Ben Ohau Station Irrigation Scheme Twizel, Mackenzie Basin Landscape Assessment Prepared by: Chris Glasson Landscape Architects Ltd PO Box 13162 Christchurch Ph: 03 365 4599 30 Jan 2014 1.0 Introduction This landscape assessment has been commissioned by Simon and Priscilla Cameron of Ben Ohau Station, Twizel, who is applying for resource consent to install and operate pivot irrigators on the land, 3km north of Twizel. Ben Ohau Station consists of 3793ha of varying terrain. The report assesses the potential landscape and visual effects of pivot irrigation on the existing landscape character and highlights possible mitigation measures, which will assist to integrate the operation into the surrounding landscape. 2.0 The Proposal The proposal is for the implementation of three pivot irrigators on flat farmland on the south side of the Pukaki – Ohau canal and 1km west of SH8. The canal provides the water source for the irrigation. Pivot no.1 is located between the Fraser River and Dry Stream, and pivot no.2 and 3 between Dry Stream and the Twizel River. The pivots have been sited at some distance away from SH8, as this is the main public viewpoint throughout the Mackenzie Basin. The road on the southern and eastern side of the canal is sometimes used by travellers and recreationalists. The intake structure will be located west of pivot no.1 at the canal. This will be a small concrete structure housing a pipe. 3.0 Landscape Context The Mackenzie Basin as a whole is an outstanding landscape, and contains many individual features within it, such as high mountains, lakes, rivers, vast open spaces, recreational parks and wildlife areas, all of which are surrounded by mountain ranges. This landscape caters for a range of tourist ventures and recreational activities from water sports (fishing, water skiing, rowing and boating) to four-wheel driving, mountain biking, hunting, tramping, horse riding and nature walks. The contrasts of this landscape, from the basin’s vastness to the abruptness of the Southern Alps are a real highlight to tourists and local users of this area. The climatic conditions throughout the seasons also create a contrast that can send the area into Ben Ohau Irrigation Scheme 1 Landscape Assessment – CGLA # 1330 Jan 2014 extremely low temperatures in winter to hot and dry periods with minimal rainfall in summer. Post glacial and other geological events that have shaped this area and provide a high degree of scientific and educational value. Notable landscape formations include moraines, terraced valley sides, flood plains, fans and wetlands, much of which is a result of the glacial period. The vegetation of the floor consists of mainly short tussock grasslands and remnant native scrub such as tussock, matagouri and coprosma species. In dry areas wilding pines are among the more invasive tree species, along with heiracium being the dominant and invasive weed. Forested areas are found higher up into the valley systems with large stands of silver and mountain beech being the dominant tree species, especially in areas like the Ohau catchment and Ruataniwha Conservation Park. Farming has modified much of the low-lying areas over time with dairy farms becoming prevalent in the Waitaki District between Oamarama and Twizel. Animal pests such as rabbits, causing vegetation depletion and subsequent soil erosion, have been a real problem in the past for farmers while ferrets and stoats have had a major impact on wildlife in the basin. The most enduring landscape features of the basin are its vastness and openness contained by the grandeur of a mountain backdrop. In short, the basin’s main landscape elements include: vastness of scale sense of openness a high degree of naturalness large panoramic views of mountains large turquoise colored water bodies contrasting landforms and colours defined limits of vision tawny colouration of landscape isolated coniferous shelterbelts and woodlots small well-defined settlements extensive low intensity grazing Ben Ohau Irrigation Scheme 2 Landscape Assessment – CGLA # 1330 Jan 2014 The Pukaki Landscape This is a vast area of glacial outwash bordered by Lake Pukaki, Simons Pass, the Grampians and Ohau River. In the northern part of this area, near to Lake Pukaki, the rocky and undulating moraine hills are a significant feature, giving topographical relief to an otherwise flat basin landscape of river terraces, wetlands and flats. Ruataniwha Conservation Park is to the west of the Ben Ohau Station property containing the large catchment area for Lake Ohau. A large portion of the Ben Ohau Range is also managed by the Department of Conservation containing a defined Ben Ohau hunting block (see map in graphic supplement). Panoramic views form part of the travel experience through this area with the focus not only on the expansive landscape but also Mt Cook and the Southern Alps. Two Scenic Viewing Areas (SVA) in the MacKenzie District Plan are located at the southern end of Lake Pukaki along SH8, 3km from the site. Lakeside Protection Areas (LPA) exist around Lake Pukaki, while Sites of Natural Significance (SNS) include the Tekapo and Pukaki Rivers and parts of the Ohau River, Lake Pukaki, and the flats between Lake Pukaki and the settlement of Twizel. The landscape is most frequently appreciated from SH8 and the canal roads as they weave their way across this flat to a gently undulating landscape. Views can also be gained from the power stations of Ohau B and C, while an elevated observation point exists at the southern end of Lake Pukaki. It is an area that is sensitive to change because of the visibility of its vastness and open landscape, and the consistency of land cover and colour. Albeit, there is an ever- increasing presence of wilding pines and other modifications that include irrigated areas of pastoral grassland, elements of the upper Waitaki hydro scheme, shelterbelts and woodlots, farm dwellings, milking sheds, pylons and the settlement of Twizel. The Pukaki, Twizel and Ohau Rivers and Lake Pukaki contribute significantly to recreational pursuits (fishing, mountain biking and tramping) and the inherent scenic and amenity value of this area. As well, camping facilities are found in several locations, Ben Ohau Irrigation Scheme 3 Landscape Assessment – CGLA # 1330 Jan 2014 most notably at Twizel and Lake Benmore. The Twizel River has recreational value for sightseeing and trout angling.1 4.0 The Site Ben Ohau Station consists of three different types of landscapes. We are only concerned with the moraine flats. On these flats an irrigated command area is proposed and within it is likely to contain three pivot structures, all adjacent to the Pukaki-Ohau canal road. The pivots range in distance from 1km to 3.5km from SH8. The land is essentially flat but there are existing and old water courses traversing the site, as well as a low stopbank along the river, the elevated canal, willow trees along the rivers, stands of matagouri and coprosma throughout. The flats are a thick layer of porous outwash gravels overlying tertiary sediments. The overlying soils are shallow and stony and have low fertility without additional water. The moraine debris and alluvial outwash have created low undulations between the canal and the Fraser River. The vegetation consists of improved grasslands, short tussock and matagouri shrublands near to the streams. Willow trees line the Twizel River and Fraser Rivers, giving an element of containment to the proposed irrigated areas. Exotic species are prevalent throughout this landscape especially in the dry, gravelly soils. These include sweet vernal, browntop, hawkweed, brier rose. The more fertile soils, such as between the Fraser and Dry Streams and near to the homestead site have been cultivated and have no limited species. There are some few conifer shelter belts on the site as well as willows and isolated poplar trees. While parts of the site have been cleared a considerable amount of matagouri shrubs exist, giving the stock shelter and enriching the soil quality. As well, in the newly sown pastoral areas the land management regime displays an integrated approach with the retention of undulations and vegetation as well as allowing for grazing to occur. 1 Environment Canterbury (Adrian Daly). Inventory of Instream Values for Rivers and Lakes of Canterbury, New Zealand. Report U 10/13, 2004 Ben Ohau Irrigation Scheme 4 Landscape Assessment – CGLA # 1330 Jan 2014 The main areas of exotic vegetation are the willow trees lining the Twizel and Fraser Rivers. When viewed from the canal road these rows form a distinctive edge and assist to define the site from this viewpoint. The site itself has no Recommended Areas of Protection (RAP) or has been assessed with an ecological value. Beyond the site, but still within Ben Ohau Station, are two RAP’s, one being east of SH8 near to the aerodrome and the other is west of the canal. This latter one is known as the Ben Ohau Swamp, a natural deep wetland where the vegetation is dominated by Carex species. Ben Ohau is an interesting example from a cultural viewpoint. Major modifications have occurred within its land boundaries including. It is part of one of New Zealand’s largest hydroelectric power developments as well as Twizel airport and SH8. In terms of recreation there are marginal strips along both sides of Fraser, Dry and Twizel Rivers for the entire lengths. The rivers are the main focal points on the property for fishing and passive recreational activities. Other fishing areas in wetlands, and tracks are beyond the site. The rivers and wetland areas are prime bird habitats. 5.0 Outstanding Natural Features and Landscapes Section 6b & c concerns the “…protection of outstanding natural features and landscapes from inappropriate subdivision, use and development:” and “protection of areas of significant indigenous vegetation and significant habitats of indigenous fauna.” The Environment Court has defined the Mackenzie Basin as an Outstanding Natural Landscape (ONL) (Decision No.