GRAIN traders face a huge task to whittle down wheat stored in the nation's granaries.

According to the Australian Bureau of Statistics, Australia's major bulk handlers held 24.6 million tonnes of wheat in their storages at the end of December - the highest level in many years.

Milling wheat accounted for 17 million tonnes of the December stocks, with feed grades making up the remaining 7.6 million tonnes.

The largest tonnage stored is in Western Australia, where CBH Group recently reported the biggest season for grain receivals in the state's history.

The 9.1 million tonnes of wheat held in WA at the end of December accounted for 37 per cent of the nation's stocks.

CBH was still receiving grain at its storages last week.

Receivals of all grain into CBH's storage network was inching towards 15 million tonnes this week.

The ABS data showed NSW held the second largest wheat stocks, accounting for 5.9 million tonnes, or one quarter of Australian stocks.

The December stocks figure nationwide was 6.4 million tonnes more than that stored at the same time in the previous year.

Australia has had two large wheat crops in a row, resulting in the huge stocks.

The ABS data shows wheat stocks did not fall below about 7.5 million tonnes for the whole of last year.

Stocks peaked at just more than 22 million tonnes in January and took until October to reach the lowest point for the year.

Last season was also a big year for bulk wheat exports from Australia.

According to the Wheat Export Authority, 18.5 million tonnes of wheat was shipped out of the country for the year ended September 30, 2011.

National wheat stock levels are expected to fall from their December peak from now on as exporters increase their shipping programs.

Wheat was still being harvested on some farms in Victoria's Western District last week.

But most of the crop yet to be harvested in the region is barley sown in spring.

Growers had to switch from wheat to other shorter season crops in spring when their paddocks became too wet to sow during the normal winter sowing period.

Harvesting of some of those crops is still a couple of weeks away.

South Australia's harvest will drag out for the same reason. Bulk handler Viterra said last week a small number of growers in the state's southeast corner were yet to complete their harvest.

"These crops were sown later due to seasonal conditions," it said.