By national and international standards, the West Coast region receives a generous and reliable rainfall. Near the Main Divide this exceeds 8,000 mm annually and declines to 2,000 mm at the coast. The mid- to upper Grey Valley possesses the lowest rainfall in the region (West Coast Regional Council, 2005). The West Coast Regional Council (WCRC) reports that issues associated with highly allocated catchments and aquifers are not yet experienced on the West Coast due to the quantity of the region’s resource and low demand pressures. The council maintains that as a water-rich region with low demand, the proposed NES “has little relevance for the West Coast in terms of any need to improve water management”.43 A limited number of takes are currently measured.44
The Ministry for the Environment’s consent database suggests that the total annual allocation of consented water takes on the West Coast is 271 million m3/annum, 90 per cent of which is sourced from surface water. Fifty-four per cent of consented water take is associated with the mining industry (Figure A1). The WCRC reports that although water take by the mining industry is consented, it is not consumptive because it is primarily related to “dredge ponds” and is returned to the environment following settling.44 If mining is ignored, consumptive take on the West Coast is 127 million m3/annum, just 1.3 percent of the national consented annual allocation (≈ 9,908 million m3/annum) of water take.
We estimate that as a result of the proposed NES, the West Coast region will incur a PV10% cost of $2.2 million. This is approximately 5 per cent of the total national cost of the proposed NES. No benefits associated with the potential improvement in allocative or technical efficiency have been identified.
43 West Coast Regional Council, submission on proposed NES.
44 Simon Moran, West Coast Regional Council, July 2007.
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Annex III: West Coast Regional Council
May 2008
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