The Parliamentary Commissioner for the Environment is urging the Government to intervene in consent hearings for intensive dairy farming in the Upper Waitaki.
The proposal to house about 17,000 cows indoors for part of the year on farms in the Ohau and Ahuriri catchments has been criticised by environmental groups and tourism operators.
The commissioner, Dr Jan Wright, says the proposal could have significant adverse effects on the lakes and the landscape.
She has written to Environment Minister Nick Smith asking him to call in, or review, the resource consent hearings to discharge effluent.
Dr Smith says the discharge consent applications need to be heard along with the applications to take water, and this wouldn't be possible if he called in the discharge hearings.
However, he says he will consider Dr Wright's advice when he makes a decision next week on whether to intervene.