As evacuated residents in Sydney's south-western outskirts waited anxiously for news of their decimated suburbs on Sunday afternoon, a convoy of vehicles arrived bearing swiftly gathered gifts from one generous community 40 minutes' drive away.

Gillian Bufton, a nurse from Russell Vale, north of Wollongong, had spent Thursday night thinking about how she could help communities affected by the Green Wattle Creek fire. She posted to a local Facebook group, asking if anyone else felt the same.

Community members from Russell Vale deliver water, food and other supplies for families affected by bushfires. Credit:James Brickwood

Within a couple of days, that post turned into several vehicles' worth of supplies and more than $3000 in gift vouchers being dropped off to Wollondilly council on Sunday.

"It took off … we started off with just a thought, a bubble, and it's just blown into this," Ms Bufton said, gesturing to about five trailers' worth of food, water and other "survival mode" supplies waiting to be distributed to communities hit by fires.