Arnold Development Win Win for All
As part of TrustPower’s commitment to enhancing and optimising existing assets, an extensive programme focuses on this area.
Many of our hydro schemes are small scale, and have been operating for many years, so by using existing infrastructure and resources there are potentially gains to be had. These gains are driven by achieving more generation output, but they also open up the possibilities for cultural, recreational and environmental gains.
In many cases these gains can be achieved without any significant changes to structures, while others require larger changes but rely on portions of existing infrastructure. Once an economically viable option is selected, we initiate the process of consultation and investigation in preparation for applying for consents.
Key to this process is meeting the requirements of the Resource Management Act which emphasises (amongst other things):
• the efficient use and development of natural and physical resources
• the effects of climate change
• the benefits of renewable energy.
While it can still take an extended period to consent a project of this type, generally the time frame is shorter than that for consenting a new scheme.
An example of a large project of this type nearing completion of the consent process is TrustPower’s Arnold Hydro Electric Power Scheme. This project focuses on the existing Arnold dam on the West Coast of the South Island and involves a new canal structure which makes its way from the existing dam to a new powerhouse much further down river resulting in a dramatic increase in output. This increase in output is approximately 10 times the existing scheme, and is very important in terms of the West Coast’s electricity supply.
This project demonstrates that it is not only TrustPower that benefits from these developments. Some of the cultural, recreational and environmental gains for the Arnold scheme include:
• improved fish passage
• improved fish screening
• 195 hectares of indigenous vegetation restored and protected for the loss of 45 hectares
• extensive weed management programme initiated
• the existing power station site turned into a recreational and amenity area including picnic areas, toilets and a learn to fish pool
• employment opportunities and increased local expenditure arising from construction
• improved roading
• new recreational opportunities.
One specific example of these is the development of an “out of river” white-water course. Initially it was proposed to construct an in-river course but through the consultation process it was agreed that the out of river option provided more benefits and increased the recreational opportunities on offer in the region.
The course will comprise of a number of different sections, as identified in the diagram opposite. There is a top pool, with slow water for launching boats, and instructional pool, a slow moving section suitable for tubing and instruction, a white water section, and a finishing pool for taking boats out, which may also be suitable for swimming.
The course will provide for a range of recreational users, ranging from those directly involved in the use of the course for white-water sports, to education providers who will use the course as part of their educational programmes, to the general public who will use the picnic areas and walking tracks.
Studies undertaken during the consultation and investigation phase, suggest the course will provide between 6,000 and 9,000 user days, with 1,700 individual users.
The overall feeling amongst those spoken to during consultation was that the white-water course will be an added attraction to one of the world’s top white water destinations. Experienced kayakers will be able to play in the features on days off, or when rivers are unsuitable. For those less skilled, the park will add a graduated or easier experience before moving to the larger rivers.