Council CEO David Waddell announced on Thursday without any rain Orange would be forced onto the toughest restrictions in the nation in just 112 days time.

And he said without extra inflow into the city's water supplies Orange would "be close to empty" by December and empty by early next year.

The city's supplies are now down to just 23 per cent.

Mr Waddell said residents had done all they could to cut water use, "leading the country," but now the top 50 business users would be asked to do their bit.

"We will focus on the top 50 non-residential users with the aim of reducing their consumption," he said.

"If we can make gains in the non-residential sector we could delay Level 6 and extend the life of the supply or delay Level 6.

"Our engineering team and the state government are working on 12 projects all of which could push out Level 6 restrictions significantly, as of course rain will."

He said the council executive and councillors would review the situation weekly and give public information.

"We will be working with the Top 50 business water users. Our staff are out there already working with them and we will target, between now and May 1, all of those businesses to try to postpone Level 6 restrictions," he said.

The city's top users include schools and hospitals.

VIDEO: The dry situation at Suma Park Dam

"The most vulnerable ones would be schools and hospitals and that sort of sector. But we're not proposing to start with schools and hospitals. We are going to start looking at industry, some of the high water users there," he said.

"Those industrial users have the opportunity to find alternative water sources, it's not just a question of turning off the tap. There must be a lot of people using potable water who can use bore water and there are a quite a good number of bores still around Orange, and dams.

"We will be working with those businesses to try to see if they can find alternative sources."

"We've seen car yards working off bores, we've seen some scaling back already and their businesses are still going."

Mr Waddell said council was by-passing Level 5A restrictions because "they didn't add up to give us any significant gains".

Orange mayor Cr Reg Kidd said every drop of rain was vital as was the city's stormwater-harvesting schemes.

He said a storm on Tuesday had produced enough rain to add one day's water supply. "[And] the [Molong] creek is still flowing into Lake Canoblas from the mountain from the late snowfall we had."