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
Little Wanganui – Wangapeka Link Route Investigation Report
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
Little Wanganui – Wangapeka Link Route Investigation Report
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
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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).
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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.
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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.
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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
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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.
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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