The Department of Transportation announced the immediate availability of $100 million in emergency relief funds for North Carolina in the wake of Helene, which devastated roads and bridges in the western part of the state.

"We are providing this initial round of funding so there’s no delay getting roads repaired and reopened, and re-establishing critical routes," Transportation Secretary Pete Buttigieg said in a statement.

"Further support will follow," Buttigieg tweeted.

Hundreds of thousands of customers in the South are still without power, more than one week after Hurricane Helene made landfall.

More than 174,000 customers are in the dark in South Carolina and 179,000 are without power in North Carolina. Another 151,000 are without power in Georgia.

"This has been a historic storm. We've never seen anything like this," Duke Energy spokesperson Bill Norton said this week. "The biggest challenge has been the unprecedented flooding. It’s not just poles and wires that are down -- it's the backbone of our system, the transmission infrastructure and substations."

Around 400 nurses and 40 doctors from states around the country have arrived at Mission Health, a hospital in Asheville, North Carolina, to provide support in the aftermath of Helene, hospital officials said Friday.

"This is a difficult time and we are doing all we can to bring help and relief to those in need," HCA Healthcare, which runs the hospital, said in a statement.

-ABC News' Youri Benadjaoud

Asheville Assistant City Manager Ben Woody stressed the importance of the North Fork Water Treatment Plant, which supplies 80% of Asheville's water.

"Restoring service after the storm depends on this system," Woody said.

He detailed storm damage, including the washout of two major waterlines -- a 36-inch and a 24-inch -- mirroring a 2004 disaster.

The city’s top repair priority is a 36-inch bypass line installed after that event, he said.

"If we get this bypass online, we can restore 80% of the system," Woody said, noting progress as of October 3.

Woody also confirmed the Mills River Water Treatment Plant, serving South Asheville, Buncombe and parts of Henderson County, is fully operational, producing five million gallons per day—about 20% of the system’s needs.

"There’s still a long way to go," he added.

-ABC News' Jason Volack

Hurricane Helene has caused "complete devastation" to North Carolina's roads, bridges and water systems, Gov. Roy Cooper said on Thursday.

"Our focus right now is on restoring primary arteries for supplies, medical aid and utility crews," Cooper said, noting that billions of dollars will be required to fully rebuild the region’s infrastructure.

"We need to rebuild in a more resilient way, understanding that this kind of destruction is now a real possibility,” he said.

Over 1,000 National Guard troops and 32 aircraft are delivering supplies daily, Cooper said, and the government has "surged hundreds of thousands of pounds of food and water" to impacted communities.

Search and rescue are still ongoing, Cooper added.

The governor stressed that recovery will be a long-term process.

"We know people will need assistance for a while, especially with power and water systems down," he said.

-ABC News’ Jason Volack