The variation, approved by DOC this month, was sought by Griffin Creek Hydro Limited after they reconsidered their original scheme details. It allows more space for construction to take place, before returning to the smaller footprint, allowance for larger trees to be assessed for removal and a new alignment for part of the pipeline route.
DOC Operations Director West Coast Mark Davies says the effects of the varied scheme details are not materially different to what had already been authorised in 2011, but the existing construction and operational plan must be varied and approved before construction begins.
"We expect the effects of this variation can be easily managed and mitigated through existing concession conditions, and new conditions imposed through the grant of the variation."
In 2011 the concessionaire was authorised by DOC to construct a hydro-electric power scheme, which included a track, pipeline and intake structures. According to the applicant, the scheme could power around 2,000 homes. No dam is included in the proposal.
The 2011 concession application was publicly notified at the time and was subsequently granted a 30-year term, however construction, other than part of an access track, has not begun.
The variation allows for; a partially new alignment for the pipeline route; a larger area for the construction of the intake structure – from 45 sqm to a maximum of 100 sqm, reducing to 45 sqm on completion; allowance for larger trees to be assessed for removal – a maximum of 50 cm diameter at breast height from 20 cm; and the easement area to increase from 0.5 ha to 0.6 ha during construction, reducing to 0.5 ha for ongoing operation.
No increased water take was requested.
In the years since the initial hydro scheme was publicly notified and approved, Griffin Creek has become a location known for recreational canyoning, Mark Davies says.
"Since about 2013, the area has seen increased visitation from recreational canyoners. We acknowledge that this has increased interest in the activities permitted on this stretch of river.
"However, the increased effects of this amendment are minor - no change in the quantity of water-take was sought and the location and scale of the intake infrastructure will not change significantly. Because of this, DOC did not publicly notify the variation application.
"We did however ask for and receive input from the NZ Canyoning Association (NZCA) on the four proposed variations to better understand the potential effects on recreation values from their perspective. DOC also received input from 2 other parties. DOC appreciates the input of these groups."
The opportunity was taken in the variation process to correct a typographical error in the original concession. This clarified that the original intent was to approve 45 sqm and not 12 sqm for the intake structures.
Griffin Creek Hydro Ltd decision support document (PDF, 5,114K)
Background information
Griffin Creek is approximately 25 km east of Kumara township on the West Coast, on stewardship land.
The concession authorising construction, operation, maintenance and repair of the hydro scheme was granted following public notification on 1 February 2011. At the time, no major impacts on recreational use such as canyoning were raised.
A small amount of track work was undertaken by the applicant following the granting of the authorisation however construction did not begin on the main scheme.
In the intervening years the applicant has collected more hydrological data and considered the scheme's design.
A variation was first sought by the concessionaire in 2019. DOC advised that variation would require public notification. This variation was withdrawn by the applicant before public notification was initiated. The concessionaire subsequently submitted a new application to vary their current conditions, the effects of which were considered by expert advice to be materially like what was already approved in 2011. This variation is what has been approved.
