FMU History and Land Use

Climate

The climate of the East Coast Complex is one of the driest in Marlborough, with low annual rainfall of between 600 and 700mm. High evaporation rates are caused by hot temperatures in summer combined with strong north-westerly winds. Rainfall does increase towards the southwestern, more mountainous part of the FMU with mean annual rainfalls of 1,200mm.

Geology and soils

Geology in the FMU is complex and includes a range of rock types that have been modified by folding and faulting. The rocks in the northern part of the FMU are known as the Ward Syncline which comprise layers of mudstone rocks, thousands of metres thick, folded into a basin shape. This is overlain by a thin veneer of aquifer-forming gravels. The basement rock mudstones are known as papa-rock and occur along with greywacke, sandstone, and rarer carbonaceous rocks.

Moving south, the Flaxbourne catchment is also dominated by folded sedimentary rock. Most of the upper catchment consists of Pahau basement sandstone, which also contains mudstone, basalt and limestone. Towards the coast, the surface geology is dominated by alluvial gravels among pockets of exposed siltstone. Furthest to the east, sandstone and limestone have formed in narrow bands parallel to the coast, which are seen as coastal outcrops at Chancet Rocks and Needles Point. Limestone geology then becomes dominant in the Waima (Ure) catchment in the southern part of the FMU with steep valleys and gorges.

Bodies of water

The northern part of the FMU which encapsulates a number of small streams including the Boundary stream and Toe Toe Creek, are now proposed to be part of the Awatere FMU following engagement round 1 feedback.

The southern part of the FMU comprises three main catchments—Blind River, Flaxbourne River, and Waima (Ure) River.

Blind River is the most northerly of the three rivers and flows in a north-easterly direction from its source in the Haldon Hills to reach the coast towards the centre of Clifford Bay. Blind River has smaller tributary streams, which are primarily situated to the south of the river. Both Blind River and its tributaries flow intermittently due to low rainfall and a lack of large aquifers to sustain flows. Because many areas dry up during the summer months, there are many earth dams within the catchment that are required to capture and retain water for crop irrigation.

To the southeast of the Blind River catchment is Lake Grassmere. Until 1800 years ago, it was an estuary characterised by alternating seasons of dry and dusty summers followed by being covered in water during the winter months. In 1938, three-quarters of the lake area east of the railway line was surveyed by the Government and officially designated as Land for Aviation Purposes. In 1942, a licence to manufacture salt was granted, with the current ponds constructed in 1943.

The Flaxbourne River is situated in the centre of the FMU, between the Haldon Hills to the north and the Blue Mountain Range to the south. The river flows in an easterly direction for most of its length before heading in a more south-easterly direction at the State Highway. It reaches the coast between the Chancet Rocks and Needles Point at Ward Beach. The river has two main tributaries to the south, Needles Creek and Tatchell Creek, which join it east of the township of Ward not far from the coast.

Lake Elterwater is a shallow coastal lake with outlets that flow into the Flaxbourne River during periods of high rainfall. Lake Elterwater is rarely more than one meter deep and has dried up at least 10 times over the past 1,000 years, four of which occurred in the past 20 years. The lake is filled by rainfall and streams from the lake catchment. The largest stream is Elterwater Stream, which collects rainfall from more than half of the 1,600 hectares of lake catchment before flowing into the lake at the northern end.

More than 90 dams within the lake catchment reduce the amount of rainfall run-off available to fill the lake. Most of the dams are small and serve to supply stock water, but three larger irrigation dams also exist. The 2016 Kaikōura earthquake raised the southern outlet end of the lake, and therefore the lake is likely to retain water for longer periods in times of drought.

The most southerly river in the FMU is the Waima (Ure) River which rises in the Blue Mountain Range and flows in a southerly direction until reaching the Chalk Range. Here, it changes to a more easterly direction until it reaches the coast south of Needles Point, just north of Wharanui. For much of its 30 kilometre length the river flows through limestone landscapes, with high cliffs and gorges, until its lower reaches where its bed widens and becomes braided. Several smaller tributaries join the river along its length, the largest being Dunsandel Creek, while Isolation Creek is a well-known small stream which flows through the spectacular Sawcut Gorge. Much of this landscape was affected by the 2016 Kaikōura earthquake.

Flora and fauna habitats

The FMU contains small remnant areas of native vegetation, particularly in steep valleys and in the upper gorges of the area, which contain plant species that have become rare in South Marlborough. These include lowland totara, leafless clematis, lancewood, ongaonga, and red rock daisy. Across the FMU, fish habitats are present for the banded kokopu, common bully, upland bully, bluegill bully, giant bully, īnanga, longfin eel and shortfin eel. Lake Elterwater provides bird habitats for pied stilts, dabchick, crested grebe, shags, paradise shelduck, grey teal and other waterfowl, with other areas of the FMU providing habitats for banded dotterel, black shag and New Zealand scaup and marsh crake.

Land use and cover

Prior to human settlement the upper hills and mountains would have been clad in broad leaf and Totara Forest with matai and ferns on lower slopes closer to the sea. Human arrival led to widespread land clearance by fire. As a result, only small areas of native vegetation remain in the natural shelter of steep slopes, primarily in the upper catchments. Importantly, historically there would have been more extensive native wetland cover in this area, particularly around the lakes. The area was highly prized by early Māori for the abundant waterfowl and other mahinga kai due to the wetlands. The lower areas, in particular the Flaxbourne catchment, would have also provided large areas of harakeke which was also highly prized.

Swift land use change occurred from the 1840s onwards, with large sheep runs being established. In the 1850s to the 1870s the area was home to one of the first and largest pastoral stations, Flaxbourne Station, which was 23,000 hectares in size and ran over 70,000 sheep. This large station was subsequently split into smaller farms, however pastoral farming has continued in this location with significantly less viticulture and forestry development than just north in the Awatere FMU.

The below graph shows the surveyed vineyard area across Flaxbourne, Grassmere, and Kekerengu. Kekerengu is geographically part of north Canterbury and not included in the East Coast Complex FMU area. It is however amalgamated into this data set, so the planted areas highlighted in yellow are more than the plantable area in the ECC FMU alone. However, the data does assist with giving a general understanding of the scale of viticulture in this area – which is very small compared to the regional total and less than 9% of the total FMU area.

This is shown on the graph below where the blue bars (yellow highlighted areas) for development in this FMU are very small compared to the regional total.

Today, medium scale pastoral systems dominate most of the territory in this FMU, around 80% of the total area. A small number of niche systems also exist here including pine nut orchards. Viticulture continues to be a minor land use in this FMU. The most recent 2021 survey for vineyard plantings south of Lake Elterwater reported only 291ha (including Kekerengu) with only minor growth in area over the previous 5 years.

The below ECC FMU map shows up to date land use/land cover classes in this area, which supports the smaller amount of viticulture and large amount of drystock farming.

The Land Air Water Aotearoa (LAWA) website shows the changes in land cover and use in the Waima/Ure and Flaxbourne catchments between 1996 and 2018, combined and summarised in the chart below. We can see from the chart that the general area has not had significant land cover change over that time. The majority of both catchments is in grassland cover. The next most predominant cover is shrub, which is to be expected given the location, contour, altitude, and other factors of the area. Viticulture shares a very small portion of the overall cover, as described above in the small area of plantings.

Go to the LAWA website

There are three large wind farms in the area, situated along the eastern coastline. One near at Lake Grassmere and the other two further south near the Waima River. All were established between 2009 and 2011 and contribute power to the Marlborough Lines network. One of the farms alone produces around 350-400 homes’ worth of electricity.

The largest urban area in the East Coast Complex FMU is Ward, the southernmost township in Marlborough. The town is a small rural service town on State Highway 1 with a school and service station with café. In the 1850s to 1870s the area was part of the Flaxbourne Station. However, this was later split up by the Government and the town was established in 1905, with the railway line arriving in 1911. Ward township continues to be a small but important service area with recently renovated town hall, service station, and motels. The population was 81 people at the 2018 census.

Māori history in the area

The council has an ongoing work stream with local iwi to identify their visions, values, and aspirations for freshwater in the FMU. These will be collated with views from the wider community.