The controversy around the massive Ruataniwha Dam irrigation scheme is spreading with the Green Party today claiming GNS scientists concerned about water quality issues were effectively gagged by Hawkes Bay Regional Council which is pushing the project.

Conservation Minister Nick Smith has faced calls for his resignation from the Greens after they said he was responsible for the suppression of a Department of Conservation report which raised concerns about the project and an associated water management plan.

It has also emerged that the Ministry of Primary industries expressed concerns about water quality issues stemming from the project but those concerns were watered down in its submission.

Today in Parliament Green Party Co-leader Russel Norman claimed that Geological and Nuclear Science (GNS) scientists hired by the Hawkes Bay Regional Council to conduct groundwater modelling work related to the dam raised "serious concerns'' about information provided by the council to support that work.


Questioning Science and Innovation Minister Steven Joyce, Dr Norman asked whether those scientists were pressure to complete their report on the dam by the council, "despite their objecting strenuously to the accuracy of the information they were supplied to work with''.

Dr Norman asked whether the scientists' contract with the council was terminated after they insisted on recording their concerns in their final report.

Answering on behalf of Mr Joyce, Nikki Kaye said the contract was a matter for the council and GNS and she no knowledge of what Dr Norman was alleging.

Dr Norman continued his attack asking for confirmation the council ended up using an earlier GNS report which did not set out the scientists' concerns in its application for resource consents for the project.

He also asked whether Mr Joyce was concerned "that science is not being listened to in the Tukituki catchment process around this dam''.

"The Department of Conservation's scientific submission has been suppressed, the concerns of the Ministry for Primary Industries were suppressed, and now GNS Science scientists' concerns were also suppressed.''

Meanwhile, Dr Smith also faced a further grilling from Labour's conservation spokeswoman Ruth Dyson over whether he knew of a 34 page draft submission from his department which was critical of the scheme. The report was reduced to two paragraphs after Dr Smith expressed concerns about the submission. However he maintains the decision to alter the submission was entirely down to senior department staff.

The $256 million Ruataniwha irrigation scheme involves the construction of an 83m dam on the Makaroro River in Central Hawke's Bay, creating a reservoir capable of storing 91 million cubic metres of water which could potentially irrigate 20,000-30,000ha, depending on land use.


The board of inquiry considering the project begins hearings next month and is expected to issue its decision next April.

The Greens say the project could be used as model for future developments and the regional council's planning regime for water quality could be copied elsewhere.