Decisions on the future of the estimated $620,000 still held in Federated Farmers' Adverse Trust account are yet to be made, but a desire to ensure all farmers are treated equally, and the absence of ways to achieve that, could see the money returned.
The federation's president and a trustee, Don Nicolson, said $120,000 of the $740,000 donated by companies was spent on food packages delivered immediately after the storm.
Mr Nicolson estimated between 1200 and 1500 farmers nationwide were hit by the week-long storms to various degrees, and this created a problem of how to treat farmers equally and avoiding "picking winners".
"While it is a lot of money, it doesn't go far over a lot of names."
The financial effect of the storm would be felt hardest in autumn, when many farmers would have fewer-than-usual stock to sell, so no decisions would be made on the future of the money until expenditure options for this period were considered, he said.
The trust's purpose is to offer general assistance to farmers during adverse events rather than helping individuals on a case-by-case basis.
"We have a lot of ideas [on how to spend the money], but invariably they involve picking winners, which will advantage one farmer over his neighbour. For example, assisting someone with interest payments on money used to buy capital stock will mean someone not buying capital stock could be disadvantaged."
"None of them [the proposals] stand the generic good test."
Proposals also should not conflict with what Government agencies were doing, he said.
"If the Government is doing it, we're going nowhere near it."
The last time the trust was activated was during the Manawatu floods, when it was used, for example, to help repair remote infrastructure such as bridges and roads that would have taken weeks to fix if left to councils.
September's storm mainly hit lambing ewes and calving cows, with Beef and Lamb New Zealand estimating Southland farmers tailed 735,000 fewer lambs last spring than in 2009 and Otago 431,000 fewer. Some of that decline was because of changing land use.
Lambing data shows the average Otago lamb drop fell from 122.5% in 2009 to 115% in 2010, and Southland's from 133.5% to 113.5%Nationally, the spring lamb crop was 10% lower than in 2009 at 25.11 million, with an expected export kill of 19.5 million.
Some southern farmers lost both ewes and lambs, while others lost large numbers of lambs, with reports of 700 to 800 lamb deaths per farm common.
Dairy farmers were also hit by the bad weather, but Fonterra agreed to pay for milk farmers had to dump when bad weather prevented tankers leaving its Edendale factory.
Mr Nicolson said, while after the storm some farmers needed urgent help, that need soon eased, evident by the low turnout at post-storm farm management seminars in late spring.
As for the future of the funds, a decision would be made later this year in consultation with the donor companies, he said.
If it was returned, he would push for it to be done on a pro-rata basis to take account of the money spent.
"They gave it to us in good faith and it will be a gesture of goodwill and good faith that, if we cannot find a good use for the money, then we offer it back."