Coal trains recommenced travelling between Newcastle and Maitland after flood waters receded around Sandgate on Thursday.
"These services will operate in a limited capacity while we continue to monitor the situation and assess conditions," an Australian Rail Track Corporation spokesman said.
The flooding meant trains had been unable to access the Port of Newcastle since the afternoon of Thursday, March 18.
As a result, production at some of the region's biggest mines was slowed or suspended.
Newcastle Coal Infrastructure Group (NCIG) - one of three coal terminals at the Port of Newcastle - was also forced to suspend the loading of the fuel onto ships due to equipment issues.
The weather forced a backlog of ships outside the Port of Newcastle, with 40 vessels lined up.
The interruption caused thermal coal prices to jump to their highest level since the 2018 floods halted rail supplies to Newcastle and saw vessels unable to dock.
The loading of wheat at the port's two terminals was also halted.
Pacific National hauls grain to Newcastle along the Hunter line.
Agricultural manager Hugh Cox said the line closure had stopped 16-20 trainloads of grain from getting to port.
A Port of Newcastle spokesman said the port was continuing to monitor the conditions and was scheduling vessels in consultation with Port Authority NSW.
"Each vessel is assessed on a case-by-case basis for its suitability at the time of each scheduled movement," he said.
"The shipping schedule has been continually adapted relative to the weather conditions and safety assessments.
"This type of temporary weather event does not typically have any lasting impact. The port continues to operate and is monitoring conditions closely."
The Australian Rail Track Corporation said the interstate network between Telarah and Grafton remained closed following inclement weather.
"High rainfall, strong winds, fallen trees and debris, power failures and fallen power lines and power poles are all concerns which led to operations being halted," a spokesman said.
"We are currently undertaking a full assessment of rail operations where it is safe to do so.
"Initial observations show significant restoration works will be required at various points along the network where there was severe localised flooding.
The network between Narrabri North and Moree also remains closed due to continued flooding in the north west of the Hunter Valley Network.
