Central Queensland cotton farmers say they have lost almost 1,000 hectares of crops to flooding in the past week.

The Dawson River at Theodore, south-west of Rockhampton, peaked at 13 metres on Friday night, inundating properties on the flood plain.

Farmers are bracing for another peak later this week, with many of the same properties also suffered losses during flooding in March.

Dawson Valley Cotton Growers Association president Fleur Anderson says it is hard to put a dollar figure on the devastation.

"There are some worse affected than others," she said.

"There are a couple of growers that have certainly reached the devastation level that would come close to what they saw in March, if not the same.

"Some growers are experiencing half-a-million-dollars on their own, let alone as an aggregate."

She says it is not only the growers who are affected.

"The flow-on effects from devastation like this, from flood, they do go on many times through the local economy," she said.

"We've got local harvesters and agronomists and service providers that all rely heavily on this cotton crop as a really big part of their income."

Ms Anderson says it will be difficult for some growers to recover.

"Still trying to stay positive - it does get harder and harder to face two floods like this in nine or 10 months," she said.

"[It] is well above what anyone puts into their risk management portfolio.

"It is something that's getting harder to grin and bear but we are trying to look forward and see what we can do over the next 12 months."