Instead of waiting for the river to reach 108 megalitres of flow a day at the Long Point crossing before being able to supplement the city's water storage, the council will only have to wait for 38 megalitres.

Last year, the river level meant council was able to pump on 56 days, but had the trigger point been lower, it would have been able to pump on 148 days.

However, the river has been flowing at just two and three megalitres a day for the past week.

Mayor Reg Kidd acknowledged on the current flows, the council would not be pumping, but said it was part of "a suite of tools".

"It is only for emergencies while this drought persists... and where sufficient flows are in that river," he said.

Cr Kidd said the modelling had shown extracting more water would not harm the river's ecology for downstream users, with ongoing native animal monitoring, including the platypus and the rakali.

Nationals upper house member Sam Farraway said the trigger point was the first to be considered as part of the Critical Needs Water legislation, introduced last year to fast track water infrastructure by up to six months.

He said the council's approval would last 12 months.

"It will lapse at the end of 12 months unless there is an additional application for an extension of six months made to the water minister," he said.

Mr Farraway said the approval would be voided earlier if the combined storage of Suma Park and Spring Creek dams exceeded 50 per cent.

They are currently sitting at 21.3 per cent.

He commended the Department of Planning, Industry and Environment for turning the approval around in six weeks.

"Changing the pumping trigger point is a significant change from 108 down to 38," he said.

He said without the additional water, Orange would not have 12 months-worth of supply remaining, despite residents' "impressive" efforts to cut consumption.

"I would say Orange, across regional NSW, is leading the way, taking the issue seriously and minimising their water usage," he said.

The stormwater harvesting system has already harvested 16 megalitres a day, or two day's supply from weekend rain, with more expected.