Ashburton hydro scheme gains consents

The Ashburton Community Water Trust (ACWT) and Ashburton District Council have been granted resource consents to use Rakaia River water to generate electricity.

The Rakaia Terrace hydro scheme proposes to take up to 40 cubic metres of water per second (cumecs) from Highbank and discharge it at Barrhill.

The ACWT jointly applied for 40 cumecs of Rakaia River water with Central Plains Water Trust (CPWT). The CPWT irrigation scheme will reopen in October this year after commissioners recently met to consider how that scheme might proceed without its water storage component. (http://www.ecan.govt.nz/Resource+Consents/Central+Plains+Water/Hearings.htm)

If it obtains consents, CPWT would use its allocation during the irrigation season, whereas ACWT would use the water outside the irrigation season.

The commissioners have previously noted that the ACWT scheme is a much simpler application with less environmental effects that the proposed CPWT proposal.
The ACWT scheme returns the water to the river, CPWT would use up to 40 cumecs for irrigation. The proposed takes are at different locations on opposite sides of the river.

The application was heard by Environment Canterbury and Ashburton District Council -appointed commissioners Philip Milne (chair), Andrew Fenemor and Ray O’Callaghan.

The commissioners had issued interim consents in December 2008, subject to a full ecology survey from Highbank to Barrhill to determine potential effects on the environment, in particular birdlife and lizards.

They have now concluded that any adverse effects on the environment would be adequately avoided, remedied or mitigated and that the scheme is sustainable. They considered it unlikely that the diversion of water would lead to any sediment build-up upstream of Barrhill as a result of the maximum 23 cumec flow reduction. The Rakaia Water Conservation Order ensures that water can only be taken at relatively high flows, commissioners said.

The consents have been issued until January 28, 2035, a date that coincides with the expiry of the Barrhill Chertsey Irrigation and the Electricity Ashburton Limited consents.

A summary and a full copy of the decision are online at http://www.ecan.govt.nz/Resource+Consents/Hearing+Decisions/