Murrumbidgee general security water allocations went up by a paltry 4 per cent on Monday, giving farmers access to 30 per cent of their entitlement at the crucial time of deciding the scale of their summer crop.

Whitton cotton grower Roger Commins said the local cotton industry, worth roughly $150 million, was forced to rely on a "best guess" because the Department of Primary Industries' Office of Water was too conservative.

"It is so frustrating that the dams are 70 per cent full and up, but you have to be conservative now," Mr Commins said.

"They just have to come out with a figure of what they realistically think the allocation will be, otherwise the opportunity is lost for summer croppers.

"In our instance, we will only be prepared to plant somewhere around 60 per cent of our capacity, because we can't take the risk with any more than that it's just too much money to outlay."

Mr Commins said overly conservative allocations were everyone's problem, given the city of Griffith was financially dependant on agriculture.

"Over $150 million from cotton comes back into this town and the towns of Hay, Coleambally and others," he said.

Mr Commins and other cotton and rice farmers had already begun preparing the ground for sowing, without knowing how much water he will have to irrigate the crop with.

Mayor John Dal Broi was furious allocations were still so low given the Burrinjuck and Blowering dams were 79 and 71 per cent full respectively.

"The whole system has been corrupted by bureaucrats and farmers have something to worry about," Cr Dal Broi said. "Our future economic viability in Griffith is dictated to by bureaucrats in Sydney well I would challenge them to tell me why they are holding all the water back when the dams are nearly 80 per cent full, is it for the environment?

"Farmers are still in limbo about what they're going to do with their crops, unless they've purchased an enormous amount of water to carry over.

"For the average farmer without carry-over to only have 30 per cent allocation is an absolute disgrace they are messing around with people' futures."