From an overall $400 million to fix country lines, the NSW Government will spend $5 million re-opening part of the Demondrille -Young-Cowra- Blayney branch line, a 56 kilometre section from near Harden, to Maimuru, a silo siding north of Young.

Upgrading branch lines like this one will trigger flow-on benefits, such as GrainCorp's $200 million infrastructure upgrade on loading bins, rolling stock and associated infrastructure.

Losing profits from their gran harvest to inefficient freight systems, the farmers banded together with five councils to push for upgrading the 120-year-old line from Harden to Blayney.

The partial re-opening has raised hopes the entire 180-kilometre track will eventually re-open, saving councils money and making roads safer.

Former Harden mayor and farmer Chris Manchester, said the Maimuru-Demondrille section needed the least amount of work. "I am hopeful we see some trains on it within the next 12 months," he said.

Cowra mayor and farmer Bill West has led the campaign since 2011. Cr West says much detail from the NSW Government is still missing from the re-opening plans, but sees multiple benefits. Cr West says Transport Minister Duncan Gay has been a key driving force.

He said as well as grain going to Port Kembla, freight including fertilisers, chemicals and fuel could come out of the port on trains instead of trucks and into the region.

"No one has ever done a study on savings for roads, we know it will be a savings on local and state roads, and in the community's mind, a road safety issue," Cr West said..

The re-opening follows earlier funding of $8 million to upgrade Cunningar siding near Harden. GrainCorp, farmers, Harden's benevolent Geoffrey Kruger Trust and the federal government are funding the project, so trains can load up with grain in 24 hours, rather than 48 hours.

This is estimated to remove 4,000 truck movements per year from local roads.

Harden Silo Committee chairman Barry Alcorn said farmers would save $10 a tonne, or 30 per cent of their freight costs, once the siding is upgraded. "Trains had to split up and 10 wagons at a time had to go back into Harden and shunt back and forward because they could not pull a full train out of [Cunningar siding] because of access onto the line," Mr Alcorn said..

"It would take longer than 48 hours to shunt and load them, and to hook onto a big locomotive and pull 40 wagons down to Port Kembla," Mr Alcorn said.

Another big advantage from a quicker trip to port was buyers offering a premium for a late load of grain to complete filling a ship, he said.