In all, agencies spent nearly $46.9 million - much of it in the months after the grounding.
At the height of the response, approximately 600 to 800 people were working in the oil spill response team.
After negotiations with the shipowners, the Government secured $27.6 million in compensation and to restock the pollution fund, with the possibility of a further $10.6 million if a proposed resource consent application to leave most of the wreck on the Astrolabe Reef is granted.
But Green MP Gareth Hughes said taxpayers were still set to get stung by at least $8.8 million - something he said would never happen if the Government had better prepared itself for the event of a major spill.
The Government was left embarrassed when it was revealed it had tarried on signing up to an international fund that would have raised the cap for claims against shipowners from $12 million to $29 million.
"I think most New Zealanders would expect that when a company causes an oil spill, they will pick up the tab," Mr Hughes said last night.
"New Zealand wasn't prepared, and the taxpayers had to pick up the bill."
Maritime New Zealand had since proposed to raise an oil pollution levy on operators to increase the fund's annual base revenue from just over $3 million to $4.5 million, while a further $3 million would be drawn over three years to buy more response equipment and make improvements.
The levy-funded Oil Pollution Fund held about $12 million a decade ago, but had fallen to $4 million before the Rena spilled 350 tonnes of heavy fuel oil into the ocean.
Maritime NZ spokesman Steve Rendle said the disaster was "obviously going to cost a lot of money".
Cost of disaster in dollars
• Maritime New Zealand - 36,834,000
• New Zealand Defence Force - 7,296,000
• Department of Conservation - 907,000
• Ministry for the Environment - 803,000
• Ministry of Transport - 490,000
• Ministry of Social Development - 192,000
• Ministry for Primary Industries - 128,000
• New Zealand Police - 110,000
• New Zealand Transport Agency - 31,000
• New Zealand Customs Service - 27,000
• Te Puni Kokiri - 22,000
• Environmental Protection Authority - 18,000
• Inland Revenue Department - 12,000
• Ministry of Foreign Affairs and Trade - 9000
• Ministry of Business, Innovation and Employment - 8000
• Department of the Prime Minister and Cabinet - 3000
• State Services Commission - 1000
TOTAL $46,891,000