FMU History and Land Use

While the FMU takes its name from the Waiau-toa/Clarence River, located in the south of the FMU, the longest river in the FMU is the Acheron River. Rising in its headwaters near the Acheron Saddle in the northeast of the FMU, the Acheron River flows 60km south – southwest to its confluence with the Waiau-toa/Clarence River at the southwestern boundary of the FMU. The Acheron River has several major tributaries, the Saxton and Severn Rivers in the north, the Alma River and Tarndale Brook joining from the west and the Yarra and Guide Rivers and Five Mile Creek in the south.

The upper reaches of the western tributaries of Tarndale Creek and the Alma River are characterised by a plateau some 1000m in altitude, which extends east towards the Acheron River. A series of lakes, tarns and wetlands known as the Tarndale Lakes are in this expansive area, which include Bowscale Tarn, Lake Sedgemere and Island Lake, draining towards the Acheron River.

To the southeast of the FMU the Dillon River is the longest tributary of the Waiau-toa/Clarence River in this part of the FMU. Along with Blinkers Stream, Rough Creek, Elliot Stream and Spray Stream, the Dillon River joins the Waiau-toa/Clarence River from the north. Another northern tributary, Red Hill Stream marks the far eastern edge of the FMU and the regional authority boundary between Marlborough and the northern Kaikōura Districts. Also, on this northern side of the Waiau-toa/Clarence River, is Lake McRae which formed when two large landslides dammed the valley at the end of the last ice age about 15 thousand years ago. The lake is 42 metres deep and covers an area of 67 hectares, sitting at an altitude of 883 metres. Two tributaries of the Waiau-toa/Clarence River join the river from the south, the Hossack River and Tinline Creek.

Flora and fauna habitats

There is a long history of rural use in this FMU by both Māori and Pakeha. Early Māori called the area Rangitahi, meaning “converging skies” and used routes through the area to collect mahinga kai and to access pounamu on the West Coast. A number of iwi in the area are recorded as travelling through the land gathering weka, quail, whio, and eels. These initial routes were later described to early Pakeha settlers and are the origins of the routes used today.

The Rangitahi/Molesworth station as it is known now has a rich farming history dating from the 1850s. Initially held under private ownership in four separate large runs, over the decades the areas were sold, leased, amalgamated, and went through a variety of structures and owners which eventuated in a sale to the government in 1938 following the Great Depression.

Historically, there were a number of accommodation houses throughout the FMU which severed as overnight stops for travellers between Nelson, Blenheim, the West Coast and Canterbury. However, “urban” land uses have never occurred in this area due to the remoteness and climate. The accommodation houses were established from 1863 (Acheron) and at height of use there were seven in total across the regions. Today, only the Acheron and 1885 Rangitahi/Molesworth cob cottages survive within the FMU boundary.

Ownership of the area can be summarised as below:

• Māori - travel and mahinga kai gathering Pre 1850
• Establishment of four original runs, private ownership 1850s-60s
• Original runs combined into larger unit 1900s
• Licence surrendered to Department of Lands and Survey 1938
• Landcorp take over lease of Rangitahi/Molesworth 1990
• DOC takes over management; Landcorp as leaseholders 2005

Today, there is no urban settlement in the FMU due to its remote nature and the majority of the area being the Rangitahi/Molesworth Station. Over 98% of the land in this FMU is open space zone, reflecting the reserve status of the station.

Rangitahi/Molesworth has an extensive management plan which can be read in full here, which is currently under review. The 2013 station management plan summaries the area as follows:

“As well as its national significance to the New Zealand farming community, Rangitahi/Molesworth attracts people from all walks of life who want to visit the iconic high-country landscape, often simply to ‘have a look’. The Tophouse Road has been open to the public for many years, at least as far as Lake Tennyson from the south. The Acheron Road was first opened to the public in 1988, during January and February, with a toll exacted for road maintenance and visitor management. The road continues to open each summer, fire risk permitting, with the road toll removed in 2005/06.

In 2003 the Government decided to add Rangitahi/Molesworth to the network of high-country parks and reserves under the administration of the Department of Conservation, retaining farming, under lease to Landcorp, with the intention of enhancing conservation and recreation values. Thus, Rangitahi/Molesworth continues its long history as Crown land managed for farming purposes with enhanced emphasis placed upon other values important to New Zealanders.

The long history of pastoral farming on Rangitahi/Molesworth has provided a wealth of knowledge which has been used to develop farming practices suitable for Rangitahi/Molesworth. Since the 1940s, when cattle were introduced, a rotational grazing regime has been followed, which continues today. Cattle are farmed on Rangitahi/Molesworth because they do not graze the plant cover as closely as do sheep. The lack of safe winter country for sheep, and the unfavourable complementary grazing of sheep (stock) and rabbits (pests), were other compelling reasons for not farming sheep. The evidence of the past 65 years is that extensive cattle grazing, with numbers limited by the winter carrying capacity, has substantially aided vegetative recovery.

Most grazing occurs on the valleys floors and lower hill slopes. Stock wintered on Rangitahi/Molesworth number up to 10,000 head (including up to 3,500 breeding cows), with variations according to seasonal limitations. The cattle herd consists of the Angus and Hereford breeds and their crosses, with increasing numbers of pure Angus through the sole use of Angus bulls for breeding. These are early-maturing breeds with a good ability to forage and fend for themselves. Over the years, management has changed from selling store cattle (animals not yet ready for processing) to finishing the cattle on Rangitahi/Molesworth or other nearby Landcorp farms.

As part of the rehabilitation programme on Rangitahi/Molesworth, around 50,000 hectares, particularly the lower slopes and valley floors, have been aerially over-sown with grass and clover seed over the years. To maintain improved pastures, approximately one-third of this area is topdressed every year, with occasional re-seeding as required. The maintenance of Rangitahi/Molesworth’s stock carrying capacity at today’s levels requires significant inputs in the form of over-sowing, fertiliser application, weed control, and pest and wild animal control.”

The below FMU land use map shows the extensive grassland over the area. The small utilities patch at the bottom of the map is part of the Rainbow ski area.