Following the failure of the tailings dam in March last year, consulting firm Golder is understood to have provided modelling to Newcrest Mining suggesting the mine could run out of water in two months' time.

CVO has continued to extract water from the tailings stored in the open pit since the failure, but the pumping barge hit the bottom of the Upper Rodds Creek storage in February.

Newcrest needs about 160 million litres of water a day to operate Cadia, with about 40 million litres required to come from river pumping, rainfall and groundwater bores.

General manager Peter Sharpe confirmed water requirements and storage were being reviewed daily as part of its water strategy.

"Cadia will not run out of water in July and currently has sufficient water on site," he said.

"Cadia is utilising water from its current onsite water storage facilities, Orange's effluent water in accordance with an agreement with Orange City Council, as well as existing borefields, return water from the tailings storage facilities and water collected from the Cadia extended pit in accordance with project approval requirements."

Electric pumps recently replaced diesel pumps to extract water faster.

Years-long negotiations are still under way on the effluent agreement with the council, with CVO still operating under the original conditions.

But Mr Sharpe did say CVO was turning to other external water sources, purchasing Belubula general security water released from Carcoar Dam.

CVO has also been buying farm properties next to the mine, although the company has maintained it was not in an effort to accumulate water licences.

"It is being purchased through a water broker to maintain independence and fair distribution across several water users and we are only purchasing water from landowners expressing interest to sell their water shares," Mr Sharpe said.

He also said the Department of Water had approved plans to stop flows from Cadiangullong Dam, provided a detailed ecological monitoring program was implemented and Cadia continued to consult with surrounding landholders and key representative groups, including the Belubula Irrigators and Water NSW regarding its water strategy.

Orange is under level four water restrictions.