The Green Party’s West Coast-based MP Kevin Hague today lodged a submission in support of a proposed hydro scheme on the Stockton Plateau.

Hydro Developments Ltd has applied for consent to divert water contaminated by mining from the Stockton area into reservoirs and tunnels that will use a 500m drop to sea level to generate approximately 240 gigawatt hours per year.

“The scheme can power more than 30,000 homes,” Hague says “and the Stockton Plateau is heavily modified by coal mining operations so the reservoirs have a small ecological footprint. Diverting polluted water will actually improve water quality in the Ngakawau River.

“This is in contrast to Meridian Energy’s proposed hydro dam in the nearby Mokihinui River that would irreversibly impact rainforest and river species. The Stockton scheme shows we don’t need to damn the Mokihinui to satisfy local electricity demand. It completely undermines Meridian’s argument.

“Damning the Mokihinui in the face of environmentally-positive alternatives like the Stockton proposal would be bloody-minded vandalism. Meridian should withdraw its proposal which is now patently unnecessary and I invite West Coast Tasman MP Chris Auchinvole to join me in this call.”

While supporting sustainable renewable generation like Stockton Hydro, the Green Party also reiterates the urgent need to pursue energy conservation and efficiency measures such as the $1 billion fund for insulation and clean heating recently dumped by the National Government, Hague says.

“Our submission does identify some aspects of the Stockton Hydro that need to be addressed such as avoiding any risk to Hectors dolphins from discharging the scheme’s water into the sea.”

The beautiful Mokihinui River

Photo Credit: Q

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.