Local regulators have notified the public of an application by New Zealand generator TrustPower Ltd. to add a 46-MW hydro station to the existing Arnold Dam small hydro site. Public comments are due January 19.
TrustPower proposes to use the existing Arnold Dam, located near Greymouth on the west coast of New Zealand’s South Island. Arnold Dam would divert flows from the Arnold River into a new pond, then to a new powerhouse. The existing 3-MW Arnold powerhouse would be retained to provide residual flow into the river, which is an important trout fishery.
The West Coast Regional Council and the Grey District Council are to study the application for resource consent and weigh any comments received before conducting resource consent hearings. Information is available from a joint council Internet site linked to www.arnoldpower.co.nz.
The proposed scheme, to cost NZ$185 million (US$124 million) and generate 220 gigawatt-hours annually, evolved from TrustPower’s original Dodson generation proposal to help the West Coast meet growing demand. The generator has refined the plan from a 2000 proposal for a 70-MW plant.
TrustPower already obtained consents to refurbish Arnold Dam in the next several years. In assessing the needed repairs, company engineers also determined the possibility of expanding the project’s generating capacity.
Works would include a canal, a new dam impounding a new reservoir, a tunnel, and a powerhouse. Capture of flow currently spilled at Arnold Dam, plus increased head, would provide the increased hydraulic potential. The construction period would be about two years.