Wairoa continues to lead the rate at which voting papers are being returned, with 46.99 per cent having been received, expected to exceed the 62 per cent vote at the 2013 election.
The referendum is to decide whether the Napier City and Hastings, Wairoa and Central Hawke's Bay district councils and the Hawke's Bay Regional Council should amalgamate to form a single Hawke's Bay Council, in what would be the biggest shake-up of the region's governance since nationwide local government reform in the late 1980s.
While Napier was almost untouched in that reform, Hastings became the largest authority by a merger of the Hastings City, Havelock North Borough and Hawke's Bay County councils in 1989, the Wairoa district had been formed with a merger of its borough and county councils three years earlier, and the Central Hawke's Bay council was an evolving merger from borough and county councils based in Waipukurau and Waipawa.
Voting in the referendum is open to people aged 18 or over by September 15 and who are resident in the region or absentee ratepayers.
Non-resident ratepayers need to make application to go on the ratepayer roll, but chief returning officer Warwick Lampp said it's a legislated part of the process "to ensure that it is only one person one vote in any election".
The 110,905 on the roll before voting began included fewer than 120 recorded as non-residential ratepayers.
No details are yet available on numbers of people who have reported not receiving voting papers, which were delivered on August 24-28, or on numbers who have applied to vote since the published roll was closed in July.
Mr Lampp said inquiries on the contact line 0800 666033 had been "very light", and there had been "no issues, no surprises".
"If anyone has any queries, they are best to call our office or me direct," he said.