Washout

It's being described as a disastrous finish to harvest, as heavy rains across most of the grainbelt threaten to downgrade millions of tonnes of grain.

Several Wheatbelt and Great Southern areas have been hit by the wettest December on record, leaving some growers unable to get onto paddocks for weeks.

Last week a huge area south of Great Eastern Highway, including Hyden, Lake King and Narembeen, was hit by torrential rain and falls of up to 130mm over two days.

Roads and paddocks were flooded and Brookton Highway was closed.

Less than a week later and it's a similar story for the Great Southern where farmers around Williams and Narrogin have suffered the most damage.

CBH grain operations manager Max Johnson said it remained unknown just how badly grain quality would be affected but with another four million tonnes expected to be delivered he was bracing for the worst.

"It's looming as a disaster for the growers out there, to be honest," he said.

"It's looking very likely that grain quality will be badly affected.

"Already we've opened up a lot more feed services … in some of those southern regions.

"Most of the Albany zone operators won't be finishing until mid to late January anyway and it's going to be January until a lot of these guys even start again."

The wet December is proving a logistical nightmare for CBH. The rail line to Albany was damaged by this week's rain.

"The Great Southern railway line from Wagin to Albany has been shut until further notice," Mr Johnson said.

"That means all rail in the Albany zone is now redundant until we can get this back up again.

"First we had trouble with QR National's performance and now we've got trouble with the lines being washed out.

"We're struggling to get grain into the port and it's making it even tougher now.

"We've also still got a lot of stacks we're moving from last week's rain to try to dry them out and now they are wet again.

"That's just created some logistical issues for us."

The Esperance Port zone has also experienced persistent rain events, leading to downgrades in grain quality and falling numbers results as low as 62.

Mr Johnson said falling numbers machines might be diverted from Geraldton, which was expected to hit a record three million tonne mark yesterday.

"Even though it's cool and damp, Geraldton is still pushing on quite strongly and that will allow the Geraldton zone to close off a lot of those sites that have falling numbers machines and that being the case we can deploy them further south," Mr Johnson said.

As yet the rain hasn't caused huge shifts in feed wheat prices but it could be just a matter of time.

On Tuesday, AWB was offering $177 per tonne for feed wheat and Viterra $174/t.

Glencore Grain State manager Rob Haddrill said the price for feed wheat actually moved up $4-$5/tonne after Monday evening's rains.

"The Australian dollar is a little softer and the market is a tiny bit firmer," he said.

"But like any commodity, if it does start to get a whole heap of selling pressure on it then it's going to move prices downward.

"At the moment there appears to be some demand out there for WA feed wheat, which is why we're seeing feed wheat prices only $2-$5/tonne under GP, which is very narrow.

"I'd imagine WA feed wheat is very competitive at the moment on the world scale but obviously farmers are going to have to be fairly switched on with their grades and have to hunt around and make sure they can get what they want quickly.

"Once the pressure comes on a few grades it may be bad on prices."

The good news for growers is that the rains are likely to stay away - at least for now.

The Bureau of Meteorology's Neil Bennett said the rest of the week was likely to be clear.

"It looks as if we are going to have a relatively benign three or four days," he said.

"It will start to move into more typical summer conditions for WA with troughs developing down the west coast but nothing particularly active (this week)."