Railroad and ferry operator KiwiRail says the year ended June was challenging, partly due to the Aratere being out of action.
Its annual revenue from Interislander passengers dropped $9.2 million. Overall, the group's year-on-year losses went up from $175 to $248 million.
KiwiRail chief financial officer David Walsh said the company was now putting aside money to cope with unforseen disruption.
"We're certainly building a contingency headroom largely for weather events on the network - that's the rail infrastructure. We're providing somewhere between about $4 and $10 million a year as a consequence of that but how that unfolds in any year will depend on the events of that year."
Mr Walsh said there had been no specific funding for such events until about a year ago. He said the company had not set aside funding previously as it had been running a very tight ship.
"But we're learning, and it's a great learning that we've had."
Meanwhile, KiwiRail chief executive Peter Reidy said the company's operations were being reviewed from top to bottom.
"I can't speculate on what path that might take, but I can say it is our intention to improve the performance of rail, have an investment ready to enable the growth of this country and to ensure that we deliver economic benefits for New Zealand."
He said 2014 had been a tough year, but in the next year KiwiRail would improve its safety performance and simplify its business to reduce costs and improve efficiency.