Around half-a-million people in NSW are subject to an evacuation order or warning as the state grapples with an unprecedented flood crisis.

Acting Chief Health Officer Marianne Gale says anyone isolating because of COVID must evacuate if they are ordered to do so by the State Emergency Service.

"If you are told to evacuate, you must evacuate," she said on Thursday.

"Under no circumstances should you remain in self-isolation at your residence - your safety is our highest concern and an emergency evacuation is a valid reason to leave your home."

NSW Health advises COVID-19 positive people at flood evacuation centres to notify staff, wear a mask and physically distance from others.

There are 1035 COVID patients in hospital, 43 of them in intensive care.

One of the seven men and two women who died from the virus on Wednesday was aged in their 30s.

A person in their 40s also died, as did two people in their 50s, one person in their 60s, two people in their 70s, one person in their 80s and one person in their 90s.

It's the second consecutive day that cases have inched above 10,000 after two weeks of cases tracking below that benchmark.

NSW Health reports 54.8 per cent of people have received their booster shot of a COVID-19 vaccine, 79 per cent of people aged 12-15 have had two doses, and 47.6 per cent of children aged 5-11 have had one jab.

Restrictions have eased this week with masks no longer required in most indoor settings, and people being encouraged to return to work in city centres.

Mask mandates in most indoor settings were dropped on Friday, and they were lifted in schools on Monday.

Australian Associated Press