The government is giving a further $200,000 contribution to mayoral relief funds across Nelson Tasman and Marlborough, the Minister for Emergency Management Kieran McAnulty says.
Days of heavy rain have caused widespread slips and floods and cut off access and basic infrastructure for some communities in the region.
Marlborough will receive $100,000 and an additional $100,000 will be contributed to Nelson Tasman to support these communities in their recovery after severe weather in the past week.
The Nelson fund had already been promised $200,000 for its mayoral fund.
"This past week has been really tough on the top of the South Island, with a long and challenging recovery ahead," McAnulty said.
"This additional contribution will support these communities as they assess the full extent of the damage and begin the clean-up."
McAnulty said given the scale of the damage, it was likely the government would need to donate more but the initial grants would enable some urgent work to be completed.
"Local communities and councils understand where the immediate needs are and how to help. Mayoral relief funds help local communities to support whānau, community organisations and marae after an emergency."
Marlborough's mayor John Leggett said he was relieved by the government's announcement.
He said roading crews were worried about the next front of rain, which was due to reach the region on Thursday.
McAnulty has thanked people who have helped during the weather emergency, including the regional Civil Defence groups, volunteers, emergency services, contractors, Waka Kotahi NZTA "for their mahi getting roads cleared", and "kindly neighbours checking in on each other".
"This community has really pulled together and it's wonderful to see."