The Ministry of Culture and Heritage began a review of the New Zealand Historic Places Act last year.
Preliminary findings proposed disestablishing the local branch committees and changing the size of the trust's national board and the way appointments were made to it.
The committees complemented the work of the trust by promoting and advocating for it and, according to the trust's website, were an "important part" of the organisation.
Arts, Culture and Heritage Minister Christopher Finlayson said disestablishing the committees would enable local advocacy interests to be separated from the regulatory functions of the trust.
This would result in local activists not being constrained by having to work within the priority-setting framework of a Crown entity, he said.
Over the coming months, the trust would discuss with branch committees ways in which new arrangements could be put in place for local heritage advocacy, he said.
Otago branch committee chairman Daniel Pollard was informed of the proposal on Thursday.
He had been on the committee for two years and said it was a "sad thing" he would be the last chairman for the Dunedin area.
"It's one of those things, unfortunately."
However, he believed "any step to improve the service NZHPT can provide is a good one".
He was yet to meet the committee's six other members and was unsure how they would continue their role in supporting the region's heritage.
NZHPT chief executive Bruce Chapman would not comment on the appropriateness of the "significant" proposed changes, saying "it's a matter of Government policy".
Meetings with the branch committees would allow for several details to be worked through, he said.
"We don't have any fixed views about how it will work at this stage. Clearly, we want local advocacy organisations to continue."
Chairmen of the North Otago and Central Otago branch committees could not be contacted.
Also, under the proposal the national board would drop from nine members to eight.
All positions would be appointed by the Government, rather than having three elected by the wider membership.
