Other data out also showed the impact of the floods on the housing market with approvals to build new homes sliding 15.9 percent in January, unwinding a 10 percent rise the month before. Approvals in Queensland fell almost 30 percent, but should revive strongly now rebuilding is underway.

Australia’s trade surplus of A$1.88 billion in January was down modestly from A$2.08 billion in December and beat forecasts of $1.5 billion. It was the tenth straight month the surplus had topped a billion dollars, easily the strongest run in history.

Stratospheric prices for key commodities like iron ore and coal promise to keep the cash rolling in, boosting profits and funding record spending binge by the resource sector.

“The trade data is holding up better than expected coming into this year,” said Scott Haslem, chief economist at UBS.

“We expect that coal exports will be rising and contributing strongly to growth through the second quarter.”

The once-in-a-century boom in export earnings is a major reason the Reserve Bank of Australia (RBA) is confidently looking ahead to years of rapid economic growth and is still expected to lift its 4.75 percent cash rate again.

Interbank futures imply little risk of a move until later in the year with August a 50-50 proposition and a hike to five percent not fully priced in until November.

The RBA can afford to be relaxed in part because Australians are choosing to save more and spend less.

The restraint was evident in figures for new vehicle sales out on Thursday that showed a 1.6 percent drop in February, compared to the same month a year ago.

That was in stark contrast with the US where vehicle sales jumped 27 percent in February, even though the US unemployment rate of 9 percent is four percentage points above Australia’s.

Data out on Wednesday also showed gross household incomes grew by a wallet-bulging 8.7 percent last year, but people chose to save much of that.

“There’s enough evidence to suggest the economy is not pushing above trend just yet, or immediately needs the already restrictive setting of interest rates,” said Haslem at UBS.

The flooding had even more of an impact in January, with coal exports falling no less than A$1.07 billion, or 29 percent.

The Bureau of Statistics estimated export volumes of hard coking coal slid 39 percent, while semi-soft fell 32 percent and that will be a heavy drag on economic growth this quarter.

That pulled down overall exports by four percent in January to A$23.6 billion but that was still 15 percent higher than January last year, illustrating the benefit of higher prices.

Imports fell 3.8 percent in January, from December, to stand at A$21.76 billion. Much of the drop was due to a 29 percent drop in fuel imports, a typically volatile sector.

Imports of consumption goods eased 1.4 percent while imports of capital goods rose 3.2 percent, pointing to further strength in business investment.

The outlook for export earnings remains bright with the RBA’s index of Australian commodity prices shooting to new peaks and mining firms revising up already ambitious spending plans.

The RBA’s index has climbed 7.7 percent in the past two months to be up 48 percent for the year when measured in special drawing rights. Even taking account for the higher Australian dollar, the index is up 32 percent on the year.

Australia’s official commodity forecaster this week predicted export earnings from resources would rise 29 percent in the year to June 2011, and a further 14 percent the following year to reach a staggering quarter of a trillion dollars.

The agency also believes earnings would keep climbing until at least 2015/16, when they would reach A$290 billion.

Seeking to make the most of sky-high prices, miners have embarked on a record-breaking investment spree. Spending is set to rise 58 percent in the year to June, and then a further 38 percent in 2011/12 to reach A$76 billion.

All this spending should in turn boost export volumes, employment, wages and tax receipts, helping the government return the budget to surplus while most other developed nations are still struggling with record levels of red ink.