Defects in TrustPower's Wairau proposals
12 January 2006 Wellington
Reports show defects in TrustPower's Wairau proposals
Independent reports for Marlborough District Council reveal glaring inadequacies in TrustPower's application for a hydro scheme on the Wairau River, Marlborough, Forest and Bird said today.
"Comprehensive reports by NIWA, Kingett Mitchell Ltd, and DamWatch Ltd support Forest and Bird's position that Trust Power's application for a hydro scheme on the river is flawed," says Forest and Bird Regional Officer, Debs Martin.
"The NIWA report asks the Council to not make decisions on granting the applications until the recommended investigations are carried out and the further information is provided."
"The Wairau is an internationally important braided river, home to two endangered birds and is one of the last free-flowing braided rivers without major abstraction." says Ms Martin.
"Key issues such as groundwater, water quality, and the effects of flow fluctuations on the river - even below Marchburn - are not adequately addressed," says Ms Martin. "Factually incorrect statements have been made about the effects on the endangered birds and fish populations, and these have been carefully criticised by these reports."
"Given the hearing is expected to start in April, we hope the Marlborough District Council will ensure further information is sought from TrustPower and the hearing is delayed until this information is available."
The Wairau River is home to two endangered bird species the black-fronted tern and the black-billed gull. The river contains one of New Zealand's largest breeding populations of the endangered black-fronted tern. The Wairau River provides important habitat for the endangered black-billed gull. Reduced flows in the river will result in decreased habitat, increased exposure to mammalian predators, and less food supply for these birds.
Demand for hydro schemes on braided rivers threatens these very important ecosystems, of which New Zealand's braided rivers have amongst the highest rates of endemism in the world.
Forest and Bird is in the process of seeking formal recognition of the importance of the Wairau River as a wetland of international importance under the Ramsar Convention. Farewell Spit already has this status in New Zealand.
In July 2005, TrustPower lodged a resource consent application with Marlborough District Council to construct a 70 MW hydro-electric power scheme on the biologically internationally significant Wairau River.
Marlborough District Council commissioned the National Institute of Water and Atmospheric Research (NIWA), Kingett Mitchell Ltd and DamWatch Services Ltd to provide independent expert advice on the completeness and adequacy of TrustPower's application. TrustPower asked the Council to publicly notify the resource consent applications, despite the Council not yet receiving these reports. As a result, the resource consent applications were notified in early September 2005 and closed on 4 November 2005.
The reports were finally received by the Marlborough District Council on 23 December and were formally received by interested submitters on 10 January. These reports show significant concerns about TrustPower's application.
Some examples are: (our emphasis in bold):
Under moderate flows, variable amounts of water will be diverted through the Scheme throughout the day ...cause short-term flow fluctuations in the residual river. There is no description of these, or any assessment of the effects of this on river ecology...
The effect of the altered flow regime, particularly extended periods of low flow, on vegetation growth and channel stability has not been considered. This would be relevant to riverbed bird nesting and feeding habitat...
There has been no quantitative assessment of potential changes in water temperature...
There has been no prediction of water quality in the residual river, in the canal, at the outfall site or downstream during the operation phase. A reduction in flow will affect the residual river's capacity to dilute and assimilate contaminants. (pvii)
Given the conservation status of black-billed gulls it is unfortunate that the vulnerability of nesting sites of this species were not assessed too. (p131)
The report is disappointing in the way that it understates the significance of the bird populations of the Wairau River ... and fails to make meaningful comparisons of the bird numbers on the Wairau compared to other braided rivers ...
The summary makes several factually inaccurate and/or unsubstantiated statements about the significance of the Wairau River bird community and the effects of the proposed HEPS [scheme]. (p133)
The NIWA report concludes:
We recommend that MDC does not make decisions on granting the applications until the recommended investigations are carried out and the further information is provided. ... We recognise that ... would impose significant costs and time delays to Trustpower. (pix)
Similar statements can be found in the other reports:
The various reports relating to this set of effects do not provide adequate specific and quantitative assessment of effects on groundwater. (Kingett Mitchell Ltd, Hydrogeology report, p12)
The Applicant has not undertaken any site specific consequence assessments to determine the effects of potential canal failure along the canal route. This means that there is no specific assessment of public safety, environmental or other effects related to potential canal failure ...
The risk of canal failure due to tributary flood flows entering the canals has not been adequately addressed. This is a significant issue. (DamWatch Services Ltd, pi)