PYRAMID-Boort irrigators have been told they face water price hikes of up to 22 per cent a year for the next three seasons under a draft Goulburn Murray water plan.

The price hike would more than double irrigators' water prices by 2012-13.

Other irrigators in the Rochester irrigation district have been told they face a 17 per cent annual hike in their water bills in the same period.

The Goulburn Murray Water corporation has immediately gone on the defensive, refusing to detail what pricing proposals it has put to its water service committees.

But Nationals Member for Rodney Paul Weller said a local irrigator had confirmed a draft increase of 17 per cent was going to be applied to at least one district.

Mr Weller said he understood the price hike was in part due to higher maintenance costs resulting from the food bowl irrigation modernisation works.

However, GMW chief financial officer Peter Guy said the pricing proposals put to water service committees were nothing more than what would apply if the highest level of service and asset maintenance was applied to every part of each district.

"We've given them the Rolls Royce version," Mr Guy said.

He said it was now up to GMW and the water service committees to trade off short-term versus long-term investments and costs in running their districts.

Mr Guy said the ultimate price would depend on:

How irrigators paid their $100 million share of the $1 billion stage-one food bowl modernisation project.

How they wanted to repay accumulated deficits resulting from previous poor seasons.

How much of their advanced maintenance program they wished to meet.

Victorian Farmers Federation water council chairman Richard Anderson said the reality was irrigators were not going to be paying the sort of price hikes that were flying around the rumour mill.

He said whatever was being proposed would be subject to negotiation.

Mr Anderson said he felt irrigators' $100 million contribution to the food bowl project should be spread over 10 years and much of the maintenance program should be set aside until it was clear how much of that work would be done under the food bowl project.

The Weekly Times understands the draft three-year price increases range from less than 5 per cent to more than 22 per cent.