It's a journey that brings life to some of the most remote parts of Australia, and following months of dry, punishing heat, the parched gibber plains of Queensland's Channel Country are being recharged by floodwaters.

But that's not the end of their travels.

The water is slowly threading through vein-like tributaries towards South Australia's Lake Eyre.

Water arrived in the South Australian outback town of Innamincka before dawn on Friday, with flows expected to peak in the Queensland town of Birdsville over the weekend.

Outback pilot Trevor Wright said Birdsville — 1,953 kilometres from Brisbane — would be cut off in the coming days, with some water already flowing down the Diamantina River towards the South Australian border.

From there, floodwaters will weave through channels that cut through vast cattle stations and desert plains before arriving at the great inland salt basin of Lake Eyre, 647 kilometres north of Adelaide.

"We will see Birdsville start to be isolated in the next couple of days, with water that is already trickling down from Queensland starting to build," Mr Wright said.

"It's an event that will last a few months."

Roads around Birdsville have been closed as the Diamantina River rises. ( Supplied: Darren Collins )

Jo Fort, general manager of the Birdsville Hotel and Innamincka Hotel, said floodwaters had arrived down the Cooper Creek in Innamincka on Friday at 6:00am.

"The relief is tangible — it has been dry here since December," she said.

The roads south and east of Birdsville were closed on Friday as water levels rose on the Diamantina, with water peaking at Roseberth Station upstream earlier in the week.

In Birdsville, locals have watched the river to the east of the township steadily rise, with flood markers showing water rising above 1.5 metres late on Friday.

"We expect the water to peak [Saturday] or Sunday," Birdsville Hotel assistant manager Darren Collins said.

"It's the start of the tourism season so this is great news for us.

"Channel Country looks fantastic in flood and once the waters subside we'll start to see the grasses and wildflowers arrive."

Mr Wright said he had no doubt the floodwaters would eventually make their way down to Lake Eyre via the Warburton after filling Goyder's Lagoon, but most importantly they would give nearby cattle stations welcome reprieve from dry conditions along the way.

It's been dry in Birdsville since December, locals say. ( Supplied: Karl Musser )

Water a welcome reprieve for pastoralists

Bureau of Meteorology rainfall records for the region show the past 12 months have been dry, with below average rainfall across the border of the Northern Territory, Queensland and South Australia.

Senior hydrologist Paul Lainio said the "useful flood" was much needed and was sufficient to replenish local water sources and billabongs.

"This is lifegiving for the region and will renew longer term water sources for cattle and farmers," he said.

"We do think there will be a flow that makes it to Lake Eyre but we don't expect it to fill."