wangapeka link route investigation report...

Little Wanganui – Wangapeka Link Route Investigation Report

Prepared by Chris J. Coll Surveying Ltd for Buller District Council

Chris J. Coll Surveying Ltd | Little Wanganui – Wangapeka Link Route Investigation | November 2015 i


Table of Contents 1. Introduction ........................................................................................................................................................... 1

2. The Impetus for a Link Road ........................................................................................................................... 1

3. Historic Tracks ...................................................................................................................................................... 1

4. Route Investigations ........................................................................................................................................... 2

4.1 The Wangapeka Track and Low-level Route..................................................................................... 2

4.2 The Routes of Dobson, Jennings, Campbell et al. ............................................................................. 3

4.3 The Saxon Route ........................................................................................................................................... 3

4.4 Simulation ........................................................................................................................................................ 4

5. Relevant Land Tenure States .......................................................................................................................... 4

5.1 Legal Roads ..................................................................................................................................................... 4

5.2 Kahurangi National Park ........................................................................................................................... 4

5.2.1 Wangapeka Track ..................................................................................................................... 4

5.2.2 Heaphy Track .............................................................................................................................. 5

5.3 Mokihinui River Catchment Addition .................................................................................................. 5

6. Construction of the Saxon Route ................................................................................................................... 5

6.1 Approximate Gradients .............................................................................................................................. 5

6.2 Extent of Disturbance ................................................................................................................................. 6

7. Conclusion ............................................................................................................................................................... 7

Appendices

Appendix A - Saxon Route and Low-level Route

overlaid on LINZ Topo50 topographical information ................................................................................. 8

Appendix B - Saxon Route and Low-level Route

overlaid on an aerial photograph .......................................................................................................................... 9

Appendix C - S.O. 1933 prepared by Arthur Dudley Dobson ................................................................... 10

Appendix D - S.O. 2035 prepared by J. H. Jennings ...................................................................................... 11

Appendix E - S.O. 1930 prepared by Edward Campbell ............................................................................. 12

Appendix F - Photographs of archived print of Proposed Road Karamea to Wangapeka Saddle prepared by John B. Saxon ..................................................................................................................................... 13

Appendix G - Longitudinal Section of the Saxon Route ............................................................................. 16

Appendix H – Screenshots of fly-through simulation ................................................................................. 17

Appendix I - Map of Kahurangi National Park

sourced from the Department of Conservation ............................................................................................ 20

Chris J. Coll Surveying Ltd | Little Wanganui – Wangapeka Link Route Investigation | November 2015 1


1. Introduction There has been significant and ongoing local interest in Buller for a legal road linking the

northern Buller and Nelson regions. The economic challenges faced by the Buller (and wider

West Coast) in recent times have provided an impetus to revisit this possibility and assess its

viability. Local advocates comprehend the advantages and the challenges presented by such a

project and have recognised that, prior to any feasibility assessment, an appropriate route must

be determined. This report summarises the findings of a desktop exercise investigating a

number of potential route options.

A virtual “fly-through” simulation has been prepared illustrating the two most promising routes

identified: a lower route generally following the present Wangapeka Track and a second route

following a graded alignment proposed in 1880-90 by John B. Saxon (Appendices A and B).

2. The Impetus for a Link Road The concept of a “link road” running through the Little Wanganui and Wangapeka saddles

providing a direct connection between the northern Buller/Karamea area to the

Nelson/Motueka area has long been a subject of local discussion.

At present, the journey from Karamea to Nelson by road is approximately 328 kilometres. The

link between existing legal roads would require the construction of approximately 56

kilometres of new road and would almost halve the journey from Karamea to Nelson to

approximately 169 kilometres.

Decreased transport times would offer opportunities for economic growth in the agricultural

and horticultural industries on the northern West Coasts via improved accessibility to markets

and processors. Additionally, the northern West Coast is considered something of a “dead end”

in terms of tourism with visitors to the area being required to “double-back”. A link road has the

potential to invigorate the region as a whole by increasing the numbers of tourists travelling to

and through the region. The consequential positive effects of a link road on the local economy

are considered to be significant.

3. Historic Tracks Gold was discovered in the Wangapeka Valley around 1860 and a track between the West Coast

(Little Wanganui River) and Nelson-Tapawera (Wangapeka River) was built between 1862 and


1899. This track was traversed by early Europeans including Dobson, Rochfort, Brunner, Saxon

and Hochstetter. However, a track of some form may have been utilised even earlier by Maori

travellers using it to access the West Coast from the Nelson region.

By 1867, a pack horse track had been built on the Nelson side approximately 12 kilometres

beyond the Rolling River junction or 1 kilometre passed Cecil Kings Hut. Pastoral lessees had

grazed sheep on the Wangapeka tops from Mt Gomorrah to Mt Patriarch in the early 1900s.

There have been historic graded pack tracks on both sides of the two main saddles (the Little

Wanganui Saddle and the Wangapeka Saddle). On the west side, a pack horse track had been

constructed to the Anaconda Mine and the Mt Zetland side of the Little Wanganui Saddle.

4. Route Investigations Research into old plans and history around the area reveals that early explorers, surveyors,

miners and pastoral farmers have invested considerable energy into searching for a suitable

route between Nelson and Buller. As part of this present investigation, two possible routes were

considered the most promising and have been thoroughly examined: a route that

predominantly follows the line of the existing Wangapeka Track referred to as the “Low-level

Route” and a route traversed by John Saxon between 1880-1890 referred to as the “Saxon

Route”.

Foot-tracks have a greater capacity to handle steeper gradients and often follow lines between

hut sites and, as such, are not always the most optimal alignments for road construction. An

analysis of gradients and potential earthwork requirements indicates that currently the Saxon

Route is the superior option.

4.1 The Wangapeka Track and Low-level Route

The Wangapeka Track is a tramping track approximately 56 kilometres long running between

the Wangapeka Road carpark at the end of the road on the West Coast (at the Little Wanganui

River) to the Rolling River carpark in the Waimea Basin. In sequence, the track crosses the

valleys of the Little Wanganui River, Taipo River, Karamea River and Wangapeka River and

finishes at the junction of the Rolling River and the Wangapeka River. It crosses two passes at

the heads of the major rivers, the first one being the Little Wanganui Saddle having an

approximate elevation of 1,100 metres and the second one being the Wangapeka Saddle having

an approximate elevation of 1,020 metres. There are five standard Department of Conservation

huts along the main tramping track (Belltown Manunui Hut, Taipo Hut, Helicopter Flat Hut,

Stone Hut and Kings Creek Hut).


When the Low-level Route alignment was examined following, in a general manner, the existing

Wangapeka Track, several problems were identified. One significant problem with this route

was that, in order to avoid very steep grades, two zig-zag switchbacks are required to climb to

the top of the Little Wanganui Saddle and descend down the east side of the Wangapeka Saddle.

The Low-level Route would also require more bridges for stream crossings than the Saxon

Route. The main advantage of the former route is that it is an established and long-standing

track location. Over time there has been storm damage and slips that have made parts of the

track difficult to traverse.

4.2 The Routes of Dobson, Jennings, Campbell et al.

Between 1865-90, a number of surveyors were investigating possible routes between the

Karamea River and/or Little Wanganui River through to the Motueka River and/or junction of

the Wangapeka and Rolling Rivers.

The 1867 survey S.O. 1933 prepared by Arthur Dudley Dobson (of Arthurs Pass fame) shows a

number of tracks (including those of Dutton, Jones, Hough and Rochfort) between the Karamea

Bend and the Motueka River (Appendix C). In 1875, the surveyor J. H. Jennings produced the

survey plan S.O. 2035 (Appendix D). He explored a route to reach the top of the Little Wanganui

Saddle from the West Coast side. Jennings opted for a line along the northern (true right bank)

side of the Little Wanganui River.

In September 1886, Edward Campbell, a contract surveyor for the Department of Lands and

Survey, produced the survey plan S.O. 1930 showing various track options from the Karamea

River to the junction of the Wangapeka River and the Rolling River for the “Wangapeka-

Karamea Road Survey” (Appendix E).

4.3 The Saxon Route

At some point between 1880-90, John Saxon, a Nelson surveyor, also investigated and proposed

a new route. The Saxon Route climbs out of the Little Wanganui River valley along the southern

(true left bank) side to Kiwi Saddle then to the top of Little Wanganui Saddle. The route then

descends down the northern bank of the Taipo River and up the Karamea River valley until

reaching the Wangapeka Saddle and on to the Rolling River junction at the formed Wangapeka

River Road. In several places, the Saxon Route and the Low-level Route join and coincide,

particularly along the first 6 kilometres and the last 20 kilometres.


The Saxon Route is shown on the reproduction plan titled “Proposed Road Karamea to

Wangapeka Saddle” stored in Archives New Zealand (Appendix F). The line of the Saxon Route

and Low-level Route overlaid on topographical information (from Land Information New

Zealand (LINZ) Topo50 1:50,000 map sheets) as well as on an aerial photograph is appended

(Appendices A and B). A longitudinal section has been prepared to demonstrate the

approximate grades and chainages of the Saxon Route (Appendix G).

4.4 Simulation

A Google Earth virtual “fly-through” simulation illustrating the approximate line of both

proposed routes has been prepared to demonstrate the steepness of the terrain and to allow a

better appreciation of the advantages of the preferred Saxon Route in comparison to the Low-

level Route (Appendix H).

5. Relevant Land Tenure States

5.1 Legal Roads

9-10 kilometres of road reserve with no formation exists at each end of the Wangapeka Track.

Resource consent would be required to form the roads. If a roading project were to proceed,

approximately 46 – 47 kilometres of road through Kahurangi National Park would require

legalisation by gazettal.

5.2 Kahurangi National Park

The Kahurangi National Park was gazetted in 1996 and is over 452,000 hectares in size. A map

of the national park sourced from the Department of Conservation is appended (Appendix I).

The Saxon Route is totally encompassed by the Kahurangi National park. The Wangapeka Track

and Heaphy Track are also located in the Kahurangi National Park. The Mokihinui River

catchment is currently located outside and to the south-west of the park.

5.2.1 Wangapeka Track

The Wangapeka Track is categorised on the Department of Conservation website as “Advanced:

Tramping track. Expert: Route”. Visitor numbers to the track continue to decline. Present

assessments by the Department estimate user numbers as being at 700 per year (the Heaphy

Track to the north has around 6000 users per year). The Department’s current strategy involves

working to downgrade the Wangapeka Track from “Track” status to “Route” status. This would

release the Department from some of its obligations regarding maintenance and investment.


5.2.2 Heaphy Track

The Heaphy Track is the most well-known track in the Kahurangi National Park and is one of

New Zealand’s Great Walks. In the 1970s-1980s, a similar proposal for a road through to

Collingwood from Karamea via the Heaphy Track was mooted. Considerable opposition from

conservationists and government departments saw the legal road along the Heaphy Track

stopped by proclamation. This gazettal effectively eliminated any chance of local authorities

being able to promote a road built along existing legal roads. No alternatives to this road

stopping were offered in exchange.

5.3 Mokihinui River Catchment Addition

A campaign presently underway by Forest and Bird would involve adding the Mokihinui River

catchment to the Kahurangi National park, increasing the area of the park by approximately

45,000 hectares. This would result in a total park area of over 495,000 hectares. The addition

would increase the area by approximately 10% and is significant. The Mokihinui River has some

20 kilometres or more of legal roads along its banks. Some of these roads were formed at the

time they were surveyed. Others provide legal frontage to parcels of land. These roads would all

be stopped.

At present, the proposed link road would skirt inside the perimeter of the National Park.

However, once the Mokihinui River catchment area is added to the park, the road would be

perceived as going through the “middle” of the park. This consequent perception would be a

significant obstacle to the success of the proposal. If the road is not approved at this stage, then

an opportunity will almost certainly be irrevocably lost for the foreseeable future.

6. Construction of the Saxon Route The investigation of the Saxon Route from an engineering point of view provides some

interesting challenges. However, with modern techniques and suitable equipment, these

challenges do not appear insurmountable. The line of the route and its associated gradients

discussed below have been derived from preliminary desktop investigation. Ground-truthing

would lead to adjustment of the route to maintain as steady and comfortable grades as possible.

6.1 Approximate Gradients

The Saxon Route climbs along the southern side of the Little Wanganui River at a consistent

gradient from the Little Wanganui River flats opposite Belltown Hut near Specimen Creek

toward a pass called Kiwi Saddle at an elevation of approximately 900 metres. A road along this


route would face north with a sunny aspect and there are fewer streams to cross in comparison

to other possible routes. From Kiwi Saddle, an achievable gradient 1 in 11 (9%) transitions into

a benign gradient 1 in 33 (or 3%) to the Little Wanganui Saddle.

Once the top of the Little Wanganui Saddle is reached, the road could then descend into the

valleys of the Taipo River and Karamea River. Again, Saxon has determined an excellent line that

allows acceptable gradients of 1 in 9 (or 11%) and 1 in 14.3 (or 7%). His route heads into

Pannikin Creek (away from the Wangapeka tramping track) and sidles along the true left bank

of the Taipo River until it joins the upper Karamea River. The proposed road would turn up the

Karamea River above Saxon Falls (no doubt named after the same Saxon) climbing at a gradient

of between 1 in 33 (or 3%) and 1 in 25 (4%) until reaching the Wangapeka Saddle (elevation

1,020 metres). Over this section, the proposed route generally follows the existing tramping

track.

After the Wangapeka Saddle, the Saxon Route encounters its gradients of approximately 1 in 7.7

(or 13%) for 2 to 2.5 kilometres. With some more intensive route finding, there is confidence

that a grade of 1 in 12.5 (or 8%) could be achieved without the need to lengthen the road. The

last section of 17 kilometres to the Rolling River junction at the formed Wangapeka River Road

would have a gentle gradient of between 1 in 25 (4%) and 1 in 50 (or 2%). This section has the

potential to absorb the steeper 2 to 2.5 kilometre section after the Wangapeka Saddle crossing

and ease the steep section below the Wangapeka Saddle.

6.2 Extent of Disturbance

Total distance of road construction along this route would be approximately 56 kilometres. The

land required for the road corridor and ancillary works is estimated to be less than 450

hectares. To give some context to the scale of this proposal, it is helpful to observe that the

proposed addition of the Mokihinui River catchment to the Kahurangi National Park would be

approximately 45,000 hectares. Therefore, the roading requirement for the Saxon Route is

equivalent to about 1% of the area of the Mokihinui River proposal or about 0.1% of the present

Kahurangi National Park.

Carefully managed side-casting into the hillside would be required to minimise the visual effects

and could be planned so as to leave sections of the Wangapeka Track that could still be walked.

Parts of the track could become significantly more accessible and open to a much wider range of

tramping abilities. In places, where the track and the proposed road coincide, thought should be

given to re-routing the track away from the road so that the two could co-exist.


Slopes and terrain would be similar to the Lewis Pass area between Reefton and Christchurch.

There are many modern examples that demonstrate how, with modern-day earthmoving

techniques and equipment, roads in such an environment can be built with minimal scarring

and disturbance. One example is in the Arthur’s Pass National Park where the road is being

realigned from Arthurs Pass Township through the Mingha Bluffs to Rough Creek on State

Highway 73.

The link road can be graded carefully so that cuts and fills across knobs and gullies are

minimised. If the road formation is predominantly in “cut” with the sloping batter vegetation on

the outside, the downhill side of the road can remain largely intact. This would provide several

advantages. It would minimise the “scar” of roadworks, provide soil stabilisation by retaining as

much of the original vegetation as possible and keep the footprint as narrow as possible.

Existing examples of this technique include roads through the Rahu Saddle from Reefton and

over the Lewis Pass from Maruia Springs.

7. Conclusion Historic interest in developing a connection between the northern Buller and Nelson regions is

clear from the depth of past investigation and the number of routes explored. The contemporary

enthusiasm and momentum for the project is obvious from current discussion in the region and

the consequent advocacy by local leadership.

This modern desktop exercise has been able to take advantage of the level of thorough historic

investigation by earlier surveyors, explorers and engineers as well as more recent topographic

data and virtual simulation capabilities. It has determined that the Saxon Route is currently the

most promising option for a potential road link.

To determine if a link road is viable, further geotechnical, civil engineering, resource

management and legal investigation will be required. It is not the place of this report to

investigate the feasibility of the project but, after preliminary assessment, it would appear that

acceptable gradients required by a road constructed along the Saxon Route are achievable.

Appendix A

Saxon Route and Low-level Route overlaid on LINZ Topo50 topographical information

Appendix B

Saxon Route and Low-level Route overlaid on an aerial photograph

Appendix C

S.O. 1933 prepared by Arthur Dudley Dobson

Appendix D

S.O. 2035 prepared by J. H. Jennings

Appendix E

S.O. 1930 prepared by Edward Campbell

Appendix F

Photographs of archived print of Proposed Road Karamea to Wangapeka Saddle prepared by John B. Saxon

Appendix G

Longitudinal Section of the Saxon Route

Appendix H

Screenshots of fly-through simulation

Start of Saxon Route at Wangapeka Road (legal road) and Little Wanganui River

Saxon Route and Low-level Route split prior to Belltown Hut

Saxon Route turning at Kiwi Saddle

Saxon Route crossing Little Wanganui Saddle Saxon Route crossing Pannikin Creek

Saxon Route turning at upper Karamea River below Wangapeka Saddle

Saxon Route merging with Wangapeka River Road (legal road) at Rolling River junction

Appendix I

Map of Kahurangi National Park sourced from the Department of Conservation

wangapeka link route investigation report...

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