The Ministry of Culture and Heritage has proposed disestablishing the committees - 10 in the South Island and 11 in the North Island - and retaining the HPT as a Crown entity with its existing legislative and statutory responsibilities for heritage sites.
The move would mean the end of the Otago, Central Otago and North Otago committees.
Ms Crighton, of Christchurch, told the Otago branch annual meeting in Dunedin last night a new structure operating separately from the HPT but in co-operation with it, "can be done and must be done, otherwise heritage will suffer".
Local communities, particularly rural areas which had limited access to HPT staff and resources, needed the new structure.
"They need a touchstone, or heritage will disintegrate".
The Otago annual meeting last night could be its last. If the proposals went through as planned, legislative changes could be in place by July next year, Ms Crighton said.
Her own seat and that of the two other elected members on the board would also go. They would be replaced by two members appointed by the Minister of Culture and Heritage, at present Chris Finlayson.
Ms Crighton said the elected members were so alarmed at the proposal to do away with branch committees they called branch heads to a meeting in Wellington last month.
After a day of "very focused discussion", the majority decision was to establish a parallel advocacy network, possibly a federation-style organisation with a national body and local branches.
A steering committee had been set up, chaired by Ms Crighton.
The organisation would be "unrestrained", she said.
"You would be neutral and independent. You could speak up. You could be a watchdog on Government and HPT policy. You could be a lobby group for heritage locally and nationally."
People would be invited to join the new organisation but might also stay with the HPT, she said.
Otago branch member Ray Beardsmore suggested it could be called the New Zealand Heritage Trust.
The HPT offers its members benefits in this country and overseas. Branch member Peter Petchey said the new organisation might be "starved of members" because it could not offer the same membership deals.
