Councils are barred from making decisions at such gatherings, which have been characterised as informal briefings and forums for discussion outside of formal meetings.
Chief ombudsman Judge Peter Boshier said having workshops open to the public, instead of behind closed doors, should be the default setting for councils.
"Transparency supports accountability, encourages high performance and increases public confidence," he said.
Otago Regional Council chief executive Richard Saunders said the council would look into its processes.
"We are very conscious of the need for transparency to ensure public confidence and to ensure we are operating in accordance with any guidance from the chief ombudsman," Mr Saunders said.
"We already hold a number of workshops publicly and ensure that recordings are made available online, along with proactively releasing any previously non-public information where no reason to withhold that information still exists."
ORC councillor Michael Laws has been a leading critic of council secrecy, arguing it has sometimes been unlawful and undermined democratic accountability.
Mr Saunders said the regional council accepted the need to maintain transparency where possible and "any future approach to workshops or briefings should reflect this".
Queenstown Lakes District Council chief executive Mike Theelen said the ombudsman made a range of recommendations and clarified some expectations of councils’ conduct relating to workshops and excluding the public from parts of meetings.
"Like other councils, QLDC will review the recommendations and expectations to understand the full set of actions required," Mr Theelen said.
"Staff will also need to engage with elected members to discuss and agree any changes in practice ahead of implementing them across the organisation."
Central Otago District Council business support group manager Saskia Righarts said the council was confident it adhered to legal processes correctly, but "we will take the time to consider the report and make any amendments, as necessary".
The Invercargill City Council was one council that had made changes earlier this term.
Mayor Nobby Clark had expressed his desire for workshops to be livestreamed and governance and legal manager Michael Morris said this led to the public having access to various workshops both through the livestream and in person.
"The only time part of a workshop has been closed to the public is when it includes sensitive information," Mr Morris said.
"This is the same process we would take in any other council meeting."
Environment Southland strategy, science and engagement manager Rachael Millar said councillors and staff were considering the ombudsman’s findings.
The council had made some changes in recent months.
"These relate to the reporting and wider publication of details of our workshops, such as those held for the development of our next long-term plan," Ms Millar said.
"Environment Southland fully endorses open and transparent governance and engaging with our communities and ratepayers on important issues."
The Dunedin City Council announced this week a change of policy to make workshops open to the public from next month, unless there were grounds for privacy, such as commercial sensitivity.
The Clutha District Council already had open workshops as its default setting.
The Gore District Council will discuss the ombudsman’s report and its implications next week.
