John Barilaro on Sunday said the NSW coalition would spend $650 million raising the Wyangala Dam wall in the state's central west, the first major allocation of cash from the Snowy Hydro Legacy Fund.

An extra $400 million from the fund will be allocated to improving regional internet, Mr Barilaro said in a speech centred upon the slogan "it's your time".

"We are on the brink of reaping the benefits of all this hard work," Mr Barilaro told the crowd at the town's performing arts centre.

"That's why now isn't the time to change the jockey mid race."

Mr Barilaro said he had a healthy respect for the minor parties in the bush, and added the coalition was fighting against history to win a third term.

"It's been 50 years since we've won a third term, so the reality is we don't take it for granted, we are the underdogs," Mr Barilaro told reporters after his speech.

"You want to call it 'terrified,' I actually call it respect."

Mr Barilaro also revived an almost century-old inland irrigation plan that would funnel water from Queensland, through NSW and into South Australia.

Mr Barilaro promised the government would allocate $25 million to researching the merits of the Bradfield scheme amid record-breaking drought.

The Nationals leader said he would write to Prime Minister Scott Morrison this week to "start the discussion" on the plan that Deputy Prime Minister Michael McCormack had already expressed interest in.

The plan would need the consent of Queensland, South Australia and the federal government, but dismissed that it was a short-term policy thought bubble ahead of a tight election on March 23.

"In the past it's been looked at ... it's had some failings. What we're saying is let's pick that up and have another look at it in this day and age," Mr Barilaro told reporters following his speech.

However Queensland Natural Resources Minister Anthony Lynham was skeptical of the NSW government's interest in the policy.

'For nearly a century, whenever politicians are in trouble, they roll out the Bradfield Scheme," Dr Lynham told AAP in a statement.

Mr Barilaro said raising the Wyangala Dam wall would bolster water security for towns in the Lachlan Valley, including Cowra, Forbes and Condobolin.

"There is nothing more important for our regional communities and businesses than to have access to safe and reliable water," Mr Barilaro said.

NSW Premier Gladys Berejiklian made a brief appearance at the campaign launch where she attacked NSW Labor's alternative plan for regional communities.

"Every four years you witness NSW Labor cynically blow the dust off the Country Labor brand," Ms Berejiklian said.

Mr Barilaro also announced the coalition would introduce a new minister for regional youth, given the task of addressing underemployment and suicide in teens and young adults living in the bush.

"Our regional towns are losing the very people they need to stay, so it's our job to give them the opportunities and support they need to live great lives outside of big cities," he said.

Australian Associated Press