File: N/3/11/11 Date: 13 June 1990

HUTT RIVER FLOOD CONTROL SCHEME

BANK PROTECTION IN THE VICINITY OF POMARE RAILBRIDGE

1. INTRODUCTION

High flood velocities, a steep river slope and a bend in the river combine to cause erosion of the river bed and true left berm in the vicinity of the Pomare Railway Bridge. Over recent years, short to medium return period floods have led to this erosion becoming of concern.

A large portion of the berm between the stopbank and the left river bank was removed during a flood in January 1980. The berm was subsequently reinstated and low-cost protection works undertaken (wooden groynes etc). Some damage to the protection was suffered in the May 1981 flood. Most recently, a fresh in September 1988 removed a significant portion of river berm and exposed a previously covered set of bridge piers (one of the three sets not repiled to below the potential scour level in the 1970s). This has left both the rail bridge subject to greater risk of pier failure and the stopbank more exposed to possible berm erosion.

While an immediate temporary response was made to this latest damage, it was recognised that an approach was needed that offered protection beyond the short-term future. This report attempts to develop such an approach. The report will define and discuss the problem, discuss options for overcoming the problem and conclude by recommending an option.

2. CURRENT SITUATION - ANALYSIS OF PROBLEM

Some general observations and preliminary conclusions can be made regarding the current situation and the "problem" can be made at this stage. It should be noted that the Hutt River Flood Control Scheme Review (HRFCSR) will address the situation in more detail than can be done or justified here. However it may be some years before any long term solution is found, authorised and implemented from the HRFCSR.

The Pomare Bridge is located over a meander, the outer bend of which cuts into the left river berm. Here normal flows are entrenched in a narrow channel, while flood flows also are directed at the left bank. Flood flows are then converged by the upstream rail embankment and finally constricted at the bridge abutment. Furthermore, backwater analysis indicates that average main channel flood velocities in the bridge vicinity could approach 4m/s. The left berm is composed of loose alluvium and is particularly vulnerable to such velocities, especially when steepened by continual erosion from normal flows.

The problem is exacerbated by the bridge piers, which create a disturbance to the flow, increasing the turbulence of the flow and causing local scour. (The bridge cross-section is significantly deeper than the upstream and downstream sections.)

The river bed at the site has also degraded. This degradation has steepened the adjacent banks, increasing their erosion potential. A riffle exists at the site, likely resulting from the degradation and possibly with a tendency to move upstream. Regardless, the riffle increases local velocities and further directs the flow towards the left berm.

An unsteady-state hydraulic model of the river, developed in a separate investigation, indicates that the left stopbank has freeboard at flows greater than 3000m3/s. However, the toe of the stopbank could fail if the berms were sufficiently eroded. Thus the attack of the river on the left bank at this location could have serious consequences for the bridge and the Hutt Valley.

3. APPROACHES TO THE PROBLEM

3..1 Short-Term Solutions

The immediate response to the 1988 flood damage was to crossblade river bed material above the bridge, from the right bank to the left bank, to deflect the main flow away from the exposed pier set and the eroded berm. However, the material is only loose gravel and can not be expected to withstand a flood. A temporary groyne was installed as well, using site gravels, concrete blocks and some rock.

Previous attempts to deal with the erosion have also involved mass filling of the eroded berm, crossblading, debris fencing and constructing light groynes. These attempts have afforded only short-term protection to the berm and have not properly addressed the situation at the apex of the bend in the river (where there is extra turbulence due to the bridge piers).

3..2 Medium-Term Solution

This report identifies and discusses options that will mitigate flood damage at the site in the medium-term future - that is, in the new few years. These options will involve preserving the existing channel bed and protecting the existing banks.

3..3 Need for a Long-Term Solution - HRFCSR

Any longer-term approach would need to be consistent with the outcome of the HRFCSR. The Review will investigate in depth hydrology, hydraulics, river mechanics, environmental, social, economic and risk issues, amongst others. The Review will also link with a wider-still Hutt Catchment Management Plan (HCMP). It is possible that the outcome of the HRFCSR and the HCMP will require that a medium-term solution at Pomare be modified or extended. Such a medium-term solution should therefore not limit future options.

4

ETERS AND CONSTRAINTS

and discussing possible options, it is useful to identify constraints.

od Control Scheme Review

sed above, any works should not restrict options that the HRFCSR suggest. The design of the works should also take into consideration

y findings of the HRFCSR.

Physical Limitations

The existing bridge presents a major restriction to the design: the river channel cannot be widened nor significantly realigned without extra work to the bridge. The stopbank and the adjacent High Street similarly restrict options. Construction of some works may also be hindered by the low clearance under the bridge.

i 4..3 Materials

Any materials used must be technically, visually and environmentally suitable for the site. Generally accepted materials for protection works include rock and vegetation. Concrete is another material that may be used, but it does not always meet technical and visual standards.

4..4 General Engineering Acceptance of Method

The method selected should be appropriate for gravel-bed rivers. (Many techniques used overseas are thus unsuitable). The method should also have some measure of recognised success under NZ conditions. Ideally, failures of each method should be noted and any records of the type of failures and their effects taken into consideration. General acceptance of a method by catchment authority engineers in NZ is a good guide to the suitability of the method.

4..5 Scour

Significant scour is possible at the site. The protections need to be founded below the maximum scour depth, or be flexible enough to settle into scoured bed.

4..6 Risk and Consequence of Failure

The design flood has been taken to be a 100 year return event. This allows the minimum velocities that the protections must withstand, to be estimated. (It is worth noting that these velocities would not be significantly reduced if a lesser return period flood was chosen.)

Selection of a 100 year event implies that the maximum acceptable probability of failure is 1% per year. If any longer-term approach selected from the HRFCSR takes five years to implement, then the probability that the protection would fail within this period is not more than approximately 5%.

However, the complexity of the causes of failure and the uncertainty associated with the variables involved are such that failure may occur with lesser floods. No solution will be 100% successful. Thus the consequences of failure in lesser floods need to be considered.

4..7 Environmental Considerations

The Hutt River is an important environmental feature of the Hutt Valley, indeed of the Wellington Region. Therefore the impacts of any works on the general environment, during and after construction, need to be considered. Specific aspect considerations include the visual impact of structure(s), ecological effects, habitat changes, chemicals from materials and recreational impacts. A related consideration is public safety; for example do the works pose a risk to children playing on, falling from or swimming around them?

4 . 3 Cost

It was noted above that the solution was to afford protection against a 100 year flood. A comparison of the costs of various methods to reach this level of protection needs to be made. Note that the existence of other constraints as discussed above implies that the least cost method will not necessarily be selected. However, the cost needs to be acceptable to the WRC.

6 7

5. OPTIONS

5..1.2 Structural Protection Charlton (1982) classifies protection methods into three categories: 8 ~ l t h o ~ g h not included in the discussion of bank armouring in the context of (1) Bank armouring, eg., riprap, concrete lining or mattress. fluvial erosion by Charlton, sheet piling could protect the banks if driven (2) Flow deflection, eg., vanes, sills, groynes, stub groynes. II sufficiently deep to avoid scour. Such so-called structural options can give a (3) Flow retardation, eg., downstream weir. more secure protection to the banks than other options. Two possibilities are

sheet-piled walls and diaphragm walls. 5..1 Bank Armouring rS. Charlton notes that it is difficult and expensive to drive sheet piling in gravel- Bank armouring is the process of increasing the bank strength to resist the bed rivers. Thus the amount of sheet piling should be minimised. This can erosive tendencies of the river. Forms of bank armouring that have been 1P be done if vegetation is used to protect the banks at higher levels and the used in New Zealand rivers include rock riprap, concrete rubble, willow length of sheet piling reduced by only using it over the most critical reach and planting, willow cabling, concrete mattresses or linings, debris fences, rail iron

II using riprap elsewhere. A major advantage of such an approach is that the

retards and gabion type structures. None of these methods have been amount of heavier rock required can be reduced. com~letely successful and failures are common. Currently favoured among catchment authorities are those methods using plant materials, due to

CI Similarly diaphragm walls are expensive and should be used here to reduce

comparatively low cost and rock riprap where stronger methods are required the need for heavy rock. and can be afforded. The other methods complete the range between cost and susceptibility to failure.

M Technical difficulties such as driving piles under the bridge and dewatering trenches would need to be overcome if a structural options was implemented.

5..1.1 Riprap These could add considerably to the cost.

Riprap lining of the river bank is a solution that has been used on other II Structural options could be less aesthetic than other options. Furthermore, sections of the Hutt River (eg., Upper Hutt By-pass). It is one of the more a high vertical wall could exist after scour; this could pose a danger to people. environmentally acceptable methods of river control and bank protection. In particular, it provides habitat for some aquatic life. a ~f the HRFCSR subsequently dictates that a structural solution for the

Pomare problem is not desirable, most of the cost of the Structure would not Crossblading would be needed to divert the river away from the bank while m be recoverable. construction was taking place. Thus some disruption to the river ecology would occur, but this crossblading would regularly be needed if no extra

5.2 Flow Retardance protection is given to the bank.

CI 5..2.1 Weir Ideally, greywacke rock would be used. This is chemically inert, sufficiently dense and free of failure surfaces. The flood velocities expected over the II A weir to locally control the bed level, slopes and velocities would be a study reach are high, however, and it may be difficult to obtain large enough structure across the total channel. The length would therefore be in the rock to withstand the flow. order of 100 to 150 metres. The weir would have to be founded deeply

CI enough to prevent undermining. Total concrete volumes could be in the The riprap can be constructed so as to fail in sections rather than as a whole. order of 2000 cubic metres ($1200 000). Thus failure can be controlled and limited to some degree. Subject to the availability of rock, maintenance is then a simple matter. However, the rate L1 Other materials may be used for the weir such as driven steel piles with heavy at which rock will need to be replaced cannot be predicted and so timber facings. To successfully utilise this method a series of weirs may be maintenance costs are unknown.

R needed.

Bank protection can be enhanced if debris fencing and planting is undertaken Protection work for the weir would be needed. At both banks riprap will be in conjunction with the riprap placement.

II required to prevent outflanking of the structure. Riprap may also be required

. . on the downstream side of the weir. Charlton (1982) notes that such extra The riprap can be retrieved should the HRFCSR decide that the alignment work may make a weir designed solely for bank protection u ~ ~ ~ ~ n o m i c . chosen here is not the optimum. ~ l l o w $30 000 for protection works. . -

A weir is likely to tr sediment supply downstream and induci our hole downstream. A weir is also likely to cause ecological disruptions and to be visually unappealing in the river landscape.

Flow Deflection

The principle of flow deflection is to separate the main flow from the bank being protected. The effect of the works, if successful, is to reduce the flow velocities along the bank and therefore reduce the tractive force. Commonly used forms of flow deflection include groynes and vanes.

5..3.1 Vanes

Vanes are vertical panels placed at slight angles to the main flow direction. Submerged vanes have been used successfully overseas to control secondary flow (ie., perpendicular to the main flow direction) characteristics in bends. Thus bank erosion in bends and aggradation or degradation downstream of the vane can be controlled.

Charlton (1982) suggests that vanes perform better in sand or fine gravel beds and does not recommend their use in gravel bed rivers. They are not a common means of protection in NZ.

5..3.2 Stub Groynes

Stub groynes (sometimes referred to as spurs) could be used in series to displace the high velocity river flow laterally away from the bank being protected. Williams (1982) states that the groynes should deflect flow with minimum disturbance to that flow.

Groynes have been used in the Hutt River in the past, although not of the size required at Pomare. Environmentally, groynes compare favourably with riprap in the context of the Hutt.

Suitably durable material to use would be rock, blanketing an earth core. As with riprap, a potential problem could obtain rock of sufficient size to withstand the high velocities expected over the reach of concern.

Groynes in a series could be constructed over a period of time as required, therefore spreading the capital expenditure over several years. In this case it is possible that only two groynes would be constructed in the first year.

Eddies tend to generate at the downstream end of a g rope and thus erosion between groynes is possible. For this reason an ASCE Taskforce recommended against their use in general (ASCE, 1972). However, Charlton states that such erosion can be avoided if the groynes are placed sufficiently close together.

Having groynes in series also means that failure of one groyne will not necessarily lead to total failure of the system. As with riprap, rock in a groyne can be readily replaced. Again, rock replacement and other maintenance costs cannot be predicted.

Should the HRFCSR eventually decide that the groynes are not needed, much of the rock can be retrieved and used elsewhere.

5..4 Summary

Of the above options, two can be eliminated at this stage. A weir is unsuitable on cost and environmental grounds, while vanes are not suitable in gravel-bed rivers. The remaining options - groynes, riprap and structural/riprap are discussed in further detail below.

DETAILED OPTION ASSESSMENT

The three feasible options identified in the previous section are now given greater consideration. These options must be reduced to a single recommended option. Preliminary designs have been completed for the options and are appended to this report. The following discussion summarises the designs, gives cost estimates for each and further deals with their relative advantages and disadvantages.

Riprap Revetment

Design

The riprap has been designed to blanket the edge of the left bank, following a transition curve from (1988) cross-sections 40 to 420 (see illustration, appendix). Fill would need to be placed to construct this curve. Debris fencing and planting would need to be undertaken to increase the integrity of the system.

Two gradings of rock would be used. The median rock of the heavier grading has an equivalent cubic dimension of 1250mm and is designed to protect against a local velocity of twice the mean main channel velocity. It would be used in the critical reach under the bridge and on a "kickoff' at the downstream end of the transition curve. (The kickoff is intended to deflect flow away from unprotected bank.) The volume of rock required in this grading is 3400m3.

The median rock of the lighter grading has an equivalent cubic dimension of 600mm and is designed to protect against a local velocity of 1.5 times the mean main channel velocity. It would be used for the remainder of the riprap. 4500m3 of rock is required for this grading.

The top level of the riprap has been taken to be at 0.5m below the annual flood. This is a somewhat arbitrary level, but should protect against the higher velocities in the channel. Extra riprap extends into the bank (1.5m and 2m for the lighter-grading and heavier-grading rock, respectively) to protect against erosion at this level, to key the riprap into the bank and to allow for slumping of the riprap further down the slope.

The batter is to be placed at a 2:l batter; the heavy rock being 2m thick and the light rock 1.2m.

The top of the toe (at the base of the riprap) has been assumed to be at the channel thalweg level. The toe is 2m deep in the case of the heavy rock and 1.5m for the light rock. In both cases the toe (or apron) is 3m wide. The toe provides rock to armour the bank should the base of the riprap suffer scour.

The heavy rock under the bridge is to be keyed in at each end, 10m into the bank. This allows the rock to stay in place should the adjacent lighter rock fail. Similarly the lighter rock is keyed in at the upstream and downstream ends of the transition curve, to preserve it should the unprotected bank fail.

11

6..1.2 Construction

Channel Diversion

It will be necessary to divert the whole river flow to the right bank. This will allow unhindered access to the batter and allow the toe to be excavated more readily.

Bank Clearance

Vegetation near the edge of the bank will need to be cleared and topsoil should be stripped, to be saved and reinstated after battering is complete.

Fill Placement

As noted above, a transition curve needs to be established. This should be constructed from compacted clay fill, on a gravel base. It will be necessary to import suitable cohesive material to the site. Below the water table, it will probably be necessary to use gravel as fill. The fill needs to be placed in layers and each layer to be compacted to an appropriate standard. The fill will need to be battered to a suitable slope.

Some reinforcement (eg., geotextile) may be necessary in the fill.

Construction Platform

A construction platform on the river side will be necessary, especially for the toe excavation. Such a platform could be constructed using cross bladed material if available, otherwise material will have to be imported.

Filter

A gravel filter needs to be placed between the fill and the riprap.

Placement of Rock

Rock should be end-tipped and placed by hydraulic excavator.

Additional Protection

Finally, willow stakes should be planted on the berm and debris fences erected.

Maintenance

The rock will need occasional topping up and maintenance of the willows and i.\~ \ debris fences will be necessary.

6..2 Groynes

6..2.1 Design

The design for the groynes calls for four groynes to be placed on the same transition curve as the riprap, at locations as shown on the attached drawing. Each groyne consists of rock blanketing an earth core.

The rock gradings required are also as for the riprap; the heavier rock to form the "head of the groyne and the lighter rock to form its "arm". the head is to be approximately circular in plan, but to also extend 10m into the bank. Its top level is again to be at 0.5m below the annual flood level. The arm is to slope into the bank at a batter of between 10:l and 20:1, for a distance of 15m in the case of the upstream groyne and 10m otherwise. The top of the arm is to be 4m wide, to allow machinery access to the end of the groyne.

The side slopes are again to be at 2:l batters.

The toelapron is to be 3m wide and 2m deep for the heavy rock and lm wide and 1.2m deep for the light rock.

Such groyne dimensions require a total of 3200m3 of heavy rock and 1900m3 of light rock.

6..2.2 Construction

Each groyne would be fully constructed individually before the next, to minimise potential flood damage.

Channel Diversion

Any channel diversion will be localised to each individual groyne.

Groyne Construction

Each groyne would probably be constructed from the landward side. A trench needs to be excavated in the berm, as illustrated. Note that an in-situ core should be left. Where possible the core should be undisturbed material.

Construction Platform

A platform may need to be built on the river side, to allow the groyne toe and head to be constructed. Otherwise the core could be used as a platform.

Gravel Filter

A gravel filter may need to be placed between the core and the riprap, where the core grading is too fine.

Placement of Rock

The rock should be end-tipped with placement by hydraulic excavator, or placed directly by crane where there are lifting eyes in the rock.

Finishing

The top of each groyne arm should be smoothed sufficiently to allow machinery access along it. This could be done by placing earthlgravel on the surface.

Additional Protection

The berms between groynes should be battered to an even slope and planted with willow and debris fences erected.

Maintenance

The rock will need occasional topping up and the willows and debris fences will need regular maintenance.

6..3 Structural Option

The design for this option is as for the riprap option, apart from having a wall or piles instead of heavy rock over the 45m under the bridge and the 10m cutoff at each end of this 45m.

The design so far has only been on a conceptual level.

Diaphragm Wall

The wall is to be on the curve and have the same top level as the riprap. While the riprap and groynes options do not require that rock be placed to the potential scour depth, as extra rock placed can settle into any scour hole, a wall or piling structure needs to be founded below the scour depth. This depth is approximately 13.7m datum, or 3m below the minimum thalweg under the bridge. It has been assumed that the structure should be founded to 11.5m datum, giving a minimum of 2.2m embedment after scour. Thus the depth required, in what will be saturated gravellsand material, is significant. If a trench is constructed, it will be difficult to maintain stability.

One method of overcoming instability may be to use a slurry trench technique, constructing a diaphragm wall. Below the water table a diaphragm wall would be required, while above the water table a conventional wall (or even rock if available) would be adequate.

The wall would need to be anchored by tie-backs. These could be drilled through the wall and backfill compacted around them behind the wall.

The construction of the wall would need to be preceded by a channel diversion and followed by backfilling and site finishing (including erecting debris fences and planting willows) as in the case of the riprap option.

Sheet Piling

Again, the same top level, the same driven depth and the same curve are to be used for the sheet piling as for the wall option.

The soffit level of the bridge causes particular difficulties for driving the sheet piling. It will probably be necessary to have a lower top level of the piling under the bridge (with rock or other protection up to the design top level) and to thread each pile in short sections onto the adjacent pile (with the sections then welded together). Such adjustments will add considerably to the cost. Note that even then it may not be possible to drive under the bridge.

Some form of anchoring is required: a series of tie-backs would serve this purpose.

Channel diversion will again be necessary and the finishing is as for the other options.

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7. COMPARISON OF OPTIONS

Before an option is recommended, it will be helpful to summarise the advantages and disadvantages of the three options under consideration.

7..1 Riprap Revetment

Advantages

Proven method Smooth transition curve

Disadvantages

Higher capital cost than groynes Total failure possible Probably must be constructed as a single job Large earthfill required to establish transition curve All rock required before construction begins Total diversion of river required Difficulties in construction - formation of construction platform

- excavation of toe - Placement of rock around piers

Piers obstruct rock settlement Maintenance costs uncertain

7..2 Groynes

Advantages

. Failure less dramatic, as failure of one groyne still leaves three others intact Staged construction possible according to rock supply . Easier to construct than other options Lesser interference with river during construction Lower capital cost than other options

Disadvantages

. Performance of groynes not well documented . Erosion between groynes possible, (although minimised by correct spacing) . Effects of overtopping during flooding uncertain . Maintenance costs uncertain

7..3 Structural Options

Advantages

. Higher structural integrity than rock protection . Do not have to obtain large rock . Smooth transition curve

Disadvantages

. Higher capital cost than groynes Difficult to drive street piling in gravel and under bridge (sheet piling option) Difficult to dig trench to required depths, especially near piers (diaphragm wall option) Total failure possible Possibly less aesthetic Possible danger to public Earthfill required to establish transition curve

CONCLUSION

Several design criteria were identified on page 4. When considering the thre feasible options, riprap, groynes and structural - in terms of the criteria, i becomes apparent that the groynes option is the most desirable.

The groynes option compares less well in terms of its general engineerin acceptance. Groynes have not been used as extensively as riprap or structur: options in NZ, although there is sufficient experience in their use on whic to base design. Further, the maintenance costs of groynes are unknown, s is the case for riprap. The option may also not have the structural integrit of a structural option.

However, the disadvantages of groynes appear to be more than compensate by their advantages. Firstly, the groynes option is several hundred thousan dollars cheaper than the others. Secondly, the groynes can be constructe individually over a period as rock becomes available. A final advantage that construction should not meet with the difficulties that the others face excavation need not be around the bridge piers and the height of the bride should cause few problems.

Groynes meet the environmental and public safety criteria equally as well i does the riprap option and better than structural options. Scour can t accommodated. Finally, much of the rock can be retrieved should tt HRFCSR adopt a different long-term approach.

It is therefore recommended that the groynes option be adopted as tl preferred option, subject to the availability of rock.

DESIGN CALCULATIONS

CONTENTS

Backwater Analys~s of Flow

Flow Sensitivity

Scour Estimation

Rock Sizrng

Rock Thickness

Riprap Option

Llghcer Riprap Protactlon Heavler Rlprap Protect~on Rock. Volumes - Llghter Rock Rock Volumes - Heavler Rock

Groynes Option

Rock Volumes - Heavier Rock Rock Volumes - Lighter Rock Gravel Filter Quantities

Structural Option

Attachments

Riprap Sizing - Comments by Gary Williams

Riprap Design Method Notes

Minutes of Meeting re River Mechanics

Drawings

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1 THE WELLINGTON REGIONAL COUNCIL Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . File No

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123 11910. 2t1.7:3 :301;.5 4.02 XSECT 1.24 12008. 20.YS 4 4.1.l:l X S F: I.: T 1 2 s 12108. 29.47 263.8 3.64 XSECT 126 1:2;!0'3. 2 CJ . Ii 0 ::I fl8 . !I ::I . 4 6 *Ah** I H B C H E C K F O R CRITIi:AL L.L.OUli IdALi IIHBIIUCE

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4 THE WELLINGTON REGIONAL COUNCIL . . . . . . . . . . . . . . . . Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . File No.

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4 THE WELLINGTON REGIONAL COUNCIL . . . . . . . . . . . . . . . . Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . File No.

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THE WELLINGTON REGIONAL COUNCIL . . . . . . . . . . . . . . . . Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . File No.

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1 THE WELLINGTON REGIONAL COUNCIL .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Project File No. . . . . . . . . . . . . . . . .

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4 THE WELLINGTON REGIONAL COUNCIL Qo*f-e - SiAk ?mtcct;or, Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . File No. . . . . . . . . . . . . . . . .

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9 THE WELLINGTON REGIONAL COUNCIL . . . . . . . . . . . . . . . . Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . FileNo.

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THE WELLINGTON REGIONAL COUNCIL

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1 THE WELLINGTON REGIONAL COUNCIL .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Project File No. . . . . . . . . . . . . . . . .

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9 THE WELLINGTON REGIONAL COUNCIL

THE WELLINGTON REGIONAL COUNCIL Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . File No. . . . . . . . . . . . . . . . .

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THE WELLINGTON REGIONAL COUNCIL . . . . . . . . . . . . . . . . ............................................................. Project File No.

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THE WELLINGTON REGIONAL COUNCIL . . . . . . . . . . . . . . . . Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . File No.

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I THE WELLINGTON REGIONAL COUNCIL . . . . . . . . . . . . . . . . Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . File No.

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THE WELLINGTON REGIONAL COUNCIL .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Project File No. . . . . . . . . . . . . . . . .

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I THE WELLINGTON REGIONAL COUNCIL

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1 THE WELLINGTON REGIONAL COUNCIL . . . . . . . . . . . . . . . . Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . File No.

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THE WELLINGTON REGIONAL COUNCIL .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Project File No.

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4 THE WELLINGTON REGIONAL COUNCIL . . . . . . . . . . . . . . . . Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . File No.

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