WAITAHA HYDRO SCHEME Application for Concessions and Assessment of Effects July 2014 Prepared by: Westpower West Coast Planning Ltd 146 Tainui Street 6 Dowling Road Po Box 375 Paroa Greymouth 7805 Greymouth 7805 Telephone: (03) 768 9300 Telephone: (03) 762 6554 ii EXECUTIVE SUMMARY Westpower Limited is applying for concessions from the Minister of Conservation for the construction, operation and maintenance of a run-of–river hydro scheme on the Waitaha River. The proposal is to develop a hydro-electric power scheme based on a renewable resource for the benefit of the West Coast community served by Westpower. The Waitaha Hydro Scheme is located on conservation land administered and managed by the Department of Conservation. The land is classified as Stewardship Land. Concessions in the form of lease, license and easement are required to occupy and have access to the site. The application and proposed concession provide for both the temporary and permanent structures, works and activities associated with the construction and operation of the Waitaha Hydro Scheme. THE APPLICANT Westpower Limited (Westpower) is a 100% West Coast community owned company with its head office in Greymouth. Since 1999, when it was required by legislation to divest itself of a set of generation assets within the West Coast, Westpower has principally been an electricity distribution company, responsible for transporting electricity from the national grid to consumers. In the mid 2000’s the Government allowed distribution companies to re-enter the generation market. At this time Westpower and Harihari Hydro Ltd formed a joint venture company Amethyst Hydro Ltd and built a run- of-river hydro-electric power scheme on the Amethyst River north of Harihari. The Amethyst Hydro Scheme was commissioned in June 2013. The intake for the Amethyst Hydro Scheme is located in the Amethyst Ravine, with a penstock conveying water via a 1.1 km tunnel. From the tunnel to the powerhouse the penstock is mostly underground. An access road was constructed between the tunnel portal and the powerhouse. This scheme (except for the powerhouse) is predominantly on conservation land. Through the successful development of the Amethyst Hydro Scheme, Westpower has demonstrated the skills and experience required to develop a hydro generation scheme on conservation land. The Waitaha Hydro Scheme (Scheme) on the Waitaha River is to be developed in response to a need for improving the reliability and security of supply within the West Coast, and more specifically within the Westpower distribution area. The focus is on developing renewable power generation to meet the needs of present and future generations. Westpower also has a responsibility to look for investments that will provide sustainable returns for Westpower consumers (the shareholders and also the community). The benefits of these returns remain on the West Coast and within the Westpower distribution area. THE SCHEME The Waitaha River is located 38 km south of Hokitika and extends from the Main Divide of the Southern Alps to the Tasman Sea on the West Coast. The Waitaha Catchment falls 2640 m over a length of 40 km with a total catchment area of 223 km2. The Scheme is located within and on the true right bank of the Waitaha River between the lower end of Kiwi Flat and Macgregor Creek within the Waitaha Valley, and within the northern half of the Westland District. It is predominantly on Stewardship Land managed by the Department of Conservation (DOC). Sections of the access road, at or on the north bank of Macgregor Creek are located on land that is privately owned or crown land administered by Land Information New Zealand (LINZ). The Scheme will produce approximately 110-120 GWh per year with a maximum or peak output of about 16 – 20 MW. This is equivalent to providing electricity to approximately 12,000 households. Currently the annual peak demand in the Westpower distribution area is 50 MW with up to 25 MW being generated on the West Coast by a number of small power stations including the new Amethyst Hydro Scheme (7.6 MW). Future demand is expected to increase over time. The Scheme once developed would significantly Westpower: Waitaha Hydro Scheme Application for Concessions and Assessment of Environmental Effects – July 2014 iii increase the percentage of power generated and owned by the local community, and would make the Westpower area almost self-sufficient in power generation. Technical and engineering feasibility studies have identified the Waitaha Valley as a good site for a run-of-river hydro scheme because of the ability to generate power economically and efficiently from a Scheme that has a small physical and environmental footprint. This is a run-of-river scheme with no instream storage. It includes a low weir and diversion structure at the upstream end of Morgan Gorge. There will be no formation of a lake and no submergence of native vegetation, land or terrestrial habitat as a consequence of the weir. A tunnel approximately 1.5 km long will convey water from the intake to a powerhouse located below Morgan Gorge. The diverted water is returned to the Waitaha River via a tailrace. An access road is required to the powerhouse site from the end of the existing public Waitaha Road. This is for the construction of the tunnel, powerhouse and associated structures which are all located on the true right of the river. Upon commissioning of the Scheme, this road will be retained for routine maintenance and inspection of the Scheme infrastructure. The transmission route within conservation land will follow this access road route. It is proposed that the maximum volume of water to be diverted will be 23 cumecs (23 m3/s) but the water take will vary depending on the flows in the river and the minimum residual flow. Westpower is proposing a minimum residual flow of 3.5 cumecs (or 3.5 m3/s) immediately below the intake. The residual flow was established at a level which makes the most efficient and effective use of the hydro resource whilst ensuring that the life supporting capacity of the river is maintained. Side streams that enter the Waitaha River below the intake will increase the residual flow below the weir before full flow is restored to the river at the outlet of the tailrace, below the powerhouse. The abstraction reach would include approximately 2.6 km of the Waitaha River, including the Morgan Gorge. A summary of the key features of the Scheme is provided in Table 1. DEVELOPMENT ENVELOPE Westpower is applying for a development envelope (envelope) within which the project (or construction) and operational footprint will be located. The project and operational footprints represent the maximum footprints required for the Scheme and these will not change within the envelope. The envelope represents the outer physical boundaries within which the Scheme will be located as well as providing some flexibility for final design, layout, construction methods and equipment while adhering to best practice standards for construction and the conditions required. This approach enables the most efficient and effective development of the Scheme with an ability to respond to technical, site and environmental matters as they arise. This is an approach Westpower has some experience with through the successful development of the Amethyst Hydro Scheme. Any final design changes will fit within this maximum envelope and will not be out of character or scale with, or raise higher levels of potential effect than, the matters outlined in this application. The expert consultants engaged on this Scheme took this approach into account in assessing the effects of the Scheme and the preparation of their reports. The potential effects on natural values will not change as a result of the final design, layout, construction method or equipment used. A suite of draft conditions is suggested to ensure that this is the case. There is the potential for final construction designs to have less effect than those assessed, and Westpower seeks the ability to be able to achieve the best outcome possible for the Scheme within this location. Westpower: Waitaha Hydro Scheme Application for Concessions and Assessment of Environmental Effects – July 2014 iv THE APPLICATION PROCESS The technical reports commissioned for the Scheme and the Assessment of Environmental Effects have been prepared for both the concession and resource consent processes. This application focuses on the process and requirements for concessions from DOC, including the relevant legislation and planning documents. Westpower decided to apply for concessions prior to the relevant consents because it is considered that the permission of the landowner of the conservation estate is critical to the success of the Scheme. If concessions are granted, Westpower can proceed to apply for resource consents from the West Coast Regional Council (WCRC) and the Westland District Council (WDC). THE EXISTING ENVIRONMENT Westpower has commissioned a range of ecological assessments to understand the ecological values within the area in which the Scheme is proposed and to provide a baseline for subsequent surveys in preparation of the AEE. This work commenced in 2005. Additional survey work was undertaken following a preliminary review of the original studies by DOC in 2012 and as suggested by DOC. These studies were further refined with the selection of the intake and powerhouse sites. Prior to commissioning these reports there was a paucity of information. A wealth of new information about this area has been recorded and documented during these investigations. There have been significant key findings as a result of this work, for example the discovery of a significant long tailed bat population in the Kiwi Flat area and that the native koaro is the only fish found in the Waitaha River upstream of Morgan Gorge. ASSESSMENT OF EFFECTS The potential effects on the environmental associated with the Scheme fall into two general phases: construction and operational.