A group of Labour MPs who went on a site visit of the proposed Ruataniwha Dam say they have more questions to pose to the project's promoter, the Hawke's Bay Regional Council and its investment company.
MPs Moana Mackey, Ruth Dyson and Maryan Street were taken on a guided tour of the dam site near the Makororo River in the foothills of the Ruahine Range yesterday morning.
In the afternoon they met representatives of Hawke's Bay Fish and Game and Transparent Hawke's Bay to get "a balanced view" of the pros and cons of the controversial water scheme.
Ms Street said she did not realise the enormity of the project until she visited the site yesterday.
"When I saw the area that was going to be filled in (with water) I thought, this dam is going to be bigger than anything we have seen before," she said.
The three MPs told those at the afternoon meeting there were more questions which needed to be answered before the Labour Party could take a position on the project.
And Ms Dyson said the Hawke's Bay Regional Council indicated it was happy to respond to additional questions as a result of the site visit or the afternoon meeting.
Ms Street said she was particularly worried about the elevated level of nitrogen proposed to be allowed in the tributaries leading out from the dam, including the Tukituki river, as a result of more intensive farming in the Ruataniwha Plains.
"There's no doubt it's a huge proposal and we still have questions around the finance of the project and its environmental impacts.
"I can't see how an increase in nitrogen is going to be good for anything accept the things we don't want. We have got a lot of questions before we find a position on it," she said.
Agribusiness consultant Barrie Ridler and scientist Corina Jordan appeared for Fish and Game to speak to the MPs at the afternoon meeting.
They said their research suggested the dam wouldn't stack up economically and the Ruataniwha Plains weren't suitable for major arable crops, which could lead to dairy being the main option for production on the land.
Ms Jordan said levels of nitrogen and phosphorus needed to be reduced together to control the problematic periphyton (algae and slime) which had appeared in some parts of the Tukituki river.
Mr Winder said the long-held idea of New Zealand upping its primary production to be an export market leader needed to be changed because the country was not able to compete with bigger producers.
"We've got to be thinking smarter and look at what other options there are, looking forward to the future rather than hanging on to this notion."