Meridian’s proposed MHP cites these benefits:

The Mokihinui Hydro Proposal would:

1. produce between 310 and 360 gigawatt hours (GWh) per year of renewable electricity generation.
2. meet the current and immediate future electricity needs of the South Island’s West Coast
3. provide security of supply to the West Coast region
4. on average – reduce the nodal price on the West Coast in the setting of wholesale electricity prices
5. significantly reduce transmission losses currently experienced which can be as much as 50% at peak demand times
6. provide an upgrade of and new sections of the 16km degraded walking track from near the entrance of the Mokihinui Gorge to the Mokihinui Forks area.
7. Include the formation of a Trust with other individuals and interested parties to investigate the potential to provide a further walking track that would link the Mokihinui Forks to the Lyell.

Points 2 to 5 all assume that there is no West Coast alternatives to generate the required power. The West Coast’s peak demand is about 65MW and projected to increase to around 80-90MW in the near future. Current supply capacity on the Coast is 18.5MW, but the addition of Arnold makes 63.5MW, and a new Stockton dam (subject to due diligence on the environmental impact of that proposal) would cover the projected growth in demand. And this doesn’t even include efficiency and co-generation options in the coal and dairy industries on the Coast, which are the primary drivers of growing demand. Hence, points 2-5 can be met without destroying the Mokihinui.

Points 6 and 7 are misnomers. The track upgrade and developments can be done without the dam, and the Trust is proceeding on this basis already.

Only point 1 remains valid. Inherent in any new project is new generation, that’s self-evident, but the question is at what cost, fiscally and environmentally. The environmental cost of MHP is huge, and the economics of other renewables nationwide are comparable, so that is where some national strategic planning of new generation would be useful. Add to this that the proposed National Policy Statement on renewable energy recognises the inherent irreversibility of a large hydro dam, and well, it’s not rocket science that the MHP is a non-essential and environmentally undesirable proposal.

Hence if we proceed with the MHP, we are simply sacrificing premium biodiversity, a pristine wild river, and our conservation credibility, unnecessarily and irreversibly.

Saving the Mokihinui was not just an election year campaign for the Greens, it continues to be top of mind, and now we have two new South Island-based MPs to help fight it. Hopefully Meridian will see the writing on the dam wall and gracefully withdraw.