2 Exchange Place

5 Willeston Street

PO Box 25442

Panama Street

Wellington 6146 New Zealand

T: +64 4 499 3016 F: +64 4 472 1493

www.marshallday.com

Project: RUATANIWHA WATER STORAGE SCHEME

Prepared for: Hawke's Bay Regional Investment Company Limited Private Bag 6006 Napier 4142

Attention: Graeme Hansen

Report No.: Rp001 R07 2011549W

Disclaimer

Reports produced by Marshall Day Acoustics Limited are prepared based on the Client’s objective and are based on a specific scope, conditions and limitations, as agreed between Marshall Day Acoustics and the Client. Information and/or report(s) prepared by Marshall Day Acoustics may not be suitable for uses other than the original intended objective. No parties other than the Client should use any information and/or report(s) without first conferring with Marshall Day Acoustics.

Copyright

The concepts and information contained in this document are the property of Marshall Day Acoustics Limited. Use or copying of this document in whole or in part without the written permission of Marshall Day Acoustics constitutes an infringement of copyright. Information shall not be assigned to a third party without prior consent.

Document control

Status: Rev: Comments Date: Author: Reviewer:

Draft 00 2 Feb 2012 M Halstead

Draft 2 01 17 Feb 2012 M Halstead

Draft 3 02 For review 13 July 2012 M Halstead C Wassilieff

Draft 4 03 For review 16 July 2012 M Halstead C Wassilieff

Draft 5 04 For review 1 Mar 2013 M Halstead C Wassilieff

Draft 6 05 For review 7 Mar 2013 M Halstead C Wassilieff

Final Draft 06 For review May 2013 M Halstead C Wassilieff

Final 07 For issue May 2013 M Halstead C Wassilieff

This document may not be reproduced in full or in part without the written consent of Marshall Day Acoustics Limited

Y:\Project\2011\2011549W - Ruataniwha Water Storage Scheme\Docs Out\Rp001 R07 2011549W mmh Ruataniwha Noise Effects Assessment Final.doc

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EXECUTIVE SUMMARY

The Ruataniwha Water Storage Scheme comprises very significant earthworks and construction activity in and around the Makaroro River. Significant amounts of noise will be produced over approximately a 4-1/2 year construction timeframe. This report considers the noise sources, reviews the standards and assessment methods for evaluating noise effects, presents predicted noise levels from the activity, and recommends mitigations to avoid, remedy or mitigate noise effects.

Potential Scheme Effects

The noise effects which are expected to arise from the proposed water storage scheme are almost entirely related to construction activities. These include construction of access roads, excavation and transport of aggregate, placement of aggregate and spoil, blasting, concrete batching and placement, and site reinstatement. This will occur in the vicinity of the proposed dam site and to a much lesser extent near the water intake site and along the water distribution network. These sites are generally at large distances from dwellings.

The noise effects from the operation of the water storage scheme will be very limited, and will generally consist of a modification of natural noises rather than introduction of man-made noise.

The Beach Nourishment Scheme has potential noise effects associated with the transport and deposition of sediment.

Assessment Undertaken

This assessment of noise effects has been made by comparing predicted noise levels from construction activities to the applicable noise standards, including district plan noise limits and the Construction Noise standard (NZS6803:1999).

Noise predictions have been made on the basis of typical construction machinery sound power levels, with geometry and duration as described in the Tonkin & Taylor Project Description document (Tonkin & Taylor May 2013a). Noise is predicted using the ISO9613-2 Industrial Noise Model, implemented in SoundPLAN software.

Results of Assessments

Construction noise levels are predicted to comply with daytime construction noise limits in NZS6803:1999 at all dwellings, and night-time construction limits at most dwellings.

The noise effects at all dwellings are considered to be reasonable provided that adequate consideration of night-time noise mitigation at near dwellings Rec 6, 7 and 9 is taken into



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account during certain specific periods of construction. This may require limiting activities at night-time, or providing some other means of mitigation to the residents of those dwellings.

The noise levels in the working rural environment are considered to be reasonable, and are not predicted to have adverse effects.

The noise level and character of the ongoing operation of the water storage scheme are consistent with the expectations of rural land near a water course, and no adverse noise effects are predicted.

Noise effects from the Beach Nourishment Scheme are predicted to be minor or less than minor, except along the residential portion of Haumoana and Domain Roads where noise effects from truck traffic may be significant for a (likely) one-week period each year. We would consider this noise effect reasonable given its short duration, and relative to noise levels provided for in NZS6803:1999.

Suggested Approach for Effects Identified

Our recommendation to address construction noise issues in a construction noise management plan has been implemented by the applicant in the Construction Environmental Management Plan (CEMP). In my opinion the CEMP will ensure that construction activities are carried out in a manner which avoids unreasonable noise emissions, and which ensures that adverse noise effects are appropriately mitigated at the three dwellings identified as well as at any noise sensitive locations which are found to be affected near the headrace construction. The CEMP will also provide a means for good communication with the community and a pathway for feedback to the project team regarding noise concerns.

With this CEMP, adverse noise effects will be avoided or appropriately mitigated.



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TABLE OF CONTENTS

1.0 INTRODUCTION ........................................................................................................................ 7

2.0 PROPOSED DEVELOPMENT ..................................................................................................... 7

2.1 Noise Sensitive Activities ......................................................................................................... 8

2.2 Existing Noise Environment ................................................................................................... 11

3.0 NOISE STANDARDS ................................................................................................................. 11

3.1 District Plan Noise Limits ....................................................................................................... 12

3.2 Construction Noise Standard ................................................................................................. 12

4.0 CONSTRUCTION NOISE .......................................................................................................... 13

4.1 Activities .................................................................................................................................. 13

4.1.1 Road Upgrade and Construction ........................................................................................... 13

4.1.2 Excavation of Aggregate ........................................................................................................ 15

4.1.3 Batching and Screening .......................................................................................................... 17

4.1.4 Spoil Disposal .......................................................................................................................... 18

4.1.5 Diversion channel and tunnel construction, dam construction.......................................... 20

4.1.6 Blasting .................................................................................................................................... 23

4.1.7 Intake Site Construction ......................................................................................................... 23

4.1.8 Water Distribution Network construction ........................................................................... 24

4.1.9 HCV and worker vehicle movements on public roads ......................................................... 24

4.2 Noise Predictions .................................................................................................................... 24

4.2.1 Road Upgrade and Construction ........................................................................................... 24

4.2.2 Excavation of Aggregate ........................................................................................................ 24

4.2.3 Batching/Screening ................................................................................................................ 25

4.2.4 Spoil Disposal .......................................................................................................................... 25

4.2.5 Diversion channel and tunnel construction, dam construction.......................................... 25

4.2.6 Upstream Water Intake Site Construction ........................................................................... 27

4.2.7 Downstream Water Intake Site Construction ...................................................................... 29

4.2.8 Water Distribution Network construction ........................................................................... 30

4.3 Noise Effects ........................................................................................................................... 31

4.3.1 Road Construction Noise Effects ........................................................................................... 31

4.3.2 Dam and Intake Construction ................................................................................................ 31

4.3.3 Water Distribution Network Construction ........................................................................... 32

4.3.4 Public Road Traffic Noise ....................................................................................................... 32

5.0 OPERATIONAL NOISE ............................................................................................................. 33

5.1 Water Spill Noise .................................................................................................................... 33

5.2 Hydroelectric Turbines ........................................................................................................... 33

6.0 BEACH NOURISHMENT .......................................................................................................... 34



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6.1 Activity Description ................................................................................................................ 34

6.2 Material Extraction Noise ...................................................................................................... 34

6.3 Material Transportation Noise .............................................................................................. 34

6.4 Deposit and Spreading of Material ....................................................................................... 35

6.5 Noise Effects ........................................................................................................................... 35

7.0 CONCLUSIONS AND RECOMMENDATIONS .......................................................................... 37



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1.0 INTRODUCTION

The Ruataniwha Water Storage Scheme has been described elsewhere in the application for resource consent. Marshall Day Acoustics has been engaged to consider the noise effects which may arise from the construction and operation of the Scheme.

This report describes the noise-producing aspects of the construction and operation, predicts the noise levels which will be produced, considers the appropriate context for the assessment of noise, and presents conclusions regarding compliance with appropriate noise standards and an assessment of noise effects which arise.

The Application Design on which this report is based is described in the Tonkin & Taylor report Ruataniwha Water Storage Scheme: Project Description, May 2013 (Tonkin & Taylor May 2013a).

2.0 PROPOSED DEVELOPMENT

The project involves the construction of a dam with associated diversion and spillway structures. Hydroelectric generation turbines will be included in the dam. Two water intake structures will be built, one located downstream from the dam to feed the water distribution network in Zones A, B, C and D; and the second to feed water into the Zone M water distribution network.

Construction of the project will produce noise related to the following activities:

Road upgrade and construction;

Excavation of aggregate;

Aggregate screening and concrete batching;

Spoil disposal;

Diversion channel and dam construction;

Intake site construction;

Headrace construction; and

HCV vehicle movements on public roads.

Operation of the project will produce noise related to the following activities:

Water spill;

Hydroelectric turbine operation;



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2.1 Noise Sensitive Activities

The effects of noise are most critically assessed at dwellings, schools, and other locations where residential activities occur. The rural working environment is generally considered to be less sensitive to noise, as rural working activities themselves are often significant sources of noise.

Dwellings within the Rural Zone are protected by the District Plan within a “notional boundary” which is defined in the noise standards as a boundary 20 metres from the exterior of a dwelling.

We have identified dwellings or other noise sensitive locations near the Dam construction site as shown in Figure 1, and described in Table 1.

Table 1—Dwellings near Dam Site

Dwelling Owner Comments Rec1 JL Worsnop Rangimarie Farm House Rec2 JL Worsnop Rangimarie Farm House Rec3 RB Chrystall Trust Rec4 Dept of Conservation Rec5 Camp Wakarara Camp Building Rec6 RB Chrystall Trust Rec7 BC Preston Rec8 BC Preston Rec9 Wilson Parks Peak Station



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Figure 2—Dwellings near Dam Site



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Dwellings identified near the Upstream Water Intake Site are shown in Figure 3, and described in Table 2.

Table 2—Dwellings near Intake Site

Dwelling Owner Comments Intake Dwelling 1 JL Nash Mowbray Intake Dwelling 2 RB Chrystall Trust Intake Dwelling 3 DJ Holden Springvale Station Intake Dwelling 4 P & W Butler Nga Maunga Intake Dwelling 5 Whitiaaiki Farm Ltd

Figure 3—Dwellings near Intake Site



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2.2 Existing Noise Environment

We have visited the site where the proposed dam is to be built, and the intake and general water distribution network areas.

The land affected by the proposed works is rural in character, and generally supports farming activity. The ambient noise environment near the river is dominated by river flow, with sound levels varying with distance from the river, with flow rates, and with the character of intervening terrain at any given listening point.

Traffic flows are generally low and are not significant contributors to the noise environment in the vicinity of dam and intake construction areas. Traffic noise levels in the general area of water distribution network corridor may be more significant, however are still sufficiently low to be intermittent events rather than producing a steady traffic noise.

The noise environment near dwellings is dominated by farming and residential activities, and by wind and animal noise. Long term noise levels have not been measured at these areas, but we have made short-term measurements to verify that ambient sound levels are typical of rural areas, and lie in the range of 35 – 55 dBA over varying weather conditions.

The noise environment we observed during our visits does not, in our opinion, warrant any modification to the recommended noise limits which would be applied either by the District Plan noise limits or those recommended by the Construction Noise Standard.

3.0 NOISE STANDARDS

Noise emissions at the properties concerned are controlled by the Central Hawke’s Bay District Plan. The District Plan refers to the following New Zealand Standards (NZS) with regards to methods of measurement and assessment of sound or noise:

NZS 6801:1991 Measurement of Sound;

NZS 6802:1991 Assessment of Environmental Sound;

NZS 6803P:1984 The Measurement and Assessment of Noise from Construction, Maintenance and Demolition Work;

The District Plan also advises that any subsequent amendments to these standards may be referenced. When assessing noise from permitted activities this provision should be regarded with caution, as changes to the standards may have the effect of changing noise rules without appropriate consultation.

When applying these standards in a resource consent, it is reasonable to consider the most up-to-date versions. NZS6801 and NZS6802 have been revised in 2008, and NZS6803 was most recently revised in 1999.



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3.1 District Plan Noise Limits

The noise limits which are used in an assessment of noise using NZS 6801 and 6802 for measuring and assessing noise from permitted activities in the Rural Zone are given in the District Plan, section 4.9.11:

4.9.11 Noise

On any site, activities, , shall be conducted such that the following noise levels are not exceeded at nor within the notional boundary of any residential unit, other than residential units on the same site as the activity:

55dBA L10 - 6:00am - 11.00pm Monday to Saturday

45dBA L10 - at all other times

75dBA Lmax - at all other times

3.2 Construction Noise Standard

Limits on Construction Noise, and methods for its measurement and assessment are controlled by NZS6803:1999 in the District Plan. The relevant limits for projects of long duration are as follows:

Table 3 -- New Zealand Standard 6803:1999 Recommended Upper Limits (dBA) for Levels of Construction Work Noise Received in Dwellings in Rural Areas—Long Term Project Duration

Period Noise Level (dBA)

Weekdays Saturdays Sundays and Public

Holidays

Leq Lmax Leq Lmax Leq Lmax

0630-0730 55 75 45 75 45 75

0730-1800 70 85 70 85 55 85

1800-2000 65 80 45 75 45 75

2000-0630 45 75 45 75 45 75

These limits are applied at dwellings or other buildings which may be affected by construction noise, including workplaces.



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4.0 CONSTRUCTION NOISE

The construction programme is expected to take 4-1/2 years from the time the contract is awarded. Construction will occur within the river, along the river terraces, along the headrace and pipeline corridors, and along road access corridors.

4.1 Activities

Noise will be produced by a number of activities, which are described in the following sections. The assumptions of intensity, location, and sound power level are described in this section. The resulting noise levels and noise effects will be described in subsequent sections.

4.1.1 Road Upgrade and Construction

In the preparation of construction of the dam, roads will be upgraded and constructed to provide access to the site, and to provide access between the material extraction, spoil, and dam sites within the construction site. Additionally, a road will be constructed to replace internal access to the farm, replacing a road which will be inundated following the dam construction.

These activities will generally occur in areas as shown in Figure 4.



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Figure 4—Road Upgrade and Construction Sites

Road construction equipment will likely consist of a unit of equipment with sound power levels as follows:

Table 4—Road construction equipment sound power levels

Sound Power Level, dB re 10-12 W

Octave Band Frequency (Hz): A 63 125 250 500 1000 2000 4000 Bulldozer/Scraper 113 117 111 105 109 106 105 105 Loader 110 114 115 108 106 105 103 97 Offroad Dump Truck 111 97 104 112 109 106 100 95 Road-going Truck 98 98 98 96 95 94 90 85 Total Road Construction Package

116 119 117 114 113 111 108 106



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This activity will generally occur at distances of 1000 metres or more from dwellings, will briefly draw as near as 50 metres from dwelling Rec 7, 250 metres from Rec 6, and 200 metres from Rec 9 (see Figure 2 above).

4.1.2 Excavation of Aggregate

Aggregate will be extracted from several borrow areas, including the bed of the river upstream from the dam site. This material will be extracted using bulldozers and excavators, and transported to the dam site using off-road dump trucks. At some locations blasting may be used (as managed in accordance with the CEMP, see CEMP Section 4.5.6).

We have assumed that three such units may be operating within the general area of a given borrow area at one time. The distance between working faces within the pit are likely to be small relative to the distance to the nearest noise sensitive location, so it is reasonable to use the aggregate sound power level of this equipment as a single noise source in these predictions.

We have not taken into account shielding of the excavation activity by the working faces, as this will vary significantly over the course of operation.




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Figure 5—Aggregate Extraction Sites

The sound power level used to predict noise levels from extraction activities is as follows:

Table 5—Aggregate Extraction equipment sound power levels


Octave Band Frequency (Hz): A 63 125 250 500 1000 2000 4000 Bulldozer x 3 118 122 116 111 115 111 110 110 Excavator x 3 112 118 125 112 104 103 99 95 Offroad Dump Truck x 3 116 102 109 117 114 111 105 100 Total Aggregate Extraction Package

121 123 126 119 118 114 111 111

Aggregate extraction in the areas identified in Figure 5 above will occur at distances greater than 1300 metres from the nearest dwellings, except that the Alternate Gravel Borrow Zone 2B is 250m from Rec 9 at its closest point.



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4.1.3 Batching and Screening

Aggregate will be processed at areas near the material extraction locations. Processing will include screening of aggregate and batching of concrete.

In our modelling we have assumed that batching and screening will occur at all three proposed sites, and at each site have used the aggregate sound power level of typical batching and screening equipment as a single noise source in these predictions.


Figure 6—Potential Batching/Screening Sites

The sound power level used to predict noise levels from batching/screening activities is as follows:



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Table 6—Batching/Screening equipment sound power levels


Octave Band Frequency (Hz): A 63 125 250 500 1000 2000 4000 Total Batching Screening Package

113 116 117 110 108 108 106 101

Batching/Screening in the areas identified in Figure 7 above will occur at distances greater than 500 metres from the nearest dwellings, except at Rec 9 where the screening/batching site could be placed as close as 250 metres to the dwelling.

4.1.4 Spoil Disposal

Spoil will potentially be deposited at several sites which lie to the west and east of the dam location. This material will be transported to these sites using off-road dump trucks and processed with a bulldozer and compactor. We have assumed that one such unit may be operating within the general area of a given spoil deposit area at one time.

We have not taken into account shielding of the spoil deposit activity by the terrain, as this will vary significantly over the course of operation.




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Figure 7—Spoil Disposal Sites

The sound power level used to predict noise levels from spoil deposit activities is as follows:

Table 7—Aggregate Extraction equipment sound power levels


Octave Band Frequency (Hz): A 63 125 250 500 1000 2000 4000 Bulldozer 113 117 111 106 110 106 105 105 Compactor 114 123 114 111 109 105 109 104 Offroad Dump Truck 111 97 104 112 109 106 100 95 Total Aggregate Extraction Package

118 124 116 115 114 110 111 108

Soil Disposal in the areas identified in Figure 7 above will occur at distances greater than 600 metres from the nearest dwellings.



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4.1.5 Diversion channel and tunnel construction, dam construction

Construction at the dam site will include dump trucks importing aggregate along haul roads from the excavation sites, truck and trailer units importing steel, cement and other materials along access roads, blasting for tunnel construction, rock crushing, concrete batching, excavators, scrapers, graders and tractors. Additionally hand tools such as hammers and grinders will be used.


Figure 8—Dam Construction Site

At the peak of dam construction we have estimated that aggregate movements could be as high as 17 trucks per hour. We have modelled this activity as a line noise source along the indicated haul road between the gravel borrow area and the dam site. Over the more typical portions of construction movements are likely to be around 4 - 5 trucks per hour; however



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we have used the peak construction intensity for calculating the contribution of vehicle movement noise.

These activities will generally occur along the path shown in Figure 9.

Figure 9—Haul Roads

The assumed sound power level for each truck which travels on this path is as follows:

Table 8—Offroad Dump Truck sound power levels


Octave Band Frequency (Hz): A 63 125 250 500 1000 2000 4000 Offroad Dump Truck 111 97 104 112 109 106 100 95



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At the peak of dam construction regular deliveries of material are intended. We have modelled these as typical on-road truck and trailer units, and assumed four deliveries per hour at peak construction. We have modelled this activity as a line noise source along the indicated site access road between the Wakarara Road and the dam site. We understand that during an average day of construction the actual number of vehicle movements would be lower. These activities will generally occur along the path shown in Figure 10.

Figure 10—Site Access Road

The assumed sound power level for each truck which travels this path is as follows:

Table 9—On-road Truck sound power levels


Octave Band Frequency (Hz): A 63 125 250 500 1000 2000 4000 On-Road Truck s 105 116 100 97 99 100 99 95



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The plant operating at the Dam site (also for the construction of the spillway and diversion channels) is as follows.

Table 10—Dam Works equipment sound power levels


Octave Band Frequency (Hz): A 63 125 250 500 1000 2000 4000 Bulldozer/Scraper x 3 118 122 116 111 115 111 110 110 Compactor x 3 119 128 119 116 114 110 114 109 Offroad Dump Truck x 3 116 102 109 117 114 111 105 100 Concrete Batching Plant 114 102 109 112 111 107 106 105 Rock Crushing Plant 122 118 121 124 121 112 112 107 Chipping Hammers x 3 111 76 83 84 85 84 83 87 Total Dam Works Package 126 129 124 126 123 117 118 114

For modelling purposes this sound power has been divided equally into two sources at each side of the dam, and modelled 50 metres above current ground level to consider the propagation condition which occurs as the dam height is built up.

4.1.6 Blasting

Blasting is expected to be required, particularly in the construction of the diversion tunnel construction. Blasting is controlled by reference in NZS6803:1999 to Australian Standard 2187:Part 2, which requires that good blasting practice be employed to limit impulsive noise and vibration. Section 4.5.6 of the CEMP is considered to be consistent with this.

4.1.7 Intake Site Construction

Works at the Intake Sites will likely include excavation and placement of material, and importing of construction items. We have assumed that at the peak of activity noise output will be dominated by one bulldozer, one excavator, one compactor, one off-road dump truck and one road-going truck.

The sound power level used to predict noise levels from Intake site activities is as follows:

Table 11—Intake Site equipment sound power levels


Octave Band Frequency (Hz): A 63 125 250 500 1000 2000 4000 Bulldozer 113 117 111 106 110 106 105 105 Excavator 107 113 120 107 99 98 94 90 Compactor 114 123 114 111 109 105 109 104 Offroad Dump Truck 111 97 104 112 109 106 100 95 On-road Truck 105 116 100 97 99 100 99 95 Total Intake Site Construction Package

118 125 121 116 114 111 111 108

Construction at the Intake Sites will occur at distances greater than 1500 metres from the nearest dwellings.



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4.1.8 Water Distribution Network construction

Table 12— Water Distribution Network equipment sound power levels


Octave Band Frequency (Hz): A 63 125 250 500 1000 2000 4000 Bulldozer 113 117 111 106 110 106 105 105 Excavator 107 113 120 107 99 98 94 90 Grader 110 100 108 108 106 105 103 100 On-road Truck 105 116 100 97 99 100 99 95 Total WDN Construction Package

116 120 121 112 112 109 108 107

4.1.9 HCV and worker vehicle movements on public roads

The project will cause an increase in the number of Heavy Commercial Vehicles (HCV) on public roads. While noise from such vehicle movements is not controlled, the noise effects which arise may be considered as part of the overall project effects.

4.2 Noise Predictions

4.2.1 Road Upgrade and Construction

Road upgrade and construction will occur as an initial construction activity, at distances typically of 1000 metres or greater. At 1000 metres, the predicted noise level during road construction is 40 dB LAeq.

At dwelling Rec 7 (near the intersection of the new access road and Wakarara Road), road upgrade and construction will occur as near as 50 metres to the dwelling for a brief period of the order of several days, and is predicted to reach 70 dB LAeq during this time. As construction moves to more distant portions of the access road the noise level will diminish.

At dwelling Rec 6 (across Wakarara Road from the intersection of the access road), noise levels would reach 55 dB LAeq as construction approaches the intersection.

At dwelling Rec 9 (near the gravel borrow area 2B), road upgrade and construction will occur as near as 200 metres to the dwelling, and is predicted to reach 47 dB LAeq during this time.

4.2.2 Excavation of Aggregate

Aggregate extraction will occur as part of the general construction activity in the vicinity of the dam site, and will generally occur at distances greater than 1300 metres from dwellings.

At 1300 metres, the predicted sound level from this activity alone is 41 dB LAeq without taking into account terrain screening. With the screening effect of the terrain, the level of aggregate extraction is 31 dBA or less.

At dwelling Rec 9, the Alternate Gravel Borrow Area 2B lies as close as 250 metres to the dwelling. When excavation activity occurs at this nearest point, the predicted sound level at Rec 9 is 52 dBA LAeq. We note that this Borrow Area is long and slender, and most extraction



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activity would occur at significantly greater distances than the worst-case point 250 m from the dwelling, generally resulting in noise levels of less than 45 dBA LAeq at Rec 9.

4.2.3 Batching/Screening

Batching and Screening would generally occur at distances of greater than 500 metres from dwellings. At this distance, and ignoring terrain shielding, the predicted sound level is 45 dB LAeq. With terrain screening, the maximum noise level from Batching Screening at dwellings aside from Rec 9 is 33 dB LAeq.

At Rec 9, the Gravel Borrow Area 2B batching/screening plant may be located as close as 250 metres from the dwelling. The predicted sound level without terrain screening is 51 dB LAeq; with terrain screening the predicted level is 41 dB LAeq.

4.2.4 Spoil Disposal

Soil Disposal will occur as part of the general construction activity in the vicinity of the dam site, and will generally occur at distances greater than 600 metres from dwellings.

At 600 metres, the predicted sound level from this activity alone (ignoring terrain shielding) is 46 dB LAeq. Taking terrain into effect, the maximum noise level from Spoil Disposal across the nearest dwellings is predicted to be 38 dBA LAeq.

4.2.5 Diversion channel and tunnel construction, dam construction

Construction activities at the dam site, for both construction of the diversion works and the dam and embankment, will generally run concurrently with excavation and spoil disposal. The total noise level predicted from all three of these activities (including material transport noise) is shown in Figure 11. This noise contour includes the effects of terrain attenuation (assuming excavation at the present ground level, and dam construction 50 metres above the present ground level.



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Figure 11—Dam Site Noise Prediction



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The predicted noise level for peak construction activities at the dwellings as illustrated in Figure 11 are shown in Table 13.

Table 13—Predicted Dam Construction Noise Levels at Dwellings

Dwelling dB LAeq Rec 1 38 Rec 2 39 Rec 3 41 Rec 4 42 Rec 5 42 Rec 6 43 Rec 7 44 Rec 8 38 Rec 9 53

Note that the above table does not include the short-term road construction noise which may occur, particularly at Rec 7 and Rec 9 where the peak level as described in Section 4.2.1 is predicted to be 70 dB LAeq and 47 dB LAeq respectively for a short period.

4.2.6 Upstream Water Intake Site Construction

Construction at the Upstream Water Intake Site will occur at distances greater than 1800 metres from nearest dwellings.

The predicted noise level for the area surrounding the Upstream Water Intake Site construction works is illustrated in Figure 12.


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Figure 12—Upstream Intake Site Noise Prediction



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The predicted noise level for peak construction activities at the dwellings as illustrated in Figure 12 are shown in Table 14.

Table 14—Predicted Upstream Intake Site Construction Noise Levels at Dwellings

Dwelling dB LAeq

Dwelling 1 29 Dwelling 2 29 Dwelling 3 24 Dwelling 4 24 Dwelling 5 28

4.2.7 Downstream Water Intake Site Construction

The nearest dwellings to the Downstream Water Intake Site are approximately 1.5 km away. The predicted construction noise level at this distance is approximately 31 dB LAeq, and will be lower at further dwellings.



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4.2.8 Water Distribution Network construction

Water Distribution Network (WDN) construction will occur along a corridor which is described in the Project Description. The proposed works generally lie at least 200 metres from identified dwellings, at which distance the predicted construction noise level is 55 dB LAeq.

If variations in this alignment occur as a result of site conditions, the following guidelines will be useful in assessing the requirement for any further management of construction noise.

At a distance of 50 metres from the site of the WDN construction, the predicted sound level is 70 dB LAeq. This assumes no shielding by terrain. Should there be a dwelling at this distance from construction, the daytime construction noise limits would be just met at that dwelling. At closer distances the limit is predicted to be exceeded.

At a distance of 600 metres from the site of the WDN construction, the predicted sound level is 45 dB LAeq. This assumes no shielding by terrain. Should there be a dwelling at this distance from construction, the night-time construction noise limit would be just met at that dwelling. At closer distances the limit is predicted to be exceeded.

Table 15 lists the predicted noise level at various distances from the point of construction of the WDN, assuming no terrain attenuation.

Table 15—Predicted Noise Level vs. Distance from WDN Construction

Distance (m) dB LAeq

50 70 100 64 200 58 300 53 400 50 500 48 600 45

1000 39



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4.3 Noise Effects

Noise effects in the rural zone would arise as a result of noise impacts at dwellings. Noise levels in the rural working environment are not controlled by the district plan. It is generally accepted that the rural working environment is considered differently from the areas near dwellings, and it is expected that activities with elevated noise levels occur as a result of rural activities.

4.3.1 Road Construction Noise Effects

The predicted noise levels for short-term road construction activities is predicted to be generally less than 40 dB LAeq at dwellings, although for a brief period at Rec 7 noise may reach 70 dB LAeq, 55 dB LAeq at Rec 6, and 47 dB LAeq at Rec 9.

At all dwellings the noise level of road construction is predicted to comply with daytime construction noise limits (70 dB LAeq, as described in Table 3).

At dwellings Rec 6 and Rec 9, road construction noise is predicted to exceed night-time and Sunday/Public Holiday noise limits (45 dB LAeq). At dwelling Rec 7, construction at the nearest point to the dwelling would comply with the noise limit only between 0730 and 1800 on Monday – Saturday.

At all other dwellings road construction noise levels would comply with night-time construction noise limits.

The predicted sound levels from construction activities at the intake site are less than the night-time construction noise limit of 45 dBA.

Using the rules in the District Plan and the limits in NZS6803 as guidelines, we conclude that the predicted road construction noise levels at dwellings is reasonable and would produce noise effects that are less than minor, provided that road construction is limited to appropriate hours when working near dwellings Rec 6, Rec 7, and Rec 9.

4.3.2 Dam and Intake Construction

The predicted levels of noise from all construction activities is predicted to be less than 45 dB LAeq, except near dwelling Rec 9 during Alternate Gravel Borrow activities at the northern-most extent of the Borrow Area.

With the exception of this particular Gravel Borrow activity, the construction noise standard would be met at all times on all days.

Using the rules in the District Plan and the limits in NZS6803 as guidelines, we conclude that the predicted construction noise levels at dwellings is reasonable and would produce noise effects that are less than minor, provided that Gravel Extraction is limited to appropriate hours when working at the closest point to dwelling Rec 9.



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4.3.3 Water Distribution Network Construction

The construction of the Water Distribution Network will produce noise at the site where construction is occurring, and whether this has significant noise effects will depend on the proximity of this corridor to dwellings or other noise sensitive locations.

The proposed alignment is predicted to produce 55 dB LAeq or less at dwellings which lie along the corridor. Construction noise limits are predicted to be met by this construction activity during daytime hours Monday – Saturday, and noise effects are predicted to be no more than minor.

Should the alignment be modified, the guidelines provided in Table 15 may be used to assist in the alignment of this corridor to avoid adverse noise effects, considering that noise levels of 70 dB LAeq would be acceptable for daytime construction of limited duration, and that levels of 45 dB LAeq would be considered acceptable for indefinite noise exposure at all hours in this Zone.

4.3.4 Public Road Traffic Noise

Noise from trucks on the public road is not directly controlled by the Construction Noise standards. However additional road traffic caused by the construction activity is considered a construction effect.

A significant increase in trucks along Wakarara Road is expected to occur, as sand, fly ash, cement, steel, manufactured components, and machinery are required to be delivered to the site.

It is anticipated that these deliveries will occur during daytime hours. The potential for noise effects is limited to dwellings located very near to the public road (within about 15 metres). We have identified one such dwelling near McLeod Road where noise effects should be considered within the Construction Noise Management Plan.

In our opinion noise effects from trucks on the public road will be no more than minor provided deliveries are constrained to daytime hours excluding Sunday and public holidays.



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5.0 OPERATIONAL NOISE

Noise from the operation of the water collection scheme is considered in this section.

5.1 Water Spill Noise

The primary modification to the long-term environment caused by the operation of the water collection scheme is replacement of distributed noise from running water in the river corridor, by noise which is at times somewhat more intense at the spillway, and a greatly reduced noise level in the inundated areas.

The general character of water flow noise will be similar, and in our experience is generally accepted as a “natural noise”.

5.2 Hydroelectric Turbines

The optional installation of electricity generating turbines is not expected to significantly alter the noise emissions from the dam/spillway. The mechanical components of the turbines are to be housed such that noise emissions are mostly contained, and in our experience noise from such installations which does escape to the environment is masked by the sound of water in the spillway.

The typical sound levels measured in the vicinity of such an arrangement are around 50 dB LAeq at a distance of 100 metres. At the closest dwellings for this project, this noise level would be insignificant. In the rural working environment this noise level would be significantly less than that which would be considered to cause an adverse noise effect. The character of the noise would not be out of context for rural land near a water course.



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6.0 BEACH NOURISHMENT

Noise effects from the Beach Nourishment Scheme, as described in the Project Description, section 8, has been assessed. The potential noise sources include gravel extraction, gravel transport, and deposition at the beach locations.

6.1 Activity Description

Approximately 3400 m3 of river sediment will be deposited each year, in a process likely to occur over a one-week period. Half of this material would be moved by truck to the Richmond Road beach access, and spread along a portion of the beach between Richmond Road and the Conservation Area at the river mouth. The other half of the material would be transported to the beach south of the Conservation Area via Domain Road, and deposited along the spit for spreading along the beach site.

6.2 Material Extraction Noise

Material would be removed by excavator, working in the river bed between Tennant Road and Black Bridge. This extraction comprises part of the HBRC annual gravel allocation process. As this extraction is consented independently, and the proposal does not increase the scale of this activity, the noise effects of material extraction are not relevant to this application.

6.3 Material Transportation Noise

Material will be transported from the river bed extraction area shown in Tonkin & Taylor May2013a. While this activity would already occur as part of the existing annual gravel allocation process, the Beach Nourishment Scheme utilizing material from the gravel extraction area would cause a relatively high intensity of truck traffic along the chosen route for the (likely ) one-week period each year. While the intensity of effect over a longer period would be reduced, a one week period is conservatively applied in this assessment as I understand it to be feasible, and it may be easier and more efficient to manage the process in that way in practical terms.

The proposed material transport would involve approximately 280 return trips during the week, divided equally between the two indicated truck routes, and as required to be used by proposed consent conditions. This is approximately 4 round trips per hour on each route, or a truck pass roughly every 7 minutes.

Along the Tennant Road / Tuki Tuki Road / Haumoana Road route feeding the South beach access, the majority of the trip follows a 100km/h highway, with rural dwellings located around 40 metres from the carriageway. From traffic data available on the HDC website we have calculated that the traffic noise level would increase approximately 1 decibel during this operation. This represents a less-than-minor noise effect at these properties, and remains characteristic of the existing road environment.



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Along the latter part of the Haumoana Road route, feeding into the Domain Road beach spit access, the road fronts a number of dwellings in a residential setting. Typical setbacks are 6 – 12 metres between the road and dwelling facades. The predicted noise level from truck traffic is 60 - 65 dB LAeq(15min) at these dwellings. We anticipate that the noise impact of the week’s truck activity would produce a significant noise effect, although one which would be acceptable due to its short duration, and relative to noise levels provided for in NZS6803:1999 (as discussed below).

Along the Lawn Road / Grey Street / Richmond Road route feeding the North beach access, the trip generally follows a smaller rural road. The dwellings along this route are generally rural in character, with larger setbacks from the road. As with the South beach access road we have not carried out a site visit or noise measurements, but have calculated that the traffic noise level would increase by approximately 3 decibels during this operation. This represents a minor noise effect. The nearest activity to the deposition site is the Hastings Wastewater Treatment plant.

6.4 Deposit and Spreading of Material

Material is to be spread on the two Beach sites using a bulldozer. At both deposit locations, the spread sites appear to be shielded from view of beach front dwellings by a bund with an effective height of around 4 metres. We would expect this to provide significant noise reduction (typically around 10 decibels) in addition to the attenuation due to distance (approximately 100 metres) between the deposition areas and the nearest dwellings.

The predicted noise level of the dozer activity at the nearest dwellings is around 45 – 50 dB LAeq. This may be audible depending on sea conditions, but is likely to be typical of the ambient daytime level in this area, and would readily comply with the construction noise limit of 80 dB LAeq in NZS6803 Acoustics – Construction Noise at these dwellings.

In addition to sea noise, we understand there is presently vehicle noise from users of the beach, and from normal residential activity. We anticipate that noise effects from material deposition would be minor or less than minor.

6.5 Noise Effects

The proposed activity may produce some noise effects from the transport and deposition of sediment on the Beach locations.

The most significant noise effects would result from truck traffic delivering material to the South beach site, along the residential portion of Haumoana Road and Domain Road. Noise effects would be similar to a construction activity occurring at a neighbouring property. While noise from trucks on the road is not directly controlled by the Construction Noise standard, the predicted level of 60 – 65 dB LAeq is well within the construction noise limit for short term activities (the limit being 80 dB LAeq during daytime hours).

Minor or less than minor noise effects may arise at other locations, due to truck activity and material spreading.



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The activity is likely to occur for one week out of each year, and this would generally fit within the scope of short-term Construction and Maintenance Activities, for which elevated daytime noise levels are considered to be tolerable.

We would recommend that these activities occur during daytime hours on weekdays, and in particular that the transport of material along Haumoana Road and Domain Road not occur during early morning or evening periods.

We would recommend that all activities proceed with consideration for noise effects as recommended in New Zealand Standard 6803:1999 Acoustics - Construction Noise. This includes avoiding unnecessary noises (such as unnecessary truck idling within residential areas, use of unnecessary audible alarms or communications noise) and that machinery be maintained to a good standard to avoid unnecessary noise generation.

Good communications with residents on likely noise effects, and a channel of communication to discuss noise concerns is advised.



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7.0 CONCLUSIONS AND RECOMMENDATIONS

The noise effects which are expected to arise from the proposed water storage scheme are almost entirely related to construction activities.

The noise levels from initial road construction activities are predicted to comply with daytime construction noise limits at all dwellings, and night-time construction limits at all dwellings except Rec 6, 7 and 9.

The noise levels from Dam and Intake Site construction are predicted to comply with daytime construction noise limits at all dwellings, and night-time construction limits at all dwellings except Rec 9 during the operation of the northern-most end of the Gravel Extraction activity at the Borrow Area 2B.

The noise effects at all dwellings are considered to be reasonable provided that adequate consideration of night-time noise management at these locations is taken into account.

In the case of road construction, this is likely best addressed by restricting construction activities near dwellings to daytime hours.

In the case of the operation of Gravel Borrow Area 2B, extraction at the northern-most end of the area should be restricted to daytime hours.

Alternative mitigations may be acceptable if these are reached in discussion with the affected parties.

The noise levels in the working rural environment are considered to be reasonable, and will not have adverse effects.

Road traffic noise effects will be reasonable provided deliveries are made during daytime hours. If significant numbers of night-time heavy vehicle movements are necessary, consideration should be given to noise effects at dwellings within 15 metres of Wakarara Road.

The noise level and character of the ongoing operation of the water storage scheme are consistent with the expectations of rural land near a water course, and no adverse noise effects are predicted.

Noise effects from the Beach Nourishment Scheme are predicted to be minor or less than minor, except along the residential portion of Haumoana and Domain Roads where noise effects from truck traffic may be significant for a one-week period each year. We would consider this noise effect reasonable given its short duration, and relative to noise levels provided for in NZS6803:1999.

We have recommended that a Construction Noise Management Plan (CNMP) be prepared to ensure that construction activities are carried out in a manner which avoids unreasonable



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noise emissions, and which ensures that adverse noise effects are appropriately mitigated at Rec 6, 7 and 9, and any noise sensitive locations which are found to be affected near the water distribution network construction. The CNMP should also provide a means for good communication with the community and a pathway for feedback to the project team regarding noise concerns.

This has been implemented by the applicant in this Scheme by the preparation of a Construction Environmental Management Plan (CEMP) which incorporates the above recommendations. In my opinion, the draft CEMP I have reviewed meets these requirements.

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