The Rail Tram and Bus Union is calling for unused railway lines to cart water to drought-stricken towns

There's a new idea being thrown around to connect drought-stricken NSW towns with water, and it involves rail.

Rail Tram and Bus Union NSW Secretary Alex Claassens thinks disused railway lines across regional areas could be used to transport drinking water to towns with a dwindling supply.

It's already being done to support two mines near Lithgow. He said Southern Shorthaul Railroad (SSR) were carting 725,000 litres per day to Centennial Coal's Charbon and Airlie mines and this signaled the possibility for other areas to do the same.

He has flagged the Armidale to Tenterfield line, Blayney to Demondrille line, Casino to Murwillumbah line, and Rylstone to Mudgee line as ones that could be used to make this plan a reality.

"There are disused rail lines in many parts of the state that are begging to be reopened or, at a minimum, properly preserved," Mr Claassens said.

"The SSR example in regional NSW is a great one. Transporting water between sites by train is not only helping drought affected areas, but it's also creating jobs.

"Rail is a much better alternative to road for a myriad of reasons. There's little doubt the smartest and safest way of transporting goods."

The idea comes at a time when the Bureau of Meterology is predicting little rainfall for most of the state between now and October. The forecast for summer already looks like it will be hotter than average with lower than usual rainfall.

Right now 94.4 per cent of NSW is in intense drought, drought or drought-affected according to state government mapping.

The drought has gone on so long that entire towns are now feeling the pinch. Some shops have already been forced to close while others are hanging on by a thread.

Communities in the Upper Hunter and northern NSW are enduring the worst of the conditions in the state at the moment.

The falling water supply in many areas is also another hurdle for residents.

Mr Claassens said many communities were already thinking about the future of railway lines that were no longer being used.

"Particularly at the moment, when our regional communities are being hit hard by drought and unemployment, we've got to start looking at smarter ways of doing things and rail is often the answer," he said.

"Our governments should be looking at rail as a realistic, sensible solution for assisting drought-affected businesses and communities; getting trucks off our roads; and boosting employment."