The decline of the postal system threatened the viability of postal voting in New Zealand, the issues paper noted.
However, introducing online voting would carry security risks.
"While online voting is often suggested as a viable alternative to postal voting, all attempts since the mid-1990s to trial it for local elections have been unsuccessful, largely due to security or cost issues."
The Local Government New Zealand paper was released this morning and it explored why people did not vote, the public's understanding of local government, media trends and civics education.
It also delved into the possibility of bringing in a four-year electoral term.
LGNZ electoral reform working group chairman and Nelson Mayor Nick Smith is due to talk about the issues paper in Dunedin tomorrow at a local government regional conference.
In his foreword, Dr Smith said practical changes were needed.
"The decline in participation in local elections is an existential threat to local government," he said.
"It is getting so low that it is a risk to our mandate and is about half the turnout of central government elections."
The collapse of "snail mail" was an urgent challenge to deal with, he said.
The issues paper said many councils had countered a reduction in post boxes by providing drop-off points for completed voting papers at supermarkets, malls and libraries.
Voting in booths was a system significantly more expensive than postal voting, the paper said.
Dr Smith said there was room for improvement in ensuring New Zealanders understood the role of councils.
"There are problems with voters knowing who the candidates are and what they stand for," he said.
"This is exacerbated by the growth of social media and the decline of traditional media."
A three-year term was unusually short by international standards, he said.
"The case for councils to move to four years is that it will better enable us to deal with long-term challenges such as infrastructure, housing and climate change."
A Horizon Research nationwide survey after the 2022 local elections found the most common reasons for not voting were that people did not know enough about the candidates (31%) and their policies (26%) and could not work out who to vote for (22%).
Post-election surveys suggested voters in local elections were more likely to be: women than men; older or retired; from the South Island; and had lived at the same address for 10 years or more.
European or Pākehā people were more likely to vote than those who identified as Māori, and they were more likely to vote than people who identified as Pasifika, and the lowest participation rate was those identifying as Asian.
Building understanding was viewed as one way to increase engagement and participation with councils, including voting in local elections.
"While the school curriculum is a key starting point for civics education, community-wide education is also important."
Consultation on the issues paper closes on January 19 next year.
